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Aims/hypothesis: Most Caucasians with Type I (insulin-dependent) diabetes mellitus develop an autoimmune form of diabetes known as Type IA diabetes, based on the presence of humoral responses to islet autoantigens. Alleles at the HLA locus account for the strongest susceptibility to this form of diabetes, which requires insulin therapy. Because a number of patients who develop insulin-requiring diabetes are islet autoantibody negative, the HLA class II haplotypes, DQA1*0501-DQB1*0201 and DQA1*0301-DQB1*0302, were evaluated to assess whether they are an independent risk factor for progression to insulin requirement in first-degree relatives of Type I diabetic patients., Methods: Both HLA-DQ genotyping and islet cell autoantibody assessment (insulin, GAD65, IA-2 autoantibodies and cytoplasmic islet cell antibodies) were evaluated prospectively in 74 relatives of Type I diabetic patients who developed diabetes treated with insulin (prediabetics) and in 426 control subjects who did not develop insulin-requiring diabetes. Based on the presence of DQA1*0501-DQB1*0201 and/or DQA1*0301-DQB1*0302, the number of HLA-DQ high-risk haplotypes was assigned as 0, 1 or 2., Results: A higher prevalence of 2 HLA-DQ high-risk haplotypes was present in seronegative prediabetic subjects as compared to non-diabetic autoantibody negative first-degree relatives (33.3 % vs 10.1 % respectively; p < 0.05). Moreover, in seronegative relatives who developed insulin-requiring diabetes, the presence of 2 HLA-DQ high-risk haplotypes conferred an increased cumulative risk of developing insulin requirement of 27 % at 12.5 years of follow-up, compared to a risk of 6 % for non-diabetic relatives who were antibody-negative and had 0 or 1 HLA-DQ high-risk haplotypes (Log rank p = 0.01)., Conclusion/interpretation: These data provide evidence for a phenotype, which is associated with the absence of conventional islet autoantibodies at initial screening, while usually remaining seronegative, and the presence of 2 HLA-DQ high-risk haplotypes with progression to clinical Type I diabetes after a prolonged follow-up. Given the fact that in humans the highest risk-conferring locus associated and linked to the disease is the HLA cluster, and that HLA-DQ molecules play a key role in the development of autoimmune diabetes, our observations imply that as yet unidentified immunologic abnormalities could well exist in seronegative relatives at risk of developing clinical diabetes and carrying 2 HLA-DQ high-risk haplotypes.

Objective: To compare the frequency of islet cell antibodies (ICA) and antibodies to GAD65 and IA-2(ICA512) between black and white children and adolescents at the diagnosis of IDDM in a large consecutive series of cases from Children's Hospital of Pittsburgh., Research Design and Methods: ICA and antibodies to GAD65 and IA-2 were measured in 437 white and black children and adolescents who were diagnosed with IDDM at < 19 years of age at Children's Hospital of Pittsburgh from January 1983 to December 1985, from January to December 1989, and from January 1996 to December 1997., Results: The prevalence of ICA(H), GAD65, and IA-2 antibodies was significantly lower in blacks than whites at onset of the disease. In contrast, the prevalence of ICA(R) alone was higher in blacks. None of the antibodies were present in 12% of the blacks compared with 4% in whites. The same pattern was seen in both sexes. The prevalence of antibodies in white patients with onset of IDDM at <11 years of age was no different than in those who developed IDDM during adolescence. In contrast, black patients showed a significantly lower prevalence of almost all antibodies in the adolescent group., Conclusions: Black adolescents were more likely to not have antibodies, suggesting either that they have a nonautoimmune type of diabetes or that antibodies are not being detected by these assays.

Background: Allocation of cadaver kidneys by graded human leukocyte antigen (HLA) compatibility scoring arguably has had little effect on overall survival while prejudicing the transplant candidacy of African-American and other hard to match populations. Consequently, matching has been proposed of deduced amino acid residues of the individual HLA molecules shared by cross-reactive antigen groups (CREGs). We have examined the circumstances under which compatibility with either method impacted graft survival., Methods: Using Cox proportional hazards regression modeling, we studied the relationship between levels of conventional HLA mismatch and other donor and recipient factors on primary cadaver kidney survival between 1981 and 1995 at the University of Pittsburgh (n=1,780) and in the United Network for Organ Sharing (UNOS) Scientific Registry during 1991-1995 (n=31,291). The results were compared with those obtained by the matching of amino acid residues that identified CREG-compatible cases with as many as four (but not five and six) HLA mismatches., Results: With more than one HLA mismatch (> 85% of patients in both series), most of the survival advantage of a zero mismatch was lost. None of the HLA loci were "weak." In the UNOS (but not Pittsburgh) category of one-HLA mismatch (n=1334), a subgroup of CREG-matched recipients (35.3%) had better graft survival than the remaining 64.7%, who were CREG-mismatched. There was no advantage of a CREG match in the two- to four-HLA incompatibility tiers. Better graft survival with tacrolimus was observed in both the Pittsburgh and UNOS series., Conclusions: Obligatory national sharing of cadaver kidneys is justifiable only for zero-HLA-mismatched kidneys. The potential value of CREG matching observed in the one-HLA-mismatched recipients of the UNOS (but not the Pittsburgh) experience deserves further study.

The authors attempted a replication of an earlier study of African-Americans, in which they detected a negative association of schizophrenia with HLA DQB1*0602. Patients with schizophrenia (n = 75, DSM-III-R criteria) and screened adult controls of African-American ethnicity (n = 66) were genotyped with respect to HLA DQB1*0602 using a combination of two polymerase chain reaction (PCR) based assays: amplification with sequence specific primers and a dot blot assay. A significant negative association with HLA DQB1 was not noted overall, but was present among women (female patients vs. female controls: odds ratio, OR = 0.42, 95% confidence intervals, CI = 0.32, 0.55). Reanalysis of the earlier study also revealed a gender related association. When the present and earlier samples from both genders were combined, the association persisted (OR 0.48; 95% CI: 0.12, 0.52). The present findings support and association between schizophrenia and the HLA DQB1 gene locus among African-Americans.

This paper presents preliminary data regarding the prevalence and risk factors for autoimmune thyroid disease in IDDM probands ascertained from the Children's Hospital of Pittsburgh IDDM Registry for 1950-1965 (n = 669). Living IDDM probands who participated in the 1990 follow-up survey (n = 380) were recruited for the Familial Autoimmune and Diabetes Study. Siblings and parents were also invited to participate. To date, 255 IDDM probands and 597 parents and siblings have been evaluated. The diagnosis of autoimmune thyroid disease was based on a clinical evaluation, medical history, and laboratory determinations. Graves disease was rare in this cohort (n = 5). However, Hashimoto's thyroiditis was common among women. Prevalence rates ranged from 54% for IDDM women age < 40 years to 75% for those > 50 years. Corresponding age-specific estimates for female relatives were 22% and 44%, respectively. Approximately one-half of the Hashimoto's individuals were euthyroid; they were more likely to have other autoantibodies and a positive family history than those who were hypothyroid or had no thyroid disease. Genetic analyses revealed a 2-fold increase in DQA1*0501-DQB1*0201 among the Hashimoto's compared to the non-Hashimoto's haplotypes. These findings suggested that Hashimoto's thyroiditis was common in IDDM families, which may be due, in part, to common disease susceptibility genes.

1. In an unselected adult renal transplant population, FK506 as the primary immunosuppressive agent yielded one- and 2-year actuarial patient survival rates of 95% and 93% and one- and 2-year actuarial graft survival rates of 89% and 83%, respectively. Forty-nine percent of successfully transplanted patients were weaned off steroids. 2. In pediatric renal transplant patients, FK506 has been associated with 100% one- and 3-year actuarial patient survival rates and 98% and 85% one- and 3-year actuarial graft survival rates, respectively. Sixty-two percent of successfully transplanted patients were taken off prednisone, with dramatic improvements in height. 3. FK506 has been used successfully in rescuing 70-74% of adult or pediatric renal transplant patients with an acute rejection that failed conventional therapy. 4. Kidney/bone marrow transplantation under FK506 therapy has been successfully performed without graft-versus-host disease and with routine augmentation of chimerism. 5. The side effects of FK506 included nephrotoxicity, neurotoxicity, and diabetogenicity; they were comparable to those seen with CsA. 6. FK506 is an important new addition to the immunosuppressive armamentarium in renal transplant patients.

The risk for insulin-dependent diabetes mellitus (IDDM) associated with genetic susceptibility markers at the human leukocyte antigen (HLA) DQA1 and DQB1 loci was evaluated among individuals with and those without islet cell antibodies. A total of 108 antibody-positive parents and siblings of IDDM patients from the Pittsburgh registry were identified among 1,592 who were screened. HLA-DQ molecular typing was performed on 79 of these individuals and on 78 antibody-negative relatives. There were similar proportions of homozygotes for both of the diabetogenic alleles DQA1 arginine-52 (R/R) and DQB1 non-aspartate-57 (nD/nD) among the antibody-positive and antibody-negative relatives (19.0 and 15.4%, respectively). However, subsequent development of IDDM was restricted to individuals who were both antibody positive and carried the potential to make at least one diabetogenic DQ heterodimer. A dose-response effect was observed among the antibody-positive relatives, in which two of 18 capable of generating one diabetogenic heterodimer and six of 29 generating two heterodimers became insulin requiring. Nine of 15 who were homozygous for both R/R and nD/nD, coding exclusively for diabetogenic variants, became diabetic over the course of the follow-up. With a multivariate model, the relative risk for IDDM among those with islet cell antibodies who were also R/R and nD/nD was estimated to be 229.3 compared with those lacking both, after age and sex were controlled for. The data suggest that while autoimmunity, indicated by the presence of cytoplasmic islet cell antibodies may be relatively common, it progresses only in those with variant HLA-DQ molecules.

Objective: To determine the descriptive epidemiological patterns of the secondary attack rate of insulin-dependent diabetes mellitus (IDDM) among siblings of probands through older ages., Research Design and Methods: A family history analysis was performed on 1774 IDDM probands who were diagnosed or seen within 1 yr of diagnosis at Children's Hospital of Pittsburgh from 1 January 1950 through 31 December 1981. The probands were discharged on insulin and were diagnosed at less than 17 yr of age. The time frame permitted the risk of IDDM for siblings of probands to be calculated over a broad spectrum of age., Results: Risk estimates for the 3966 full natural siblings through 10, 20, and 30 yr of age were 1.6, 4.1, and 6.3%, respectively. Secondary attack rates were equivalent for male and female siblings through 15 yr of age (3%); however, the risk to males increased an additional 4% between 16 and 30 yr of age compared with 2.5% for females (P = 0.01). There was no evidence of an excess sex concordance among affected sibling pairs., Conclusions: Males have a greater secondary attack rate of IDDM at older ages than females. This may be due to an increased exposure to environmental agents among males or protective influences operating among females.