GAD, IA-2 and insulin autoantibodies in relation to some risk factors in siblings of Egyptian children with type 1 diabetes

The aim of the present work has been to screen siblings of children with type 1 diabetes for some immunological markers of the disease, namely GAD, IA-2 and insulin autoantibodies and to study their possible relation with other risk factors. Siblings of 151 child with type 1 diabetes [287 healthy siblings] besides 100 healthy control subjects matched for age and sex. Subjects were subjected to estimation of GAD antibodies using radiolig and binding assay developed by Peterson et al, in 1994, IA-2 antibodies by radiolig and assay and insulin autoantibodies [IAA] using ELISA technique. Subjects with positive immunological markers were screened for HLA-DR3 and DR4 and first phase insulin release [FPIR] arter IV glucose infusion. revealed that 39.7% of healthy siblings were positive for one or more autoantibodies, 22.8% for 2 antibodies and 4.38% for 3 antibodies. GAD antibodies were present in 27.9%, IA-2 antibodies in 9% and IAA in 15.3% of healthy siblings. These prevalences were statistically significantly higher than those found in control subjects: 7%, 2%, 1.5% respectively No relation could be elicited between positivity of immunological markers in siblings and their age, sex, duration of breast feeding, age at cow's milk feeding nor with parents consanguinity. On the other h and, HLA-DR3, HLA-DR4 and DR3/DR4 were found in 29.4%, 64.7% and 88.2% respectively in seropositive subjects while in 27.5% 32.5% and 45% in seronegative healthy siblings. Conclusion the high prevalence of positivity of autoantibodies among siblings of type 1 diabetic children suggests the importance of an environmental factor, perhaps via a mechanism of antigenic mimicry. Also the results in relation to other risk factors may help to a better underst and ing of the immuno-genetic susceptibility and /or pathogenesis of type 1 diabetes in a particular population

Clinical and radiological study of first degree relatives of patients with ankylosing spondylitis in relation to HLA-B27

The aim of the present work was to define the frequency of HLA- B27 in patients with AS and their first degree relatives in a sample of Egyptian subjects, searching for an eventual association of this antigen with the clinical or subclinical findings in patients and/or their first degree relatives. For this purpose, 8 probands and 32 of the first degree relatives have been included in this study, in addition to 100 healthy control subjects. All subjects have been investigated for HLA-B27, rheumatoid factor, ABO blood grouping, echocardiography [when needed], ophthalmologic examination and radiographic imaging. The results pointed to the value of combining serological, immunogenetic and radiological studies when investigating patients with AS as well as for screening their first degree relatives for early detection of the disease in this population at risk