HLA-DRB1 and HLA-DQB1 Are Associated with Adult-Onset Immunodeficiency with Acquired Anti-Interferon-Gamma Autoantibodies

Long-term successfull management of recurrent episodes of nontuberculous mycobacterial infection in an apparently healthy Chinese woman

BACKGROUND

Disseminated non-tuberculous mycobacteria (dNTM) infections are mostly reported among individuals with an underlying congenital or acquired immunodeficiency or receiving immunosuppressive treatment, but are rarely documented in otherwise healthy subjects.

CASE PRESENTATION

We describe a case of recurrent disseminated mycobacterial infection in an apparently immunocompetent Chinese woman. Mycobacterium szulgai and Mycobacterium avium-complex were identified in distinct episodes. Long-term antimycobacterial therapy was administered given the occurrence of recurrent events when off-treatment. Successful management over more than 10 years and immunologic data are reported.

CONCLUSIONS

This case-report highlights that dNTM should be suspected also among apparently immunocompetent hosts and that thorough assessment of underling immune-impairments is helpful to define patients' management. Long-term antimycobacterial therapy and close monitoring is required to grant successful outcomes in case of recurrent dNTM infections.

Autoantibodies Neutralizing GM-CSF in HIV-Negative Colombian Patients Infected with Cryptococcus gattii and C. neoformans

BACKGROUND

Cryptococcosis is a life-threatening disease caused by Cryptococcus neoformans or C. gattii. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) in otherwise healthy adults with cryptococcal meningitis have been described since 2013. We searched for neutralizing auto-Abs in sera collected from Colombian patients with non-HIV-associated cryptococcosis in a retrospective national cohort from 1997 to 2016.

METHODS

We reviewed clinical and laboratory records and assessed the presence of neutralizing auto-Abs against GM-CSF in 30 HIV negative adults with cryptococcosis (13 caused by C. gattii and 17 caused by C. neoformans).

RESULTS

We detected neutralizing auto-Abs against GM-CSF in the sera of 10 out of 13 (77%) patients infected with C. gattii and one out of 17 (6%) patients infected with C. neoformans.

CONCLUSIONS

We report eleven Colombian patients diagnosed with cryptococcosis who had auto-Abs that neutralize GM-CSF. Among these patients, ten were infected with C. gattii and only one with C. neoformans.

Rare Filaggrin Variants Are Associated with Pustular Skin Diseases in Asians

Reactive pustular eruptions (RPEs) can manifest in a variety of conditions, including pustular psoriasis (PP) and adult-onset immunodeficiency syndrome due to anti-interferon-γ autoantibody (AOID). These RPEs can be attributed to different causes, one of which is genetic factors. However, the genetic basis for pustular skin diseases remains poorly understood. In our study, we conducted whole-exome sequencing on a cohort of 17 AOID patients with pustular reactions (AOID-PR) and 24 PP patients. We found that 76% and 58% of the AOID-PR and PP patients, respectively, carried rare genetic variations within the filaggrin (FLG) gene family. A total of 12 out of 21 SNPs on FLG had previously received clinical classifications, with only p.Ser2706Ter classified as pathogenic. In contrast, none of the FLG3 SNPs identified in this study had prior clinical classifications. Overall, these variations had not been previously documented in cases of pustular disorders, and two of them were entirely novel discoveries. Immunohistochemical analysis of skin biopsies revealed that FLG variants like p.Ser860Trp, p.Gly3903Ter, p.Gly2440Glu, and p.Glu2133Asp caused reductions in FLG levels similar to the pathogenic FLG p.Ser2706Ter. These results highlight rare FLG variants as potential novel genetic risk factors contributing to pustule formation in both AOID and PP.

The ouroboros of autoimmunity

Human autoimmunity against elements conferring protective immunity can be symbolized by the 'ouroboros', a snake eating its own tail. Underlying infection is autoimmunity against three immunological targets: neutrophils, complement and cytokines. Autoantibodies against neutrophils can cause peripheral neutropenia underlying mild pyogenic bacterial infections. The pathogenic contribution of autoantibodies against molecules of the complement system is often unclear, but autoantibodies specific for C3 convertase can enhance its activity, lowering complement levels and underlying severe bacterial infections. Autoantibodies neutralizing granulocyte-macrophage colony-stimulating factor impair alveolar macrophages, thereby underlying pulmonary proteinosis and airborne infections, type I interferon viral diseases, type II interferon intra-macrophagic infections, interleukin-6 pyogenic bacterial diseases and interleukin-17A/F mucocutaneous candidiasis. Each of these five cytokine autoantibodies underlies a specific range of infectious diseases, phenocopying infections that occur in patients with the corresponding inborn errors. In this Review, we analyze this ouroboros of immunity against immunity and posit that it should be considered as a factor in patients with unexplained infection.

Anti-cytokine autoantibodies: mechanistic insights and disease associations

Anti-cytokine autoantibodies (ACAAs) are increasingly recognized as modulating disease severity in infection, inflammation and autoimmunity. By reducing or augmenting cytokine signalling pathways or by altering the half-life of cytokines in the circulation, ACAAs can be either pathogenic or disease ameliorating. The origins of ACAAs remain unclear. Here, we focus on the most common ACAAs in the context of disease groups with similar characteristics. We review the emerging genetic and environmental factors that are thought to drive their production. We also describe how the profiling of ACAAs should be considered for the early diagnosis, active monitoring, treatment or sub-phenotyping of diseases. Finally, we discuss how understanding the biology of naturally occurring ACAAs can guide therapeutic strategies.

From Mendel to mycoses: Immuno-genomic warfare at the human-fungus interface

Fungi are opportunists: They particularly require a defect of immunity to cause severe or disseminated disease. While often secondary to an apparent iatrogenic cause, fungal diseases do occur in the absence of one, albeit infrequently. These rare cases may be due to an underlying genetic immunodeficiency that can present variably in age of onset, severity, or other infections, and in the absence of a family history of disease. They may also be due to anti-cytokine autoantibodies. This review provides a background on how human genetics or autoantibodies underlie cases of susceptibility to severe or disseminated fungal disease. Subsequently, the lessons learned from these inborn errors of immunity marked by fungal disease (IEI-FD) provide a framework to begin to mechanistically decipher fungal syndromes, potentially paving the way for precision therapy of the mycoses.

Human Leukocyte Antigen Markers for Distinguishing Pustular Psoriasis and Adult-Onset Immunodeficiency with Pustular Reaction

Pustular skin diseases, with pustular psoriasis (PP) being the prototype, are immune-mediated diseases characterized by the presence of multiple pustules, resulting from neutrophil accumulation in the layer of epidermis. Sterile skin pustular eruption, like PP, is also observed in 20-30% of patients with adult-onset immunodeficiency syndrome (AOID) and anti-interferon γ autoantibodies (IFN-γ), leading to challenges in classification and diagnosis. While the mechanism underlying this similar phenotype remains unknown, genetic factors in relation to the immune system are suspected of playing an important role. Here, the association between human leukocyte antigen (HLA) genes, which play essential roles in antigen presentation, contributing to immune response, and the presence of skin pustules in AOID and PP was revealed. HLA genotyping of 41 patients from multiple centers in Thailand who presented with multiple sterile skin pustules (17 AOID patients and 24 PP patients) was conducted using a next-generation-sequencing-based approach. In comparison to healthy controls, HLA-B*13:01 (OR = 3.825, 95%CI: 2.08-7.035), C*03:04 (OR = 3.665, 95%CI: 2.102-6.39), and DQB1*05:02 (OR = 2.134, 95%CI: 1.326-3.434) were significantly associated with the group of aforementioned conditions having sterile cutaneous pustules, suggesting a common genetic-related mechanism. We found that DPB1*05:01 (OR = 3.851, p = 0.008) and DRB1*15:02 (OR = 3.195, p = 0.033) have a significant association with pustular reaction in AOID patients, with PP patients used as a control. A variant in the DRB1 gene, rs17885482 (OR = 9.073, p = 0.005), was observed to be a risk factor for PP when using AOID patients who had pustular reactions as a control group. DPB1*05:01 and DRB1*15:02 alleles, as well as the rs17885482 variant in the DRB1 gene, were proposed as novel biomarkers to differentiate PP and AOID patients who first present with multiple sterile skin pustules without known documented underlying conditions.

HLA sequencing identifies novel associations and suggests clinical relevance of DPB1*04:01 in ANCA-associated Granulomatosis with polyangiitis

Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease. Major contributions of HLA genes have been reported; however, HLA typing-based diagnosis or risk prediction in GPA has not been established. We have performed a sequencing-based HLA genotyping in a north Indian GPA cohort and controls to identify clinically relevant novel associations. PR3-ANCA-positive 40 GPA patients and 40 healthy controls from north India were recruited for the study. Targeted sequencing of HLA-A,-B,-C,-DRB1,-DQB1, and -DPB1 was performed. Allelic and haplotypic associations were tested. Molecular docking of susceptibility HLA alleles with reported super-antigen epitopes was performed. The association of substituted amino acids located at the antigen-binding domain of HLA was evaluated. Genetic association of five HLA-alleles was identified in GPA. The novel association was identified for C*15:02 (p = 0.04; OR = 0.27(0.09-0.88)). The strongest association was observed for DPB1*04:01 (p < 0.0001; OR = 6.2(3.08-11.71)), previously reported in European studies. 35 of 40 GPA subjects had at least one DPB1*04:01 allele, and its significant risk was previously not reported from the Indian population. Significantly associated haplotypes DRB1*03:01-DQB1*02:01-DPB1*04:01 (p = 0.02; OR = 3.46(1.11-12.75)) and DRB1*07:01-DQB1*02:02-DPB1*04:01 (p = 0.04; OR = 3.35(0.95-14.84)) were the most frequent in GPA patients. Ranging from 89 % to 100 % of GPA patients with organ involvement can be explained by at least one DPB1*04:01 allele. A strong interaction between the HLA and three epitopes of the reported super antigen TSST-1 of Staphylococcus aureus was confirmed. Our study highlighted the potential applicability of HLA typing for screening and diagnosis of GPA. A large multi-centric study and genotype-phenotype correlation analysis among GPA patients will enable the establishment of HLA-typing based GPA diagnosis.

Macrophage activation syndrome with acute hepatitis in a patient with adult-onset immunodeficiency with anti-interferon gamma antibodies: a case report

BACKGROUND

Macrophage activation syndrome is a rare disorder leading to unregulated immune activity manifesting with nonspecific constitutional symptoms, laboratory abnormalities, and multiorgan involvement. We report the case of a patient who presented with acute hepatitis secondary to macrophage activation syndrome diagnosed by liver biopsy and successfully treated with intravenous immune globulin, anakinra, and rituximab.

CASE PRESENTATION

A 42-year-old Laotian woman with adult-onset immunodeficiency with anti-interferon gamma antibodies presented with a fever, headache, generalized myalgia, dark urine, and reduced appetite in the setting of family members at home with similar symptoms. Her laboratory workup was notable for evidence of acute hepatitis without acute liver failure. After an unrevealing comprehensive infectious and noninvasive rheumatologic workup was completed, a liver biopsy was performed ultimately revealing the diagnosis of macrophage activation syndrome. She was successfully treated with intravenous immune globulin, anakinra, and rituximab.

CONCLUSION

This case highlights the importance of maintaining macrophage activation syndrome on the differential of a patient with acute hepatitis of unknown etiology in the correct clinical context and the value of a liver biopsy in making a diagnosis when noninvasive testing is unrevealing.

Anticytokine Autoantibodies in Infectious Diseases: A Practical Overview

Anticytokine autoantibodies (ACAAs) are a fascinating group of antibodies that have gained more and more attention in the field of autoimmunity and secondary immunodeficiencies over the years. Some of these antibodies are characterized by their ability to target and neutralize specific cytokines. ACAAs can play a role in the susceptibility to several infectious diseases, and their infectious manifestations depending on which specific immunological pathway is affected. In this review, we will give an outline per infection in which ACAAs might play a role and whether additional immunomodulatory treatment next to antimicrobial treatment can be considered. Finally, we describe the areas for future research on ACAAs.

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.

Loss of Function TGFBR2 Variant as a Contributing Factor in Generalized Pustular Psoriasis and Adult-Onset Immunodeficiency

BACKGROUND

Generalized pustular psoriasis (GPP; MIM 614204) is a rare multisystemic autoinflammatory disease, characterized by episodes of acute generalized erythema and scaling developed with the spread of numerous sterile pustules. Adult-onset immunodeficiency syndrome (AOID) with anti-interferon-γ autoantibodies is an immunodeficiency disorder associated with disruptive IFN-γ signaling.

METHODS

Clinical examination and whole exome sequencing (WES) were performed on 32 patients with pustular psoriasis phenotypes and 21 patients with AOID with pustular skin reaction. Histopathological and immunohistochemical studies were performed.

RESULTS

WES identified four Thai patients presenting with similar pustular phenotypes-two with a diagnosis of GPP and the other two with AOID-who were found to carry the same rare TGFBR2 frameshift mutation c.458del; p.Lys153SerfsTer35, which is predicted to result in a marked loss of functional TGFBR2 protein. The immunohistochemical studied showed overexpression of IL1B, IL6, IL17, IL23, IFNG, and KRT17, a hallmark of psoriatic skin lesions. Abnormal TGFB1 expression was observed in the pustular skin lesion of an AOID patient, suggesting disruption to TGFβ signaling is associated with the hyperproliferation of the psoriatic epidermis.

CONCLUSIONS

This study implicates disruptive TGFBR2-mediated signaling, via a shared truncating variant, c.458del; p.Lys153SerfsTer35, as a "predisposing risk factor" for GPP and AOID.

The unique diagnostic and management challenge of a patient with concomitant anti-interferon-gamma autoantibody associated immunodeficiency syndrome, IgG4-related disease, and treatment refractory, disseminated mycobacterium avium complex infection

BACKGROUND

Anti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge.

CASE PRESENTATION

A 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive.

CONCLUSIONS

This case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

Anti-Interferon-γ Autoantibodies Impair T-Lymphocyte Responses in Patients with Talaromyces marneffei Infections

Background

Although anti-IFN-γ autoantibodies predispose patients to Talaromyces marneffei infection, whether this is mediated by T cell attenuation remains elusive.

Methods

Total peripheral blood mononuclear cells (PBMCs) from healthy donors or patients with T. marneffei infection were stimulated with M1₅₈₋₆₆, and immunodominant influenza H1N1 peptide, or heat-inactivated T. marneffei in the presence of serum from anti-IFN-γ autoantibody-positive patients or healthy controls. The percentages of IFN-γ⁺TNF⁺CD8⁺ T cells and IFN-γ⁺CD4⁺ T cells were determined by flow cytometry and cytokines released in the supernatant were detected by Cytometric Bead Array. Furthermore, PBMCs from patients with T. marneffei infection and healthy individuals were stimulated with IFN-γ and anti-CD3/CD28 beads, and the levels of STAT1 and STAT3 phosphorylation were detected by Western blot.

Results

The M1-reactive CD8⁺ T cells that expressed IFN-γ⁺ TNF-α⁺ of healthy controls were clearly reduced in serum with high-titer anti-IFN-γ autoantibodies. In addition, the CD4⁺ T cell response, designated by the expression of IFN-γ, against T. marneffei in PBMCs of patients were significantly decreased when cultured in high-titer anti-IFN-γ autoantibody serum culture, compared to the healthy compartments. Moreover, the release of the cytokines IFN-γ, TNF-α and IL-2 was significantly decreased, while IL-10 was significantly increased. There was no significant difference in the phosphorylation levels of STAT1 and STAT3 protein between patients and healthy controls after IFN-γ or anti-CD3/CD28 beads stimulation.

Conclusion

Anti-IFN-γ autoantibodies presence in the serum inhibited CD4⁺ Th1 and CD8⁺ T cell immune responses. There was no congenital dysfunction of STAT1 and STAT3 in anti-IFN-γ autoantibody-positive patients with T. marneffei infection. These results suggest that the production of anti-IFN-γ autoAbs impair T-lymphocyte responses.

Gut microbiome profiles and associated metabolic pathways in patients of adult-onset immunodeficiency with anti-interferon-gamma autoantibodies

Autoantibodies against interferon-gamma (AutoAbs-IFN-γ) can cause the immunodeficiency condition following various opportunistic infections. Gut microbiota can affect the human immune system in many ways. Many studies have shown that gut dysbiosis was associated with some immune diseases, such as autoimmune diseases and human immunodeficiency virus (HIV) infection, while its relationship at anti-IFN-γ AAbs remains unknown. We aimed to identify the anti-IFN-γ AAbs specific microbiome and the possible association with immunodeficiency. We profiled fecal microbiome for two cohorts of forty subjects, including seven patients with anti-IFN-γ AAbs and 33 individuals with competent immune. The study shows that patients with anti-IFN-γ AAbs have characterized the gut microbiome and have lower alpha diversity indexes than healthy controls (HC). There are significant differences in the microbiome structure at both the family and genera level between the two cohorts. The anti-IFN-γ AAbs cohort featured some microbiome such as Clostridium, including the possible opportunistic pathogen and fewer genera including Bacteroides, Ruminococcus, and Faecalibacterium, some of them with possible immune-related genera. The PICRUSt2 pathway demonstrated the decreased abundance of some immune-related pathways and one potential pathway related to the immune alternations in the anti- IFN-γ AAbs cohort. This was the first study to examine the gut microbiome characteristics in patients with anti-IFN-γ AAbs. It could be involved in the pathogenesis of anti-IFN-γ AAbs and contribute to the derived immune condition in this disease. This could lead to new strategies for treating and preventing patients suffering from this disease.

Human autoantibodies underlying infectious diseases

The vast interindividual clinical variability observed in any microbial infection-ranging from silent infection to lethal disease-is increasingly being explained by human genetic and immunological determinants. Autoantibodies neutralizing specific cytokines underlie the same infectious diseases as inborn errors of the corresponding cytokine or response pathway. Autoantibodies against type I IFNs underlie COVID-19 pneumonia and adverse reactions to the live attenuated yellow fever virus vaccine. Autoantibodies against type II IFN underlie severe disease caused by environmental or tuberculous mycobacteria, and other intra-macrophagic microbes. Autoantibodies against IL-17A/F and IL-6 are less common and underlie mucocutaneous candidiasis and staphylococcal diseases, respectively. Inborn errors of and autoantibodies against GM-CSF underlie pulmonary alveolar proteinosis; associated infections are less well characterized. In individual patients, autoantibodies against cytokines preexist infection with the pathogen concerned and underlie the infectious disease. Human antibody-driven autoimmunity can interfere with cytokines that are essential for protective immunity to specific infectious agents but that are otherwise redundant, thereby underlying specific infectious diseases.

Anticytokine autoantibodies: Autoimmunity trespassing on antimicrobial immunity

Anticytokine autoantibodies can cause immunodeficiency or dysregulate immune responses. They may phenocopy genetically defined primary immunodeficiencies. We review current anti-type 1 and anti-type 2 interferon; anti-IL-12/23, anti-IL-17, and anti-GM-CSF autoantibodies; HLA associations; disease associations; and mechanistically based treatment options. Suspecting the presence of these autoantibodies in patients and identifying them at the onset of symptoms should ameliorate disease and improve outcomes.

Talaromyces Marneffei Infection in Lung Cancer Patients with Positive AIGAs: A Rare Case Report

Background

Talaromyces marneffei is considered to commonly cause infection in individuals with human immunodeficiency virus (HIV) infection. However, the epidemiology of T. marneffei has changed, and an increasing number of HIV-negative but immunodeficient patients are infected with T. marneffei. The mechanisms of T. marneffei infection of HIV-negative hosts are complex and diverse. We report 2 cases of HIV-negative lung cancer with T. marneffei infection and positive anti-interferon-gamma autoantibodies (AIGAs) to provide clinical experience.

Case Presentation

We report lung adenocarcinoma combined with T. marneffei infection in HIV-negative patients, and their AIGAs were measured. Both patients were male with a family history of cancer and presented with recurrent fever and cough. The patients were negative for HIV antibodies but positive for AIGAs. Chest computed tomography (CT) showed pulmonary nodules, exudative lesions and solid changes. The patients were diagnosed with lung adenocarcinoma and Talaromycosis marneffei (TSM) by pathological examination and tissue culture. Patient 1 received only antifungal treatment, refused antitumor treatment and died in February 2019, and Patient 2 unfortunately died in April 2019 after antifungal and antitumor treatments.

Conclusion

An increasing number of HIV-negative but immunodeficient patients are infected with T. marneffei. The 2 patients in this report had lung cancer and positive AIGAs, causing immunodeficiencies, but the mechanism of T. marneffei infection in such patients is complex. Clinically, we should consider a comprehensive immunological examination to avoid the omission of other immunodeficiencies. We recommend routine testing for AIGA levels in HIV-negative marneffei patients. It is difficult to distinguish between lung cancer and disseminated TSM due to similar clinical characteristics and imaging, and multiple biopsies and cultures of diseased tissue are necessary. Early antifungal treatment and standard antitumor treatment can achieve satisfactory curative effects when a patient has both diseases.

Disseminated Mycobacterium avium complex infection in a woman with anti-interferon-γ autoantibodies

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Disseminated MAC infections should always prompt investigations for immunodeficiencies.

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Anti-IFN-γ autoantibodies may lead to severe treatment refractory mycobacterial infection.

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Clinical studies investigating immunomodulating therapy of patients with anti-IFN-γ autoantibodies are lacking

Defects in the interleukin-12/interferon-gamma (IFN-γ) pathway and anti-IFN-γ antibodies have been associated with severe nontuberculous mycobacteria (NTM) infections. Consequently, disseminated NTM infections should prompt investigations for immunodeficiency. Herein, we report a case of a treatment refractory and ultimately disseminated and fatal Mycobacterium avium complex infection in a 71-year-old woman of Thai origin. Simultaneously, she had recurrent Salmonella kentucky cultured from stool samples and chronic perianal HSV-2 lesions. Late in the course of disease, anti–IFN-γ autoantibodies were demonstrated. Clinical studies investigating immunomodulating therapy and treatment among patients with anti-IFN-γ autoantibodies are lacking and, in this case, treatment seemed of a more palliative nature.

Anti-interferon-γ autoantibody-associated immunodeficiency

Anticytokine autoantibodies are an emerging disease etiology, through the disturbance of physiological functions of cognate cytokines. Anti-interferon (IFN)-γ autoantibodies (AIGAs) were first identified in patients with severe mycobacterial infections, and were considered to be an autoimmune phenocopy of inborn genetic errors of the IL-12/IFN-γ axis. More than 600 reported cases, most originating from Southeast Asia, have been diagnosed over the last decade. Specific HLA class II molecules are associated with these autoantibodies, which provide a genetic basis for the high prevalence of this immunodeficiency syndrome in certain ethnic groups. Salmonellosis and herpes zoster reactivation are observed in more than half the patients with AIGAs. Moreover, AIGAs have been shown to underlie severe Taralomyce marneffei infection in HIV-negative patients. AIGAs may, thus, be considered a new form of late-onset immunodeficiency conferring a predisposition not only to severe mycobacterial, but also to some bacterial and fungal infections.

Clinical findings of Talaromyces marneffei infection among patients with anti-interferon-γ immunodeficiency: a prospective cohort study

Background

Talaromyces marneffei (T. marneffei) infection has been associated with adult-onset immunodeficiency due to anti-IFN-γ autoantibodies. We aimed to investigate the clinical features of non-HIV-infected patients with T. marneffei infection in southern China.

Methods

Between January 2018 and September 2020, we enrolled patients with T. marneffei infection who were HIV-negative (group TM, n = 42), including anti-IFN-γ autoantibody-positive (group TMP, n = 22) and anti-IFN-γ autoantibody-negative (group TMN, n = 20) patients and healthy controls (group HC, n = 40). Anti-IFN-γ autoantibodies were detected by ELISA. Clinical characteristics and clinical laboratory parameters were recorded.

Results

Compared with anti-IFN-γ autoantibody-negative patients with T. marneffei infection, anti-IFN-γ autoantibody-positive patients did not have underlying respiratory disease; more frequently exhibited dissemination of systemic infections with severe pleural effusion; had higher WBC counts, C-reactive protein levels, erythrocyte sedimentation rates, and neutrophil and CD8⁺ T cell counts; had lower hemoglobin levels; and were more likely to have other intracellular pathogen infections. Most of these patients had poor outcomes despite standardized antimicrobial therapy.

Conclusion

T. marneffei-infected patients with higher anti-IFN-γ autoantibody titers have more severe disease and complex clinical conditions.

Identification of novel mutation in RANKL by whole-exome sequencing in a Thai family with osteopetrosis; a case report and review of RANKL osteopetrosis

Background

Osteopetrosis is a rare form of skeletal dysplasia characterized by increased bone density that leads to bone marrow failure, compressive neuropathy, and skeletal dysmorphism. Molecular diagnosis is essential as it guides treatment and prognosis. We report Thai siblings with an ultra‐rare form of osteopetrosis.

Methods

The older brother and the younger sister presented with chronic mandibular osteomyelitis in their 20s. Since childhood, they had visual impairment, pathological fracture, and skeletal dysmorphism.

Quadruplet whole‐exome sequencing was performed and confirmed with Sanger sequencing. Novel mutation in TNFSF11 (RANKL) c.842T>G, p.Phe281Cys was identified in a homozygous state in both siblings.

Results

Surgical debridement, antibiotic, and hyperbaric oxygen therapy were used and discontinued over a 6‐month period with normalization of C‐reactive protein. Hematopoietic stem cell transplantation candidacy was excluded by molecular diagnosis.

Conclusion

We report a novel mutation in an ultra‐rare form of osteopetrosis. Our siblings manifested with a milder phenotype in comparison with nine cases previously published.

Latticed Gold Nanoparticle Conjugation via Monomeric Streptavidin in Lateral Flow Assay for Detection of Autoantibody to Interferon-Gamma

Adult-onset immunodeficiency syndrome (AOID) patients with autoantibodies (autoAbs) against interferon-gamma (IFN-γ) generally suffer from recurrent and recalcitrant disseminated non-tuberculous mycobacterial diseases. Since the early stages of AOID do not present specific symptoms, diagnosis and treatment of the condition are not practical. A simplified diagnostic method for differentiating AOID from other immunodeficiencies, such as HIV infection, was created. Anti-IFN-γ is generally identified using enzyme-linked immunosorbent assay (ELISA), which involves an instrument and a cumbersome process. Recombinant IFN-γ indirectly conjugated to colloidal gold was used in the modified immunochromatographic (IC) strips. The biotinylated-IFN-γ was incorporated with colloidal-gold-labeled 6HIS-maltose binding protein-monomeric streptavidin (^6HISMBP-mSA) and absorbed at the conjugate pad. The efficacy of the IC strip upon applying an anti-IFN-γ autoAb cut-off ELISA titer of 2500, the sensitivity and specificity were 84% and 90.24%, respectively. When a cut-off ELISA titer of 500 was applied, the sensitivity and specificity were 73.52% and 100%, respectively.

Minireview: Insights into anti-interferon-γ autoantibodies

The association between the presence of anti-interferon-γ autoantibodies and the onset of immunodeficiency with intracellular infections has been clearly established. No standard regimen to control the production of these pathogenic autoantibodies, apart from antimicrobial therapy to eliminate infections, contributes to the medical burden of this syndrome, which sometimes has a fatal outcome. In this review, we summarize the findings on anti-interferon-γ autoantibodies to facilitate further research and to provide guidance for treatment strategies.

Diagnosis of NTM active infection in lymphadenopathy patients with anti-interferon-gamma auto-antibody using inhibitory ELISA vs. indirect ELISA

The anti-interferon-gamma (IFN-gamma) autoantibody is a known cause of opportunistic non-tuberculous mycobacterial (NTM) infection in adults. Diagnosis of those patients is difficult due to the low sensitivity of bacterial culture, and because detection of the neutralizing autoantibody needs special laboratory devices. We conducted a retrospective review of indirect and inhibitory ELISA, both used for detection of anti-IFN-gamma auto-antibody in 102 patients with lymphadenopathies. We assessed hospital records of NTM isolation and/or diagnosis of NTM infection. The review revealed the compatible sensitivity and superior specificity and predictive values for inhibitory ELISA over against indirect ELISA—the latter achieving 100% specificity and positive predictive value for diagnosis of NTM infection in patients with lymphadenopathies. The results confirm functional assays that show plasma samples from NTM-infected patients with positive results by either indirect and/or inhibitory ELISA are IFN-gamma neutralizing autoantibodies. The inhibitory titer of anti-IFN-gamma auto-antibody can be used to distinguish patients with active from inactive NTM infection. Inhibitory ELISA is thus a practical, rapid, high performance tool for routine detection of anti-IFN-gamma autoantibody and NTM infection diagnosis before confirmation, enabling a timely therapeutic strategy for active infection treatment.

Triple infection with Cryptococcus, varicella-zoster virus, and Mycobacterium abscessus in a patient with anti-interferon-gamma autoantibodies: a case report

Background

The most common infection in patients positive for anti-interferon-gamma autoantibodies (anti-IFN-γ AAbs) is disseminated nontuberculous mycobacterial (dNTM) infection. Here, we report a rare case of triple infection caused by Cryptococcus, varicella-zoster virus (VZV), and nontuberculous mycobacterium in a patient with anti-IFN-γ AAbs.

Case presentation

A 53-year-old Thai man presented with a progressively enlarging right cervical mass with low-grade fever and significant weight loss for 4 months. He also developed a lesion at his left index finger. A biopsy of that lesion showed granulomatous inflammation with yeast-like organisms morphologically consistent with cryptococcosis. Serum cryptococcal antigen was positive. Histopathology of a right cervical lymph node revealed chronic granulomatous lymphadenitis, and the lymph node culture grew Mycobacterium abscessus. One month later, he complained of vision loss in his left eye and subsequently developed a group of painful vesicles at the right popliteal area of S1 dermatome. Lumbar puncture was performed and his cerebrospinal fluid was positive for VZV DNA. His blood test for anti-HIV antibody was negative. Anti-IFN-γ AAbs was positive, but test for anti-granulocyte-macrophage colony-stimulating factor autoantibodies (anti-GM-CSF AAbs) was negative. He was treated with amphotericin B plus fluconazole for cryptococcosis; a combination of amikacin, imipenem, azithromycin, and levofloxacin for dNTM infection; and, intravenous acyclovir for disseminated VZV infection. After treatment, our patient’s fever and cervical lymphadenopathy were subsided, and his vision and visual acuity were both improved.

Conclusions

This is the first case of triple infection with cryptococcosis, VZV, and dNTM in a patient who tested positive for anti-IFN-γ AAbs and negative for anti-GM-CSF AAbs. This case will increase awareness and heighten suspicion of these infections in patients with the described presentations and clinical characteristics, and this will accelerate diagnosis and treatment.

A case report of Talaromyces marneffei Oro-pharyngo-laryngitis: a rare manifestation of Talaromycosis

Background

The incidence of Taralomyces marneffei infection in HIV-infected individuals has been decreasing, whereas its rate is rising among non-HIV immunodeficient persons, particularly patients with anti-interferon-gamma autoantibodies. T. marneffei usually causes invasive and disseminated infections, including fungemia. T. marneffei oro-pharyngo-laryngitis is an unusual manifestation of talaromycosis.

Case presentation

A 52-year-old Thai woman had been diagnosed anti-IFNɣ autoantibodies for 4 years. She had a sore throat, odynophagia, and hoarseness for 3 weeks. She also had febrile symptoms and lost 5 kg in weight. Physical examination revealed marked swelling and hyperemia of both sides of the tonsils, the uvula and palatal arches including a swelling of the epiglottis, and arytenoid. The right tonsillar biopsy exhibited a few intracellular oval and elongated yeast-like organisms with some central transverse septum seen, which subsequently grew a few colonies of T. marneffei on fungal cultures. The patient received amphotericin B deoxycholate 45 mg/dayfor 1 weeks, followed by oral itraconazole 400 mg/day for several months. Her symptoms completely resolved without complication.

Conclusion

In patients with anti-IFN-ɣ autoantibodies, T. marneffei can rarely cause a local infection involving oropharynx and larynx. Fungal culture and pathological examination are warranted for diagnosis T. marneffei oro-pharyngo-laryngitis. This condition requires a long term antifungal therapy.

Hypercalcaemia secondary to disseminated Mycobacterium abscessus and Mycobacterium fortuitum

The incidence and prevalence of nontuberculous mycobacteria (NTM) infection is on the rise with many cases still going unreported. Given the vague and nonspecific clinical features of NTM infections, it is often missed or mistaken for Mycobacterium tuberculosis. The presumption that NTM infections are benign and do not contribute to morbidity no longer holds true. NTM infections need to be considered in patients with disseminated multisystem disease and in those not responding to standard M. tuberculosis treatment. As NTM infection is associated with granuloma formation, it can result in hypercalcaemia. Interestingly, there is evidence that there may be other mechanisms in play contributing to hypercalcaemia besides the increased calcitriol levels.

Blockade Effects of Anti-Interferon- (IFN-) γ Autoantibodies on IFN-γ-Regulated Antimicrobial Immunity

The interferon- (IFN-) γ expression is elicited in response to microbial infections and activates immune surveillance by antimicrobial immune elements to induce microbial killing. Patients with adult-onset immunodeficiency who suffer from recurrent infections with microbes, particularly nontuberculous mycobacteria (NTM), commonly display genetic defects in IFN-γ signaling as well as the generation of anti-IFN-γ autoantibodies (autoAbs). Because IFN-γ is an activator of macrophage differentiation and a proinflammatory activator of innate immunity, the blockade effects of the autoAbs present in NTM patient serum on IFN-γ are hypothesized to regulate the antimicrobial function of macrophages. In the presence of patient serum, IFN-γ-induced type 1 macrophage (M1) differentiation was inhibited in PMA-stimulated human monocytic THP-1 cells. Treatment with patient serum significantly blocked the production of proinflammatory factors, including cytokines/chemokines and reactive oxygen/nitrogen species, by M1 macrophages. Importantly, IFN-γ-facilitated phagocytosis and degradation of heat-killed mycobacterium were decreased by cotreatment with patient serum. These results show the blockade activity of anti-IFN-γ autoAbs on IFN-γ-mediated antimicrobial immunity in macrophages.

Clinical outcome and laboratory markers for predicting disease activity in patients with disseminated opportunistic infections associated with anti-interferon-γ autoantibodies

Background

Clinical courses and treatment outcomes are largely unknown in patients with adult-onset immunodeficiency associated with anti-interferon-gamma autoantibodies due to the fact that it was recently recognized and anti-IFN-γ auto-Abs detection is not widely available.

Methods and findings

Non-HIV-infected adult patients with detectable anti-IFN-γ auto-Abs diagnosed and followed at Siriraj Hospital, Bangkok, Thailand during January 2013 to November 2016 were prospectively studied. At each follow-up visit, patients were classified as stable or active disease according to symptoms and signs, and all proven OIs were recorded. Laboratory parameters, including erythrocyte sedimentation rate, C-reactive protein, and anti-IFN-γ auto-Abs level, were compared between active and stable disease episodes. We identified 80 patients with this clinical syndrome and followed them up during study period. Seventy-nine patients developed overall 194 proven opportunistic infections. Mycobacterium abscessus (34.5%) and Salmonella spp. (23.2%) were the two most common pathogens identified among these patients. Sixty-three patients were followed for a median of 2.7 years (range 0.6–4.8 years). Eleven (17.5%) patients achieved the drug-free remission period for at least 9 months. Four patients died. Anti-IFN-γ auto-Abs concentration was significantly lower at baseline and decreased over time in the drug-free remission group compared to another group (p = 0.001). C-reactive protein, erythrocyte sedimentation rate and white cell count were found to be useful biomarkers for determining disease activity during follow-up.

Conclusions

Reinfection or relapse of OIs is common despite long-term antimicrobial treatment in patients with anti-IFN-γ auto-Abs. Treatment to modify anti-IFN-γ auto-Abs production may improve long-term outcomes in this patient population.

The risk of nontuberculous mycobacterial infection in patients with Sjögren's syndrome: a nationwide, population-based cohort study

BACKGROUND

Nontuberculous mycobacterial (NTM) infection in immunocompromized patients is currently a growing health concern, and we aimed to examine the relative risk of NTM infection in patients with Sjögren's syndrome (SS) compared with that in non-SS individuals.

METHODS

We used the 2003-2012 Taiwanese National Health Insurance Research Database to identify 6554 incident SS cases during 2007-2012 and selected 98,310 non-SS controls matched (1:15) for age, gender, and the year of first SS diagnosis date after excluding those who had rheumatoid arthritis or systemic lupus erythematosus.

RESULTS

We identified four NTM-infected patients in the SS group (three in the first year) and nine in the non-SS group (three in the first year). SS patients had a higher incidence rate of NTM infection than that in non-SS individuals (IRR, 7.56; 95% CI, 2.33-24.55), especially during the first year (IRR, 16.05; 95% CI, 3.24-79.51). After adjusting for potential confounders, the risk of NTM infection was not increased in SS patients during the entire follow-up period or during the first year, but the risk increased in SS patients treated with immunosuppressants during the entire follow-up period (HR, 17.77; 95% CI, 4.53-69.61), especially during the first year (HR, 33.33; 95% CI, 4.37-254.23).

CONCLUSION

An increased risk of NTM infection was found in SS patients treated with immunosuppressants during the first year after SS diagnosis.

Molecular investigation by whole exome sequencing revealed a high proportion of pathogenic variants among Thai victims of sudden unexpected death syndrome

Introduction

Sudden unexpected death syndrome (SUDS) is an important cause of death in young healthy adults with a high incident rate in Southeast Asia; however, there are no molecular autopsy reports about these victims. We performed a combination of both a detailed autopsy and a molecular autopsy by whole exome sequencing (WES) to investigate the cause of SUDS in Thai sudden death victims.

Materials and methods

A detailed forensic autopsy was performed to identify the cause of death, followed by a molecular autopsy, in 42 sudden death victims who died between January 2015 and August 2015. The coding sequences of 98 SUDS-related genes were sequenced using WES. Potentially causative variants were filtered based on the variant functions annotated in the dbNSFP database. Variants with inconclusive clinical significance evidence in ClinVar were resolved with a variant prediction algorithm, metaSVM, and the frequency data of the variants found in public databases, such as the 1000 Genome Project, ESP6500 project, and the Exome Aggregation Consortium (ExAc) project.

Results

Combining both autopsy and molecular autopsy enabled the potential identification of cause of death in 81% of the cases. Among the 25 victims with WES data, 72% (18/25) were found to have potentially causative SUDS mutations. The majority of the victims had at a mutation in the TTN gene (8/18 = 44%), and only one victim had an SCN5A mutation.

Conclusions

WES can help to identify the genetic causes in victims of SUDS and may help to further guide investigations into their relatives to prevent additional SUDS victims.

Patient ethnicity and causative species determine the manifestations of anti-interferon-gamma autoantibody-associated nontuberculous mycobacterial disease: a review

Nontuberculous mycobacteria (NTM) infections involving anti-interferon-gamma (IFN-γ)-neutralizing autoantibodies have been described in previously immunocompetent adults. To investigate the factors underlying various disease manifestations, we reviewed 35 articles published between January 2004 and November 2016 and identified 111 NTM patients with anti-IFN-γ autoantibodies. Rapidly growing mycobacteria (RGM) accounted for 53% of the isolated species. RGM were predominant among the NTM species isolated from Thai (73%), Chinese (58%) and Filipino (56%) patients, whereas M. avium complex (MAC) was predominant among Japanese (58%) and non-Asian (80%) patients. The commonly involved organs included the lymph nodes (79%), bones/joints (34%) and lungs (32%). Compared with the patients with MAC, the patients with RGM had a higher incidence of lymph node lesions (P<0.05) and a lower incidence of bone/joint (P<0.01), lung (P<0.01), soft tissue (P<0.01), bronchus (P<0.01) and muscle (P<0.05) lesions. Clinical manifestations of NTM disease with anti-IFN-γ-neutralizing autoantibodies differ across ethnicities and NTM species.

Identification of novel biomarkers for adult-onset-immunodeficiency (AOID) syndrome using serum proteomics

OBJECTIVE

To identify the candidate protein biomarkers of adult-onset-immunodeficiency (AOID) syndrome using serum proteomics.

METHODS

Screening and verification phases were performed in the study. A total of 97 serum samples were classified into three groups: AOID patients with opportunistic infections (active AOID), AOID patients without opportunistic infections (inactive AOID), and healthy control. In the screening phase, pooled sera collected from patients and healthy control in each group were separated by 2D-gel electrophoresis, analyzed for differentially expressed proteins and identified for biomarkers using LC/MS. In the verification phase, the protein candidates were selected for confirmation by western blotting.

RESULTS

The analysis revealed 35 differentially expressed proteins. Three proteins including haptoglobin, gelsolin, and transthyretin, were selected for verification. The results showed that the levels of haptoglobin in both active and inactive AOID groups were significantly higher than that in the control group, while the levels of gelsolin in the active AOID group were significantly lower than that in the inactive AOID group. The level of transthyretin in the active AOID group was also significantly lower than that in the control group.

CONCLUSIONS

The comparison of serum proteins between the three groups revealed three candidates which are related to chronic inflammatory diseases. Haptoglobin and transthyretin biomarkers could be applied in clinical assessment for monitor of disease outcome, including for the study of AOID pathogenesis.

Factors associated with acquired Anti IFN- γ autoantibody in patients with nontuberculous mycobacterial infection

Background

The clinical syndrome of disseminated nontuberculous mycobacterial (NTM) infection in patients who were previously healthy is now well recognized to be associated with an acquired autoantibody to Interferon gamma (Anti IFN- γ autoantibody). However, the risk factors of this syndrome remain unknown.

Method

We performed an unmatched case control study among patients with NTM diseases who were diagnosed and treated at Siriraj Hospital, Bangkok, Thailand. Anti-IFN autoantibody was detected by enzyme-linked immunosorbent assay (ELISA) method. Cases were patients with NTM diseases and detectable anti IFN- γ autoantibody. Controls were randomly selected from those with undetectable anti IFN- γ autoantibody. Data from both groups including demographic data, clinical presentation, laboratory results, other risk factors and HLA genotypes were collected. Univariate and multivariate analyses were performed to identify independent risk factors for this syndrome.

Results

70 cases (mean age 50 ± 11 years) and 70 controls (mean age 58 ± 18 years) were enrolled into the study. Mycobacterial abscessus was the most common NTM pathogen found in both groups (72.9% in cases and 41.4% in controls respectively). However, disseminated NTM disease was significantly more common in cases (92.9%) than in the controls (14.3%, p<0.001). Binary logistic regression analysis showed that previous OIs (adjusted OR14.87, 95% CI 2.36–93.86), birthplace outside Central region (adjusted OR 19.19, 95% CI 3.86–95.35), lack of comorbidities lead to immunosuppression, such as HIV infection or diabetes mellitus (adjusted OR 23.68, 95% CI 4.01–139.94), and presence of HLA DRB1*15/16 (adjusted OR 153.28, 95% CI 16.87–139.88) were independent factors associated with this syndrome.

Conclusion

Patients with NTM disease associated with anti IFN- γ autoantibody are almost always previously healthy and HIV negative. Most of these patients presented with disseminated NTM disease with generalized lymphadenitis and often with reactive skin lesions. Factors associated with detectable anti IFN- γ autoantibody are HLA-DRB1 and DQB1 alleles, and history of previous OIs in patients without comorbidity that leads to immunosuppression. Further studies are needed to better understand these associations and to improve the treatment outcome.