DR "low-resolution" PCR-SSP typing--a correction and an up-date

Recombination frequencies of human leukocyte antigen loci in hematological malignancies among Turkish population

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (HSCT) is a treatment option with growing performance for leukaemia, aplastic anaemia and genetic disorders. The frequency of MHC (Major Histocompatibility Complex) gene locus recombination is increased at loci close to the telomeres and in the female gender. The aim of the present study is to document the recombination events by pedigree diagrams with the primary goal to determine the frequency of recombination in a different ethnic population from mostly reported studies.

METHODS

Altogether 9545 allogeneic HSCT recipients and their family-based potential donors (n:36231) were included in this retrospective study.

RESULTS

Recombinations were determined in 118 (F/M:50/68) out of 9545 families enrolled on the study. These were present in 40 of the patients and 78 of healthy donors. The frequency of recombinations was 0.42% and 0.22%, in patients and donors, respectively. Of the 118 recombinations, 60 were detected in A locus (13 inpatients), 14 in B locus (3 inpatients) and 42 in DR locus (22 inpatients). In our study, due to recombinations in HLA (Human Leukocyte Antigen)-A,-B,-DR loci, we found that some patient-donor pairs became 6/5 matched instead of 6/6 (n:45), eliminating the allogeneic HSCT possibility for the patients from the full-matched siblings.

CONCLUSION

To our knowledge, this is the first study reporting the recombination frequencies in HLA loci among Turkish population and thus, providing informative data to the clinicians regarding the cross-over possibilities in Turkish patients with haematological malignancies.

Addison's disease: a survey on 633 patients in Padova

OBJECTIVE

Addison's disease (AD) is a rare endocrine condition.

DESIGN

We aimed to evaluate clinical, immunologic, adrenal imaging, and genetic features in 633 Italian patients with AD followed up since 1967.

METHODS

Adrenal cortex autoantibodies, presence of other autoimmune and nonautoimmune diseases, nonadrenal autoantibodies, adrenal imaging, and genetic profile for HLA-DRB1 and AIRE were analyzed.

RESULTS

A total of 492 (77.7%) patients were found to be affected by autoimmune AD (A-AD), 57 (9%) tuberculous AD, 29 (4.6%) genetic-associated AD, 10 (1.6%) adrenal cancer, six (0.94%) post-surgical AD, four (0.6%) vascular disorder-related AD, three (0.5%) post-infectious AD, and 32 (5.1%) were defined as idiopathic. Adrenal cortex antibodies were detected in the vast majority (88100%) of patients with recent onset A-AD, but in none of those with nonautoimmune AD. Adrenal imaging revealed normal/atrophic glands in all A-AD patients: 88% of patients with A-AD had other clinical or subclinical autoimmune diseases or were positive for nonadrenal autoantibodies. Based on the coexistence of other autoimmune disorders, 65.6% of patients with A-AD were found to have type 2 autoimmune polyendocrine syndrome (APS2), 14.4% have APS1, and 8.5% have APS4. Class II HLA alleles DRB1*03 and DRB1*04 were increased, and DRB1*01, DRB1*07, DRB1*013 were reduced in APS2 patients when compared with controls. Of the patients with APS1, 96% were revealed to have AIRE gene mutations.

CONCLUSIONS

A-AD is the most prevalent form of adrenal insufficiency in Italy, and ∼90% of the patients are adrenal autoantibody-positive at the onset. Assessment of patients with A-AD for the presence of other autoimmune diseases should be helpful in monitoring and diagnosing APS types 1, 2, or 4 and improving patients' care.

HLA genes, islet autoantibodies and residual C-peptide at the clinical onset of type 1 diabetes mellitus and the risk of retinopathy 15 years later

Aims/Hypothesis

HLA genes, islet autoantibodies and residual C-peptide were studied to determine the independent association of each exposure with diabetic retinopathy (DR), 15 years after the clinical onset of type 1 diabetes in 15–34 year old individuals.

Methods

The cohort was identified in 1992 and 1993 by the Diabetes Incidence Study in Sweden (DISS), which investigates incident cases of diabetes for patients between 15 and 34 years of age. Blood samples at diagnosis were analyzed to determine HLA genotype, islet autoantibodies and serum C-peptide. In 2009, fundus photographs were obtained from patient records. Study measures were supplemented with data from the Swedish National Diabetes Registry.

Results

The prevalence of DR was 60.2% (148/246). Autoantibodies against the 65 kD isoform of glutamate decarboxylase (GADA) at the onset of clinical diabetes increased the risk of DR 15 years later, relative risk 1.12 for each 100 WHO units/ml, [95% CI 1.02 to 1.23]. This equates to risk estimates of 1.27, [95% CI 1.04 to 1.62] and 1.43, [95% CI 1.06 to 1.94] for participants in the highest 25^th (GADA>233 WHO units/ml) and 5^th percentile (GADA>319 WHO units/ml) of GADA, respectively. These were adjusted for duration of diabetes, HbA_1c, treated hypertension, sex, age at diagnosis, HLA and C-peptide. Islet cell autoantibodies, insulinoma-antigen 2 autoantibodies, residual C-peptide and the type 1 diabetes associated haplotypes DQ2, DQ8 and DQ6 were not associated with DR.

Conclusions

Increased levels of GADA at the onset of type 1 diabetes were associated with DR 15 years later. These results, if confirmed, could provide additional insights into the pathogenesis of the most common microvascular complication of diabetes and lead to better risk stratification for both patient screenings and DR treatment trials.

Immunogenetic susceptibility to diabetes mellitus in patients with liver disease

BACKGROUND/AIM

Genetic, environmental, metabolic and infectious influences, such as hepatitis C virus (HCV) infection, are thought to impact on the development of diabetes in patients with liver disease. As specific human leucocyte antigen (HLA) alleles provide the major genetic risk factors for type 1 diabetes, our aim was to investigate whether HLA class I and II alleles constitute additional risk factors for diabetes in patients with liver disease.

METHODS

We evaluated two independent databases of 193 and 728 adult patients with chronic liver disease for the diagnosis of diabetes and the presence of specific HLA subtypes.

RESULTS

In each database, 24 and 19% of patients met criteria for diabetes. In the first database, specific class I and II alleles were observed more frequently in diabetics compared with non-diabetics: Cw7 (50 vs. 32%, P=0.04), DR51 (17 vs. 3%P=0.003) and DQ6 (37 vs. 18%, P=0.02). In the second database, DQ6 was observed in 16% of diabetics vs. 8% of non-diabetics (P=0.04). The DR2-DR51-DQ6 haplotype was higher in patients with diabetes in both databases (22 vs.7%, P=0.02 and 12 vs. 5%, P=0.02). In a subgroup analysis of patients with HCV infection, increased frequencies of Cw7, DR2/DR51, DQ6 and DR2-DR51-DQ6 were also observed to be higher in subjects with diabetes compared with those without diabetes.

CONCLUSIONS

Patients with chronic liver disease, especially those with HCV infection, have an immunogenetic risk for diabetes characterized by the presence of Cw7, DR51, DQ6 and DR2-DR51-DQ6.

Islet cell autoantibody levels after the diagnosis of young adult diabetic patients

AIMS

The aim was to determine the course of islet cell antibodies [glutamate decarboxylase (GADA), tyrosine phosphatase-like islet antigen 2 (IA-2A) and islet cell (ICA)] after the diagnosis of the diabetic patient.

METHODS

The Diabetes Incidence Study in Sweden (DISS) attempted to prospectively enrol all newly diagnosed diabetic patients aged 15-34 years during 1992 and 1993. C-peptide and autoantibody levels were determined from venous blood samples at diagnosis and again at yearly intervals for 6 years.

RESULTS

After the first year, the odds of remaining GADA positive decreased by 9% per year [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.85-0.96] while the mean GADA index remained unchanged ( = 0.8, P = 0.37). There was no change in the percentage of subjects testing IA-2A positive after the first year ( = 0.1, P = 0.75). However, the mean index decreased 0.04 per year (95% CI: 0.03-0.05)-a 7.9% decline (95% CI: 5.4-10.4%). The odds of a subject testing positive for ICA decreased by 24% per year (OR = 0.76, 95% CI = 0.70-0.82). The mean ICA levels decreased 0.75 per year (95% CI: 0.66-0.84)-a 16.4% decline (95% CI: 14.1-18.6%). The rate of change in titres for all three autoantibodies was independent of gender, human leucocyte antigen genotype and C-peptide status.

CONCLUSIONS

GADA levels remained high while ICA levels declined. In contrast to a previous study, we found that the proportion of IA-2A subjects remaining positive did not decrease after the first year, while the average index decreased slightly.

Extinction of the human leukocyte antigen homozygosity effect after two doses of the measles-mumps-rubella vaccine

We have reported associations between human leukocyte antigen (HLA) homozygosity and low measles antibody levels after one dose of the measles, mumps, and rubella (MMR) vaccine. Here, we examined associations between HLA homozygosity and immune responses to MMR after two doses of vaccine. We examined associations between HLA homozygosity and measles antibody levels in a group of 178 children (cohort 1) as well as associations between homozygosity and antibody levels and lymphoproliferative responses to MMR in 346 children (cohort 2). In cohort 1, HLA homozygotes and heterozygotes had similar increases in measles antibody levels after a second dose of measles vaccine. In cohort 2, HLA homozygosity was not associated with measles immune measures after two doses of vaccine. Homozygosity at the DPB locus was associated with increased rubella antibody levels, and homozygosity at the class IA alleles was associated with lower mumps lymphoproliferative response. Homozygosity at increasing numbers of loci was also associated with lower mumps antibody levels and lymphoproliferative response. Therefore, two doses of the MMR vaccine appear to induce sufficient antibody levels and lymphoproliferative responses against measles and rubella, regardless of HLA homozygosity status. However, children who are HLA homozygous may be less protected against mumps compared with children who are heterozygous.

Treatment of graft-versus-host disease after liver transplantation with basiliximab followed by bowel resection

Graft-versus-host disease (GVHD) after orthotopic liver transplantation (OLT) is a serious complication with mortality rates over 80%. Two patients with established GVHD after OLT were treated with Basiliximab, a chimeric murine human monoclonal antibody which binds to the alpha-chain of interleukin-2 receptor (IL-2R). Two males, aged 45 and 56 years, presented after OLT with a clinical picture consistent with GVHD. Quantitative measurements of recipient peripheral blood donor lymphocyte chimerism were carried out by flow cytometric analysis, and showed peak chimerism levels of 5% and 8%, respectively. Treatment comprised 3 doses of 1 g methyl prednisolone followed by 2 doses of 20 mg of Basiliximab. In both, treatment resulted in complete disappearance of macro-chimerism in blood. There was resolution of skin rash by day 7; however, diarrhea persisted. White cell scan showed increased uptake in the terminal ileum and small-bowel resection was performed in both patients. One patient is alive and well 36 months after OLT. The other patient had resolution of GVHD, but died of recurrent hepatitis C 1 year after OLT. The combination of immunological and surgical treatment for GVHD following solid organ transplantation has not previously been described.

Synthetic peptides identify promiscuous human Th1 cell epitopes of the secreted mycobacterial antigen MPB70

MPB70 is a secreted protein of Mycobacterium bovis and Mycobacterium tuberculosis which stimulates both cellular and humoral immune responses during infection with bovine and human tubercle bacilli. In addition, vaccination with MPB70 has been shown to induce Th1 cell responses and protection in animal models of tuberculosis. The present study was carried out to map the dominant human Th1 cell epitopes of MPB70 in relation to major histocompatibility complex (MHC) class II restriction in healthy subjects showing strong T-cell responses to complex mycobacterial antigens. Peripheral blood mononuclear cells (PBMC) from HLA-DR-typed donors were tested with complex mycobacterial antigens (whole-cell M. tuberculosis and M. tuberculosis culture filtrates), with MPB70 purified from the culture filtrate of M. bovis BCG Tokyo, and with 13 synthetic peptides (25-mers overlapping by 10 residues) covering the sequence of MPB70. The donors that responded to the complex antigens and MPB70 also responded to the cocktail of synthetic MPB70 peptides. Testing of PBMC with individual peptides showed that peptides p5 (amino acids [aa] 61 to 85), p6 (aa 76 to 100), p8 (aa 106 to 130), p12 (aa 166 to 190), and p13 (aa 181 to 193) were most frequently recognized in proliferation and gamma interferon (IFN-gamma) assays. Testing of antigen-specific CD4(+) T-cell lines with the individual peptides of MPB70 confirmed that peptides p8, p12, and p13 contain immunodominant Th1 cell epitopes of MPB70. MHC restriction analysis with HLA-typed donors showed that MPB70 and its immunodominant peptides were presented to T cells promiscuously. The T-cell lines responding to MPB70 and peptides p8, p12, and p13 in IFN-gamma assays mediated antigen-peptide-specific cytotoxic activity against monocytes/macrophages pulsed with the whole-protein antigen or the peptides. In conclusion, the promiscuous recognition of MPB70 and its immunodominant peptide defined epitopes (aa 106 to 130 and 166 to 193) by IFN-gamma-producing Th1 cells supports possible application of this secreted antigen to subunit vaccine design.

Diabetes mellitus-related autoantibodies in childhood autoimmune hepatitis

OBJECTIVE

To determine the frequency and significance of diabetes mellitus (DM)-related autoantibodies in children with autoimmune hepatitis (AIH).

RESEARCH DESIGN AND METHODS

Anti-islet cell antibodies (ICA), insulin autoantibodies (IAA), and anti-glutamic acid decarboxylase (GAD65) antibodies were assessed in 28 children (25 female) with AIH before and after 3-9 years of therapy with azathioprine and prednisone.

RESULTS

There was biochemical and clinical remission of AIH activity in 76% of the children after 1 year of immunosuppressive therapy. Positive ICA and IAA were found in 60.7% and 18.5% of the patients, decreasing to 38.5% and 12% after 3-9 years of therapy. Anti-GAD autoantibodies were present in only one patient who had Graves' disease, high ICA titer, and developed type 1 DM after 3 years. After 3-9 years of follow up, all had normal fasting glycemia, glycosylated hemoglobin (HbA1c), and, with a single exception, normal responses to oral glucose tolerance testing. No increase in the frequencies of HLA antigens was observed in ICA- and IAA-positive patients compared to antibody-negative patients or a control population. The majority of the patients with HLA-DRB1*03 or DRB1*04, however, were positive for ICA (7/10), and three of them had IAA. The frequency of high risk HLA DQB1*0302 or DQB1*02 alleles was low and similar to control frequencies, indicating low-risk for DM despite the presence of DM-related autoimmunity markers.

CONCLUSIONS

AIH in childhood is associated with high frequency of ICA and IAA, with less than expected rates of progression to DM. Immunosuppression reduced ICA and IAA frequency and titers.

A genomewide scan for type 1-diabetes susceptibility in Scandinavian families: identification of new loci with evidence of interactions

Type 1 diabetes mellitus (TIDM) has a multifactorial etiology, with major genetic-susceptibility determinants located in the HLA and insulin-gene (INS) regions. Linkage data implicating other disease-susceptibility loci are conflicting. This is likely due to (1) the limited power for detection of contributions of additional susceptibility loci, given the limited number of informative families available for study, (2) factors such as genetic heterogeneity between populations, and (3) potential gene-gene and gene-environment interactions. To circumvent some of these problems, we have conducted a genomewide linkage analysis for T1DM-susceptibility loci in 408 multiplex families from Scandinavia, a population expected to be homogeneous for genetic and environmental factors. In addition to verifying the HLA and INS susceptibility loci, the study provides confirmation of IDDM15 on chromosome 6q21. Suggestive evidence of additional susceptibility loci was found on chromosomes 2p, 5q, and 16p. For some loci, the support for linkage increased substantially when families were stratified on the basis of HLA or INS genotypes, with statistically significant heterogeneity between the stratified subgroups. Our data support both the existence of non-HLA genes of significance for T1DM and interaction between HLA and non-HLA loci in the determination of the T1DM phenotype.

Autoimmune hepatitis in Brazilian patients is not linked to tumor necrosis factor alpha polymorphisms at position -308

BACKGROUND/AIMS

Susceptibility to autoimmune hepatitis (AIH) has been linked to different HLA-DR antigens. Recently, AIH type 1 was associated with polymorphisms in the tumor necrosis factor alpha gene promoter (TNFA) at position -308. In this respect, the frequency of the TNFA*2 allele, in linkage disequilibrium with HLA-DRB1*0301, was shown to be significantly increased in whites with AIH type 1. The aim of this study was to assess the role of TNFA alleles in conferring susceptibility to AIH, studying a population where the disease is not primarily associated with HLA-DRB1*03.

METHODS

The determination of HLA-DRB1 and TNFA alleles was performed in 92 patients with AIH type 1, 29 subjects with AIH type 2 and 83 healthy controls by polymerase chain reaction-based techniques.

RESULTS

The distribution of TNFA alleles was similar in patients with AIH types 1 and 2, when compared with controls. In addition, the TNFA*2 allele was identified in patients carrying HLA-DR antigens other than HLA-DRB1*03. Interestingly, higher gammaglobulin levels were observed in TNFA*2 positive patients.

CONCLUSIONS

Our data indicate that susceptibility to AIH remains primarily linked to the HLA-DRB1 locus, and suggest that the association of AIH with TNFA*2 previously observed in whites might be secondary to a linkage disequilibrium with HLA-DRB1*0301.

A commented dictionary of techniques for genotyping

Several tools, differing in their technical and practical parameters, are available for the detection of point mutations as well as small deletions and insertions. In this article, a dictionary featuring over fifty methods for detection of mutation is presented. The distinguishing principle for each method is briefly explained. Sorting of and discussion on the methods give the reader a brief introduction to the field of genotyping.

HLA-DR4 and salivary immunoglobulin A reactions to oral streptococci

The aim of this study was to describe and compare salivary immunoglobulin A (IgA) antibody reactions to extracts of strains of three oral streptococci in human leukocyte antigen (HLA)-DR4-positive and -DR4-negative subjects. Whole paraffin-stimulated saliva samples were collected from 27 apparently healthy subjects. Previous HLA typing showed that 20 subjects were DR4 positive and 7 were DR4 negative. HLA-DRB1*04 subtyping was performed among the DR4-positive subjects. Whole-cell antigen extracts from Streptococcus mutans (KPSK 2), Streptococcus sobrinus (OMZ 65) and Streptococcus parasanguis (Nt 62) were separated in SDS-PAGE. The antigens were immunoblotted with diluted saliva (Western blot), scanned and analyzed in a computer system. All immunoblot bands were recorded in DR4-positive and DR4-negative saliva pools, and bands with an optical density >or=0.1 were selected for analysis in individual salivas. The DR4-negative subjects in general had more immunoblot bands and more distinct bands than did the DR4-positive subjects. A higher concentration of total IgA in saliva was correlated with more bands, especially to antigens separated from S. mutans. When the number of bands was calculated per IgA unit, significant differences were observed between DR4-positive and DR4-negative salivas. This was particularly seen for S. mutans and S. parasanguis. As the number of bands was analyzed in relation to DR4 subgroups, DRB1*04, there was a lower salivary IgA activity to S. mutans in the DRB1*0401 and *0404. The variable level of correlation previously demonstrated for S. mutans colonisation and serologically defined DR4 positive subjects might be explained by the heterogeneity in this group, and the relation should be sought on a subgroup level.

Immune responses to multiple antigen peptides containing T and B epitopes from Plasmodium falciparum circumsporozoite protein of Brazilian individuals naturally exposed to malaria

We have evaluated the immune responses of individuals living in a malaria endemic area of Brazil to the (T1B)4, a multiple antigen peptide (MAP) from Plasmodium falciparum circumsporozoite (CS) protein and the related monoepitope MAPs, B4 and (T1)4, and the linear peptides, T1B and B. The highest antibody frequencies were against MAPs containing the B cell epitope sequence (T1B)4 (42.2%) and B4 (28.8%), while the highest lymphoproliferative response frequencies were against the MAPs containing the T cell epitope sequence (T1)4 (47%) and (T1B)4 (36.4%). We analysed individual responses considering lymphoproliferative response to (T1)4 MAP and IgG antibody titre to (T1B)4 as patterns of ideal cellular and humoral responses, respectively. The frequency of responders, cellular and/or humoral was 66.6%, significantly higher than non responders (P = 0.003). We also determined the HLA class II haplotype of each individual but no association between these and immune response patterns to the MAPs was observed. The results showed that individuals primed against P. falciparum in their natural habitat, present a very diverse array of responses against the same peptide antigens, varying from no response in one-third of the individuals to cognate B and T cell responses. Our study underlines the importance of previous studies of vaccine candidates to guarantee that the immunization will be capable of reverting inefficient or absent responses to malaria epitopes.

Evidence for a role of HLA DRB1 alleles in the control of IgE levels, strengthened by interacting TCR A/D marker alleles

BACKGROUND

MHC class II alleles at human chromosome 6p21.1 and alleles in the TCR A/D locus at human chromosome 14q11.2 have been implicated in susceptibility to specific allergies and the modulation of total serum IgE. It has also been hypothesized that HLA and TCR allelic interactions may have a strong influence on predisposition to allergic disease.

OBJECTIVE

This study was performed to investigate the influence of HLA-DRB and DQB1 alleles and D14S50 alleles (adjacent to TCR A/D locus on 14q11.2), individually and in-combination, on total serum IgE levels, and on the development of specific allergies.

METHODS

We performed an association study between HLA-DRB, HLA-DQB1 polymorphisms, D14S50 alleles, total serum IgE expression and specific allergies to house dust mite, grass pollens and cat fur. A sample of 181 individuals was drawn from a larger set of 2415 adults, sampled at random from a district in Nottingham.

RESULTS

Strong association was observed between HLA-DRB1*0701 allele and high total serum IgE expression (P < 0.001). D14S50 alleles alone showed no evidence for independent association. However, there was a significant interaction between DRB1*0701 and D14S50 allele 170 such that, when both were present, there was a further increase in total serum IgE levels.

CONCLUSION

This study suggests that DRB1*0701 allele is involved in the modulation of total serum IgE, and that there is an interaction between DRB1*0701 and a marker adjacent to TCR A/D in the control of IgE expression.

Identification and HLA restriction of naturally derived Th1-cell epitopes from the secreted Mycobacterium tuberculosis antigen 85B recognized by antigen-specific human CD4(+) T-cell lines

Antigen 85B (Ag85B/MPT59) is a major secreted protein from Mycobacterium tuberculosis which is a promising candidate antigen for inclusion in novel subunit vaccines against tuberculosis (TB). The present study was undertaken to map naturally derived T-cell epitopes from M. tuberculosis Ag85B in relation to major histocompatibility complex (MHC) class II restriction. Antigen-specific CD4(+) T-cell lines were established from HLA-typed TB patients and Mycobacterium bovis BCG vaccinees by stimulation of peripheral blood mononuclear cells with purified Ag85B in vitro. The established T-cell lines were then tested for proliferation and gamma interferon (IFN-gamma) secretion in response to 31 overlapping synthetic peptides (18-mers) covering the entire sequence of the mature protein. The results showed that the epitopes recognized by T-cell lines from TB patients were scattered throughout the Ag85B sequence whereas the epitopes recognized by T-cell lines from BCG vaccinees were located toward the N-terminal part of the antigen. The T-cell epitopes represented by peptides p2 (amino acids [aa] 10 to 27), p3 (aa 19 to 36), and p11 (aa 91 to 108) were frequently recognized by antigen-specific T-cell lines from BCG vaccinees in both proliferation and IFN-gamma assays. MHC restriction analysis demonstrated that individual T-cell lines specifically recognized the complete Ag85B either in association with one of the self HLA-DRB1, DRB3, or DRB4 gene products or nonspecifically in a promiscuous manner. At the epitope level, panel studies showed that peptides p2, p3, and p11 were presented to T cells by HLA-DR-matched as well as mismatched allogeneic antigen-presenting cells, thus representing promiscuous epitopes. The identification of naturally derived peptide epitopes from the M. tuberculosis Ag85B presented to Th1 cells in the context of multiple HLA-DR molecules strongly supports the relevance of this antigen to subunit vaccine design.

HLA and Mooren's ulceration

BACKGROUND

Mooren's ulcer is a progressive intractable destructive peripheral ulceration of the cornea, probably of autoimmune aetiology. The disease is rare in the northern hemisphere but is more common in southern and central Africa and the Indian subcontinent. Although rare, its predominance in certain racial groups and their second generation migrants worldwide indicates a genetic as well as a geographic predisposition. The highly polymorphic human leucocyte antigens (HLA) confer genetic susceptibility to several autoimmune disorders. Therefore, a possible link between Mooren's ulcer and HLA type was investigated.

METHODS

Patients (n=22) with non-infective destructive peripheral corneal inflammatory disease were recruited worldwide. Differential diagnosis confirmed Mooren's ulceration in 12 cases. HLA typing (HLA-A, B, C, DRB, DQB) was performed by serology and PCR using sequence specific primers. The patients came from varied ethnic backgrounds and their HLA typing results were compared with published data from ethnically matched control populations.

RESULTS

Of the 12 patients with Mooren's ulcer, 10 (83%) were HLA-DR17(3) positive (including all nine patients of Asian, Indonesian, and black African origin), and 10 (83%) were HLA-DQ2 positive. The frequency of HLA-DR17(3) and DQ2 was higher in the Mooren's ulcer group compared to published data from ethnically matched control populations, where the expected antigen frequencies range between 5% and 40%.

CONCLUSION

These results suggest a possible association between HLA-DR17(3) and/or DQ2 and susceptibility to Mooren's ulcer.

HLA class II associations with rheumatic heart disease are more evident and consistent among clinically homogeneous patients

BACKGROUND

Discrepancies in reported HLA class II associations with rheumatic heart disease (RHD) may have been due to inaccuracies of serological typing reagents and/or lack of defined clinical classification of patients analyzed. The molecular association between HLA and RHD was investigated in patients with defined clinical outcome.

METHODS AND RESULTS

Class II allele/haplotype distribution was determined in 2 groups of RHD patients (n=88) and a control group (n=59). Patients were divided into the mitral valve disease (MVD) category (ie, those with mitral regurgitation with or without mitral stenosis) and the multivalvular lesions (MVL) category, with impairment of aortic and/or tricuspid valves in addition to mitral valve damage. The MVD category (n=65) accounted for 74% of patients and included significantly fewer recurrent RF episodes compared with MVL patients (P=0.002).

CONCLUSIONS

Significant increases in DRB1*0701 and DQA1*0201 alleles and DRB1*0701-DQA1*0201 haplotypes were found in patients. Removal of the MVL patients from analysis increased the strength of HLA associations among the MVD sample. The frequency of DQA1*0103 allele was decreased and the DQB1*0603 allele was absent from the patient group, suggesting that these alleles may confer protective effects against RHD. DQ alleles in linkage disequilibrium with DR alleles appear to influence risk/protection effect: whereas the DRB1*13-DQA1*0501-3-DQB1*0301 haplotype showed a trend toward risk, the DRB1*13-DQA1*0103-DQB1*0603 haplotype was absent in the RHD sample. Our data indicate that certain class II alleles/haplotypes are associated with risk or protection from RHD and that these associations appear to be stronger and more consistent when analyzed in patients with relatively more homogeneous clinical manifestations.

Association of HLA-DR11 with the anaphylactoid reaction caused by nonsteroidal anti-inflammatory drugs

BACKGROUND

Several HLA alleles have been associated with asthma induced by nonsteroidal anti-inflammatory drugs (NSAIDs). The existence of HLA markers linked to other NSAID-induced reactions, such as cutaneous and anaphylactoid reactions, has not been established.

OBJECTIVE

The purpose of our work was to study the HLA-DRB1 and HLA-DQB1 alleles in patients with cutaneous and anaphylactoid reactions caused by NSAIDs.

METHODS

We have analyzed 114 HLA DRB1 and 26 HLA-DQB1 alleles in 21 patients with anaphylactoid reactions caused by NSAIDs, 47 patients who had exclusively cutaneous reactions during single-blind, placebo-controlled oral challenges with NSAIDs, and 167 tolerant control subjects (29 of whom had also had an IgE-mediated anaphylaxis to different agents). HLA-DRB1 and HLA-DQB1 alleles were typed by the polymerase chain reaction sequence-specific primers method with genomic DNA.

RESULTS

The frequency of HLA-DR11 alleles was 58.8% in the anaphylactoid reaction group, compared with 15.9% in the NSAID-tolerant healthy control subjects (OR, 7:3; 95% confidence interval, 2.8-19.0; P <.02) and 6.3% in the group of the patients with a tolerance for NSAIDs and with IgE-mediated anaphylaxis (OR, 18.75; 95% confidence interval, 4.3-81.1; P <.004). No differences were observed among HLA-DR11 alleles analyzed. There were no significant HLA-DQB1 associations with NSAID-induced anaphylactoid reactions. Patients with cutaneous reactions had HLA frequencies that did not differ significantly from the tolerant control subjects.

CONCLUSION

The HLA-DRB1*11 alleles showed a positive association with NSAID-induced anaphylactoid reactions.

Long-term detection of microchimaerism in peripheral blood after pretransplantation blood transfusion

Renal allograft survival is prolonged after pretransplantation blood transfusion. The aim of this study was to test retrospectively the development and persistence of microchimaerism after pretransplantation blood transfusion and to assess whether the type of blood transfusion (partially matched [= sharing of at least one HLA-B and one HLA-DR antigen between blood donor and recipient] versus mismatched) influences the (continued) presence of donor-type cells. A sensitive nested PCR technique based on HLA-DRB1 allele-specific amplification using sequence-specific primers (detection level: one donor cell among 10(5) recipient cells) for detection of donor cells was implemented in our laboratory. We studied 21 patients for microchimaerism in the peripheral blood compartment, following blood transfusion. Our preliminary data show that microchimaerism was detectable up to 8 weeks after blood transfusion. In all patients receiving a partially matched blood transfusion, donor-type cells were detected in the first week after transfusion, in 7/8 patients 2-4 weeks after transfusion, and in some patients up to 8 weeks after transfusion. After mismatched transfusion a tendency to shorter duration of microchimaerism was observed.

Genetic analysis of hydatidiform moles in paraffin wax embedded tissue using rapid, sequence specific PCR-based HLA class II typing

AIMS

To determine the applicability of rapid, sequence specific polymerase chain reaction (PCR)-based HLA class II genotyping for the distinction of complete from partial hydatidiform moles (HM) using DNA extracted from formalin fixed and paraffin wax embedded tissue.

METHODS

Nine HM were studied. DNA was extracted from formalin fixed and paraffin wax embedded tissue after mechanical separation of decidual and molar components. HLA class II DRB (DRB1, -3, -4, and -5) and DQB1 genotyping was performed using a parallel series of PCR reactions, each of which contained sequence specific primers designed to amplify different HLA DRB and DQB1 alleles or allele groups (PCR-SSP analysis). In each case the HLA DRB and DQB1 genotypes identified within the decidua and HM were compared.

RESULTS

Within the decidual tissue, HLA DRB genotypes were assignable in all nine cases, and HLA DQB1 genotypes were identified in seven cases. Within the molar tissue, HLA DRB genotypes were assignable in seven cases, and at least one HLA DQB1 allele was identified in seven cases. Interpretation based on HLA class II genotyping was therefore possible in two cases classified on histological appearances as complete HM, in four classified as partial HM, and in one HM of uncertain type. Different HLA DRB and DQB1 haplotypes were identified within the decidual and molar tissue from both complete HM, consistent with a solely paternal origin and supporting the histological diagnosis. HLA DRB and DQB1 alleles common to the decidual and molar tissue were present within the four partial HM and the HM of histologically uncertain type, consistent with combined maternal and paternal genetic input to these HM, supporting the histological diagnosis in four cases and suggesting that the histologically equivocal case was also a partial HM.

CONCLUSION

PCR-SSP HLA class II DRB and DQB1 typing is reliably applicable to DNA extracted from formalin fixed and paraffin wax embedded tissue. Therefore, in a suitably equipped HLA typing laboratory, this technique provides a useful adjunct to histological examination for differentiation of complete from partial HM.

HLA-A, -B, -C, -DR, -DQ typing in a population group of Senegal: distribution of HLA antigens and HLA-DRB1*13 and DRB1*11 subtyping by PCR using sequence-specific primers (PCR-SSP)

One-hundred-and sixteen Senegalese Serere were typed for HLA antigens and compared with other ethnic groups in Gambia. We did not find significant differences (Fisher's exact test; P < 0.01) in the HLA antigens distribution between the Serere and Mandinka groups in Senegal and the Serere, Mandinka and Wolof in The Gambia. The most common HLA haplotypes found (P < 0.01; Chi square with Yates' correction) were: A1, B8; A2, B51; A32, B44; A33, B58; A2, Cw2; A2, Cw4; A33, Cw3; A2, DR17; A10, DR10; B35, Cw4; B53, Cw6; B57, Cw3; B65, Cw8; B50, DR15; B52, DR4; Cw2, DR17; DR7, DQ2; DR18, DQ4. The HLA-DRB1*13 and DRB1*11 alleles were subtyped by PCR-SSP and the frequencies of these alleles in the studied population given. HLA-DRB1*1304 and DRB1102 were the most common alleles found respectively 15.0 and 18.5%.

Serology versus PCR-SSP in typing for HLA-DR and HLA-DQ: a practical evaluation

In this study, serological HLA-DR and -DQ typing results were compared to typing results obtained with sequence-specific primers in the polymerase chain reaction (PCR-SSP). HLA-DR typing was performed on a random caucasian population consisting of 31 patients and 73 healthy individuals. Considering HLA-DR1-10, differences in typing results were found in 3 out of 73 healthy individuals and 8 out of 31 patients. When HLA-DR1-16 alleles were taken into account, differences in typing results were found in 11 out of 31 patients and 14 out of 73 healthy individuals. Typing results of PCR-SSP, different from that of serology, were all confirmed by sequencing-based typing of HLA-DRB1 alleles. HLA-DQ1-3 typings were performed on 40 individuals consisting of 17 patients and 23 healthy individuals. Differences in typing results were found in 5 out of 17 patients and 1 out of 23 healthy individuals. From the results of this study it can be concluded that serology is a reliable technique, when restricted to identification of HLA-DR1-10 and HLA-DQ1-3 antigens in healthy individuals. By PCR-SSP, however, reliable HLA-DR1-16 and -DQ1-3 typings can be obtained both in patients and healthy individuals.