Roles of CD5+, CD19+, CD41a+, CD55+ and CD59+ in Chronic Immune Thrombocytopenic Purpura (ITP).

ABSTRACT

Aims: The aim of this study was to investigate of the roles of CD5+ and CD19+ on lymphocytes, CD5+ on B lymphocytes, CD41a+ on platelets and CD55+ and CD59+ on erythrocytes in platelet destruction; and evaluate them according to the patient response status to steroid therapy and platelet counts in chronic immune thrombocytopenic purpura (ITP). Study Design: This study included 20 chronic ITP patients and 20 healthy controls. We investigated the roles of CD5+ and CD19+ expression on lymphocytes, CD5+ expression on B lymphocytes, CD41a+ expression on platelets, and CD55+ and CD59+ expression on erythrocytes, as well as the platelet counts in healthy and chronic ITP patients. Additionally, these markers were evaluated according to the patient response status to steroid therapy and platelet counts. Place and Duration of Study This study took place at the Department of Internal Medicine and Haematology, Meram Medical Faculty at Selçuk University in Turkey, between November, 2008 and July, 2009. Methodology: A total of 40 patients (26 women, 14 men, age range 19-79 years) were studied. The study group included 20 chronic ITP patients (12 women and 8 men, age range 19-78 years) and the control group included 20 healthy volunteers (14 women and 6 men, age range 22-79 years). The platelet counts and expressions of CD5+ and CD19+ on lymphocytes, CD5+ on B lymphocytes, CD41a+ on platelets, and CD55+ and CD59+ on erythrocytes were analysed in the patients and control subjects. The chronic ITP patients were evaluated according to their requirements of treatment. Five patients whose platelet counts were above 50,000 mm–3 were observed without treatment. The other 15 patients whose platelet counts were under 50.000 mm–3 and had bleeding, or whose platelet counts were under 20,000 mm–3, were given methylprednisolone treatments (1 mg/kg/day orally). Three of the 15 patients discontinued treatment for various reasons. The twelve patients who continued the methylprednisolone treatment were divided into two subgroups according to their responder status of steroid treatment. The patients whose platelet counts slowly increased above 30,000 mm–3 within three months included the steroid treatment responder subgroups. The chronic ITP patients were also divided into two subgroups according to the severity of their thrombocytopenia. The limit of the platelet count was 30,000 mm–3 for severe thrombocytopenia. These parameters were analysed according to the response status of the steroid treatment and platelet counts. The platelet counts, and the expressions of these markers, were compared between the subgroups. Results: The level of CD5+ on B lymphocyte expression (2.19 ± 1.65) in peripheral blood lymphocytes was significantly higher in the immune thrombocytopenic purpura patients than in the controls (P = .05). The CD55+ + CD59+ expression on erythrocytes (98.03 ± 1.77) was significantly higher in the ITP patients than in the controls (P = .05). There was no significant relationship between the expression of CD5+, CD19+ or CD5+ on B lymphocytes, CD41a+ expression on platelets or CD55+ and CD59+ expression on erythrocytes, according to the response status to steroid therapy in the patient group (P > 0.05). Additionally, the patients were evaluated according to platelet counts, and there was a significantly positive correlation between the level of CD41a+ expression on the platelets and the platelet count (P = .05). Conclusion: The level of CD5+ on B lymphocytes was significantly higher in the ITP patients than in the controls. A relationship between CD55+ plus CD59+ expression on erythrocytes and immune destruction of platelets was not observed in the chronic ITP patients.