Regarding Ebenezer, et al.'s MB nerve histology in clinically diagnosed bt leprosy patients
To the Editor:
I am writing concerning the paper by Ebenezer, et al. entitled "Multibacillary nerve histology in clinically diagnosed borderline tuberculoid leprosy patients," which appeared in Volume 64, No. 3 of the INTERNATIONAL JOURNAL OF LEPROSY, The findings are interesting and may be useful; however, I believe the conclusions may not be warranted and that some of their patients may not be paucibacillary. The use of one World Health Organization (WHO) term (multibacillary) and one Ridley-Jopling term (borderline tuberculoid) in the title demonstrates the source of the confusion.
The authors state: "... patients clinically classified as borderline tuberculoid (BT) and, therefore, belonging to the PB group." There is not a direct correlation between the Ridley-Jopling classification and the WHO classification. Thus, it is erroneous to state that all BT patients should be classified as PB. This would depend upon the findings in the specific patient. In addition, they state that slit-skin smears were done "... from six routine sites in all patients and selected sites in some patients." They do not state how many patients did not have slit-skin smears prepared from lesions. In patients toward the tuberculoid end of the leprosy spectrum, classifying the patient as PB without doing slit-skin smears from lesions may give erroneous results. A WHO Expert Committee report states: "Skin smears should be taken from a minimum of three sites, including one earlobe and two representative active skin lesions. In paucibacillary patients, if there is only a single skin lesion, the two smears may be taken from its active edge at sites diametrically opposite to each other." (1). The same WHO publication briefly discusses the difficulty in classifying borderline tuberculoid patients with multiple macular lesions. The report states: "Classification of these patients should therefore be undertaken only after careful consideration of all clinical features." (2). In order to deal with the problem of classifying such patients, a subsequent WHO publication recommends that any patient who has more than five skin lesions and any patient who has more than one nerve trunk involved be classified as multibacillary (3). Thus, it is unclear how many of the 21 patients in the Ebenezer paper in fact have paucibacillary leprosy.
- Richard I. Erankel, M.D., M.P.H.
Professor of Medicine
University of Hawaii at Manoa
1356 Lusitana Street
Honolulu, Hawaii 96S13-2427, U.S.A.
REFERENCES
1. WHO Expert Committee on Leprosy. Sixth report. Geneva: World Health Organization. 1988, p. 17. Tech. Rep. Ser. 768.
2. WHO Expert Committee on Leprosy. Sixth report. Geneva: World Health Organization, 1988, p. 16. Teeh. Rep. Ser. 768.
3. World Health Organization. A guide to eliminating leprosy as a public health problem. 1st edit. Geneva: World Health Organization. 1995, p. 21. WHO/LEP/95.1.