Süt Çocukluğunun Geçici Hipogamaglobulinemisinde B Lenfosit Alt Grupları

Abstract

Transient hypogammaglobulinemia of infancy (THI) is one of the most common immunodefciency disease diagnosed in immunology clinics, but its definition and pathogenesis is still unclear. In this study to see whether there is any difference between patients and controls in B cell subtypes, we evaluated B cell subtypes in peripheral blood of THI patients. We studied B cell subtypes of 20 patients with THI diagnosed between 2005-2011 in Hacettepe University Pediatric Immunology clinic whose ages were between 1 and 7 years (mean age 3,5) and as well as 40 healthy children age between 1 and 7 years. Patients and healthy controls are divided into 3 groups (0-2, 3-4 and 5-7) according to their age. We evaluated switch memory B lymphocyte (smBL) to B lymphocyte (BL) and total lymphocyte (totL); marginal (marg) BL to BL; naïve BL to BL and totL; CD27+ to BL and CD19+ BL to totL ratios. Our results showed that in healthy controls and THI patients, B cell subtypes change similarly with age. While smBL/BL, smBL/totL, margBL/BL, CD27+/BL ratios increased; naiveBL/BL, naïveBL/totL, CD19+/BL ratios decreased with age. The slopes of increase and decrease in B cell subtype ratios were similar in healthy controls and THI patients. There were statistically significant difference between THI patients and controls in margBL/BL, CD27+/BL and naiveBL/BL ratios. While CD27+/BL and margBL/BL ratios significantly decreased (p=0,041 and <0,001) and naiveBL/BL ratios were significantly increased in THI patients (p=0,001). In all age groups there was statistically significant difference in CD27+/BL ratio (p=0,013 in 0-2 age group, 0,014 in 3-4 age group and0,03 in 5-7 age group)and naiveBL/BL ratio (p=0,001 in 0-2 age group, 0,006 in 3-4 age group, 0,033 in 5-7 age group). When B cell subtypes of 8 patients whose Ig levels normalized before 36 months of age were compared with healthy controls, a statistically significant decrease in CD27+/BL ratio (p <0,001) and increase in naiveBL/BL ratio (p= 0,002) were found. CD27+/BL ratiowas also decreased in patients whose Ig levels normalized after 36 months of age (p=0,026). Our finding which showed that the most prominent difference between patients and controls was in CD27+ B cells which represent memory B cells, suggest that a delay in the development of B cells may play role in the pathogenesis of THI. Evaluating the same patients for the B cell subtypes with increasing age may help to make this possibility more clear.