مطالعه زيرگروه هاي لكوسيتي خون بيماران سيكل سل در جنوب غربي ايران

Leukocyte subpopulations of patients with sickle cell anemia in the South West of Iran

Objective: The sickle cell disease or sickle cell anemia is an inherited hematological disease which is the second most common blood disorder after thalassemia in Khozestan province. Recent studies have shown that the immune system in sickle cell patients is defected. The aim of this study was to investigate punitive leukocyte subpopulations in blood of these patients in comparison with control group. Subjects and Methods: The study included two parts. The first part was a retrospective study on data collection derived from 50 files of patients admitted in Ahvaz Shafa hospital during 2004-2005. The sample patients including sickle cell thalassemia (n=35) and sickle thalassemia P° (n=15). The data included WBC count and differential count of different leukocyte subpopulations. The second part was carried out with flow cytometry for immunophenotyping of peripheral blood lymphocytes of 22 patients (12 sickle cell: and 10 sickle thalassemia |3°) who were referred to Shafa hospital for pain crises. Two ml citrated peripheral blood was obtained from these patients, RBC lysed, lymphocytes stained with monoclonal antibodies specific for T cell and B cell (CD4, CD8, CD5, CD20) and the data finally analyzed by flow cytometry. The data were compared statistically with control group (n=30) selected from normal population. None of the patients in the study had previously been treated with hydroxyurea or had a history of splenectomy. Results: WBC count and atypical cell percentage in two patient groups were significantly increased (P<0.01). The neutrophil percentage increased in both patient groups but was significant in SCD (P<0.05). The eosinphil percentage was increased in both thalassemia groups which was significantly more so in sickle P° thalassemia patients (P<0.05). The lymphocyte percentage was reduced in both groups and was more significant in sickle cell patients (P<0.01). CD4+ and CD54" lymphocyte subpopulations were significantly reduced in both patient groups (P<0.01). CD8+ lymphocytes and CD4+/CD8+ ratio were reduced in both patients groups but did not reach significance. CD20+ lymphocyte subpopulation was significantly higher in both patient groups (P<0.01). Conclusions: It seems that immune cells, especially B and T cells are changed in the these patients. This may have an important role in occurrence of some symptoms such as infection and pain crises. Further studies in immune system role in sickle cell and thalassemia is recommended in order understanding the cause of the symptoms associated with these diseases and help in their treatment plans.