The role of human T cell lymphotrophic virus type 1, hepatitis B virus and hepatitis C virus coinfections in leprosy

Viral co-infections in leprosy: a scoping review

CONTEXT

The most reported viral co-infections in leprosy are human immunodeficiency virus (HIV), human T-cell lymphotropic virus (HTLV), hepatitis B virus (HBV), hepatitis C virus (HCV), and SARS-CoV-2. In co-infections, the burden of an agent can be increased or decreased by the presence of others. To address this issue, we need to fully understand their prevalence, risk factors, immunology, clinical manifestations, and treatment. The purpose of this scoping review is to describe the clinical and epidemiological characteristics of the most reported viral co-infections in leprosy to inform clinicians and guide future research.

METHODS

The authors conducted a literature search of five databases for articles on each of the aforementioned co-infections published prior to October 2022. Two independent reviewers conducted the selection process and identified 53 papers meeting the study inclusion criteria. The data extraction process and evidence synthesis were conducted by one reviewer and double-checked by a second one, consistent with best practice recommendations for scoping reviews.

RESULTS

For all assessed viruses, most studies reported prevalence rates in leprosy patients higher than the general population. Studies found that HTLV, HBV, and HCV chronic infections were highest in multibacillary leprosy, whereas HIV was mostly found in paucibacillary leprosy, and SARS-Cov-2 affected leprosy subtypes equally. Overall, co-infections were also associated with higher rates of leprosy reactions, except for COVID-19. Forty-six percent of the studies discussed issues related to treatment, which led to favorable outcomes for the most part.

CONCLUSIONS

This review summarizes the existing literature on viral co-infections in leprosy patients, generating valuable insights and recommending areas for future research.

Rational design of chimeric Multiepitope Based Vaccine (MEBV) against human T-cell lymphotropic virus type 1: An integrated vaccine informatics and molecular docking based approach

Human T-cell lymphotropic virus type 1 (HTLV-1) is an infectious virus that has been linked to adult T cell leukemia /lymphoma, aggressive CD4-T cell malignancy and many other immune-related medical illnesses. So far, no effective vaccine is known to combat HTLV-1, hence, the current research work was performed to design a potential multi-epitope-based subunit vaccine (MEBV) by adopting the latest methodology of reverse vaccinology. Briefly, three highly antigenic proteins (Glycoprotein, Accessory protein, and Tax protein) with no or minimal (<37%) similarity with human proteome were sorted out and potential B- and T-cell epitopes were forecasted from them. Highly antigenic, immunogenic, non-toxic, non-allergenic and overlapping epitopes were short-listed for vaccine development. The chosen T-cell epitopes displayed a strong binding affinity with their corresponding Human Leukocyte Antigen alleles and demonstrated 95.8% coverage of the world's population. Finally, nine Cytotoxic T Lymphocytes, six Helper T Lymphocytes and five Linear B Lymphocytes epitopes, joint through linkers and adjuvant, were exploited to design the final MEBV construct, comprising of 382 amino acids. The developed MEBV structure showed highly antigenic properties while being non-toxic, soluble, non-allergenic, and stable in nature. Moreover, disulphide engineering further enhanced the stability of the final vaccine protein. Additionally, Molecular docking analysis and Molecular Dynamics (MD) simulations confirmed the strong association between MEBV construct and human pathogenic immune receptor TLR-3. Repeated-exposure simulations and Immune simulations ensured the rapid antigen clearance and higher levels of cell-mediated immunity, respectively. Furthermore, MEBV codon optimization and in-silico cloning was carried out to confirm its augmented expression. Results of our experiments suggested that the proposed MEBV could be a potential immunogenic against HTLV-1; nevertheless, additional wet lab experiments are needed to elucidate our conclusion.

Causes of Death among Persons Affected by Leprosy in Korea, 2010-2013

In addition to the complications of leprosy, people affected by leprosy (PALs) can suffer from chronic diseases. We evaluated the recent pattern of deaths among Korean PALs and compared it with that in the general population. We analyzed the death certificate data of 1,359 PALs from 2010 through 2013. The all-cause and cause-specific standardized mortality ratio (SMR) and standardized mortality with 95% CI were calculated. Malignancy had the highest standardized mortality, with 130.9 deaths per 100,000 persons, followed by cardiovascular diseases (CVDs; 85.5 deaths) and respiratory diseases (38.2 deaths). Of malignancies, liver cancer caused the greatest number of cancer deaths (40.0 deaths). The all-cause mortality of PALs was significantly lower than that in the general population, corresponding to an SMR of 0.84 (95% CI 0.79-0.88). Deaths from malignancy and CVDs were significantly lower, corresponding to SMRs (95% CIs) of 0.88 (0.79-0.98) and 0.75 (0.67-0.84), respectively. The death rates for lung and stomach cancers were lower, whereas mortality due to liver cancer was higher, with an SMR of 1.79 (95% CI 1.43-2.22). Except for liver cancer and infection, the causes of mortality of PALs tend to be lower than that in the general population. The most common underlying cause of death in PALs was stroke, followed by ischemic heart disease, liver cancer, and pneumonia.

The Burden of Helminth Coinfections and Micronutrient Deficiencies in Patients with and without Leprosy Reactions: A Pilot Study in Minas Gerais, Brazil

Leprosy reactions are immune-mediated complications occurring in up to 50% of patients. The immune consequences of helminth infections and micronutrient deficiencies suggest a potential role in type 1 reactions (T1R) or type 2 reactions (T2R). We conducted a case-control study in Minas Gerais, Brazil, to evaluate whether comorbidities and other factors are associated with reactions in patients with multibacillary leprosy. Stool and serum were tested for helminth infections. Deficiencies of vitamin A, D, and iron were measured using serum retinol, 25-hydroxyvitamin D, and ferritin, respectively. Logistic regression models identified associations between reactions and helminth infections, micronutrient deficiencies, and other variables. Seventy-three patients were enrolled, 24 (33%) with T1R, 21 (29%) with T2R, 8 (15%) with mixed T1R/T2R, and 20 (27%) without reactions. Evidence of helminth infections were found in 11 participants (15%) and included IgG4 reactivity against Schistosoma mansoni, Strongyloides, and Ascaris antigens. Thirty-eight (52%) had vitamin D deficiency, eight (11%) had vitamin A insufficiency, 21 (29%) had anemia, and one (1.4%) had iron deficiency. Multivariable logistic regression showed no statistically significant associations between helminth coinfections and total reactions (adjusted odds ratios [aOR]: 1.36, 95% CI: 0.22, 8.33), T1R (aOR: 0.85, 95% CI: 0.17, 4.17), or T2R (aOR: 2.41, 95% CI: 0.29, 20.0). Vitamin D deficiency and vitamin A insufficiency were also not statistically associated with reactions. However, vitamin deficiencies and helminth infections were prevalent in these patients, suggesting a potential role for additional treatment interventions. Studying reactions prospectively may further clarify the role of comorbidities in the clinical presentation of leprosy.

Occult hepatitis B virus infection in patients with leprosy

Leprosy patients may present with immune system impairment and have a higher hepatitis B virus (HBV) seroprevalence, justifying the investigation of occult HBV infection in these individuals. The aim of this study was to verify the frequency and the clinical factors associated with occult HBV infection in leprosy patients. Between 2015 and 2016, leprosy patients from a reference center in Brazil were interviewed to assess clinical data. Blood samples were collected for the screening of HBV serological markers using enzyme-linked immunosorbent assay. Patients with negative hepatitis B surface antigen (HBsAg) that had positive anti-HBc and/or anti-HBs were selected for HBV DNA detection using real-time polymerase chain reaction. SPSS was used for data analysis. Among 114 selected patients, six were identified with occult infection (5.3%) and five of them with multibacillary leprosy. Three patients with occult infection had a history of a type 2 reaction (P = 0.072; OR, 4.97; 95% CI, 0.87-28.52). Only two patients with occult infection had isolated anti-HBc, while three had isolated anti-HBs, including those with the highest HBV DNA titers. In conclusion, in leprosy patients with negative HBsAg and positive anti-HBc and/or anti-HBs, occult HBV infection occurs in 5.3% and can be found even in patients with isolated anti-HBs.

Prevalence and risk factors for hepatitis B and C viruses in patients with leprosy

It has been reported a higher seroprevalence of HBV and HCV in leprosy patients than in the general population, but the reasons for these findings are not yet clear. On the other hand, there is evidence that these viruses may influence the onset of leprosy reactional episodes, an important cause of neurological sequelae. This study aimed to determine seroprevalence and risk factors for HBV and HCV in leprosy patients and to investigate its association with leprosy reactions. Patients attended from 2015 to 2016 at a Reference Center in Leprosy in Northeastern region of Brazil, were interviewed, had their records reviewed to investigate biological, clinical, behavioral and socioeconomic factors, and underwent blood sample collection. Biological samples were tested for HBV (HBsAg, anti-HBs and anti-HBs) and HCV (anti-HCV) serological markers by ELISA and, in anti-HCV positive samples, HCV RNA was screened by real time PCR. SPSS program was used to analyze the data. A total of 403 leprosy patients were included. Although anti-HBc was positive in 14.1%, there was no detection of HBsAg, which contradicts the hypothesis that leprosy patients have immune deficit that make them more prone to chronic HBV infection. Multibacillary leprosy (0.057), health-related work (0.011) and lower educational level (0.035) were associated with anti-HBc positivity. Anti-HCV was positive in 0.5%, with no detection of HCV RNA. No association was identified between anti-HCV and the epidemiological analyzed factors. There was also no association of anti-HBc or anti-HCV with type 1 or type 2 leprosy reactions. Thus, the seroprevalence of HBV and HCV in leprosy patients was similar to that of the general population of Northeastern region of Brazil, and no association of HBV or HCV with leprosy reactions was observed.

Viral Co-infection and Leprosy Outcomes: A Cohort Study

Background

The role of the host immunity in determining leprosy clinical forms and complications is well recognized, implying that changes in the immune status may interfere with several aspects of the disease. Therefore, we hypothesized that the presence of viral co-infections and associated immunological changes will have a clinical impact on leprosy outcomes. The aim of our study was to determine the clinical impact of human immunodeficiency virus (HIV), human T cell lymphotrophic virus type 1 (HTLV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infection on the development of reactions, neuritis, neuropathy and relapses.

Methodology/Principal Findings

Cohort study in 245 leprosy subjects from Bahia, Brazil. Patients were followed from the time of diagnosis until at least the end of multidrug therapy. Viral co-infection was detected in 36 out of the 245 patients (14.7%). Specific co-infection rates were 10.6% for HBV, 2.9% for HIV, 2.5% for HTLV-1 and 0.8% for HCV. All four groups of co-infected patients had higher rates of neuritis and nerve function impairment compared to non co-infected leprosy subjects. The relapse rate was also higher in the co-infected group (8.3%) versus patients without co-infection (1.9%); relative risk 4.37, 95% confidence interval 1.02–18.74.

Conclusions/Significance

Leprosy patients should be screened for HBV, HCV, HIV and HTLV-1 co-infections. Besides contributing to better health care, this measure will facilitate the early detection of severe complications through targeting of higher risk patients.

The clinical and social impact of leprosy, a disease caused by Mycobacterium leprae, is due to the deformities and disabilities that are consequences of skin and peripheral nerve inflammation. We believe that leprosy patients who also have an associated viral infection will have a worse outcome. This can be due to alterations in the immune system triggered by the virus co-infection, leading to an increasing inflammation of the skin or peripheral nerves affected by Mycobacterium leprae, or to a depression of the mechanisms that control the infection. We have verified if the presence of specific viral infections in leprosy subjects is associated with a higher risk of developing a worse outcome like nerve inflammation, impairment in the nerve function or relapse. We have screened the patients for human immunodeficiency virus, human T cell lymphotrophic virus type 1, hepatitis B and hepatitis C virus. These subjects were followed up during all the period of leprosy treatment (at least 6 months) in order to detect the emergence of any complication. We have found that leprosy patients with viral co-infection are at higher risk to develop nerve inflammation and damage, as well as relapse, compared to subjects without viral co-infection.