Major histocompatibility locus genetic markers of beryllium sensitization and disease

Hypersensitivity to beryllium (Be) is found in 1-16% of exposed workers undergoing immunological screening for beryllium disease using the beryllium lymphocyte proliferation test (BeLPT). However, only approximately 50% of BeLPT-positive workers present with lung granulomas (i.e. berylliosis). As berylliosis is associated with the human leukocyte antigen (HLA)-DP supratypic marker DPGlu69, the authors asked whether this marker is differentially associated with disease presentation. A population of 639 workers from a beryllium factory undergoing BeLPT screening was evaluated in a nested case-control study for the prevalence of HLA-DPGlu69, the HLA-DPB1, HLA-DQ and HLA-DR alleles and of the biallelic tumour necrosis factor (TNF)-alpha polymorphism TNF-alpha-308 in 23 individuals presenting as "sensitized" (i.e. BeLPT-positive without lung granulomas) and in 22 presenting as "diseased" (i.e. BeLPT-positive with granulomas in the lung biopsy). The HLA-DPGlu69 marker was associated with "disease" (odds ratio (OR) 3.7, p=0.016, 95% confidence interval (CI) 1.4-10.0), whilst the high TNF-alpha production-related TNF-alpha-308*2 marker was associated with both a positive BeLPT (OR 7.8, corrected p<0.0001, 95% CI 3.2-19.1) with no difference between "sensitization" and "disease". Furthermore, the HLA-DRArg74 marker was associated with "sensitization" without disease (OR 3.96, p=0.005, 95%, CI 1.5-10.1). The data indicate that tumour necrosis factor-alpha, human leukocyte antigen-DR and human leukocyte antigen-DP markers play different roles in beryllium sensitization and granuloma formation in beryllium-exposed workers.

A new DRB1*15 allele (DRB1*1506) identified by sequence-based typing

A new DRB1*15 allele (DRB1*1506) was detected during the studies of the 12th International Histocompatibility Workshop within the Allele and Haplotype Society #11 which studied the DR2 and DR51 antigens. The new allele was found in four unrelated Asian Indian individuals by sequence-based typing. It has a base substitution from T to C in codon 50 at a previously considered conserved position.

Activation and clonal expansion of human myelin basic protein-reactive T cells by bacterial superantigens

Autoreactive T cells specific for myelin basic protein (MBP) are part of the normal T cell repertoire and are present both in patients with multiple sclerosis (MS) and healthy individuals. There is evidence suggesting in vivo activation and persistent clonal expansion of MBP-reactive T cells in MS. This study was undertaken to investigate the potential role of bacterial superantigens (SA) in the activation of MBP-reactive T cells. Twenty-seven MBP-reactive T cell clones generated from 10 MS patients and one normal individual were examined for reactivity to SA, in association with their T cell receptor V beta gene usage. The majority of the clones responded to at least one of the SA tested, staphylococcal enterotoxins (SEA and SEB) and toxic shock syndrome toxin-1 (TSST-1). The clones reactive to SEA and SEB expressed various V beta genes while T cell reactivity to TSST-1 correlated with the V beta 2 expression. Furthermore, circulating MBP-reactive T cells could be expanded from lymphocyte cultures primarily exposed to respective SA in more than 50% of MS patients and normal individuals tested. However, activation and expansion of circulating MBP-reactive T cells by SA was not directly associated with the disease. This study lends support to the potential role of SA in the activation of MBP-reactive T cells and suggests that an altered regulatory mechanism may account for further expansion and persistence of MBP-reactive T cells in MS.

Myelin basic protein-specific T lymphocytes in multiple sclerosis and controls: precursor frequency, fine specificity, and cytotoxicity

A panel of 90 myelin basic protein (MBP)-specific T-cell lines were derived from peripheral blood of eight patients with multiple sclerosis and four normal subjects. The precursor frequency of MBP-reactive T cells in peripheral blood mononuclear cells ranged from 10(-7) to 9 x 10(-7) (mean, 6.7 x 10(-7)) in the group of patients with multiple sclerosis and from 0.5 x 10(-7) to 9.8 x 10(-7) (mean, 5.6 x 10(-7)) in the control subjects. This difference between the two groups was not statistically significant (p greater than 0.1). These T-cell lines expressed exclusively CD3+CD4+CD8- phenotypes and were restricted predominantly by HLA-DR molecules. When tested with fragments and synthetic peptides of human MBP, these MBP-specific T-cell lines (45 lines for each group) displayed a limited heterogeneous pattern with a biased recognition to peptide 84-102 and the C-terminal peptide 149-171. The reactivity to the 84-102 region of MBP was associated with the HLA-DR2, DRw15 (DRw15,2) haplotype, whereas the recognition to peptide 149-171 did not correlate with a particular HLA-DR allele(s). Furthermore, the majority of T-cell lines (greater than 75%) were found to exhibit substantial cytotoxic activity against MBP-coated target cells, but showing no significant difference between these two groups. This MBP-dependent cytotoxicity was not associated with epitope specificities of the T-cell lines tested.

Allo and auto crossmatches after transplantation

The development of a positive donor-crossmatch after transplantation is usually seen as a bad prognostic sign with regard to graft survival. Since a number of positive post-transplant-crossmatches with the original donor in the absence of graft rejection was noticed in our center, we started a systematic investigation of donor-crossmatches after transplantation.

Lyme arthritis in The Netherlands: a nationwide survey among rheumatologists

A nationwide survey among all 118 Dutch rheumatologists (response rate 85%) yielded 42 patients with Lyme arthritis. The arthritis was nonpersistent in all these patients. A tick bite was reported by 23 of these 42 patients (55%). Erythema migrans was recalled by 19 patients (45%). Cardiac manifestations occurred in 4 patients (9%) and neurologic symptoms in 14 patients (33%). By immunoabsorbent assay or immunofluorescence technique 37 patients (88%) had positive IgG antibodies to Borrelia burgdorferi. The distribution of HLA-DR alleles of 28 of these patients was not different from the healthy population. The response to antibiotic treatment was considered good in 34 patients (81%). The clinical features of the Dutch patients with Lyme arthritis closely resemble the description of the disease reported from the United States.

Anti-H-2Dd antibodies cross-react with HLA--A11 and Aw31

Significant correlation was found between the cytotoxicity scoring grade (CSG) of an alloimmune mouse anti--H--2Dd serum with the presence of HLA--A11 and HLA--Aw31 on human lymphocytes. The finding shows a new type of H--2/HLA cross-reactivity and a hitherto unknown relationship (XENO-CREG) between two HLA antigens.