This study was an observational study which was designed with the aim to detect thyroid autoimmunity in type-2 diabetes patients and the pattern of ABO blood group the positive thyroid antibodies (Anti-TPO & Anti-Tg) type 2 DM patients in Bangladesh. Blood group antigens are generally coded and their antigens could be the susceptible factors or resistance factors for some diseases. Few research works were there that established the thyroid autoimmunity in type 2 DM patients as well as the relationship between ABO blood group with thyroid disease and type 2 DM.

So, this study was conducted among hundred type 2 diabetic patients selected consequently from O.P.D department of Sylhet Diabetic Hospital age range (30 - 75 years) with the exclusion criteria of previous history of thyroid tissue, Hepatic disease, renal dysfunction. Their antibodies titre (Anti-TPO & Anti-Tg) were measured by RIA kit (Beijing Atom High Techno Co. Ltd, China) in nuclear medical and allied science centre and it was found 20% positive (Anti-TPO & Anti-Tg) in those patients.

Positive thyroid autoantibodies patients were evaluated further for ABO blood group pattern by Antigen-Antibody Agglutination test at Sylhet MAG Osmani Medical College, Sylhet and identified blood group O (53%), B (27%), A (13%) and AB (7%). The mean age was 51.91±8.97 years. Our study showed blood group O relatively in highest percentage and AB blood group in lowest percentage. But the variations were in percentage of blood group B & A which may be due to racial and geographical variation. The percentage of thyroid autoimmunity in our study varied with other studies may be due to relatively smaller sample size, shorter duration of study period, different analytical methods and geographical distribution.