Circulating activated suppressor T lymphocytes in hepatitis-associated aplastic anaemia.
Lymphocyte subpopulations were measured in the blood of 21 children with severe aplastic anaemia (SAA). Five children with hepatitis-associated AA appeared to constitute a unique group. Compared with children with idiopathic AA, four of five children had a striking increase in percentage of activated suppressor T lymphocytes, which were defined by binding of both anti-Leu 2a and anti-HLA DR monoclonal antibodies (children with hepatitis-associated AA, 21.8 +/- 19.9% [mean +/- SD], children with idiopathic AA, 2.9 +/- 1.2%). However, there was no difference in the mean absolute number of the activated suppressor T lymphocytes between the two groups, because the mean number of lymphocytes was markedly less in children with hepatitis-associated AA (0.28 +/- 0.06 x 10(9)/l) than in those with idiopathic AA (1.64 +/- 0.74 x 10(9)/l). The mean helper: suppressor T lymphocyte ratio was significantly lower in children with hepatitis-associated AA (0.58 +/- 0.74) than in those with idiopathic AA (1.22 +/- 0.44). On the other hand, we did not find such a remarkable alteration of lymphocyte subpopulations in children with non-A non-B hepatitis who did not develop AA. These findings suggested that an imbalance of lymphocyte subpopulations and T lymphocyte activation may have pathogenetic relevance in some of the children with hepatitis-associated AA.
Kojima
S
S
Division of Hematology/Oncology, Japanese Red Cross Nagoya First Hospital, Japan.
Matsuyama
K
K
Kodera
Y
Y
Okada
J
J
D000293:Adolescent; D000741:Anemia, Aplastic / Q000209:etiology / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006525:Hepatitis, Viral, Human / Q000150:complications*; D006801:Humans; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D006377:T-Lymphocytes, Helper-Inducer; D050378:T-Lymphocytes, Regulatory