Early Revelation of Leprosy in China by Sequential Antibody Analyses with LID-1 and PGL-I.

Pan Qiong-Hua,Li Huan-Ying,Wen Yan,Yuan Lian-Chao,Steven G Reed,Malcolm S Duthie,Zheng Zhong-Yi,Yang Jun

doi:10.1155/2013/352689

Abstract

Leprosy is a disabling chronic infection, with insidious onset that often evades early detection. In order to detect new leprosy cases in a timely manner, we conducted surveillance visits in some difficult-to-reach mountain areas in South West China where the disease is still prevalent. Our data confirm that Chinese multibacillary (MB) leprosy patients have strong antibody responses against Mycobacterium leprae antigens ND-O-BSA and LID-1. Contacts of clinically diagnosed patients were then monitored at regular intervals by both physical examinations and the laboratory determination of antibody responses in sera collected during these examinations. Elevations in antibody titers indicated the onset of MB leprosy in one of the contacts, and diagnosis was subsequently confirmed on physical examination. Our data indicate that rising antibody titers can be used as a trigger for physical examination or increased monitoring of particular individuals in order to provide early leprosy diagnosis.

Highlights

Leprosy is the clinical manifestation of infection with Mycobacterium leprae
Infection of Schwann cells predisposes infected individuals to nerve damage, rendering leprosy, a chronic disabling infection with insidious onset typically characterized by the early involvement of skin and peripheral nerves. e immune response of the leprosy patient shapes the clinical presentation [2]. e response can limit bacterial growth and dissemination, resulting in few localized skin lesions and the de nition of such patients as paucibacillary (PB)
Sera were obtained from patients with leprosy (MB and PB) or pulmonary tuberculosis (TB) and healthy household contacts (HHCs) of MB leprosy patients within a hyperendemic site in South West China

Summary

Introduction

Leprosy is the clinical manifestation of infection with Mycobacterium leprae. With a slow growth rate of division every 12-13 days at an optimum temperature of 30∘C, M. leprae bacteria infect macrophages and Schwann cells [1]. In cases where the response does not control bacterial growth, high bacterial burden arises, infection becomes systemic and many disseminated lesions and signi cant nerve function impairment can be observed; these patients are de ned as multibacillary (MB). If such cases are le untreated, leprosy can progress to dis gurement and disability. Labor-intensive physical examination for skin and peripheral nerve involvement can be conducted at regular intervals (typically every few months and/or at annually) in recognized leprosy-endemic regions to detect suspected cases before advanced clinical symptoms and disabilities are established. We applied simple ELISA to sera collected from suspected leprosy cases in Honghe Prefecture, Yunnan Province, to quantify antibodies against the PGL-I and LID-1 antigens and evaluate the utility of these within active surveillance programs for leprosy

Materials and Methods

Results and Discussion

Conclusions