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Biomedical subjects

T W Huizinga

Publications and source records attributed to T W Huizinga.

At least 55 records · Page 3Linked to original sources

Neuropsychiatric systemic lupus erythematosus is associated with imbalance in interleukin 10 promoter haplotypes.

OBJECTIVE: To investigate the association of interleukin 10 (IL10) promoter polymorphisms and neuropsychiatric manifestations of systemic lupus erythematosus (SLE). METHODS: IL10 haplotypes of 11 healthy volunteers were cloned to confirm that in the Dutch population, only the three common haplotypes (-1082/-819/-592) GCC, ACC and ATA exist. The IL10 promoter polymorphisms of 92 SLE patients and 162 healthy controls were determined. The medical records of the SLE patients were screened for the presence of neuropsychiatric involvement. RESULTS: All cloned haplotypes were either GCC, ACC or ATA. Forty two SLE patients had suffered from neuropsychiatric manifestations (NP-SLE). In NP-SLE patients, the frequency of the ATA haplotype is 30% versus 18% in the controls and 17% in the non-NP-SLE group (odds ratios 1.9, p = 0.02, and 2.1, p = 0.04, respectively), whereas the GCC haplotype frequency is lower in the NP-SLE group compared with controls and non-NP-SLE patients (40% versus 55% and 61%, odds ratios 0.6, p = 0.02 and 0.4 p = 0.006). The odds ratio for the presence of NP-SLE is inversely proportional to the number of GCC haplotypes per genotype when the NP-SLE group is compared with non-NP-SLE patients. CONCLUSIONS: The IL10 locus is associated with neuropsychiatric manifestations in SLE. This suggests that IL10 is implicated in the immunopathogenesis of neuropsychiatric manifestations in SLE.

Adult↗

Gene Therapy of Arthritis and Related Disorders--First International Meeting. 2-3 December 1998, Bethesda, USA.

The number of publications on gene therapy for arthritis has shown a logarithmic growth curve during recent years. This has resulted in the need for an international platform to exchange new ideas and data. The National Institute of Health (NIH) was the host for the First International Meeting on Gene Therapy of Arthritis and Related Disorders, which was attended by over 150 participants (70% from academic, 30% from industry) from nine different countries. All the participants were active in the field, which resulted in a lively meeting that covered most aspects of this fast moving field. The meeting was organized in eight sessions (biology and targets, vectors, non-viral therapy, adenoviral therapy, rheumatoid arthritis, immunomodulation, cartilage-osteoarthritis and clinical trials). This meeting report will follow the format of the meeting.

Journal Article↗

Determination of tumour necrosis factor-alpha and interleukin-10 production in a whole blood stimulation system: assessment of laboratory error and individual variation.

Ex vivo production of cytokines as determined by whole blood stimulation and supernatant ELISA is partly determined by heritability. To assess the ability of this system to distinguish between high and low producers the laboratory error and individual variation were investigated. Whole blood samples from healthy volunteers were collected using endotoxin-free tubes and were incubated with 0 to 1000 ng/ml lipopolysaccharide concentrations for 4 and 24 h, and subsequently centrifuged. In the supernatants, TNF-alpha and IL10 were measured by ELISA. Coefficients of variation for the day-to-day variation in the blood sampling, transport and stimulation as well as in the whole blood stimulation per se ranged from 7.5% to 12.3%. The intra-individual variation was 15% (TNF-alpha) and 19% (IL10) in contrast to the inter-individual variation of, on average, 35%. No interchanging of ranks between high and low producers was observed after repeating the whole blood stimulation on distinct days. The whole blood stimulation system is able to distinguish high and low producers of TNF-alpha and IL10.

Blood↗

Interleukin 10 secretion in relation to human IL-10 locus haplotypes.

Stimulation of human blood cultures with bacterial lipopolysaccharide (LPS) shows large inter-individual variation in interleukin 10 (IL-10) secretion, which has been shown to have a genetic component of over 70%. Alleles at two microsatellite loci in the 4 kb immediately upstream of the human IL-10 transcription initiation site in 132 individuals from 56 Dutch families were defined and assigned as haplotypes. LPS-induced IL-10 secretion was measured by ELISA and related to the IL-10 promoter haplotypes present in 78 unrelated individuals obtained from these families. Analysis showed that LPS-induced IL-10 secretion from unrelated individuals varied with IL-10 promoter haplotypes (P = 0.024; Kruskal-Wallis test). Two observations were made in relation to secreted IL-10 levels and promoter haplotypes; first, those haplotypes containing the allele IL10.R3 were associated with lower IL-10 secretion than haplotypes containing any other IL10.R allele. Second, the haplotype IL10.R2/IL10.G14 was associated with highest IL-10 secretion overall, whereas the haplotype IL10.R3/IL10.G7 was associated with lowest IL-10 secretion. These data demonstrate that the ability to secrete IL-10 can vary in man according to the genetic composition of the IL-10 locus.

Alleles↗

Clinical value of soluble IgG Fc receptor type III in plasma from patients with chronic idiopathic neutropenia.

Previous studies have shown that the plasma level of soluble IgG Fc receptor type III (sFcgammaRIII) is a measure of the total body neutrophil mass. The aim of this study was to determine whether the plasma level sFcgammaRIII is associated with the risk of contracting bacterial infections in patients with neutropenia. We collected blood from 66 patients suffering from acquired idiopathic neutropenia, whose blood was sent to our laboratory for diagnostic evaluation of neutropenia (neutrophil count <1,500 cells/microL). Soluble FcgammaRIII levels were measured in plasma. Genotype distibutions of FcgammaR polymorphisms were determined. Clinical data were obtained from the patient files. Patients were assessed as to whether or not they had suffered from a bacterial infection 3 months before to 3 months after a single sFcgammaRIII measurement. In addition, longitudinal data were obtained from 21 patients. Of the 66 neutropenic patients who were included, 15 had suffered from a bacterial infection in the period 3 months before to 3 months after sFcgammaRIII measurement. The age and sex distribution was equal among the groups with and without infections, as were the genotype frequencies of neutrophil FcgammaR polymorphisms. Both neutrophil count and plasma level sFcgammaRIII were significantly lower in the patient group with infections, compared with the noninfected group (P = .03 and P < .0001, respectively). No infections were reported for patients who had plasma sFcgammaRIII levels above 100 arbitrary units (AU; normal value, 30 to 200). After matching each infected patient with two noninfected patients having the same neutrophil count, sFcgammaRIII plasma levels remained significantly lower in the group with infections (P = . 0001). For the patients who were followed in time, no infections were reported when sFcgammaRIII levels were above 100 AU. In conclusion, our population of patients with chronic idiopathic neutropenia with plasma sFcgammaRIII levels above 100 AU did not show an increased risk of contracting bacterial infections.

Adolescent↗

Anti-C1q receptor/calreticulin autoantibodies in patients with systemic lupus erythematosus (SLE).

SLE is a disease characterized by the presence of multiple autoantibodies and high levels of circulating immune complexes. We studied the presence and functional relevance of autoantibodies directed against a receptor for the collagen-like stalks of the first subcomponent of complement, also known as calreticulin (cC1qR/CaR), in patients with SLE. In a cross-sectional study it was found that higher titres of antibodies against cC1qR/CaR are present in sera of SLE patients compared with normal donors. No association between anti-cC1qR/CaR titres and SLE disease activity was found. Following gel filtration of SLE serum it was found that anti-cC1qR/CaR reactivity is associated with the peak of monomeric IgG. Purified IgG from patients was able to specifically immunoprecipitate cC1qR/CaR. Since we have shown previously that cC1qR/CaR is able to inhibit the haemolytic activity of Clq, we determined a possible pathogenic role for anti-cC1qR/CaR on complement regulation. IgG derived from SLE serum reversed the inhibitory capacity of cC1qR/CaR in a dose-dependent fashion up to 63%, whereas IgG from normal donors had no significant effect. With respect to the capacity of anti-cC1qR/CaR antibodies to activate neutrophils, it was found that incubation of normal neutrophils with F(ab')2 anti-cC1qR/CaR resulted in a very limited oxidative burst. However, cross-linking of F(ab')2 anti-cC1qR/CaR on the neutrophils clearly induced neutrophil activation. Pre-incubation of the SLE-derived F(ab')2 with cC1qR/CaR prevented activation of neutrophils up to 81+/-5%. These results suggest that the presence of anti-cC1qR/CaR antibodies in patients with SLE may modulate complement and neutrophil activation.

Antibody Specificity↗

Female sex hormones at the onset of systemic lupus erythematosus affect survival.

Female sex hormones affect susceptibility to systemic lupus erythematosus (SLE). To determine the effect of female sex hormones at onset of SLE on the survival of these patients, a retrospective survey was performed. The charts of 168 female SLE patients were evaluated to study the disease course, in particular the presence and kind of SLE criteria. Patients were classified as either belonging to the 'high female sex hormone at onset (HH)' or 'low female sex hormone at onset (LH)' group according to age at diagnosis. The statistics of the Dutch population, matched for age, were used to control for differences in life expectancy in these groups. A Cox regression model revealed that the relative mortality risk of HH patients vs HH controls was 4.2 times higher than the relative mortality risk of LH patients compared to LH controls. No differences in the frequency of SLE criteria between HH and LH patients were found that could explain the observed difference in mortality risk.

Adolescent↗

Functional analysis of a human tumor necrosis factor alpha (TNF-alpha) promoter polymorphism related to joint damage in rheumatoid arthritis.

BACKGROUND: Functional heterogeneity in the tumor necrosis factor alpha (TNF-alpha) gene may be responsible for the TNF-alpha response in infectious and autoimmune diseases. Recently, the TNF-238 promoter polymorphism was observed as being associated with a more destructive disease in rheumatoid arthritis (RA). To determine the relation between TNF-238 and disease progression, the extent of joint destruction in a cohort of 101 RA patients followed for 12 years was analyzed. Furthermore, we have attempted to link this polymorphism to TNF-alpha gene transcription in monocytes and lymphocytes in vitro. PATIENTS, MATERIALS, AND METHODS: The extent of joint destruction determined on X-rays of hands and feet assessed after 0, 3, 6, and 12 years was compared with TNF-238 genotypes. Functional consequences of TNF-alpha gene polymorphisms using reporter gene constructs were analyzed in cells of the monocyte and lymphocyte lineage by means of transient transfection systems. RESULTS: The rate of joint damage in -238GA patients was lower than that in the -238GG patients, independent of HLA-DR4. Damage after 12 years was 76 +/- 30 for the -238GA versus 126 +/- 13 for the -238GG patients as determined by the van der Heijde's modification of Sharp's method. Furthermore, TNF-238A was found to be in linkage disequilibrium with an additional polymorphism at position -376. Functional assays revealed no significant differences in the level of inducible reporter gene expression between the TNF-238/-376 promoter constructs in the cell types tested. CONCLUSION: In a prospective study, we show that the TNF-238GG genotype contributes to progression of joint destruction in RA, independent of the presence of HLA-DR4. However, in vitro transfection assays indicate that TNF-238A by itself or in combination with TNF-376A is not likely to be of direct functional relevance for transcriptional activation. Therefore, these polymorphisms may serve as markers for additional polymorphisms in the TNF/LT locus or neighboring genes that may influence disease severity.

Adult↗

The effect of pentoxifylline on human neutrophil migration: a possible role for cyclic nucleotides.

Relatively low concentrations of pentoxifylline caused a stimulation of random migration, while high concentrations inhibited chemotactic migration activated by formyl-methionyl-leucyl-phenylalanine (fMLP). The stimulating effect of pentoxyfylline was partly chemokinetic and partly chemotactic, and was dependent on extracellular calcium. Activation of migration by pentoxifylline was not dependent on the pore size of the micropore filter, indicating that the effect was not mediated by the ability of the drug to induce membrane deformability. Inhibitors of guanylate cyclase and antagonists of cGMP-dependent protein kinase (G-kinase) inhibited stimulation of migration by pentoxifylline. Pentoxyfylline caused a transient increase in cGMP level, while only high concentrations of pentoxifylline caused an increase in cyclic adenosine monophosphate (cAMP) level. It is suggested that the increase of migration is caused by cGMP and is mediated by a G-kinase, while the inhibition of migration at high concentrations of pentoxifylline is mediated by cAMP.

1-Methyl-3-isobutylxanthine↗

Genetic influence on cytokine production and fatal meningococcal disease.

BACKGROUND: To assess the genetic influence on cytokine production and its contribution to fatal outcome, we determined the capacity to produce tumour necrosis factor-alpha (TNF alpha) and interleukin-10 (IL-10) in families of patients who had had meningococcal disease. METHODS: We studied 190 first-degree relatives of 61 patients with meningococcal disease; we also studied 26 monozygotic twins. Production of cytokines was determined during endotoxin stimulation of whole-blood samples ex-vivo. Heritability was estimated in a pedigree-based maximum-likelihood model. DNA was typed for the G to A transition polymorphisms at position -308 and -238 in the TNF gene promoter. FINDINGS: Heritability in monozygotic twins was 0.60 for the production of TNF and 0.75 for the production of IL-10. Families with low TNF production had a tenfold increased risk for fatal outcome (OR 8.9, 95% CI 1.8-45), whereas high IL-10 production increased the risk 20-fold (19.5, 2.3-165). Families with both characteristics had the greatest risk. The transition polymorphisms in the TNF gene promoter were not associated with outcome. INTERPRETATION: Genetic factors substantially influence production of cytokines. An innate anti-inflammatory cytokine profile may contribute to fatal meningococcal disease.

Adolescent↗

TNF-alpha promoter polymorphisms, production and susceptibility to multiple sclerosis in different groups of patients.

TNF-alpha production in whole blood cultures upon stimulation with LPS was determined in 179 individuals from 61 families in order to characterise the magnitude of inherited differences in TNF-alpha production. The three families characterised by highest TNF production showed 7.1 +/- 0.3 ng TNF/ml upon culture with 10 ng LPS and 10.2 +/- 0.2 ng TNF/ml upon culture with 1000 ng LPS. in contrast to the three families characterised by the lowest TNF production that showed a production of 1.6 +/- 0.1 ng TNF upon culture with 10 ng and 2.5 +/- 0.2 ng/ml upon culture with 1000 ng LPS/ml. This difference could not be attributed to the promoter polymorphisms -308 G to A. -238 G to A or -376 G to A, although the -238 GA donors produced 2.1 +/- 0.9 ng TNF upon culture with 10 ng endotoxin compared to 3.2 +/- 2.2 ng TNF for the -238 GG donors. In line with these results the frequency of the -238 GG genotype was increased in hospitalized MS patients in a nursing home (100% 238GG, n = 57) compared to MS patients in an outpatient's clinic (94% 238GG, n = 98) or Dutch controls (90% 238GG, n = 180). These results suggest that the -238 GG genotype is differently distributed in hospitalized MS patients in a nursing home.

Disease Susceptibility↗

Tumour necrosis factor alpha gene polymorphisms in rheumatoid arthritis: association with susceptibility to, or severity of, disease?

Genetic factors associated with rheumatoid arthritis (RA) might involve variant tumour necrosis factor (TNF)-alpha genes. Therefore, polymorphisms at positions -308, -238, -376, -163 and +70 relative to the transcription initiation site were studied with respect to the susceptibility to, or severity of, RA. TNF-alpha genotypes of 283 RA patients and 116 healthy individuals were determined. Clinical data were obtained from patient files and questionnaires. The distribution of TNF-alpha alleles was similar in RA patients and healthy controls. With respect to disease severity, the TNF-alpha -238GA genotype was found to be associated with the absence of erosions [odds ratio (OR) 4.1, confidence interval 1.0-17]. In addition, this genotype was associated with a lower number of hand joints affected by erosions within the first 3 yr of disease onset compared to -238GG. The association between the -238 polymorphism and radiographic progression was independent of the presence of HLA-DR4. In line with this observation, the OR for the presence of erosions in patients with both risk factors (DR4 and -238GG) compared to patients who lack these factors was 11.1 (1.8-6.8). No associations between the TNF-alpha -308, +70 and -376 alleles and susceptibility to, or severity of, RA could be demonstrated. Our data indicate that the TNF-alpha -238GA genotype is associated with decreased radiologically detectable progression of RA.

Adenine↗

Allele-specific quantification of TNFA transcripts in rheumatoid arthritis.

Clinical and laboratory studies have suggested a pivotal role for tumor necrosis factor alpha (TNFA) in the pathogenesis of rheumatoid arthritis (RA). Interindividual variation in the expression of TNFA indicates the existence of functionally distinct TNFA alleles that could play a role in susceptibility to TNFA-associated diseases such as RA. In order to determine whether differential TNFA gene expression is present in RA, we studied the relative contribution of TNFA alleles to the total amount of steady-state mRNA in peripheral blood mononuclear cells of RA patients and healthy individuals. Moreover, allelic TNFA mRNA expression was analyzed in synovial biopsy material of RA patients. For this purpose, we used the recently identified C-insertion polymorphism located in the 5' untranslated region of the first exon. The location of this polymorphism within a part of the gene that is transcribed into mRNA allowed us to discriminate between the contribution of each allele to the total amount of TNFA mRNA in heterozygous individuals. The results of this study do not indicate the existence of variation at the level of mRNA transcribed from each TNFA allele by in vitro and physiological stimulation conditions in RA patients. Therefore, our data do not suggest a role for transcriptionally distinct TNFA alleles in the susceptibility to RA.

Alleles↗

Apoptosis of cultured rat glomerular mesangial cells induced by IgG2a monoclonal anti-Thy-1 antibodies.

Anti-Thy-1 nephritis is a model of mesangial proliferative glomerulonephritis. It has been suggested that apoptosis, which is a counteracting regulatory mechanism against undesired cell proliferation, is involved in sequential histological changes in this model. In the present study, we investigated whether IgG2a anti-Thy-1 monoclonal antibody (ER4) or its F(ab')2 fragments are able to induce apoptosis of rat glomerular mesangial cells (GMC) in vitro. After co-culture with ER4 or its F(ab')2 fragments, apoptosis was assessed by morphological studies with Hoechst 33258 stain and FITC-annexin V. The latter detects the dislocation of negatively charged phospholipid, phosphatidylserine, from the inner to the outer leaflet of the membrane during apoptosis. This is a sensitive method for the detection of apoptosis. Under fluorescent microscopy, distinct nuclear condensation and positive reactivity with FITC-annexin V were observed in cells co-cultured with ER4 or its F(ab')2 fragments. The results obtained by FACS analysis with annexin V showed a direct correlation with the detection of apoptosis with the terminal deoxynucleotidyl transferase reaction (TDT). Up to 19% and 23% of rat GMC, which were co-cultured for 24 hours with 1 microgram/ml (0.5 microgram/l x 10(5) cells) of ER4 or its F(ab')2 fragments, were labeled by TDT, respectively. With annexin V, up to 34% and 31% cells displaying apoptosis were seen. The degree of apoptosis as measured by the annexin V method was dependent on the concentration of ER4 and time of incubation in the presence of ER4. Finally, apoptosis was confirmed by gel electrophoresis of DNA isolated from the cells co-cultured with each monoclonal antibody (MAb). DNA extracts from cells co-cultured with ER4 or its F(ab')2 fragments demonstrated typical internucleosomal DNA fragmentation. Medium alone, controls of anti-human C3bi receptor MAb (IB4) and anti-rat MHC class I MAb (OX18) showed neither nuclear changes nor significant labeling of the cells with the TDT reaction or with the annexin V. Taken together, these results demonstrate for the first time that anti-Thy-1 MAb is able to induce apoptosis of rat GMC in vitro. The Thy-1 antigen on rat GMC, therefore, seems to function as one of the molecules regulating cell death and thereby may determine the degree of mesangial alteration in Thy-1 nephritis.

Animals↗

HLA class I-eluted platelets as an alternative to HLA-matched platelets.

BACKGROUND: Alloimmunized refractory thrombocytopenic patients often require HLA-matched platelet transfusions. As the HLA system is very polymorphic, sufficient HLA-matched donors are not available for every patient. STUDY DESIGN AND METHODS: In vitro elution techniques with citric acid incubation of platelets at pH 3.0 showed that platelets lose expression of HLA, whereas platelet-specific glycoproteins are preserved. This technique was modified for clinical use. Random-donor platelet concentrates were incubated with citric acid, subsequently washed, and transfused to two patients. RESULTS: Platelet-specific glycoproteins were unaffected, and HLA expression decreased generally to below 25 percent of the initial expression. One alloimmunized patient who was without compatible donors because of a rare HLA type underwent repeated transfusions with acid-treated platelets. In contrast to the results with random-donor platelet transfusions, posttransfusion increments up to 47 x 10(9) per L were obtained with acid-treated platelets, and profuse gastrointestinal bleeding was stopped, while multiple skin hemorrhages were resolved. No side effects were observed. A second patient developed a severe transfusion reaction without platelet increment after one transfusion with acid-treated platelets expressing 30 percent of the original HLA antigens. Further transfusions were not given. CONCLUSION: Standardization of the acid elution technique and validation of the technique in patients is necessary. The results suggest, however, that HLA-eluted platelets prepared under specified conditions may gain a place in platelet transfusion therapy.

Adult↗