Lymphocyte subsets in healthy adult Kuwaiti Arabs with relative benign ethnic neutropenia

Relative and absolute neutropenia is frequently seen in the healthy adult Kuwaiti Arab population. Fluorescent monoclonal antibody labelling followed by flow cytometry was used to determine the lymphocyte subsets in 48 normal healthy individuals in the Kuwaiti adult population (24 males and 24 females, age 17-59 years) with relative or absolute neutropenia, and this was compared to age-matched controls (64 males and 63 females). The mean haemoglobin levels were 13.6+/-1.5 and 13.7+/-1.5 g/dl in the neutropenic and control groups, respectively. White blood cell counts, absolute neutrophil and lymphocyte counts in neutropenic individuals with the corresponding reference range, taken from the control subjects (in parenthesis) were: WBC, 6.7+/-1.6 x 10(9)/l (4-10.4 x 10(9)/l), neutrophils, 2.7+/-0.8 x 10(9)/l (1.87-6.63 x 10(9)/l), lymphocytes, 3.3+/-0.9 x 10(9)/l (1.4-3.62 x 10(9)/l). Absolute values of lymphocytes, CD2+, CD3+, CD19+, CD4+, CD8+, HLADR+ and CD45RA+ cells were significantly higher in the neutropenic group. The range of values with the corresponding reference ranges, in parenthesis, were: CD2+, 1.61-4.30 x 10(9)/l (0.95-2.99 x 10(9)/l), CD3+, 1.37-4.16 x 10(9)/l (0.83-2.71 x 10(9)/l), CD19+, 0.16-1.09 x 10(9)/l (0.05-0.61 x 10(9)/l), CD4+, 0.70-2.89 x 10(9)/l (0.45-1.65 x 10(9)/l), CD8+, 0.57-1.80 x 10(9)/l (0.29-1.17 x 10(9)/l), HLADR+ 0.27-1.74 x 10(9)/l (0.02-0.62 x 10(9)/l), CD45RA, 0.90-4.63 x 10(9)/l (0.34-2.05 x 10(9)/l), respectively. The levels of natural killer cells, CD56+ cells were significantly lower compared to controls while the values of memory T lymphocytes, CD45RO+ were comparable to controls. These results indicate that difference in the leukocyte subpopulations may also be indicative of differences in the lymphocyte subpopulations and that reference ranges for these cell types in healthy neutropenic and non-neutropenic individuals should be established.