Abstract. The effect of docosahexaenoic acid (DHA) on cyclooxygenase expression induced by interleukin (IL)-1β and phorbol 12-myristate 13-acetate (PMA) in rat vascular smooth muscle cells (VSMCs) was investigated in order to clarify the cellular mechanism of cardiovascular protective effects. DHA and eicosapentaenoic acid slightly enhanced IL-1β-induced cyclooxygenase (COX)-2, but not COX-1, expression, whereas arachidonic acid had no effect. DHA also slightly enhanced PMA-induced COX-2 expression. DHA stimulated both rapid and prolonged activation of p44 / 42, but not p38, mitogen-activated protein kinase (MAPK) induced by IL-1β and PMA. These results suggest that DHA enhances the COX-2 expression by selectively facilitating p44 / 42 MAPK activation in VSMCs.

Immunologic abnormalities including autoimmune hemolytic anemia (AIHA) and immune thrombocytopenic purpura (ITP) have been described in patients with non-Hodgkin lymphoma. In some cases, anti-red cell or platelet antibodies are produced by lymphoma cells. However, cases of the occurrence of autoimmune diseases without recurrence of lymphomas have been also reported. The relationship between autoimmune diseases with post-bone marrow transplantation and Hodgkin disease may be attributed to immune dysfunctions, particularly those involving T cells. This autoimmune phenomenon may be related to imbalances in helper/suppressor T-cell populations. Imbalances in helper and suppressor T-cell populations have been reported after R-CHOP chemotherapy, and the recovery of serum IgG and CD4+ counts was observed more than 2 years after R-CHOP therapy in patients with B-cell lymphoma. In this report, we present a case of an 87-year-old man who was treated with rituximab-containing chemotherapy and maintained complete remission. However, the immunophenotyping of peripheral blood and bone mallow mononuclear cells revealed a reversed CD4/CD8 ratio. Two years later, he developed ITP. He was treated with intravenous immunoglobulin and eltrobopag, and thrombocytopenia improved. Five years later, he developed pneumonia and sudden Coombs-positive hemolytic anemia caused by autoantibodies against D antigen and thrombocytopenia without the recurrence of lymphoma. He was treated with prednisolone and a pulse dose of methylprednisolone; however, his response to therapy was poor and he subsequently died. We herein report a case who have been showed reversed imbalances in the helper/suppressor T cell populations over 2 years after R-CHOP therapy, developed AIHA and ITP without recurrence of lymphoma. The long-term monitoring of T-cell counts after rituximab containing chemotherapies is important, and careful attention to infection signs.

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