Urinary phenolic glycolipid 1 in the diagnosis and management of leprosy

A simplified assay to measure the phenolic glycolipid 1 (PGL-1) of Mycobacterium leprae in the urine was applied to the diagnosis of leprosy and the monitoring of antileprosy chemotherapy. One hundred seventy-nine previously untreated patients and 25 normal controls were tested. The specificity of the assay was 100%. There were no false-positive results. The sensitivity of the assay varied with the type of leprosy from 92% for lepromatous leprosy to 56% for borderline lepromatous and 18% for borderline tuberculoid patients. After the onset of chemotherapy in lepromatous leprosy patients, there was often a transient increase of urinary PGL-1, followed by a steady decline. Within 3 months of multiple drug therapy, urinary PGL-1 levels were reduced by 90%-99% and were often undetectable. This assay appears to have considerable potential for monitoring chemotherapy and detecting treatment failure and relapse in patients with Hansen's disease.