Leprosy classification methods: a comparative study in a referral center in Brazil.

OBJECTIVES: Different leprosy classification methods were proposed since the 1930s. The aim of this study was to compare the current ones in a referral center in Brazil.

METHODS: The WHO operational classification (WOC) was compared to the Jopling classification (RJC), the Madrid classification and a classification based on the number of body areas affected by skin and/or neural lesions (NBAA). The correlation between the clinical and histopathological components of the RJC was accessed.

RESULTS: The agreement between the WOC and the RJC was 77.6% (kappa=0.53). The WOC tended to overestimate the number of multibacillary patients. The WOC showed its best agreement with the NBAA. There was perfect agreement between the clinical and histopathological RJC in 46.9% of the patients.

CONCLUSIONS: The agreement between the WOC and the RJC was better than any other purely clinical classification, reinforcing the importance and simplicity of the operational method. Although major disagreement between the clinical and histopathological RJC was uncommon, perfect agreement occurred in less than half the cases, and was even lower for borderline-lepromatous and tuberculoid forms. Possible causes to explain the divergent cases were discussed, showing that there may be room for improvement in the RJC histopathological criteria.