ANTI-RETROVIRUS ANTIBODIES IN INSULIN-DEPENDENT DIABETIC CHILDREN AT DIAGNOSIS AND DURING 1–2.6 YRS FOLLOW-UP

Abstract

Viruses have long been implicated in the pathogenesis of insulin-dependent diabetes (IDDM). Recently it has been observed that β-cell specific expression of endogenous retrovirus is associated with the development of insulins and diabetes in non-obese diabetic (NOD) mice. The aim of our study was to evaluate the presence of retroviral markers in 27 newly diagnosed IDDM children, aged 9.6±3.8 yrs (range 3-15.9 yrs). In all patients anti-islet cell (ICA), anti-insulin (IAA), anti-thyroid (TgA and MsA) antibodies were evaluated and HLA typing was performed. Virological studies included the search for anti-retrovirus (HTLVs) antibodies using the western immunoblotting (WIB) and the HTLV-I DNA amplification by polymerase chain reaction (PCR) for tax/rex pol, and gag (PIS) regions. At onset of IDDM ICA were present in 19 patients (70%) and IAA in 2 of them, while all patients were negative for TgA and MsA. HTLVs antibodies were detected in 10 out of the 27 patients (37%) while no HTLV-I DNA sequencies were detected using our PCR assay. Interestingly, we have observed a frequent association between the presence of HTLVs antibodies and the presence of HLA-DR3 and DQ2 antigens. Until now, during 1-2.6 yrs follow-up we could revalue 13 children, four with HTLVs antibodies and 9 without antibodies. In 2/4 patients the HTLVs antibodies disappeared and in another boy, with five antibodies at onset of IDDM (directed against p 19, rgp21, p24, p26, p36) only one antibody (directed against rgp 21) was constantly present.