Granulomatous reactivation during the course of a leprosy infection: reaction or relapse

• Published in: PLoS neglected tropical diseases 2010-12, Vol.4 (12), p.e921-e921
• Main Authors: Trindade, Maria Angela Bianconcini, Benard, Gil, Ura, Somei, Ghidella, Cássio Cesar, Avelleira, João Carlos Regazzi, Vianna, Francisco Reis, Marques, Alfredo Bolchat, Naafs, Ben, Fleury, Raul Negrão
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Biopsy; Colleges & universities; Dermatology/Dermatologic Pathology; Drug resistance; Effective capacity; Female; Granuloma - immunology; Granuloma - microbiology; Granuloma - pathology; Histocytochemistry; Histopathology; Humans; Hypersensitivity; Immune Reconstitution Inflammatory Syndrome - microbiology; Immune Reconstitution Inflammatory Syndrome - pathology; Immunology/Immunity to Infections; Infectious diseases; Infectious Diseases/Bacterial Infections; Infectious Diseases/Neglected Tropical Diseases; Leprosy; Leprosy - immunology; Leprosy - microbiology; Leprosy - pathology; Male; Microscopy; Middle Aged; Mycobacterium leprae - immunology; Mycobacterium leprae - isolation & purification; Nitric oxide; Patients; Recurrence; Tropical diseases
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0000921

Leprosy is a chronic granulomatous infectious disease and is still endemic in many parts of the world. It causes disabilities which are the consequence of nerve damage. This damage is in most cases the result of immunological reactions. To investigate the differences between a type 1 leprosy (reversal) reaction and relapse on using histopathology. The histopathological changes in 167 biopsies from 66 leprosy patients were studied. The patients were selected when their sequential biopsies demonstrated either different patterns or maintained the same pattern of granulomatous reaction over more than two years during or after the treatment of leprosy. In 57 of the patients studied, a reactivation was seen which coincided with a decrease in the bacteriological index (BI), suggesting that this reactivation (reversal reaction or type 1 leprosy reaction) coincides with an effective capacity for bacteriological clearance. In nine patients, an increase of the bacteriologic index (IB) or persistence of solid bacilli occurred during the reactivation, indicating proliferative activity, suggestive of a relapse. The histopathological aspects of the granulomas were similar in both groups. Bacterioscopy provided the only means to differentiate a reversal reaction from a relapse in patients with granulomatous reactivation. The type 1 leprosy reaction may be considered as a part effective immune reconstitution (reversal, upgrading reaction) or as a mere hypersensitivity reaction (downgrading reaction) in a relapse.