[Ocular histopathological studies in leprosy in the silent stage--II. Immunohistochemical studies]

The distribution of leprosy antigen in 21 eyes from 12 autopsy cases of lepromatous leprosy patients (5 eyes from 3 cases in the silent stage, 16 cases from 9 cases in the active stage) were examined with acid-fast staining and immunohistochemistry. Anti-BCG antibody, anti-phenolic glycolipid-I (PGL-I) antibody, and anti-lipoarabinomannan-B (LAM-B) antibody were used as primary antigens. In the active stage, anti-BCG antibody and anti-LAM-B antibody showed almost the same staining pattern. Some cases, which showed negative reaction to acid-fast staining, occasionally showed positive staining pattern with anti-BCG antibody and anti-LAM-B antibody, which had high sensitivity and the advantage of detection of leprosy antigen. Some anti-PGL-I antibody showed a different staining pattern from acid-fast staining, anti-BCG antibody and anti-LAM-B antibody. These findings seemed to be caused by the difference in structure of the epitope. In the silent stage, clinically nonpigmented epithelium of 6 cases from 4 eyes showed positive staining pattern with anti-PGL-I antibody. These findings suggested that leprosy antigen still remained in this stage.