The possible role of autoimmunity in the pathogenesis of diabetes in B-thalassemia major.

OBJECTIVE: To evaluate the possible role of autoimmunity in the pathogenesis of diabetes associated with B-thalassemia, we studied a cohort of 53 B-thalassemic individuals, under long term blood transfusion, that included twelve patients with diabetes (22.6%). MATERIAL AND METHODS: To evaluate the activation of an autoimmune response, individuals were tested for islet cell antibodies (ICA), glutamic acid decarboxylase (GAD) autoantibodies, insulin autoantibodies (IAA) and serum anti-nuclear antibodies (ANA). RESULTS: Nine of the total B-thalassemic population (16.98%) were ICA-positive. The frequency of ICA-positive subjects among thalassemic individuals was higher than in the general population. Five (41.6%) of the ICA-positive individuals were diabetic. Of these, three were serum C-peptide-negative (<0.21 nmol/l). HLA class II typing of our thalassemic population did not reveal significantly different allelic frequencies with respect to the control population. CONCLUSIONS: Our study demonstrates evidence of immune system activation against pancreatic B-cells in B-thalassemia and we propose that iron deposition may, through oxidative damage, act as an environmental factor that triggers the autoimmune response. Therefore, we speculate that pancreatic autoimmunity may contribute to selective B-cells damage in the pathogenesis of diabetes associated with B-thalassemia.

Chronic lymphoid leukemia. Clinical observations about its natural progression.

223 cases with chronic lymphoid leukemia (CLL) were subjected to a prospective study on the presence of adeno- and splenomegaly at diagnosis and their subsequent variation. Subjects with no initial organ involvement were usually female (76%) and of old age (mean 69.2 years). Adenopathy or combined lymph node and spleen enlargement were inversely proportional to the mean age at diagnosis. Subsequent organ enlargement was noted in 11.7% of patients with no initial organomegaly, splenomegaly in 15% of patients with adenopathy only and adenopathy in 15% of patients with splenomegaly only. Except in the few cases with leukopenia, particularly high leuklocyte levels were noted in patients with splenomegaly (with or without adenopathy). Anemia at diagnosis was not related to the degree of organ enlargement. It is suggested that qualitative and also quantitative differences in organomegaly in CLL merit further study to establish their underlying mechanisms. CLL must be seen as something more complex than the simple mechanical expression of progressive lymphocyte accumulation.