Postirradiation Changes of White Blood Cellsand Lymphocyte Subpopulations in Cancer Patients

Chung, Woong Ki; Nah, Byung Sik; Nam, Taek Keun; Noh, Young Hee; Ahn, Sung Ja

Abstract

PURPOSE: Radiation-induced alteration in the immune function is well known phenomenon in cancer patients. Our purpose is to evaluate the extent of immune suppression immediately after mediastinal or pelvic irradiation, which include significant volume of active bone marrow in adults.
METHODS
AND MATERIALS: 48 cancer patients with mediastinal(N=29) and pelvic irradiation(N=19) were the basis of this analysis. Age ranged from 36 to 76 and mean and median value was 57 years, respectively. Sex ratio was 1.3(M:F = 27/21). The immunological parameters were the complete blood cell(CBC) with differenial cell(D/C) count, T cel subset(CD3, CD4, CD8, CD19), NK cell test(CD16,CD56), and serum immunoglobulin (lgG,lgA,lgM) level.
RESULTS
The mean value of white blood cell(WBC) was reduced from 7017 to 4470 after irradiation (p=0.0000). In the differential count, the number of lymphocyte, neutrophil, and basophil was markedly reduced with statistical significance(p<0.01) and the number of monocyte was not changed and, on the contrary, that of eosinophil was increased by irradiation.In the lymphocyte subpopulation analysis, the number of all subpopulations, CD3(T cell), CD4(helper T cell), CD8(suppressor T cell), CD16(NK cell), CD19(B cell) was reduced with statistical significance. The mean ratio of CD4 to CD8 in all patients was 1.09 initially and reduced to 0.99 after radiotherapy(p = 0.34), but the proportional percentage of all subpopulations was not changed except CD19(B cell) after irradiation.In the immunoglobulin study, initial values of lg G, lg A, and lg M were relatively above the normal range and the only lg M was statistically significantly reduced after radiotherapy(p=0.02)
CONCLUSION
Mediastinal and pelvic irradiation resulted in remarkable suppression of lymphocyte count in contrast to the relatively good preservation of other components of white blood cells. But the further study on the functional changes of lymphocyte after radiotherapy may be necessary to conclude the effects of the radiation on the immunity of the cancer patients.