Tuberculosis and Leprosy Coinfection: A Perspective on Diagnosis and Treatment

Rare concurrence of lepromatous leprosy and cutaneous tuberculosis

The coinfection of leprosy and tuberculosis has been rarely reported in literature. A middle-aged man who was a known case of hepatitis B infection had presented with ichthyosis with claw hand deformity and submandibular swelling, which were diagnosed with lepromatous leprosy and scrofuloderma, respectively.

Concurrent pulmonary tuberculosis and lepromatous leprosy in a newly diagnosed HIV positive patient: a case report

Background

The leprosy-tuberculosis (TB) co-infection is rarely reported in recent times. However, this dual comorbidity is associated with high mortality and major morbidity. Unrecognised leprosy-TB co-infection may predispose affected patients to rifampicin monotherapy and subsequent drug resistance.

Case presentation

A 35 year old migrant, human immunodeficiency virus (HIV) positive male worker presented with 6 month history of symmetric infiltrative nodular plaques of the face and distal, upper extremities. A few days after initial dermatology presentation, a sputum positive pulmonary tuberculosis diagnosis was made at his base hospital. Subsequent dermatology investigations revealed histology confirmed lepromatous leprosy and a weakly reactive rapid plasma reagin test. The presenting clinical features and laboratory results were suggestive of lepromatous leprosy coexisting with pulmonary tuberculosis in an HIV positive patient.

Conclusions

This case illustrates the occurrence of leprosy with pulmonary tuberculosis in an HIV infected patient and the difficulties in interpreting non-treponemal syphilis tests in these patients. This case also highlights the need for a high index of suspicion for co-infection and the need to exclude PTB prior to initiation of rifampicin containing multi-drug therapy (MDT). Interdisciplinary management and social support are crucial in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01572-w.

Mycobacterium leprae transmission characteristics during the declining stages of leprosy incidence: A systematic review

BACKGROUND

Leprosy is an infectious disease caused by Mycobacterium leprae. As incidence begins to decline, the characteristics of new cases shifts away from those observed in highly endemic areas, revealing potentially important insights into possible ongoing sources of transmission. We aimed to investigate whether transmission is driven mainly by undiagnosed and untreated new leprosy cases in the community, or by incompletely treated or relapsing cases.

METHODOLOGY/PRINCIPAL FINDINGS

A literature search of major electronic databases was conducted in January, 2020 with 134 articles retained out of a total 4318 records identified (PROSPERO ID: CRD42020178923). We presented quantitative data from leprosy case records with supporting evidence describing the decline in incidence across several contexts. BCG vaccination, active case finding, adherence to multidrug therapy and continued surveillance following treatment were the main strategies shared by countries who achieved a substantial reduction in incidence. From 3950 leprosy case records collected across 22 low endemic countries, 48.3% were suspected to be imported, originating from transmission outside of the country. Most cases were multibacillary (64.4%) and regularly confirmed through skin biopsy, with 122 cases of suspected relapse from previous leprosy treatment. Family history was reported in 18.7% of cases, while other suspected sources included travel to high endemic areas and direct contact with armadillos. None of the countries included in the analysis reported a distinct increase in leprosy incidence in recent years.

CONCLUSIONS/SIGNIFICANCE

Together with socioeconomic improvement over time, several successful leprosy control programmes have been implemented in recent decades that led to a substantial decline in incidence. Most cases described in these contexts were multibacillary and numerous cases of suspected relapse were reported. Despite these observations, there was no indication that these cases led to a rise in new secondary cases, suggesting that they do not represent a large ongoing source of human-to-human transmission.

Mapping leprosy-associated coding variants of interleukin genes by targeted sequencing

Previous genotyping-based assays have identified non-coding variants of several interleukins (ILs) being associated with genetic susceptibility to leprosy. However, understanding of the involvement of coding variants within all IL family genes in leprosy was still limited. To obtain the full mutation spectrum of all ILs in leprosy, we performed a targeted deep sequencing of coding regions of 58 ILs genes in 798 leprosy patients (age 56.2 ± 14.4; female 31.5%) and 990 healthy controls (age 38.1 ± 14.0; female 44.3%) from Yunnan, Southwest China. mRNA expression alterations of ILs in leprosy skin lesions or in response to M. leprae treatment were estimated by using publicly available expression datasets. Two coding variants in IL27 (rs17855750, p.S59A, p = 4.02 × 10^-8 , odds ratio [OR] = 1.748) and IL1RN (rs45507693, p.A106T, p = 1.45 × 10^-5 , OR = 3.629) were significantly associated with leprosy risk. mRNA levels of IL27 and IL1RN were upregulated in whole blood cells after M. leprae stimulation. These data showed that IL27 and IL1RN are leprosy risk genes. Further functional study is required for characterizing the exact role of ILs in leprosy.

[Association of borderline tuberculoid leprosy and tuberculosis: A case report and review of the literature]

INTRODUCTION

In metropolitan France, nearly 20 new cases of leprosy are diagnosed each year. The incidence of tuberculosis in France is 8/100,000 inhabitants and there are very few accounts of association of these two mycobacteria. Herein we report a case of co-infection with borderline tuberculoid (BT) leprosy and disseminated tuberculosis diagnosed in metropolitan France.

PATIENTS AND METHODS

A male subject presented with diffuse painless infiltrated erythematous plaques. The biopsy revealed perisudoral and perineural lymphohistiocytic epithelioid cell granuloma as well as acid-alcohol-fast bacilli on Ziehl staining. PCR was positive for Mycobacterium leprae, confirming the diagnosis of leprosy in the BT form. The staging examination revealed predominantly lymphocytic left pleural effusion, right-central necrotic adenopathy without histological granuloma, negative screening for BK, a positive QuantiFERON-TB™ test, and a positive intradermal tuberculin reaction. The clinical and radiological results militated in favour of disseminated tuberculosis. Combined therapy (rifampicin, isoniazid, ethambutol and pyrazinamide) together with clofazimine resulted in regression of both cutaneous and extra-cutaneous lesions. This rare co-infection combines leprosy, often present for several years, and tuberculosis (usually pulmonary) of subsequent onset. The pathophysiological hypothesis is that of cross-immunity (with anti-TB immunity protecting against subsequent leprosy and vice versa), supported by the inverse correlation of the two levels of prevalence and by the protection afforded by tuberculosis vaccination. In most cases, treatment for TB and leprosy improves both diseases. Patients presenting leprosy should be screened for latent tuberculosis in order to avoid reactivation, particularly in cases where corticosteroid treatment is being given.

Revisiting the tuberculosis and leprosy cross-immunity hypothesis: Expanding the dialogue between immunology and paleopathology

OBJECTIVE

Our primary objective is to re-visit the tuberculosis and leprosy cross-immunity. hypothesis through the careful integration of immunology and paleopathology.

METHODS

Using an integrated theoretical analysis that evaluates clinical literature on human innate immunological responses, paleomicrobiology, bioarchaeology, and paleopathology, we develop a multifactorial model.

RESULTS

Past populations do not represent homogeneous immunological landscapes, and therefore it is likely that leprosy in Medieval Europe did not uniformly decline due to cross-immunity.

CONCLUSIONS

We recommend that bioarchaeological reconstructions of past disease experience take into consideration models that include variation in immune function based on past environments and social contexts. This provides a unique opportunity to conduct comprehensive analyses on complex immunological processes.

SIGNIFICANCE

Extrapolating results from experimental immunology to larger populations elucidates complexities of disease cross-immunity and highlights the importance of synthesizing archaeological, social, paleopathological and biological data as a means of understanding disease in the past.

LIMITATIONS

All extrapolations from data produced from in vitro studies to past populations, using living donors, pose significant limitations where, among other factors, the full reconstruction of past environmental and social contexts can frequently be sparse or incomplete.

SUGGESTIONS FOR FUTURE RESEARCH

To reduce the limitations of integrating experimental immunology with bioarchaeological reconstructions (i.e. how to use skeletal samples to reconstruct inflammatory phenotypes), we propose that osteoimmunology, or the study of the interplay between immune cells and bone cells, should be considered a vital discipline and perhaps the foundation for the expansion of paleoimmunology.

Examining the Complex Relationship Between Tuberculosis and Other Infectious Diseases in Children

Millions of children are exposed to tuberculosis (TB) each year, many of which become infected with Mycobacterium tuberculosis. Most children can immunologically contain or eradicate the organism without pathology developing. However, in a minority, the organism overcomes the immunological constraints, proliferates and causes TB disease. Each year a million children develop TB disease, with a quarter dying. While it is known that young children and those with immunodeficiencies are at increased risk of progression from TB infection to TB disease, our understanding of risk factors for this transition is limited. The most immunologically disruptive process that can happen during childhood is infection with another pathogen and yet the impact of co-infections on TB risk is poorly investigated. Many diseases have overlapping geographical distributions to TB and affect similar patient populations. It is therefore likely that infection with viruses, bacteria, fungi and protozoa may impact on the risk of developing TB disease following exposure and infection, although disentangling correlation and causation is challenging. As vaccinations also disrupt immunological pathways, these may also impact on TB risk. In this article we describe the pediatric immune response to M. tuberculosis and then review the existing evidence of the impact of co-infection with other pathogens, as well as vaccination, on the host response to M. tuberculosis. We focus on the impact of other organisms on the risk of TB disease in children, in particularly evaluating if co-infections drive host immune responses in an age-dependent way. We finally propose priorities for future research in this field. An improved understanding of the impact of co-infections on TB could assist in TB control strategies, vaccine development (for TB vaccines or vaccines for other organisms), TB treatment approaches and TB diagnostics.