Gupta Ruchi, Kar Hemanta Kumar, Bharadwaj Minakshi
Dept. of Dermatology, STD & Leprosy, PGIMER & Dr RML Hospital, New Delhi--110 001.
Lepr Rev. 2012 Dec;83(4):354-62.
WHO guidelines classify leprosy patients clinically into PB and MB group based on the number of skin lesions (NSL) with > or = 6 skin lesions as a criterion for MB leprosy. Other clinical criteria for classification are based on the number of body areas affected (NBAA) and on size of the largest skin lesions (SLSL). They are also fairly simple and easily practicable in the field.
The objective of this study is to explore whether sensitivity and specificity of the WHO classification can be improved by addition of clinical criteria based on NBAA and SLSL to WHO classification.
Among 100 newly diagnosed untreated leprosy patients classified into PB and MB group according to WHO classification, the NSL and NBAA were recorded and the size (longest diameter) of largest skin lesion was measured in centimeters. The Receiver Operator Characteristic (ROC) curves were plotted for each parameter to find the best cut off point (with highest sensitivity and specificity).
The sensitivity and specificity of the WHO classification tested, using slit-skin smear (SSS) and skin biopsy results as the gold standard, was found to be 63% and 85% respectively. The ROC curve for NSL found the best cut off of three and more lesions for MB group (sensitivity 90% & specificity 80%). Similarly, ROC curves for NBAA and SLSL found the best cut off points for classification into MB group to be two or more (sensitivity 90% & specificity 75%) and 5 cm or more (sensitivity 87% and specificity 65%) respectively. On combining all these criteria together sensitivity was increased to 98.5% with no significant change in specificity, which was 77.5%.
The study concluded that the sensitivity of the present clinical classification can be further improved by addition of two other clinical criteria.
世界卫生组织（WHO）的指南根据皮肤损害数量（NSL）将麻风病患者临床分为PB和MB组，以6个或更多皮肤损害作为MB麻风病的标准。其他分类的临床标准基于受累身体部位数量（NBAA）和最大皮肤损害大小（SLSL）。它们也相当简单，在现场易于实施。
本研究的目的是探讨通过在WHO分类中增加基于NBAA和SLSL的临床标准，是否可以提高WHO分类的敏感性和特异性。
在100例根据WHO分类分为PB和MB组的新诊断未治疗麻风病患者中，记录NSL和NBAA，并以厘米为单位测量最大皮肤损害的大小（最长直径）。为每个参数绘制受试者操作特征（ROC）曲线，以找到最佳切点（具有最高敏感性和特异性）。
以皮肤涂片（SSS）和皮肤活检结果作为金标准，测试的WHO分类的敏感性和特异性分别为63%和85%。NSL的ROC曲线发现MB组三个及更多损害的最佳切点（敏感性90%，特异性80%）。同样，NBAA和SLSL的ROC曲线发现MB组分类的最佳切点分别为两个或更多（敏感性90%，特异性75%）和5厘米或更多（敏感性87%，特异性65%）。将所有这些标准结合在一起时，敏感性提高到98.5%，特异性无显著变化，为77.5%。
该研究得出结论，通过增加另外两个临床标准，目前临床分类的敏感性可以进一步提高。
