IMMUNOHISTOLOGICAL STUDY IN 16 CHILDREN WITH ACUTE TUBULOINTERSTITIALNEPHRITIS

Sixteen children (7 boys and 9 girls, aged 1.9 to 14.8 years) diagnose d with acute tubulointerstitial nephritis [ATIN: 4 drug-induced, 6 inf ection, 2 tubulointerstitial nephritis and uveitis syndrome (TINU), an d 4 unclassified] were studied to characterize the nature of the inter stitial mononuclear cells involved in each clinical picture of the dis ease Six children with asymptomatic microscopic hematuria whose histol ogy was a minimal change in renal biopsy were studied as controls. The enzyme immunoassay was carried out using the biopsy specimen obtained from 4 to 42 days after the onset of illness. In ATIN, the number of renal interstitial infiltrating CD3, CD4, and CD8 T lymphocytes, respe ctively, was significant larger than that in the minimal change kidney s [CD3 T cells; median 94 (range 3.2-330)/mm(2) interstitial area vs. median 7.8 (range 1.1-23), p = 0.003, CD4 T cells; 11 (range 0.5-78) v s. 1.5 (range 0-7.7), p = 0.018. CD8 T cells; 22 (range 1.0-150) vs. 2 .9 (range 0-14), p = 0.047]. Tn addition, a positive correlation was f ound between the CD3 and CD4 T cells. On the other hand, in regard to the relationship between the CD3 and CD8 T cells, CD8/CD3 was extremel y low in 3 cases in the infection-induced group, but the other 3 group s included no extremely low CD8/CD3 cases. Although interstitial monoc ytes/macrophages were smaller than the T lymphocytes in number, a posi tive correlation was revealed between the T lymphocytes and monocytes/ macrophages (CD3 T cells vs. monocytes/macrophages; r = 0.53, p = 0.03 9). No relationship was round between the duration from the onset of i llness to renal biopsy and mononuclear cell involvement. These finding s suggest that cellular immunity, mainly T lymphocytes, may play a rol e in the pathogenesis of ATIN in children.