Mendelian Susceptibility to Mycobacterial Disease: Retrospective Clinical and Genetic Study in Mexico

Innate immunodeficiencies: a group of primary immunodeficiencies predisposing exclusively to common diseases

Background

Innate immune deficiencies can impair both cellular and humoral immune responses. In contrast, other immune functions may appear normal, leading to increased susceptibility to specific pathogens, such as severe viral infections or Mendelian Susceptibility to Mycobacterial Disease (MSMD). Studying these deficiencies is essential for understanding the pathophysiology of these infectious diseases.

Main body

While primary immunodeficiencies (PIDs) generally cause vulnerability to multiple infections, innate immunodeficiencies increase susceptibility to specific pathogens, despite normal immune responses to others. Patients with these deficiencies show normal immunoglobulins and lymphocyte subpopulations, complicating diagnosis. This review highlights genetic susceptibility to mycobacteria, pneumococci, herpes simplex virus, and candidiasis, emphasizing recognizing this subset of PIDs.

Conclusion

This review highlights the diverse spectrum of genetic mutations contributing to defects in innate and intrinsic immunity, including Mendelian susceptibility to mycobacterial disease (MSMD), chronic mucocutaneous candidiasis, and predispositions to invasive bacterial and viral infections. Identifying key mutations in pathprovideh such as TLR3, IFN signaling, and IL-17A/F immunity provides valuable insights into the pathogenesis of these conditions. Our findings underscore the need for early genetic diagnosis and targeted interventions, particularly in regions with high undiagnosed cases, to reduce the morbidity and mortality associated with defects in innate and intrinsic immunity.

Disseminated histoplasmosis from western Mexico-rethinking our geographic distribution of endemic fungal species: a case report and review of literature

BACKGROUND

Histoplasma is a fungal pathogen found in many parts of the world. In North America, its distribution is traditionally thought to be endemic to the Ohio and Mississippi River valleys. Development of histoplasmosis after Histoplasma exposure is related to degree of inoculum exposure and susceptibility, for example, immunocompromised status. Most exposed, healthy individuals are asymptomatic and few develop pulmonary symptoms. A limited number of infectious etiologies (that is, Histoplasma, Coccidioides, and Mycobacterium tuberculosis) can cause miliary pattern on chest imaging, and thus, histoplasmosis should be considered whenever a patient presents with pulmonary symptoms and these unique radiographic findings.

CASE PRESENTATION

A previously healthy 13-year-old Hispanic male presented as a transfer from an outside hospital with fever and hypoxia in the setting of a progressive, subacute gastrointestinal illness. Given hypoxia, the concern for sepsis, and unclear etiology of his illness, broad-spectrum antimicrobial therapy and noninvasive ventilation were started. Initial evaluation demonstrated miliary pulmonary infiltrates, and travel history raised suspicion for coccidioidomycosis or tuberculosis. After a complete evaluation, lab studies confirmed a diagnosis of histoplasmosis, and the patient made a full recovery after the initiation and completion of antifungal therapy.

CONCLUSION

Herein, we present a patient who acquired histoplasmosis from an area of Mexico not currently acknowledged as endemic and review recently published data emphasizing new areas of Histoplasma endemicity in North America, particularly the southwest USA and most states of Mexico. Though limited surveillance data exist, mounting case reports/series and local epidemiologic studies illustrate the expanding worldwide endemicity of Histoplasma and underscore histoplasmosis as a growing global health concern.

Disseminated Mycobacterial Infection With Reactive Polyarthritis (Poncet's Disease) During Immune-suppressive Treatment Including Ustekinumab for Pediatric Crohn's Disease

BACKGROUND

The incidence of pediatric inflammatory bowel disease is increasing. tumor necrosis factor alpha inhibitors medicines improved the prognosis of affected subjects. Nonetheless, a proportion of patients do not respond or lose response to treatment. Newer biologics, like ustekinumab, have been approved for adults. The pediatric off-label use of these drugs is increasing, despite limited safety evidence. We report a case of disseminated mycobacterial infection (MI) presenting with reactive polyarthritis (Poncet's disease, PD) in a girl with Crohn's disease receiving various immunosuppressants, including ustekinumab.

CASE REPORT

A 12-year-old girl with Crohn's disease was admitted for acute-onset migratory polyarthritis of large and small joints and opioid-resistant pain. She had recently received adalimumab and methotrexate and was currently under treatment with ustekinumab. She was vaccinated with Bacillus Calmette-Guérin and screened for tuberculosis before starting immunosuppressants. Interferon-gamma release assay, Mantoux test and chest computed tomography scan were negative. Disseminated MI with PD was diagnosed following positive cultures for Mycobacterium tuberculosis complex in blood and intestinal biopsies (with negative in synovial fluid and gastric aspirate). Whole-exome sequencing did not identify any genetic susceptibility to MI. Antituberculosis treatment eradicated MI.

CONCLUSIONS

Children with inflammatory bowel disease receiving combination immunosuppressive treatments including tumor necrosis factor alpha inhibitors and anti-IL-12/23 agents are at higher risk for MI. Disseminated MI should be considered and ruled out in these patients when presenting with pulmonary, extrapulmonary or unusual clinical manifestations, like PD. The collection of multiple specimens (including intestinal biopsies) for mycobacterial culture is recommended when mycobacterial disease is suspected.

Genetic, immunologic, and clinical features of 830 patients with Mendelian susceptibility to mycobacterial diseases (MSMD): A systematic review

BACKGROUND

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare clinical syndrome characterized by vulnerability to weakly virulent mycobacterial species, including Bacillus Calmette-Guérin (BCG) vaccines and environmental mycobacteria.

OBJECTIVE

We sought to perform a systematic review of the genetic, immunologic, and clinical findings for reported patients with MSMD.

METHODS

We searched PubMed, Web of Science, and Scopus databases for publications in English relating to MSMD. All full texts were evaluated for eligibility for inclusion. Two reviewers independently selected the publications, with a third reviewer consulted in cases of disagreement.

RESULTS

A primary systematic search and searches of other resources identified 16,155 articles. In total, 158 articles from 63 countries were included in qualitative and quantitative analyses. In total, 830 patients-436 males (52.5%), 369 females (44.5%), and 25 patients of unknown sex (3.0%)-from 581 families were evaluated. A positive family history was reported in 347 patients (45.5%). The patients had a mean age of 10.41 ± 0.42 (SEM) years. The frequency of MSMD was highest in Iran, Turkey, and Saudi Arabia. Lymphadenopathy was the most common clinical manifestation of MSMD, reported in 378 (45.5%) cases and multifocal in 35.1%. Fever, organomegaly, and sepsis were the next most frequent findings, reported in 251 (30.2%), 206 (24.8%), and 171 (20.8%) cases, respectively. In total, 299 unique mutations in 21 genes known to be involved in MSMD were reported: 100 missense (34%), 80 indel-frameshift (insertion or deletion, 27%), 53 nonsense (18%), 35 splice site (12%), 10 indel-in frame (2.7%), 6 indel (2%), and 15 large deletion/duplication mutations. Finally, 61% of the reported patients with MSMD had mutations of IL12RB1 (41%) or IFNGR1 (20%). At the time of the report, 177 of the patients (21.3%) were dead and 597 (71.9%) were still alive.

CONCLUSIONS

MSMD is associated with a high mortality rate, mostly due to impaired control of infection. Preexposure strategies, such as changes in vaccination policy in endemic areas, the establishment of a worldwide registry of patients with MSMD, and precise follow-up over generations in affected families, appear to be vital to decrease MSMD-related mortality.

Recombinant IFN-γ1b Treatment in a Patient with Inherited IFN-γ Deficiency

PURPOSE

Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Twenty-two genes with products involved in the production of, or response to, IFN-γ and variants of which underlie MSMD have been identified. However, pathogenic variants of IFNG encoding a defective IFN-γ have been described in only two siblings, who both underwent hematopoietic stem cell transplantation (HCST).

METHODS

We characterized a new patient with MSMD by genetic, immunological, and clinical means. Therapeutic decisions were taken on the basis of these findings.

RESULTS

The patient was born to consanguineous Turkish parents and developed bacillus Calmette-Guérin (BCG) disease following vaccination at birth. Whole-exome sequencing revealed a homozygous private IFNG variant (c.224 T > C, p.F75S). Upon overexpression in recipient cells or constitutive expression in the patient's cells, the mutant IFN-γ was produced within the cells but was not correctly folded or secreted. The patient was treated for 6 months with two or three antimycobacterial drugs only and then for 30 months with subcutaneous recombinant IFN-γ1b plus two antimycobacterial drugs. Treatment with IFN-γ1b finally normalized all biological parameters. The patient presented no recurrence of mycobacterial disease or other related infectious diseases. The treatment was well tolerated, without the production of detectable autoantibodies against IFN-γ.

CONCLUSION

We describe a patient with a new form of autosomal recessive IFN-γ deficiency, with intracellular, but not extracellular IFN-γ. IFN-γ1b treatment appears to have been beneficial in this patient, with no recurrence of mycobacterial infection over a period of more than 30 months. This targeted treatment provides an alternative to HCST in patients with complete IFN-γ deficiency or at least an option to better control mycobacterial infection prior to HCST.

Discovering the link between IL12RB1 gene polymorphisms and tuberculosis susceptibility: a comprehensive meta-analysis

Introduction

Numerous studies suggest that the risk of tuberculosis (TB) is linked to gene polymorphisms of the interleukin-12 receptor b subunit 1 (IL12RB1), but the association between IL12RB1 polymorphisms and TB susceptibility has not been thoroughly investigated.

Methods

A meta-analysis was conducted based on eight case-control studies with 10,112 individuals to further explore this topic. A systematic search of PubMed, Web of Science, Excerpt Medica Database, and Google Scholar up until April 6th, 2023 was performed. ORs and 95% CIs were pooled using the random-effect model. The epidemiological credibility of all significant associations was assessed using the Venice criteria and false-positive report probability (FPRP) analyses.

Results

The IL12RB1 rs11575934 and rs401502 showed solid evidence of no significant association with TB susceptibility. However, a weak association was observed between the IL12RB1 rs375947 biomarker and pulmonary tuberculosis (PTB) susceptibility (OR = 1.64, 95% CI: 1.22, 2.21).

Discussion

These findings should be confirmed through larger, better-designed studies to clarify the relationship between biomarkers in IL12RB1 gene and different types of TB susceptibility.

Inborn Errors of Immunity-the Sri Lankan Experience 2010-2022

PURPOSE

Inborn errors of immunity (IEI) are typically monogenic. Data from the Indian subcontinent are relatively scarce. This paper evaluates IEI diagnosed in Sri Lanka.

METHODS

Data of patients diagnosed with IEI from 2010 to 2022 at the Department of Immunology, Medical Research Institute, Colombo, Sri Lanka, were retrospectively analyzed.

RESULTS

Two hundred and six patients were diagnosed with IEI, with a prevalence of 0.94 per 100,000. The onset of disease was below 12 years in 84.9%, whereas in 10.9%, it was after 18 years. The male: female ratio was 1.78:1. Consanguinity was identified in 26.6%. IEI were found in all but one (bone marrow failure) of the 10 IUIS categories. Predominantly antibody deficiencies were the most common category among the nine identified (30.1%), followed by combined immune deficiencies with syndromic features (21.3%), immunodeficiencies affecting cellular and humoral immunity (19.9%), congenital defects of phagocyte number or function (13.1%), and defects in intrinsic and innate immunity (8.2%). Severe combined immune deficiency (SCID) was the commonest disease (14.6%), followed by chronic granulomatous disease (CGD) (10.6%) and X linked agammaglobulinemia (8.7%). Of the patients with a known outcome (n = 184), 51 died (27.7%). Mortality rates were high in SCID (83.3%), Omenn syndrome (OS) (100%), and CGD (31.8%) patients.

CONCLUSION

IEI in Sri Lanka are diagnosed mainly in childhood. The low diagnosis rates suggest a need for educating clinicians regarding IEI in adulthood. The high mortality rates associated with some IEI indicate the need of transplant services in the country.

Of Mycelium and Men: Inherent Human Susceptibility to Fungal Diseases

In medical mycology, the main context of disease is iatrogenic-based disease. However, historically, and occasionally, even today, fungal diseases affect humans with no obvious risk factors, sometimes in a spectacular fashion. The field of “inborn errors of immunity” (IEI) has deduced at least some of these previously enigmatic cases; accordingly, the discovery of single-gene disorders with penetrant clinical effects and their immunologic dissection have provided a framework with which to understand some of the key pathways mediating human susceptibility to mycoses. By extension, they have also enabled the identification of naturally occurring auto-antibodies to cytokines that phenocopy such susceptibility. This review provides a comprehensive update of IEI and autoantibodies that inherently predispose humans to various fungal diseases.

LitCovid in 2022: an information resource for the COVID-19 literature

LitCovid (https://www.ncbi.nlm.nih.gov/research/coronavirus/)-first launched in February 2020-is a first-of-its-kind literature hub for tracking up-to-date published research on COVID-19. The number of articles in LitCovid has increased from 55 000 to ∼300 000 over the past 2.5 years, with a consistent growth rate of ∼10 000 articles per month. In addition to the rapid literature growth, the COVID-19 pandemic has evolved dramatically. For instance, the Omicron variant has now accounted for over 98% of new infections in the United States. In response to the continuing evolution of the COVID-19 pandemic, this article describes significant updates to LitCovid over the last 2 years. First, we introduced the long Covid collection consisting of the articles on COVID-19 survivors experiencing ongoing multisystemic symptoms, including respiratory issues, cardiovascular disease, cognitive impairment, and profound fatigue. Second, we provided new annotations on the latest COVID-19 strains and vaccines mentioned in the literature. Third, we improved several existing features with more accurate machine learning algorithms for annotating topics and classifying articles relevant to COVID-19. LitCovid has been widely used with millions of accesses by users worldwide on various information needs and continues to play a critical role in collecting, curating and standardizing the latest knowledge on the COVID-19 literature.