Enhanced IL-10 production in vitro by monocytes in autoimmune haemolytic anaemia

Our previous studies on autoimmune haemolytic anaemia (AIHA) have shown a hyperactivation concerning cytokine production in T and B lymphocytes obtained from AIHA patients. In this study the production of interleukin (IL)-10, basal and stimulated by lipopolysaccharide (LPS), was determined in cultured monocytes obtained from patients affected by AIHA, either idiopathic or associated with other autoimmune diseases, e.g. idiopathic thrombocytopenic purpura (ITP), systemic lupus erythematosus (SLE), myastenia gravis (MG). In cultured AIHA monocytes the IL-10 basal production (mean+/-SD) was increased in all but one patient, compared to the controls, 125.96+/-76.10 pg/mL and 19.18+/-15.80 pg/mL respectively. Specifically, LPS stimulation was able to induce a higher IL-10 production by monocytes in two AIHA cases, whereas in five patients there was no difference and in two cases the LPS stimulated IL-10 production was even decreased compared to the levels observed in the controls. Interestingly in the latter two cases AIHA was associated with other autoimmune diseases (ITP, SLE). These results indicate a constitutively higher basal IL-10 production in monocytes from AIHA patients. The increased level of IL-10 could play an important role in the modified pathways of the immune response in AIHA.