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Biomedical subjects

G Elinder

Publications and source records attributed to G Elinder.

At least 19 recordsLinked to original sources
PubMed2004

T cell receptor V gene usage by CD4+ and CD8+ peripheral blood T lymphocytes in immune thrombocytopenic purpura.

AIM: To identify T cell expansions, i.e. increased frequencies of T cells using a particular T cell receptor (TCR) V alpha or V beta gene segment, in patients with immune thrombocytopenic purpura (ITP). METHODS: The TCR repertoires of CD4+ and CD8+ peripheral blood lymphocytes of 16 patients with chronic ITP were analysed by staining with a panel of anti-TCR V alpha and V beta antibodies followed by flow cytometry. RESULTS: Four of the 16 patients exhibited a total of 6 expansions of CD8+ T cells using a particular V beta segment, but no expansions were detected in the CD4+ subset. For three of the expansions where a follow-up blood sample after treatment with intravenous immunoglobulin was available, only one expansion remained. CONCLUSION: Overall T cell expansion frequency was the same as in healthy individuals. However, the presence of expansions that normalized with treatment suggests the presence of specific T cells implicated in the pathogenesis of ITP.

Adolescent↗
PubMed2001

[Idiopathic thrombocytopenia during pregnancy. The risk in connection with umbilical blood sampling is probably greater than the benefit].

Some fetuses whose mothers have idiopathic thrombocytopenic purpura (ITP) may themselves have low platelet count and are thought to be at risk of serious bleeding complications, especially intracranial bleeding, during vaginal delivery. The aim of the present study was to prospectively evaluate outcome for mothers with ITP and their neonates with or without the information provided by percutaneous umbilical blood sampling (PUBS). Our intention was to perform cordocentesis using PUBS to measure fetal platelet count in pregnant women with ITP, utilizing the information thus derived as an aid in planning for delivery. Thirty-five pregnancies in 34 women with ITP or low platelet count (< 105 x 10(9)/L) were monitored. PUBS was to be performed on 13 women only, five of whom were splenectomized. There were two complications related to the PUBS itself which led to cesarean sections on the same day. Twelve of the 13 fetuses with PUBS had platelet count greater than 50 x 10(9)/L in the 36th week of pregnancy, and vaginal deliveries were initially planned. After experiencing one serious complication with PUBS, we found it difficult for ethical reasons to perform PUBS on mothers with ITP. Therefore 22 pregnancies were monitored without PUBS. Nine of the 35 children (26%) were delivered by cesarean section. The frequencies of vaginal and cesarean deliveries in the groups with and without PUBS were the same. Six of 15 neonates (40%) born to splenectomized mothers had platelet counts less than 50 x 10(9)/L during the first days of life and four of these were treated with intravenous gamma globulin and/or cortisone. No intracranial bleeding was observed in any of the children. In our hands, PUBS in ITP is potentially harmful and must be questioned. The frequency of low platelet count and/or bleeding complications in neonates of mothers with ITP born vaginally is low. In our opinion, the mode of delivery should be chosen mainly on the basis of obstetric criteria.

Blood Specimen Collection↗
PubMed2000

[Familial hemophagocytic lymphohistiocytosis: diagnosis, treatment and pathophysiological mechanisms].

Familial hemophagocytic lymphohistiocytosis (FHL) is an invariably fatal disease typically seen in infancy and early childhood, with a median survival without therapy of two months. It is characterized by prolonged fever, hepatosplenomegaly, cytopenia, and deficient NK-cell activity and T-cell cytotoxic capacity. Severe neurological symptoms as well as coagulation disorders and abnormalities in liver function and lipid status may also develop. Since the mid 1980's there has been a remarkable increase in our understanding of this disease. In a large-scale international collaborative effort mediated through the Histiocyte Society, diagnostic criteria and an international treatment protocol (HLH-94) based on immunochemotherapy and BMT have been developed. A large proportion of affected children can now be cured and, moreover, successful chemotherapy in utero of FHL has been achieved. It has been shown that the symptoms and signs are mediated through a pronounced hypercytokinemia. Previous suggestions that FHL may be caused by a deficiency in apoptosis were recently confirmed when perforin gene defects were described, which may well explain the disastrous lymphohistiocytic accumulation and subsequent T-cell activation.

Apoptosis↗
PubMed2000

A microdeletion in 19q13.2 associated with mental retardation, skeletal malformations, and Diamond-Blackfan anaemia suggests a novel contiguous gene syndrome.

Diamond-Blackfan anaemia (DBA) is a constitutional red blood cell hypoplasia which may be associated with a variety of developmental abnormalities. A gene for DBA was recently mapped to chromosome 19q13.2 and subsequently cloned. Analysis of 19q marker alleles in DNA of sporadic DBA cases showed de novo microdeletions in three patients also presenting with mental retardation. We have studied one of these patients and characterised the deletion by fluorescence in situ hybridisation (FISH) to extended DNA fibres. The deletion was shown to be continuous over a 3.2 Mb region and the fibre-FISH analysis showed both chromosomal breakpoints. In combination, the clinical and molecular findings suggest a contiguous gene syndrome with a gene locus for mental retardation and, probably, skeletal malformations included in the deletion.

Bone and Bones↗
PubMed1999

Inflammatory parameters and soluble cell adhesion molecules in Swedish children with Kawasaki disease: relationship to cardiac lesions and intravenous immunoglobulin treatment.

The possible use of inflammatory parameters as a predictor of coronary artery lesions (CAL) and the effect of intravenous immunoglobulin (IVIG) treatment in 30 Swedish children with acute Kawasaki disease were investigated. All the patients were treated with IVIG (2 g/kg) and seven of them had CAL. Ten febrile children, hospitalized for treatment of severe infection, and 15 healthy children served as controls. The levels of soluble E-selectin and soluble intercellular adhesion molecule (ICAM)-1 in the Kawasaki patients were elevated in comparison to healthy, but not in comparison to febrile controls. Paired analysis of our patients before and after IVIG therapy during acute disease revealed lowered levels of C-reactive protein, interleukin-6, soluble E-selectin and soluble ICAM-1. We found no statistically significant relationships among any of these parameters as a possible predictor of CAL, but three patients with cardiac sequelae demonstrated high values for these inflammatory parameters. These findings may reflect endothelial activation in connection with vasculitis, and the anti-inflammatory effect of IVIG treatment lowering cytokine levels and subsequently decreasing the expression and shedding of adhesion molecules. In conclusion, we were unable to identify a predictor of CAL in the acute phase. The patients had higher levels of soluble E-selectin and soluble ICAM-1 than did afebrile controls, but not febrile controls. The patients' levels of C-reactive protein, interleukin-6, soluble E-selectin and soluble ICAM-1 were decreased after 1-2d of IVIG treatment.

C-Reactive Protein↗
PubMed1999

Gamma interferon treatment of patients with chronic granulomatous disease is associated with augmented production of nitric oxide by polymorphonuclear neutrophils.

Treatment with gamma-interferon (IFN-gamma) is associated with reduced frequency and severity of infections in chronic granulomatous disease (CGD), but the mechanism is unknown. Since the inducible nitric oxide (NO) synthase can be amplified by IFN-gamma in murine macrophages, for example, we hypothesized that IFN-gamma might modulate NO release from polymorphonuclear neutrophils (PMNs) in patients with CGD. Eight patients with CGD and eight healthy controls were studied. Each patient was given either 50 or 100 microg of IFN-gamma per m2 on two consecutive days. The production of NO from N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMNs was assessed as the NG-monomethyl-L-arginine-inhibitable oxidation of oxyhemoglobin to methemoglobin in the presence of catalase and superoxide dismutase. Prior to IFN-gamma treatment, the PMNs from CGD patients produced 372 +/- 27 (mean +/- standard error of the mean) pmol of NO/10(6) PMNs at 45 min, while the control PMNs produced 343 +/- 44 pmol. On day 1 after IFN-gamma treatment, NO production increased to 132% +/- 25% of that for controls, and on day 3 it reached 360% +/- 37% (P < 0.001) of that for controls. On day 8, the values still remained higher, 280% +/- 78% more than the control values. Likewise, the bactericidal capacity of PMNs increased on day 3. The present data show that IFN-gamma treatment of CGD patients is associated with an increased production of NO from PMNs when activated by fMLP. Since these PMNs lack the capacity to produce superoxide anions, it is conceivable that this increase in NO release could be instrumental in augmenting host defense.

Adolescent↗
PubMed1998

Familial hemophagocytic lymphohistiocytosis. Primary hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases including the rapidly fatal autosomal recessive disease of familial hemophagocytic lymphohistiocytosis (FHL). The onset is usually during the first years of life with fever, cytopenia, and hepatosplenomegaly. Neurologic symptoms may supervene. Similar symptoms may occur in the infection-(virus-)associated or malignancy-associated hemophagocytic syndromes (IAHS/MAHS). Triggering infections can be found in all these diseases and do not allow for reliable differentiation. An international treatment protocol (HLH-94) has been developed for FHL, but immunomodulatory treatment may be justified in IAHS and MAHS as well, since they also have a high fatality rate.

Adolescent↗
PubMed1998

Infection- and malignancy-associated hemophagocytic syndromes. Secondary hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis represents a spectrum of pathogenetically different diseases in which a T-cell induced, uncontrolled activation of phagocytosing macrophages may lead to fever, organomegaly, and pancytopenia. The underlying immunologic disturbance can either be genetically transmitted, like in FHL, or acquired, as in IAHS or MAHS. Triggering infections can be found in all these diseases and do not allow a reliable differentiation. An international treatment protocol has been developed for FHL. IAHS and MAHS also have a high fatality rate, justifying immunomodulatory treatment if the disease is progressive.

Child↗
PubMed1998

Characterization of the T-cell receptor V-beta repertoire in Kawasaki disease.

Kawasaki disease (KD) is a paediatric multisystem necrotizing vasculitis constituting the most frequent cause of acquired heart disease in childhood. Conflicting data have been reported regarding expanded T-cell populations using particular T-cell receptor (TCR) beta-chain variable (BV) gene segments, suggesting either a superantigen- or a conventional antigen-mediated immune response in this disease. In order to further investigate the role of T lymphocytes, cells were stained with an extensive panel of 21 different TCRBV specific monoclonal antibodies (MoAbs) covering almost 70% of all T-cells. Flow cytometry was employed to analyse the expression of the TCRBV repertoire in the CD4+ and CD8+ subsets separately, and of activation markers, in freshly isolated peripheral blood lymphocytes of 25 Kawasaki disease patients during the acute and convalescent phases of the disease. No abnormal usage of any TCRBV family was found, neither acutely nor during convalescence, compared with a control group of healthy children. However, a significant increase in interleukin-2 receptor (IL-2R)-expressing T lymphocytes restricted to the CD4+ subset was observed in KD patients. Our data confirm a strong immune activation in KD that might be of importance in the pathogenesis of the disease.

Child↗
PubMed1998

Identification of microdeletions spanning the Diamond-Blackfan anemia locus on 19q13 and evidence for genetic heterogeneity.

Diamond-Blackfan anemia (DBA) is a rare pure red-cell hypoplasia of unknown etiology and pathogenesis. A major DBA locus has previously been localized to chromosome 19q13.2. Samples from additional families have been collected to identify key recombinations, microdeletions, and the possibility of heterogeneity for the disorder. In total, 29 multiplex DBA families and 50 families that comprise sporadic DBA cases have been analyzed with polymorphic 19q13 markers, including a newly identified short-tandem repeat in the critical gene region. The results from DNA analysis of 29 multiplex families revealed that 26 of these were consistent with a DBA gene on 19q localized to within a 4.1-cM interval restricted by loci D19S200 and D19S178; however, in three multiplex families, the DBA candidate region on 19q13 was excluded from the segregation of marker alleles. Our results suggest genetic heterogeneity for DBA, and we show that a gene region on chromosome 19q segregates with the disease in the majority of familial cases. Among the 50 families comprising sporadic DBA cases, we identified two novel and overlapping microdeletions on chromosome 19q13. In combination, the three known microdeletions associated with DBA restrict the critical gene region to approximately 1 Mb. The results indicate that a proportion of sporadic DBA cases are caused by deletions in the 19q13 region.

Chromosome Mapping↗
PubMed1998

Role of the T cell receptor in idiopathic thrombocytopenic purpura (ITP).

During the past few decades a number of studies has described T cell defects and attempted to elucidate their role in the pathogenesis of idiopathic thrombocytopenic purpura (ITP). Some studies implicate T cells as potential initiators of autoantibody production in ITP. However, only a few of these have studied the role that the T cell receptor may play in the pathogenesis of ITP. In a variety of autoimmune syndromes interest has focused on the alpha- and beta-chains of the T cell receptor. Deviations from the normal T cell receptor gene usage have been reported in rheumatoid arthritis, systemic lupus erythaematosus and multiple sclerosis. Usually, these studies have shown a restricted heterogeneity of T cell receptor variable gene usage. The studies on the T cell receptor in ITP have included a limited number of patients, which makes it difficult to evaluate the significance of the role that the T cell receptor may play in the pathogenesis of ITP. Further studies are warranted.

Autoimmunity↗
PubMed1998

Current management issues of childhood and adult immune thrombocytopenic purpura (ITP).

The management of acute and chronic immune thrombocytopenic purpura (ITP) of children differs in many aspects from that of adults. Current paediatric and adult treatment options are discussed in this review in the light of the recently published practice guidelines for the diagnosis and treatment of ITP issued by a panel of paediatric and adult haematologists on behalf of the American Society of Hematology. Uncontrolled rather than controlled randomized studies often represent the basis for treatment decisions. Important issues in improving the management of patients with ITP include the identification of research priorities resulting in controlled clinical trials with well-defined study endpoints, the logistics and coordination of research activities and their presentation at international meetings.

Acute Disease↗
PubMed1998

Directions for research in autoimmune thrombocytopenic purpura (ITP).

All attendees participated in a round-table discussion regarding directions for research in autoimmune thrombocytopenic purpura (ITP). Suggested areas for study were grouped into five main areas: (i) improved classification of ITP identifying subsets of patients with differing clinical syndromes and response to treatment, and those more likely to have serious bleeding manifestations; identification of patients with reduced thrombopoiesis was emphasized; (ii) studies aimed at elucidating the aetiology and pathophysiology of ITP, with emphasis on distinctions between acute and chronic ITP and between patients responsive or refractory to therapy; these studies focused on measures of humoral and cellular immune dysregulation; (iii) studies of platelet function in ITP, with the intent of defining these abnormalities and correlating them with the clinical manifestations of the disease; (iv) new approaches to treatment, particularly of refractory patients; and (v) a miscellaneous group, which included development of an ITP registry, evaluation of the "burden" of disease, investigation of mood changes in ITP, etc. The discussion was not intended to be all-inclusive, but focused on the content of other talks in this symposium. It is hoped that some of these suggestions will be further developed for investigation in multicentre co-operative studies to improve the diagnosis, understanding and treatment of ITP.

Humans↗
PubMed1997

Dose-dependent enhancements by interferon-gamma on functional responses of neutrophils from chronic granulomatous disease patients.

Interferon-gamma (IFN-gamma) is recommended as prophylaxis against infections in patients with chronic granulomatous disease (CGD). However, since the optimal dose, the dosing interval, and the mechanisms of action are not well-defined, we studied the effects on CGD neutrophil (PMN) functions ex vivo of interferon-gamma (IFN-gamma). Evaluations were made on oxidative capacity, measured by superoxide anion production and chemiluminescence after stimulation with f-met-leu-phe (f-MLP) or phorbol-myristate-acetate, the killing of Aspergillus fumigatus hyphae (assessed as conversion of the tetrazolium salt MTT to formazan), and on the expression of Fc gammaRI receptor (CD64). After randomization, 9 CGD patients (4 with gp91phox, 3 with p47phox, 1 with p67phox deficiency and 1 with unspecified CGD) were given IFN-gamma, either 50 or 100 microg/m2 subcutaneously on 2 consecutive days after double blinded randomization. Furthermore, one female hyperlyonized X-linked carrier with a CGD phenotype was also studied separately after IFN-gamma treatment. Evaluations were made the day before and on days 1, 3, 8, and 18 after IFN-gamma administration. The killing of A fumigatus hyphae, being close to zero before IFN-gamma, was enhanced on day 3, being 36% higher than pretreatment values in the high-dose CGD group and 17% in the low-dose group. The expression of Fc gammaRI on PMN increased 3.7-fold in the high-dose and 2.3-fold in the low-dose CGD group, being maximal on day 1. Oxidative functions were raised in only selected patients represented by different subtypes of CGD. The hyperlyonized carrier of X-linked CGD responded to IFN-gamma with more enhanced oxidative responses and Aspergillus killing of her PMNs than the other patients. This study suggests that a higher dose of IFN-gamma than currently recommended confers transient enhancements of certain PMN functions in CGD patients.

Adolescent↗
PubMed1997

Contemporary classification of histiocytic disorders. The WHO Committee On Histiocytic/Reticulum Cell Proliferations. Reclassification Working Group of the Histiocyte Society.

Pathologists and pediatric hematologist/ oncologists of the World Health Organization's Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

Cell Lineage↗
PubMed1997

Diamond-Blackfan anaemia: genetic homogeneity for a gene on chromosome 19q13 restricted to 1.8 Mb.

Diamond-Blackfan anaemia (DBA; MIM#205900) is a rare disorder manifested as a pure red-cell aplasia in the neonatal period or in infancy. The clinical hallmark of DBA is a selective decrease in erythroid precursors and anaemia. Other lineages are usually normal and the peripheral white blood cell count is normal. In approximately one-third of cases, the disease is associated with a wide variety of congenital anomalies and malformations. Most cases are sporadic, but 10-20% of them follow a recessive or a dominant inheritance pattern. A female with DBA and a chromosomal translocation involving chromosome 19q was recently identified. We undertook a linkage analysis with chromosome 19 markers in multiplex DBA families of Swedish, French, Dutch, Arabic and Italian origin. Significant linkage to chromosome 19q13 was established for dominant and recessive inherited DBA with a peak lod score at D19S197 (Zmax = 7.08, theta = 0.00). Within this region, a submicroscopic de novo deletion of 3.3 Mb was identified in a patient with DBA. The deletion coincides with the translocation break-point and, together with key recombinations, restricts the DBA gene to a 1.8-Mb region. The results suggest that, despite its clinical heterogeneity, DBA is genetically homogeneous for a gene in 19q13.

Adult↗