Leprosy reactions: the predictive value of Mycobacterium leprae-specific serology evaluated in a Brazilian cohort of leprosy patients (U-MDT/CT-BR)

Background: leprosy reactions,reversal reactions/rr and erythema nodosum leprosum/enl,can cause irreversible nerve damage,handicaps and deformities. the study of mycobacterium leprae-specific serologic responses at diagnosis in the cohort of patients enrolled at the clinical trial for uniform multidrug therapy regimen for leprosy patients in brazil/u-mdt/ct-br is suitable to evaluate its prognostic value for the development of reactions. methodology: igm and igg antibody responses to pgl-i,lid-1,nd-o-lid were evaluated by elisa in 452 reaction-free leprosy patients at diagnosis,enrolled and monitored for the development of leprosy reactions during a total person-time of 780,930 person-days,i.e. 2139.5 person-years,with a maximum of 6.66 years follow-up time. principal findings: among these patients,36% (160/452) developed reactions during follow-up: 26% (119/452) rr and 10% (41/452) had enl. at baseline higher anti-pgl-i,anti-lid-1 and anti-nd-o-lid seropositivity rates were seen in patients who developed enl and rr compared to reaction-free patients (p<0.0001). seroreactivity in reactional and reaction-free patients was stratified by bacilloscopic index/bi categories. among bi negative patients,higher anti-pgl-i levels were seen in rr compared to reaction-free patients (p = 0.014). in patients with 0