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Biomedical subjects

H Hooijkaas

Publications and source records attributed to H Hooijkaas.

At least 19 recordsLinked to original sources

[A retrospective study on the role of antibodies against soluble liver antigen (anti-SLA antibodies) and other autoantibodies in the diagnostics of autoimmune hepatitis].

OBJECTIVE: To determine the diagnostic value of antibodies against soluble liver antigen (anti-SLA antibodies) and a number of other antibodies for the diagnosis ofautoimmune hepatitis (AIH). DESIGN: Retrospective. METHOD: Anti-SLA, antinuclear antibodies (ANA), antibodies against smooth muscle (anti-SMA), anti-neutrophil cytoplasm antibodies (peri-nuclear pattern; pANCA) and antibodies against liver-kidney microsomal antigen type 1 (anti-LKM-1) were determined in the sera of 97 patients with AIH and 121 patients with other liver disorders including viral, drug-related and alcoholic liver disease. The sensitivity and specificity of each of the antibodies, or a combination ofantibodies, were calculated for the diagnosis 'AIH'. RESULTS: Anti-SLA antibodies were found only in AIH patients (specificity: 100%); 1 in 7 AIH patients (14%) had these antibodies and in 2% they were the only detectable antibodies. Anti-LKM-1 antibodies also showed a 100% specificity for AIH although the sensitivity was much lower (2%). Whilst the sensitivity of ANA (53%), pANCA (39%) and SMA (39%) was higher, the specificity of these antibodies for AIH was lower. 20% of AIH patients tested negative for all autoantibodies. The simultaneous presence of more than one antibody increased the probability of AIH diagnosis. CONCLUSION: When AIH is suspected, the presence of one or a combination ofanti-SLA, ANA, anti-SMA, anti-LKM-1 and pANCA antibodies is helpful for the often difficult differential diagnosis between AIH and other liver disorders. Anti-SLA antibodies are specific for AIH and appear to be a useful diagnostic parameter.

Autoantibodies↗

A hampered chemoattractant-induced cytoskeletal rearrangement in granulocytes of patients with unexplained severe chronic and relapsing infections of the upper and lower airways. In vitro restoration by G-CSF exposure.

Granulocytes play a major role in host defense against bacterial infections. Severe inborn defects in granulocyte function are associated with fulminant bacterial infections in early childhood. Subtle disturbances in granulocyte function might contribute to an enhanced susceptibility to bacterial infections in adulthood. We investigated chemoattractant (N-formyl-methionyl-leucyl-phenylalanine, fMLP and casein) induced cytoskeletal rearrangements (polarization) of blood granulocytes in 77 adults with chronic and recurrent therapy-resistant infections of the upper and lower airways. These infections could not be explained by B- and/or T-cell defects or local anatomic abnormalities. Besides polarization, chemotaxis of blood granulocytes was measured in 33 patients, as well as granulocyte superoxide production in eight patients. The chemoattractant-induced cytoskeletal rearrangement in patient blood granulocytes was significantly lower as compared to healthy control values with both fMLP and casein as stimuli. About two-thirds of the patients showed a defective polarization response to fMLP. Granulocyte colony-stimulating factor (G-CSF) when added in vitro corrected the defective polarization responses; responses in the normal range were not enhanced. The chemotactic motility of patient blood granulocytes was also slightly, but significantly lowered. However, it did not correlate to the lowered polarization. Granulocyte superoxide production was comparable in patients and in healthy controls. Our data thus show that subtle abnormalities in chemoattractant-induced cytoskeletal and motile function of blood granulocytes are frequent in patients with severe therapy-refractory bacterial infections of the upper and lower airways.

Adult↗

Therapeutic immune reconstitution in HIV-1-infected children is independent of their age and pretreatment immune status.

OBJECTIVE: To evaluate long-term immune reconstitution of children treated with highly active antiretroviral therapy (HAART). METHODS: The long-term immunological response to HAART was studied in 71 HIV-1-infected children (aged 1 month to 18 years) in two prospective, open, uncontrolled national multicentre studies. Blood samples were taken before and after HAART was initiated, with a follow-up of 96 weeks, and peripheral CD4 and CD8 T cells plus naive and memory subsets were identified in whole blood samples. Relative cell counts were calculated in relation to the median of the age-specific reference. RESULTS: The absolute CD4 cell count and percentage and the CD4 cell count as a percentage of normal increased significantly (P < 0.001) to medians of 939 x 106 cells/l (range, 10-3520), 32% (range, 1-50) and 84% (range, 1-161), respectively, after 48 weeks. This increase was predominantly owing to naive CD4 T cells. There was a correlation between the increase of absolute naive CD4 T cell counts and age. However, when CD4 T cell restoration was studied as percentage of normal values, the inverse correlation between the increase of naive CD4 T cell count and age was not observed. In addition, no difference in immunological reconstitution was observed at any time point between virological responders and non-responders. CONCLUSIONS: Normalization of the CD4 cell counts in children treated with HAART is independent of age, indicating that children of all age groups can meet their CD4 T cell production demands. In general, it appears that children restore their CD4 T cell counts better and more rapidly than adults, even in a late stage of HIV-1 infection.

Adolescent↗

Molecular and flow cytometric analysis of the Vbeta repertoire for clonality assessment in mature TCRalphabeta T-cell proliferations.

Clonality assessment through Southern blot (SB) analysis of TCRB genes or polymerase chain reaction (PCR) analysis of TCRG genes is important for diagnosing suspect mature T-cell proliferations. Clonality assessment through reverse transcription (RT)-PCR analysis of Vbeta-Cbeta transcripts and flow cytometry with a Vbeta antibody panel covering more than 65% of Vbeta domains was validated using 28 SB-defined clonal T-cell receptor (TCR)alphabeta(+) T-ALL samples and T-cell lines. Next, the diagnostic applicability of the V(beta) RT-PCR and flow cytometric clonality assays was studied in 47 mature T-cell proliferations. Clonal Vbeta-Cbeta RT-PCR products were detected in all 47 samples, whereas single Vbeta domain usage was found in 31 (66%) of 47 patients. The suspect leukemic cell populations in the other 16 patients showed a complete lack of Vbeta monoclonal antibody reactivity that was confirmed by molecular data showing the usage of Vbeta gene segments not covered by the applied Vbeta monoclonal antibodies. Nevertheless, this could be considered indirect evidence for the "clonal" character of these cells. Remarkably, RT-PCR revealed an oligoclonal pattern in addition to dominant Vbeta-Cbeta products and single Vbeta domain expression in many T-LGL proliferations, providing further evidence for the hypothesis raised earlier that T-LGL derive from polyclonal and oligoclonal proliferations of antigen-activated cytotoxic T cells. It is concluded that molecular Vbeta analysis serves to assess clonality in suspect T-cell proliferations. However, the faster and cheaper Vbeta antibody studies can be used as a powerful screening method for the detection of single Vbeta domain expression, followed by molecular studies in patients with more than 20% single Vbeta domain expression or large suspect T-cell populations (more than 50%-60%) without Vbeta reactivity.

Adolescent↗

Flow cytometric analysis of the Vbeta repertoire in healthy controls.

BACKGROUND: Analysis of the T-cell receptor (TCR)-Vbeta repertoire has been used for studying selective T-cell responses in autoimmune disease, alloreactivity in transplantation, and protective immunity against microbial and tumor antigens. For the interpretation of these studies, we need information about the Vbeta repertoire usage in healthy individuals. METHODS: We analyzed blood T-lymphocyte (sub)populations of 36 healthy controls (age range: from neonates to 86 years) with a carefully selected most complete panel of 22 Vbeta monoclonal antibodies, which together recognized 70-75% of all blood TCRalphabeta(+) T lymphocytes. Subsequently, we developed a six-tube test kit with selected Vbeta antibody combinations for easy and rapid detection of single ("clonal") Vbeta domain usage in large T-cell expansions. RESULTS: The mean values of the Vbeta repertoire usage were stable during aging in blood TCRalphabeta(+) T lymphocytes as well as in the CD4(+) and CD8(+) T-cell subsets, although the standard deviations increased in the elderly. The increased standard deviations were caused by the occurrence of oligoclonal T-cell expansions in the elderly, mainly consisting of CD8(+) T lymphocytes. The 15 detected T-cell expansions did not reach 40% of total TCRalphabeta(+) T lymphocytes and represented less than 0.4 x 10(9) cells per liter in our study. Vbeta usage of the CD4(+) and CD8(+) subsets was comparable for most tested Vbeta domains, but significant differences (P < 0.01) between the two subsets were found for Vbeta2, Vbeta5.1, Vbeta6.7, Vbeta9.1, and Vbeta22 (higher in CD4(+)), as well as for Vbeta1, Vbeta7.1, Vbeta14, and Vbeta23 (higher in CD8(+)). Finally, single Vbeta domain expression in large T-cell expansions can indeed be detected by the six-tube test kit. CONCLUSIONS: The results of our study can now be used as reference values in studies on distortions of the Vbeta repertoire in disease states. The six-tube test kit can be used for detection of single Vbeta domain expression in large T-cell expansions (>2.0 x 10(9)/l), which are clinically suspicious of T-cell leukemia.

Adolescent↗

External quality assessment of flow cytometric HLA-B27 typing.

A biannual external quality assurance (EQA) scheme for flow cytometric typing of the HLA-B27 antigen is operational in The Netherlands and Belgium since 1995. We report here on the results of the first seven send-outs to which 36 to 47 laboratories participated. With the send-out, four specimens from blood bank donors, who had been typed for HLA Class I antigens by complement-dependent cytotoxicity, were distributed. Subtyping of the HLA-B27 allele was performed by PCR-SSP. Ten samples were HLA-B27(pos) (all HLA-B*2705) and 18 were HLA-B27(neg). For flow cytometry, the most widely monoclonal antibody (MoAb) used was FD705, followed by GS145.2 and ABC-m3. The majority of laboratories used more than 1 anti-HLA-B27 MoAb for typing. The HLA-B27(pos) samples were correctly classified as positive by the large majority of participants (median 95%; range 85% to 100% per send out); some participants considered further typing necessary and misclassification as negative was only sporadically seen. The classification of HLA-B27(neg) samples as negative was less straightforward. Ten samples were correctly classified as such by 97% (82% to 100%) of the participants, whereas 64% (range 53% to 70%) of the participants classified the remaining eight samples as HLA-B27(neg). There was no significant prevalence of a particular HLA-B allele among these eight "poor concordancy" samples as compared to the ten "good concordancy" samples. Inspection of the reactivity patterns of the individual MoAb with HLA-B27(neg) samples revealed that ABC-m3 showed very little cross-reactivity apart from its well-known cross-reactivity with HLA-B7, whereas the cross-reactivity patterns of GS145.2 and FD705 were more extensive. The small sample size (n = 18) and the distribution of HLA-B alleles other than HLA-B27 did not allow assignment of specificities to these cross-reactions. Finally, we showed that standardized interpretation of the combined results of two anti-HLA-B27 MoAb reduced the frequency of false-positive conclusions on HLA-B27(neg) samples. In this series, the lowest frequency of false-positive assignments was observed with the combination of the FD705 and ABC-m3 MoAb.

Antibodies, Monoclonal↗

Two different types of sialoadenitis in the NOD- and MRL/lpr mouse models for Sjögren's syndrome: a differential role for dendritic cells in the initiation of sialoadenitis?

Sjögren's syndrome is an autoimmune disease that primarily affects the salivary and lacrimal glands. In these glands, focal lymphocytic infiltrates develop. Little is known about the initiation of this autoimmune disease. Antigen-presenting cells (APC) such as dendritic cells (DC) can play a role in the initiation of autoimmunity. To date, no data on the presence of DC in Sjögren's syndrome are available. Several mouse strains, the nonobese diabetic (NOD) and the MRL/Ipr mouse, can be used as models for Sjögren's syndrome. We compared the development of sialoadenitis in the submandibular glands (SMG) of NOD and MRL/Ipr mice with particular focus on the presence of APC. DC, macrophages, T cells, and B cells in the SMG were studied by means of immunohistochemistry, after which positively stained cells were quantified. NOD-severe combined immunodeficiency (SCID) mice were used to study the presence of APC in the SMG in the absence of lymphocytes. Before lymphocytic infiltration, increased numbers of DC were detected in the SMG of NOD mice compared with those numbers in control mice and MRL/Ipr mice, which suggests that DC play a role in the initiation of sialoadenitis in NOD mice. In the SMG of NOD mice, lymphocytic infiltrates organized in time. In MRL/Ipr mice, however, lymphocytic infiltrates were already organized at the time of appearance. This organization was lost over time. In conclusion, two types of sialoadenitis are described in two mouse models for Sjögren's syndrome. Differences exist with regard to early events that may lead to the development of sialoadenitis and to the composition and organization of inflammatory infiltrates. It is possible that different types of sialoadenitis also exist in humans and that the pathogenetic process in both the early and late phases of the autoimmune reaction differs among patients.

Animals↗

Professional antigen presenting cells in minor salivary glands in Sjögren's syndrome: potential contribution to the histopathological diagnosis?

Sjögren's syndrome is an autoimmune disease in which lymphocytic infiltrates develop in the salivary and lacrimal glands. We have shown that dendritic cells (DC) infiltrate the submandibular gland of the nonobese diabetic (NOD) mouse, a mouse model for Sjögren's syndrome, before lymphocytic infiltration, suggesting that these antigen-presenting cells (APC) may play a role in the initiation of Sjögren's syndrome. In later stages, DC and macrophages also form an important part of the infiltrate of the NOD sialoadenitis. To find out if DC and macrophages form part of the infiltrate in Sjögren's syndrome as well, and to determine whether they may be useful in the histopathological diagnosis of Sjögren's syndrome, we studied their presence in minor salivary glands (MSG) of patients with Sjögren's syndrome and patients with focal lymphocytic sialoadenitis (FLS), but without clinical or serological criteria of Sjögren's syndrome. Immunohistochemistry was applied, followed by semiquantitative analysis. DC and macrophages were present in all MSG; however, there were clear differences in marker expression between Sjögren's syndrome and FLS, on the one hand, and control tissue, on the other hand. CD1a+ DC and RFD9+ macrophages were mainly observed in MSG in which a focal lymphocytic infiltrate was present. In fact, the diffuse presence of single CD1a+ DC and RFD9+ macrophages correlated closely with the presence of a focal lymphocytic infiltrate in the MSG. This indicates that these cells could be of help during the evaluation of a MSG. Because the detection of APC is technically less cumbersome than a focal score, this parameter may perhaps replace the focal score in the histopathological diagnosis of Sjögren's syndrome. This study therefore prompts further investigation focusing on the presence of CD1a+ and RFD9+ cells in the MSG of a large cohort of patients.

Adult↗

Regeneration pattern of precursor-B-cells in bone marrow of acute lymphoblastic leukemia patients depends on the type of preceding chemotherapy.

Immunofluorescence stainings for the CD10 antigen and terminal deoxynucleotidyl transferase (TdT) can be used for the detection of leukemic blasts in CD10+ precursor-B-acute lymphoblastic leukemia (precursor-B-ALL) patients, but can also provide insight into the regeneration of normal precursor-B-cells in bone marrow (BM). Over a period of 15 years, we studied the regeneration of CD10+, TdT+, and CD10+/TdT+ cells in BM of children with (CD10+) precursor-B-ALL during and after treatment according to three different treatment protocols of the Dutch Childhood Leukemia Study Group (DCLSG) which differed both in medication and time schedule. This study included a total of 634 BM samples from 46 patients who remained in continuous complete remission (CCR) after treatment according to DCLSG protocols VI (1984-1988; n = 8), VII (1988-1991; n = 10) and VIII (1991-1997; n = 28). After the cytomorphologically defined state of complete remission with CD10+ and CD10+/TdT+ frequencies generally below 1% of total BM cells, a 10-fold increase in precursor-B-cells was observed in protocol VII and protocol VIII, but not in protocol VI. At first sight this precursor-B-cell regeneration during treatment resembled the massive regeneration of the precursor-B-cell compartment after maintenance treatment, and appeared to be related to the post-induction or post-central nervous system (CNS) therapy stops in protocols VII and VIII. However, careful evaluation of the distribution between the 'more mature' (CD10+/TdT-) and the 'immature' (CD10+/TdT+) precursor-B-cells revealed major differences between the post-induction/post-re-induction precursor-B-cell regeneration (low 'mature/immature' ratio: generally <1.0), the post-CNS treatment regeneration (moderate 'mature/immature' ratio: 1.2-2.8), and the post-maintenance regeneration (high 'mature/ immature' ratio: 5.7-7.6). We conclude that a therapy stop of approximately 2 weeks is already sufficient to induce significant precursor-B-cell regeneration even from aplastic BM after induction treatment. Moreover, differences in precursor-B-cell regeneration patterns are related to the intensity of the preceding treatment block, with lower 'mature/immature' ratios after the highly intensive treatment blocks. This information is essential for a correct interpretation of flow cytometric immunophenotyping results of BM samples during follow-up of leukemia patients. Particularly in precursor-B-ALL patients, regeneration of normal precursor-B-cells should not be mistaken for a relapse.

Antineoplastic Combined Chemotherapy Protocols↗

Effect of an inhaled glucocorticoid on reactive oxygen species production by bronchoalveolar lavage cells from smoking COPD patients.

Oxidative stress in the lung is important in the pathogenesis of COPD. Published data indicate that glucocorticoids inhibit blood cells in their capacity to produce reactive oxygen species (ROS). We investigated the effect of Fluticasone propionate (FP) on the ROS production capabilities of pulmonary cells. Bronchoalveolar lavage (BAL) was performed in smoking COPD patients, before and after a six month, placebo-controlled treatment with FP. BAL cells were stimulated with phorbol myristrate acetate (PMA) alone, and together with superoxide dismutase (SOD). From kinetic plots of ferricytochrome-c conversion we calculated the maximal rate of superoxide production: V(max). We also examined BAL cell subsets and performed correlation analyses on ROS production and relevant clinical determinants. Paired results were obtained from 6 FP- and 9 placebo-treated patients. No significant change of V(max) was found in both patient groups. Also BAL cellularity was unchanged. Correlation analyses showed a significant (inverse) association of V(max) with the number of cigarettes smoked per day. We concluded that a potent inhaled glucocorticoid had no effect on the ROS production capability of BAL cells from smoking COPD patients. Apparently, heavy smoking impaired the ability of alveolar macrophages to produce ROS, which was not further decreased by FP.

Administration, Inhalation↗

Autoimmune lymphoproliferative syndrome (ALPS) in a child from consanguineous parents: a dominant or recessive disease?

Autoimmune lymphoproliferative syndrome (ALPS) is characterized by autoimmune features and lymphoproliferations and is generally caused by defective Fas-mediated apoptosis. This report describes a child with clinical features of ALPS without detectable Fas expression on freshly isolated blood leukocytes. Detection of FAS transcripts via real-time quantitative PCR made a severe transcriptional defect unlikely. Sequencing of the FAS gene revealed a 20-nucleotide duplication in the last exon affecting the cytoplasmic signaling domain. The patient was homozygous for this mutation, whereas the consanguineous parents and the siblings were heterozygous. The patient reported here is a human homologue of the Fas-null mouse, inasmuch as she carries an autosomal homozygous mutation in the FAS gene and she shows the severe and accelerated ALPS phenotype. The heterozygous family members did not have the ALPS phenotype, indicating that the disease-causing FAS mutation in this family is autosomal recessive.

Autoimmune Diseases↗

Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children.

Prenatal exposure to polychlorinated biphenyls (PCBs) and dioxins is associated with changes in the T-cell lymphocyte population in healthy Dutch infants. We investigated whether these changes persist into later childhood and whether background exposure to PCBs and dioxins is associated with the prevalence of infectious or allergic diseases and humoral immunity at preschool age. The total study group consisted of 207 healthy mother-infant pairs. We estimated prenatal exposure to PCBs and dioxins by the sum of PCBs 118, 138, 153, and 180 (sigmaPCB) in maternal and cord plasma and in breast-fed infants by the dioxin, planar, and mono-ortho PCB toxic equivalent (TEQ) levels in human milk. At 42 months of age, current body burden was estimated by the PCB in plasma. We assessed the prevalence of infectious and allergic diseases by parent questionnaire, and measured humoral immunity by antibody levels for mumps, measles, and rubella after primary vaccination. We performed immunologic marker analyses of lymphocytes in a subgroup of 85 children. Prenatal PCB exposure was associated with an increased number of lymphocytes, T-cells, and CD3CD8(+) (cytotoxic), CD4(+)CD45RO(+) (memory), T-cell receptor (TcR) [alpha]ss(+), and CD3(+)HLA-DR(+) (activated) T cells and lower antibody levels to mumps and measles at preschool age. Adjusted for confounders, prenatal PCB exposure was associated with less shortness of breath with wheeze, and current PCB body burden was associated with a higher prevalence of recurrent middle-ear infections and of chicken pox and a lower prevalence of allergic reactions. A higher dioxin TEQ was associated with a higher prevalence of coughing, chest congestion, and phlegm. We conclude that in Dutch preschool children the effects of perinatal background exposure to PCBs and dioxins persist into childhood and might be associated with a greater susceptibility to infectious diseases. Common infections acquired early in life may prevent the development of allergy, so PCB exposure might be associated with a lower prevalence of allergic diseases.

Antibody Formation↗

[Immunology in medical practice. XXI. Laboratory tests for immunologic diseases].

Clinical immunology has gained its firm place in health care. There are now established laboratory tests giving insight into the functioning of the immune system in the normal and diseased individual. The laboratory diagnostic tests are related to immune deficiencies, infectious diseases, allergic diseases, autoimmune diseases (both generalized and organ-specific ones), the HLA system and malignancies of immune cells. In this review the application of a number of laboratory tests in the diagnosis of immunological diseases is discussed. In the Netherlands a laboratory specialist, the 'medical immunologist' deals with the development, implementation and performance of the immunological diagnostic tests in health care.

Allergy and Immunology↗

The immunological and psychological effects of bereavement: does grief counseling really make a difference? A pilot study.

This study evaluates psychological and immunological functioning after bereavement and the influence of group counseling. Eighteen widows (bereaved within 3 months of enrolment) and a reference group of 10 married control subjects were asked to fill in self-report scales and to donate a blood sample (T1). After T1, half of the widows (the experimental group) were randomly assigned to grief counseling (13 sessions over 4 months), while the other subjects (the control group) received no treatment. Seven months after bereavement (T2) or, in the case of the experimental group, immediately after the intervention, a follow-up was conducted in the widowed subsample using the same measures. Blood samples were analyzed to determine the total number of white blood cells, number of lymphocyte subsets, natural killer cell activity (NKCA) and lymphocyte proliferative response to phytohemagglutinin (PHA), anti-CD3 and pokeweed mitogen (PWM). At T1, we found significant differences between widows and non-widows regarding both psychological and immunological measures. Widows felt more anxious, depressed, hostile and agoraphobic. At T1, widows had a lower number of the CD19+CD5+ B cell subpopulation. The cell function tests for T and B cells showed higher responses in widows (lymphocyte proliferation response to PHA, anti-CD3 and PWM). No significant difference in NKCA was found between widows and non-widows. At T2, there appeared to be no significant difference between widows and non-widows on the psychological measures. With respect to the immunological measures, widows and non-widows showed no significant differences for the total number of white blood cells, number of lymphocyte subsets and NKCA. Consistent with our findings at T1, the lymphocyte proliferation response to PHA, anti-CD3 and PWM at T2 appeared to be higher in widows than in non-widows. Comparing the experimental group (widows) and the control group (widows) with respect to psychological measures at T1, widows in the experimental group felt more insufficient and had more sleep disturbances. With respect to the immunological measures, no differences were found between those two groups. When the same two groups were again compared at T2, no differences were found in any of the psychological or immunological measures (lymphocyte sub-populations, proliferation tests and the NKCA).

Aged↗

The effect of intranasal and inhaled corticosteroids in healthy volunteers on the number of circulating lymphocytes and lymphocyte subsets.

BACKGROUND: There has been an increasing interest in the potential systemic effects of inhaled corticosteroids. METHODS: The effect of locally inhaled corticosteroids in the nose and lung on blood lymphocytes was measured in two studies. In the first study, budesonide (BUD) (200 and 800 microg), fluticasone propionate (FP) (200 and 800 microg), and placebo were administered in the nose, and BUD (1600 microg) and FP (1500 microg) were inhaled into the lungs in a blinded, randomized fashion by 12 healthy volunteers. Blood samples were taken before and 4 h after the administration of the drug, and total lymphocyte count and different subpopulations were determined. In the second study, 15 healthy volunteers were randomized to BUD (1600 microg), FP (1600 microg), or placebo inhaled into the lungs. Blood samples were taken before and 4, 8, 24, 48, and 148 h (=7 days) after inhalation of the medication. RESULTS: Neither the nasal applications nor the inhalation of FP (1500 microg/1600 microg) showed significant differences in total lymphocyte count or different subpopulations between baseline and 4 h after the administration. In both studies, a significant reduction was found in the total lymphocyte count, B cells, T cells, and the CD4+ and the CD8+ fractions 4 h after application of BUD 1600 microg. CONCLUSIONS: Nasal application of BUD or FP in doses up to 800 microg do not induce lymphopenia. BUD 1600 microg inhalation in the lung reduces lymphocytes and their subfractions. Further studies have to be done to determine whether the results obtained in this study in healthy volunteers will also be found in patients with diseased mucosa and whether there is any correlation with adverse effects such as growth inhibition or osteoporosis.

Administration, Inhalation↗

Early recovery of CD4+ T lymphocytes in children on highly active antiretroviral therapy. Dutch study group for children with HIV infections.

INTRODUCTION: Regeneration of CD4+ T lymphocytes has been shown to be thymus-dependent in bone marrow transplant recipients and after intensive chemotherapy. The rate of CD4+ T cell regeneration is correlated positively with enlargement of the thymus, as shown on radiographs, and higher rates of CD4+ T lymphocyte regeneration were observed in children as compared with adults, consistent with thymic function diminishing with age. We hypothesized that in HIV infected patients CD4+ T cell recovery during highly active antiretroviral therapy (HAART) may also be thymus dependent. Therefore, repopulation of naive (CD45RA+), memory (CD45RO+) and total CD4+ T lymphocytes and total CD8+ T lymphocytes in peripheral blood was assessed in 13 HIV infected children during the initial 3 months of HAART. RESULTS: Significantly higher recovery rates of naive, memory and total CD4+ T cells were observed in children below the age of 3 years as compared with older children. Kinetics of total CD8+ T cells showed no relation to age. Moreover, recovery rates of naive CD4+ T cells in patients below 3 years of age were 10-40 fold higher as compared with previously reported naive CD4+ T cell recovery rates in adults on HAART. CONCLUSIONS: High recovery rates of naive, memory and total CD4+ T cells can be achieved in children below 3 years of age. Changes in CD8 counts did not correlate with age. These results indicate that regeneration of CD4+ T cells during HAART may be a thymus-dependent process.

Adolescent↗