Concordance of Acid-Fast Stain Result and Histopathologic vs Clinical Diagnosis of Leprosy: A Three-year Retrospective Study in a Tertiary Government Hospital and Sanitarium in the Philippines

Abstract

Objectives. In the Philippines, there has been a lack of information on the concordance between classifications
of Hansen’s disease or leprosy clinically, histopathologically, and with AFS results. The study ultimately aimed to
determine the concordance between the clinical diagnosis, histopathological results, and AFS results of patients with leprosy seen at the Dr. Jose N. Rodriguez Memorial Hospital and Sanitarium (DJNRMHS).

Methods. This is a descriptive, retrospective, single-center study conducted at the DJNRMHS, a tertiary government hospital and one of the last remaining sanitaria in the country located in northern Metro Manila in the Philippines. The study reviewed and included all the patient records from the years 2017-2019 which included skin biopsy results and slit-skin smear with AFS. Leprosy patients were then classified based on the following classifications: World Health Organization (WHO) and Ridley-Jopling classifications; and the concordance of clinical diagnosis vs the histopathologic findings and clinical diagnosis vs AFS results were determined using kappa testing.

Results. A total of 48 patients from 2017-2019 were included in the study analysis. Based on the WHO classification, 3 (6.3%) presented clinically with paucibacillary (PB) leprosy and 45 (93.7%) with multibacillary (MB) leprosy. The slitskin smear with AFS results of these patients ranged from 0 to 4 with the majority being 0. PB results are composed of 28 (58.3%), while MB is at 20 (41.7%). The paucibacillary forms had the highest agreement percentage at 66.7% (2/3) and multibacillary had the lowest percentage of agreement at 19/45 (42.2%). The overall data analysis showed an agreement of 21/48 (43.8%), considered no agreement (kappa = 0.0195, p = 0.05). Using the Ridley-Jopling classification, patients can be clinically stratified with most comprising lepromatous leprosy (LL) at 19 (39.6%) and indeterminate spectrum having the least with only 2 (4.2%). The histopathologic result of these patients reported a majority of LL comprising 24 (50%) and the indeterminate spectrum comprising the least with 2 (4.2%) reported. The inde-terminate and tuberculoid spectrum were those with the highest percentage of agreement: 2/2 (100%) and 5/5 (100%), respectively. The borderline lepromatous spectrum presented an agreement of only 4/10 (40%), and thus the lowest agreement. The overall data analysis showed an agreement of 36/48 (75%), considered moderate agreement (kappa = 0.661, p = 0.05). 

Conclusion. In the findings of this study, AFS can suffice only for the detection but not for the accurate classification of the different leprosy spectra of patients based on its low overall agreement. On the other hand,
histopathology yielded moderate agreement with clinical classification. It is therefore highlighted that AFS, histopathology, and clinical findings are needed to properly detect and classify leprosy patients, leading to
appropriate management and treatment.