Leprosy reaction as a manifestation of immune reconstitution inflammatory syndrome: a case series of a Brazilian cohort

Leprosy as immune reconstitution inflammatory syndrome in patients living with HIV: Description of French Guiana’s cases over 20 years and systematic review of the literature

Background

HIV infection is highly prevalent in French Guiana, a territory where leprosy is also endemic. Since the introduction of Highly Active Antiretroviral Treatment (HAART) in the management of HIV, leprosy has been reported as part of the immune reconstitution inflammatory syndrome (IRIS).

Methodology/Principal findings

We aimed to present a general description of these forms of leprosy as IRIS, highlighting clinical and therapeutic specificities. A retrospective study was conducted in French Guiana, including patients living with HIV (PLHIV) with advanced infection (CD4 < 200/mm3) and developing leprosy or a leprosy reaction within six months of HAART initiation, from 2000 to 2020. Clinical, histological and biological data were collected for all these patients. Six patients were reported in French Guiana. A systematic review of the literature was conducted, and its results were added to an overall analysis. Overall, seventy-three PLHIV were included. They were mainly men (74%), aged 22–54 years (median 36 years), mainly from Brazil (46.5%) and India (32.8%). Most leprosy cases (56.2%) were borderline tuberculoid (BT). Leprosy reactions were frequent (74%), mainly type 1 reaction (T1R) (68.5%), sometimes intense with ulceration of skin lesions (22%). Neuritis was observed in 30.1% of patients. The outcome was always favorable under multidrug therapy (MDT), continuation of HAART and additional corticosteroid therapy in case of neuritis or ulceration. There was no relapse.

Conclusion

Leprosy as IRIS in PLHIV mainly presents as a BT leprosy in a T1R state, sometimes with ulcerated skin lesions. Response to MDT is usually good. Systemic corticosteroids are necessary and efficient in case of neuritis.

Leprosy is an infection caused by Mycobacterium leprae characterized by skin and nerve lesions. Leprosy reactions can be observed, depending on variations in host-specific cellular immunity. Leprosy is described after antiretroviral therapy (HAART) initiation in immunocompromised PLHIV from countries where leprosy and HIV infections are endemic. This is known as immune restoration inflammatory syndrome (IRIS), a brutal inflammatory response directed against a latent or quiescent pathogen. In this study we searched for cases of leprosy as IRIS in French Guiana and those published in the literature in order to describe their clinical characteristics. Overall, our results show that these cases are mostly observed as borderline tuberculoid leprosy, associated with or quickly followed by a type 1 leprosy reaction, sometimes with neuritis and/or ulceration of lesions. The outcome is favorable under standard leprosy treatment with HAART maintenance.

Macrophage Polarization in Leprosy-HIV Co-infected Patients

In HIV-infected individuals, a paradoxical clinical deterioration may occur in preexisting leprosy when highly active antiretroviral therapy (HAART)-associated reversal reaction (RR) develops. Leprosy–HIV co-infected patients during HAART may present a more severe form of the disease (RR/HIV), but the immune mechanisms related to the pathogenesis of leprosy–HIV co-infection remain unknown. Although the adaptive immune responses have been extensively studied in leprosy–HIV co-infected individuals, recent studies have described that innate immune cells may drive the overall immune responses to mycobacterial antigens. Monocytes are critical to the innate immune system and play an important role in several inflammatory conditions associated with chronic infections. In leprosy, different tissue macrophage phenotypes have been associated with the different clinical forms of the disease, but it is not clear how HIV infection modulates the phenotype of innate immune cells (monocytes or macrophages) during leprosy. In the present study, we investigated the phenotype of monocytes and macrophages in leprosy–HIV co-infected individuals, with or without RR. We did not observe differences between the monocyte profiles in the studied groups; however, analysis of gene expression within the skin lesion cells revealed that the RR/HIV group presents a higher expression of macrophage scavenger receptor 1 (MRS1), CD209 molecule (CD209), vascular endothelial growth factor (VEGF), arginase 2 (ARG2), and peroxisome proliferator-activated receptor gamma (PPARG) when compared with the RR group. Our data suggest that different phenotypes of tissue macrophages found in the skin from RR and RR/HIV patients could differentially contribute to the progression of leprosy.

PGL-1 and LID-1 antibody levels in HIV-infected and HIV-uninfected individuals in a Hansen's disease (leprosy) endemic area of Brazil

Serological tests for subclinical Mycobacterium leprae infection based on antibodies to phenolic glycolipid-1 (PGL-1) and leprosy IDRI diagnostic-1 (LID-1) have not been compared in HIV-infected and uninfected individuals. PGL-1 seropositivity by ELISA was 6.0 % (21/350) in HIV-infected compared with 29.1 % (102/350) in HIV-uninfected individuals (p < 0.001); LID-1 seropositivity was 45.4 % (159/350) in HIV-infected compared with 50.3 % (153/304) in HIV-uninfected individuals (p = 0.21). In HIV-infected individuals, LID-1 but not PGL-1 antibody levels were inversely associated with CD4+ cell count (p = 0.02). These differential associations of HIV infection and CD4 count with PGL-1 and LID-1 have implications for M leprae immunodiagnostic tools and require replication.

Clinical Pearls: Leprosy Reactions

Leprosy reactions are acute inflammatory episodes that occur in the setting of Mycobacterium leprae infection. Precipitants of reactions can be pharmacologic and nonpharmacologic. Both type 1 and type 2 reactions typically occur before and during leprosy treatment but may also occur after treatment has been completed. Reactions cause morbidity due to nerve damage, and prompt corticosteroid therapy is warranted to minimize nerve damage due to reactions.

Comparison between histopathologic features of leprosy in reaction lesions in HIV coinfected and non-coinfected patients

BACKGROUND

Leprosy and HIV are diseases that have a major impact on public health in Brazil. Patients coinfected with both diseases, appear to be at higher risk to develop leprosy reactions.

OBJECTIVE

The aim of this study is to describe the histopathological aspects of cutaneous lesions during reactional states in a group of patients with HIV-leprosy coinfection, compared to patients with leprosy, without coinfection.

METHODS

Two groups were established: group 1 comprised of 40 patients coinfected with HIV-leprosy; group 2, comprised of 107 patients with leprosy only. Patients presenting reactional states of leprosy had their lesions biopsied and comparatively evaluated.

RESULTS

Reversal reaction was the most frequent feature in both groups, with dermis edema as the most common histopathological finding. Giant cells were seen in all group 1 histopathological examinations. Dermis edema was the most common finding in patients with erythema nodosum leprosum.

CONCLUSION

Few histopathological differences were found in both groups, with reversal reaction as the most significant one, although this fact should be analyzed considering the predominant BT clinical form in the coinfected group and BB form in the group without HIV. Larger prospective studies in patients with HIV-leprosy coinfection are needed to confirm and broaden these results.

Leprosy Reactions in Patients Coinfected with HIV: Clinical Aspects and Outcomes in Two Comparative Cohorts in the Amazon Region, Brazil

BACKGROUND

Leprosy, caused by Mycobacterium leprae, can lead to scarring and deformities. Human immunodeficiency virus (HIV), a lymphotropic virus with high rates of replication, leads to cell death in various stages of infection. These diseases have major social and quality of life costs, and although the relevance of their comorbidity is recognized, several aspects are still not fully understood.

METHODOLOGY/PRINCIPAL FINDINGS

Two cohorts of patients with leprosy in an endemic region of the Amazon were observed. We compared 40 patients with leprosy and HIV (Group 1) and 107 leprosy patients with no comorbidity (Group 2) for a minimum of 2 years. Group 1 predominantly experienced the paucibacillary classification, accounting for 70% of cases, whereas Group 2 primarily experienced the multibacillary classification (80.4% of cases). There was no significant difference in the prevalence of leprosy reactions among the two groups (37.5% for Group 1 vs. 56.1% for Group 2), and the most frequent reaction was Type 1. The appearance of Group 1 patients' reversal reaction skin lesions was consistent with each clinical form: typically erythematous and infiltrated, with similar progression as those patients without HIV, which responded to prednisone. Patients in both groups primarily experienced a single episode (73.3% in Group 1 and 75% in Group 2), and Group 1 had shorter reaction periods (≤3 months; 93.3%), moderate severity (80%), with 93.3% of the patients in the state of acquired immune deficiency syndrome, and 46.7% presenting the reaction at the time of the immune reconstitution inflammatory syndrome.

CONCLUSIONS/SIGNIFICANCE

This study used a large sample and makes a significant contribution to the clinical outcomes of patients in the reactive state with comorbid HIV and leprosy. The data indicate that these diseases, although concurrent, have independent courses.

Epidemiological and clinical patterns of 92 patients co-infected with HIV and Mycobacterium leprae from Rio de Janeiro State, Brazil

BACKGROUND

Many articles have shown that HIV infection can modify the clinical course of leprosy, but very scant epidemiological and clinical data about this co-infection are available in the peer-reviewed literature.

METHODS

We herein describe the geographical distribution and demographic characteristics of 92 HIV/Mycobacterium leprae co-infected patients assisted in a Brazilian Leprosy referral center. A multivariate analysis was performed in order to establish clinical factors associated with type 1 reaction.

RESULTS

Co-infected patient admissions have steadily increased over the last years at this referral center. Most patients were men, with a mean age of 32.3 years and presenting with the paucibacillary form of leprosy. The use of antiretroviral therapy (ART) was the only factor associated with type 1 reaction. Most patients were living in the metropolitan area and the north sub area of Rio de Janeiro City.

CONCLUSION

Co-infected patients receiving ART have a greater chance to develop type 1 reaction. Patients living with both HIV and leprosy are likely to live in regions characterized by a high density impoverished population.

Role of CD8(+) T cells in triggering reversal reaction in HIV/leprosy patients

It has been reported that the initiation of highly active anti-retroviral therapy (HAART) is associated with the development of reversal reaction (RR) in co-infected HIV/leprosy patients. Nevertheless, the impact of HIV and HAART on the cellular immune response to Mycobacterium leprae (ML) remains unknown. In the present study, we observed that ex vivo peripheral blood mononuclear cells (PBMCs) of both RR and RR/HIV patients presented increased percentages of activated CD4(+) T cells when compared with the healthy individuals (HC) group. The frequency of CD8(+)  CD38(+) cells increased in the PBMCs of RR/HIV patients but not in RR patients when compared with the HC group. Both RR and RR/HIV skin lesion cells presented similar percentages of activated CD4(+) cells, but the numbers of activated CD8(+) cells were higher in RR/HIV in comparison to the RR group. The frequency of interferon-γ-producing cells was high in response to ML regardless of HIV co-infection. In ML-stimulated cells, there was an increase in central memory CD4(+) T-cell frequencies in the RR and RR/HIV groups, but an increase in central memory CD8(+) T-cell frequency was only observed in the RR/HIV group. ML increased granzyme B(+) effector memory CD8(+) T-cell frequencies in the RR/HIV PBMCs, but not in the HC and RR groups. Our data suggest that the increased expression of effector memory CD8(+) T cells, together with greater perforin/granzyme B production, could be an additional mechanism leading to the advent of RR in co-infected patients. Moreoever, this increased expression may explain the severity of RR occurring in these patients.

Immune reconstitution reactions in human immunodeficiency virus-negative patients: report of a case and review of the literature

BACKGROUND

Immune reconstitution inflammatory syndrome (IRIS) is a phenomenon initially described in patients with human immunodeficiency virus. Upon initiation of combination antiretroviral therapy, recovery of cellular immunity triggers inflammation to a preexisting infection or antigen that causes paradoxical worsening of clinical disease. A similar phenomenon can occur in human immunodeficiency virus-negative patients, including pregnant women, neutropenic hosts, solid-organ or stem cell transplant recipients, and patients receiving tumor necrosis factor inhibitors.

OBSERVATIONS

We report a case of leprosy unmasking and downgrading reaction after stem cell transplantation that highlights some of the challenges inherent to the diagnosis of IRIS, especially in patients without human immunodeficiency virus infection, as well as review the spectrum of previously reported cases of IRIS reactions in this population.

CONCLUSIONS

The mechanism of immune reconstitution reactions is complex and variable, depending on the underlying antigen and the mechanism of immunosuppression or shift in immune status. Use of the term IRIS can aid our recognition of an important phenomenon that occurs in the setting of immunosuppression or shifts in immunity but should not deter us from thinking critically about the distinct processes that underlie this heterogeneous group of conditions.

Evaluation of cellular phenotypes implicated in immunopathogenesis and monitoring immune reconstitution inflammatory syndrome in HIV/leprosy cases

BACKGROUND

It is now evident that HAART-associated immunological improvement often leads to a variety of new clinical manifestations, collectively termed immune reconstitution inflammatory syndrome, or IRIS. This phenomenon has already been described in cases of HIV coinfection with Mycobacterium leprae, most of them belonging to the tuberculoid spectrum of leprosy disease, as observed in leprosy reversal reaction (RR). However, the events related to the pathogenesis of this association need to be clarified. This study investigated the immunological profile of HIV/leprosy patients, with special attention to the cellular activation status, to better understand the mechanisms related to IRIS/RR immunopathogenesis, identifying any potential biomarkers for IRIS/RR intercurrence.

METHODS/PRINCIPAL FINDINGS

Eighty-five individuals were assessed in this study: HIV/leprosy and HIV-monoinfected patients, grouped according to HIV-viral load levels, leprosy patients without HIV coinfection, and healthy controls. Phenotypes were evaluated by flow cytometry for T cell subsets and immune differentiation/activation markers. As expected, absolute counts of the CD4+ and CD8+ T cells from the HIV-infected individuals changed in relation to those of the leprosy patients and controls. However, there were no significant differences among the groups, whether in the expression of cellular differentiation phenotypes or cellular activation, as reflected by the expression of CD38 and HLA-DR. Six HIV/leprosy patients identified as IRIS/RR were analyzed during IRIS/RR episodes and after prednisone treatment. These patients presented high cellular activation levels regarding the expression of CD38 in CD8+ cells T during IRIS/RR (median: 77,15%), dropping significantly (p<0,05) during post-IRIS/RR moments (median: 29,7%). Furthermore, an increase of cellular activation seems to occur prior to IRIS/RR.

CONCLUSION/SIGNIFICANCE

These data suggest CD38 expression in CD8+ T cells interesting tool identifying HIV/leprosy individuals at risk for IRIS/RR. So, a comparative investigation to leprosy patients at RR should be conducted.

Leprosy and HIV coinfection: a critical approach

An increase in leprosy among HIV patients, similar to that observed in patients with TB, was expected approximately 20 years ago. Studies conducted in the 1990s together with those reported recently seemed to indicate that a coinfection with HIV did not alter the incidence and the clinical spectrum of leprosy and that each disease progressed as a single infection. By contrast, in countries with a high seroprevalence of HIV, TB was noted to increase. Explanations may be provided by the differences in the incubation time, the biology and toxicity of Mycobacterium leprae and Mycobacterium tuberculosis. After the introduction of HAART the leprosy-HIV coinfection manifested itself as an immune reconstitution inflammatory syndrome (IRIS), typically as paucibacillary leprosy with type 1 leprosy reaction. The incidence of leprosy in HIV-infected patients has never been properly investigated. IRIS-leprosy is probably underestimated and recent data showed that the incidence of leprosy in HIV patients under HAART was higher than previously thought.

Immunophenotype of skin lymphocytic infiltrate in patients co-infected with Mycobacterium leprae and human immunodeficiency virus: a scenario dependent on CD8+ and/or CD20+ cells

BACKGROUND

Leprosy occurs rarely in human immunodeficiency virus (HIV)-positive patients. In contrast to tuberculosis, there has been no report to date of an increase in HIV prevalence among patients with leprosy or of differences in leprosy's clinical spectrum. While several studies describe the systemic immune response profile in patients co-infected with HIV and leprosy, the local immune skin response has been evaluated in only a small number of case reports and limited series of patients.

OBJECTIVE

To investigate the interaction between Mycobacterium leprae and HIV infection in the skin.

METHODS

We investigated the presence and frequency of cells positive for CD4, CD8, CD20, TIA-1, FOXP3 and CD123 in lymphocytic infiltrates from 16 skin biopsies taken from 15 patients with HIV-leprosy co-infection.

RESULTS

CD4+ cells were absent in infiltrates from 6 (38%) skin biopsies and present in 10 (62%) cases at low levels (<1·16%) of the lymphocytic infiltrate. CD8+ was the predominant phenotype in the infiltrate (99·4%), followed by TIA-1, expressed by >75% of CD8+ cells. FOXP3+ cells were also present, representing 3·4% of the lymphocytic infiltrate. CD20+ cells were detected in 75% of the cases; however, in two cases (12%) these cells represented 25-50% of the infiltrate, while in the other 10 cases (62%) they were present only focally (<25% of the infiltrate). CD123+ cells were not observed in any of the studied specimens.

CONCLUSIONS

Data presented here suggest that cell-mediated immune responses to M. leprae are preserved at the site of disease and that in the absence of CD4+ cells, CD8+FOXP3+ and CD20+ cells may be involved in granuloma formation.

Skin infections in HIV-infected individuals in the era of HAART

PURPOSE OF REVIEW

Clinicians should be aware of the shift in the cutaneous infectious disease burden in human immunodeficiency virus-infected individuals as a reflection of immune restoration in the era of highly active antiretroviral therapy (HAART).

RECENT FINDINGS

As in the general population but to greater extent, methicillin-resistant Staphylococcus aureus (MRSA) soft-tissue infection is a rising problem among those with human immunodeficiency virus (HIV). Human papilloma virus (HPV) is exceedingly prevalent and persistent despite HAART, and HPV-associated malignancy is increasing as those with HIV live longer. Herpes, syphilis, and Kaposi's sarcoma continue to plague individuals with HIV. Immune reconstitution inflammatory syndrome (IRIS) is common and often presents with infectious cutaneous manifestations.

SUMMARY

This review implicates the importance of the acknowledgment of MRSA infections risk factors, screening for HPV-related neoplasia, continuance of trials to establish the efficacy of herpes vaccines, and awareness of prevalent cutaneous infections presenting with IRIS in those with HIV.

Unique aspects of the care of HIV-positive Latino patients living in the United States

Latinos are disproportionately affected by HIV, with a higher risk of infection and a delayed presentation to care as compared to non-Hispanic whites. Over the last decade many Latinos, especially foreign-born migrants, have settled in regions of the country with historically low Latino representation. Therefore, clinicians who care for HIV-infected patients are likely to encounter Latino patients, regardless of their practice location. Providing optimal care to this population may be especially challenging for clinicians practicing in areas of newer Latino expansion, where culturally appropriate services may be sparse. In this article, we argue that an understanding of the HIV epidemic among Latinos requires an appreciation of the diversity and heterogeneity of the Latino population in the United States. We also review unique clinical aspects of HIV care among Latinos, including manifestation of co-infections with pathogens endemic in Latin America but rare in the United States.