Borderline leprosy. Study on new borderline cases in Japan

Abstract

This report results from the clinical, bacteriological, immunological and histological studies on 18 new borderline cases in Japan. These cases were clinically classified as BT (6 cases), BT/BB (2), BB (1), BB/BL (1), BL (7) and B (1). The maximum score of B.I. in these cases fell into two main groups, i.e., a group of B.I. 0 and that of B.I. 5-6. Results of the late lepromin-reaction test were weak positive in 8 cases, doubtful in 4 and negative in 5. In 3 cases, the lepromin test was done on both the inside and outside of their annular skin lesion, and there was no significant difference between them in all cases tested. The test by FLA-ABS method revealed significantly higher titers in the BL group than in BT and BT/BB groups. Among 7 cases clinically diagnosed as BL, 5 cases were histologically classified as LL. One other case showed different features in biopsy specimens of two different lesions. Epitheloid cell granuloma in the foamy cell infiltration was observed in 6 cases. The granuloma varied from BT to BL with varying degrees of lymphocytic infiltration and appearance of giant cells. These changes were interpreted as those resulting from some acquired delayed hypersensitivity against. Mycobac. leprae antigens, which developed after lepromatous lesions were established. These findings are unusual in the new patient, and the changes observed were tentatively termed in this report as 'reaction from L' because Ridley and Jopling's classification was not applicable in these cases. While the 'Madrid' classification has officially been adopted in Japan since 1979, several propositions on the classification in Japan are made in an attempt to prevent confusion in clinical and statistical studies in this disease.