A novel indirect ELISA for serodiagnosis of mucormycosis using antigens from Rhizopus arrhizus.

BACKGROUND: Due to a delay in diagnosis by conventional techniques and high mortality, the development of a standardised and rapid non-culture-based technique is an unmet need in pulmonary, gastrointestinal, and disseminated forms of mucormycosis. Though limited studies have been conducted for molecular diagnosis, there are no established serologic tests for this highly fatal infection. OBJECTIVE: To develop and evaluate an indirect in-house enzyme-linked immunosorbent assay (ELISA) utilising antigens of Rhizopus arrhizus for detecting anti-Rhizopus antibodies (IgG and IgM) in sera of patients with mucormycosis. METHODS: We extracted both secretory and mycelial Rhizopus antigens using standardised protocols. Bradford assay was used for protein quantification. We then standardised an indirect ELISA using R. arrhizus mycelial and secretory antigens (10.0 µg/mL in bicarbonate buffer pH 9.2) for detecting anti-Rhizopus IgG and IgM antibodies in patient sera. We included patients with mucormycosis, other fungal infections, and healthy controls. Antibody index value (E-value) was calculated for each patient sample. RESULTS: Asparagine broth culture filtrate utilising 85% ammonium sulphate salt fractionation and mycelial homogenate grown in yeast extract peptone dextrose (YPD) broth precipitated with trichloroacetic acid (TCA) yielded a large amount of good-quality protein for the assay. We included 55 patients with mucormycosis (rhino-orbito-cerebral mucormycosis [ROCM, n = 39], pulmonary [n = 15], gastrointestinal [n = 1]), 24 with other fungal infections (probable aspergillosis [n = 14], candidiasis [n = 10]), and healthy controls (n = 16). The sensitivity of the antibody test for diagnosing mucormycosis ranged from 83.6-92.7% for IgG and 72.7-87.3% for IgM, with a specificity of 91.7-92.5% for IgG and 80-82.5% for IgM. The sera from patients with other fungal infections and healthy individuals did not show significant cross-reactivity. CONCLUSION: The detection of anti-Rhizopus IgG antibody performed significantly better in comparison to IgM-based ELISA for diagnosing both ROCM (sensitivity of 84.6% vs. 69.2%) and pulmonary cases (86.6% vs. 80.0%). More extensive studies are required to confirm our findings.

Chronic pulmonary aspergillosis incidence in newly detected pulmonary tuberculosis cases during follow-up.

BACKGROUND: Chronic pulmonary aspergillosis (CPA) is known to complicate patients with post-tubercular lung disease. However, some evidence suggests that CPA might co-exist in patients with newly-diagnosed pulmonary tuberculosis (P.TB) at diagnosis and also develop during therapy. The objective of this study was to confirm the presence of CPA in newly diagnosed P.TB at baseline and at the end-of-TB-therapy. MATERIALS AND METHODS: This prospective longitudinal study included newly diagnosed P.TB patients, followed up at third month and end-of-TB-therapy with symptom assessment, anti-Aspergillus IgG antibody and imaging of chest for diagnosing CPA. RESULTS: We recruited 255 patients at baseline out of which 158 (62%) completed their follow-up. Anti-Aspergillus IgG was positive in 11.1% at baseline and 27.8% at end-of-TB-therapy. Overall, proven CPA was diagnosed in 7% at baseline and 14.5% at the end-of-TB-therapy. Around 6% patients had evidence of aspergilloma in CT chest at the end-of-TB-therapy. CONCLUSIONS: CPA can be present in newly diagnosed P.TB patients at diagnosis and also develop during anti-tubercular treatment. Patients with persistent symptoms or developing new symptoms during treatment for P.TB should be evaluated for CPA. Whether patients with concomitant P.TB and CPA, while receiving antitubercular therapy, need additional antifungal therapy, needs to be evaluated in future studies.

Antibody Isolation in C. neoformans.

The importance of humoral immunity to fungal infections remains to be elucidated. In cryptococcosis, patients that fail to generate antibodies against antigens of the fungus Cryptococcus neoformans are more susceptible to the disease, demonstrating the importance of these molecules to the antifungal immune response. Historically, antibodies against C. neoformans have been applied in diagnosis, therapeutics, and as important research tools to elucidate fungal biology. Throughout the process of generating monoclonal antibodies (mAbs) from a single B-cell clone and targeting a single epitope, several immunization steps might be required for the detection of responsive antibodies to the antigen of interest in the serum. This complex mixture of antibodies comprises the polyclonal antibodies. To obtain mAbs, B-lymphocytes are harvested (from spleen or peripheral blood) and fused with tumor myeloma cells, to generate hybridomas that are individually cloned and specifically screened for mAb production. In this chapter, we describe all the necessary steps, from the immunization to polyclonal antibody harvesting, hybridoma generation, and mAb production and purification. Additionally, we discuss new cutting-edge approaches for generating interspecies mAbs, such as humanized mAbs, or for similar species in distinct host backgrounds.

Methods of Cryptococcal Polysaccharide Analysis Using ELISA.

One of the standard assays for the fungal pathogen Cryptococcus neoformans is the glucuronoxylomannan (GXM) ELISA. This assay utilizes monoclonal antibodies targeted against the critical virulence factor, the polysaccharide (PS) capsule. GXM ELISA is one of the most used assays in the field used for diagnosis of cryptococcal infection, quantification of PS content, and determination of binding specificity for antibodies. Here we present three variations of the GXM ELISA used by our group-indirect, capture, and competition ELISAs. We have also provided some history, perspective, and notes on these methods, which we hope will help the reader choose, and implement, the best assay for their research.While it has long been referred to as the GXM ELISA, we also suggest a name update to better reflect our updated understanding of the polysaccharide antigens targeted by this assay. The Cryptococcal PS ELISA is a more accurate description of this set of methodologies and the antigens they measure. Finally, we discuss the limitations of this assay and put forth future plans for expanding the antigens assayed by ELISA.

Identification of the Most Immunoreactive Antigens of Candida auris to IgGs from Systemic Infections in Mice.

The delay in making a correct diagnosis of Candida auris causes concern in the healthcare system setting, and immunoproteomics studies are important to identify immunoreactive proteins for new diagnostic strategies. In this study, immunocompetent murine systemic infections caused by non-aggregative and aggregative phenotypes of C. auris and by Candida albicans and Candida haemulonii were carried out, and the obtained sera were used to study their immunoreactivity against C. auris proteins. The results showed higher virulence, in terms of infection signs, weight loss, and histopathological damage, of the non-aggregative isolate. Moreover, C. auris was less virulent than C. albicans but more than C. haemulonii. Regarding the immunoproteomics study, 13 spots recognized by sera from mice infected with both C. auris phenotypes and analyzed by mass spectrometry corresponded to enolase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, and phosphoglycerate mutase. These four proteins were also recognized by sera obtained from human patients with disseminated C. auris infection but not by sera obtained from mice infected with C. albicans or Aspergillus fumigatus. Spot identification data are available via ProteomeXchange with the identifier PXD049077. In conclusion, this study showed that the identified proteins could be potential candidates to be studied as new diagnostic or even therapeutic targets for C. auris.

Coincidence of antibodies against Hwp1 and ASCA, two distinct molecular targets of Candida albicans, reinforces the link between this fungal species and coeliac disease.

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibodies (ASCA), a serological marker of Crohn's disease. ASCA has also been reported in other autoimmune diseases, including coeliac disease (CeD). A strong antibody response against Hwp1, a protein associated with invasive hyphal form of C. albicans which presents peptide sequence homologies with gliadin, has also been described in CeD. This observation supports the hypothesis that C. albicans hyphal transition in C. albicans may trigger CeD onset through a mechanism of molecular/antigenic mimicry. In this study, we assessed whether the anti-C. albicans oligomannose and anti-Hwp1 protein responses may be linked despite their different pathophysiological significance. The measurement of ASCA levels in a cohort of patients involved in our previous Hwp1 study showed a significant correlation between the two biomarkers. This new observation further reinforces the link between C. albicans and CeD.

Histoplasma antigens as novel players for the development of new enzyme immunoassays for the serodiagnosis of histoplasmosis: A comparative study of their analytical performance.

Definitive diagnosis of histoplasmosis relies on culture and/or cytology/histopathology; however, these procedures have limited sensitivity and cultures are time-consuming. Antibodies detection by immunodiffusion has low sensitivity in immunocompromised individuals and uses histoplasmin (HMN), a crude antigenic extract, as reagent. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques to obtain standardized and specific reagents for diagnosing histoplasmosis. To compare the analytical performance of novel enzyme-linked immunosorbent assays (ELISAs) for antibodies testing for diagnosing histoplasmosis using different Histoplasma capsulatum antigens as reagents. The H. capsulatum 100 kDa protein (Hcp100), the M antigen and its immunoreactive fragment F1 were produced by DNA-recombinant techniques. Galactomannan was purified from both the yeast and mycelial cell walls (yGM and mGM, respectively). The analytical performance of the ELISA tests for the serological detection of antibodies against these antigens was evaluated and compared with those obtained using HMN as reagent. Antibodies detection by the Hcp100 ELISA demonstrated 90.0% sensitivity and 92.0% specificity, versus 43.3% sensitivity and 95.0% specificity of the M ELISA, 33.3% sensitivity and 84.0% specificity of the F1 ELISA, 96.7% sensitivity and 94.0% specificity of the yGM ELISA, 83.3% sensitivity and 88.0% specificity of the mGM ELISA, and 70.0% sensitivity and 86.0% specificity for the HMN ELISA. In summary, Hcp100 is proposed as the most promising candidate for the serodiagnosis of histoplasmosis. The primary immunoreactive element in HMN proved to be GM rather than the M antigen. Nevertheless, a higher incidence of cross-reactions was noted with GM compared to M.

Hcp100 is a promising serodiagnostic candidate for histoplasmosis, boasting high sensitivity and specificity. Notably, GM, rather than M antigen, emerged as the primary immunoreactive element in HMN, despite a higher incidence of cross-reactions with GM compared to M.

The structure of a C. neoformans polysaccharide motif recognized by protective antibodies: A combined NMR and MD study.

Cryptococcus neoformans is a fungal pathogen responsible for cryptococcosis and cryptococcal meningitis. The C. neoformans' capsular polysaccharide and its shed exopolysaccharide function both as key virulence factors and to protect the fungal cell from phagocytosis. Currently, a glycoconjugate of these polysaccharides is being explored as a vaccine to protect against C. neoformans infection. In this study, NOE and J-coupling values from NMR experiments were consistent with a converged structure of the synthetic decasaccharide, GXM10-Ac3, calculated from MD simulations. GXM10-Ac3 was designed as an extension of glucuronoxylomannan (GXM) polysaccharide motif (M2) which is common in the clinically predominant serotype A strains and is recognized by protective forms of GXM-specific monoclonal antibodies. The M2 motif is a hexasaccharide with a three-residue α-mannan backbone, modified by ß-(1→2)-xyloses (Xyl) on the first two mannoses (Man) and a ß-(1→2)-glucuronic acid (GlcA) on the third Man. Combined NMR and MD analyses reveal that GXM10-Ac3 adopts an extended structure, with Xyl/GlcA branches alternating sides along the α-mannan backbone. O-acetyl esters also alternate sides and are grouped in pairs. MD analysis of a twelve M2-repeating unit polymer supports the notion that the GXM10-Ac3 structure is uniformly represented throughout the polysaccharide. This derived GXM model displays high flexibility while maintaining a structural identity, yielding insights to further explore intermolecular interactions between polysaccharides, interactions with anti-GXM mAbs, and the cryptococcal polysaccharide architecture.

Anti-Candida Antibodies of Patients with Invasive Candidiasis Inhibit Growth, Alter Cell Wall Structure, and Kill Candida albicans In Vitro.

Invasive candidiasis (IC), caused by Candida yeasts, particularly Candida albicans, poses a significant threat with high mortality rates. Diagnosis is challenging due to Candida's common presence in human microbiota. To address this, our research group developed an immunofluorescence assay detecting Candida albicans Germ Tube Antibodies (CAGTA) in IC patients. CAGTA, indicative of invasive processes, is associated with a lower mortality rate in ICU patients. Based on this premise, this study aims to provide results regarding the lack of knowledge about the potential activity of CAGTA against invasive infections in humans caused by the fungus Candida albicans. Therefore, in order to characterize the activity of CAGTA produced by patients with IC, we used sera from 29 patients with IC caused by either C. albicans or non-albicans Candida species. Whole serum IgG antibodies were fractionated into anti-blastospores, CAGTA-enriched, and purified CAGTA and the assessments included XTT colorimetric assays for metabolic activity, CFU counts for viability, and microscopy for growth, viability, and morphological analysis. The CAGTA-enriched IgG fraction significantly reduced the metabolic activity and viability of C. albicans compared to anti-blastospores. Purified CAGTA altered germ tube cell wall surfaces, as revealed by electron microscopy, and exhibited fungicidal properties by DiBAC fluorescent staining. In conclusion, antibodies in response to invasive candidiasis have antifungal activity against Candida albicans, influencing metabolic activity, viability, and cell wall structure, leading to cell death. These findings suggest the potential utility of CAGTA as diagnostic markers and support the possibility of developing immunization protocols against Candida infections.

Sensitivity and specificity of LDBio Aspergillus ICT lateral flow assay for diagnosing allergic bronchopulmonary aspergillosis in adult asthmatics.

BACKGROUND: Aspergillus fumigatus-specific IgG estimation is crucial for diagnosing allergic bronchopulmonary aspergillosis (ABPA). A point-of-care LDBio immunochromatographic lateral flow assay (LFA) had 0%-90% sensitivity to detect IgG/IgM antibodies against A. fumigatus. OBJECTIVE: To assess the accuracy of LDBio-LFA in diagnosing ABPA, using the modified ISHAM-ABPA working group criteria as the reference standard. The secondary objective was to compare the diagnostic performance between LDBio-LFA and A. fumigatus-specific IgG (cut-offs, 27 and 40 mgA/L), using a multidisciplinary team (blinded to A. fumigatus-IgG and LDBio-LFA results) diagnosis of ABPA as the reference standard. METHODS: We prospectively enrolled adult subjects with asthma and ABPA. We performed the LDBio-LFA per the manufacturer's recommendations. We used the commercially available automated fluorescent enzyme immunoassay for measuring serum A. fumigatus-specific IgG. We used the same serum sample to perform both index tests. The tests were performed by technicians blinded to the results of other tests and clinical diagnoses. RESULTS: We included 123 asthmatic and 166 ABPA subjects, with a mean ± SD age of 37.4 ± 14.4 years. Bronchiectasis and high-attenuation mucus were seen in 93.6% (146/156) and 24.3% (38/156) of the ABPA subjects. The sensitivity and specificity of LDBio-LFA in diagnosing ABPA were 84.9% and 82.9%, respectively. The sensitivity of serum A. fumigatus-specific IgG ≥27 mgA/L was 13% better than LDBio-LFA, with no difference in specificity. There was no significant difference in sensitivity and specificity between LDBio-LFA and serum A. fumigatus-IgG ≥40 mgA/L. CONCLUSION: LDBio-LFA is a valuable test for diagnosing ABPA. However, a negative test should be confirmed using an enzyme immunoassay.

Comparison of coccidioidal complement fixation and quantitative immunodiffusion serology at a reference laboratory.

The incidence of coccidioidomycosis continues to increase. The diagnosis frequently relies on non-invasive diagnostic testing with immunodiffusion and complement fixation (CF) testing the current gold standard. A direct comparison of quantitative immunodiffusion and CF for IgG antibodies has not been previously reported. In a comparison of 368 samples, there was close concordance observed (360/368 = 97.8%) (P-value < .001). These tests can be considerably interchangeable in the reference laboratory setting.

There are several diagnostic methodologies available in coccidioidomycosis. Direct comparisons of these methods are limited. Prior studies have not compared quantitative immunodiffusion to complement fixation testing. Our results show these tests are highly concordant.

Synthetic Glycans Reveal Determinants of Antibody Functional Efficacy against a Fungal Pathogen.

Antibodies play a vital role in the immune response to infectious diseases and can be administered passively to protect patients. In the case of Cryptococcus neoformans, a WHO critical priority fungal pathogen, infection results in antibodies targeting capsular glucuronoxylomannan (GXM). These antibodies yield protective, non-protective, and disease-enhancing outcomes when administered passively. However, it was unknown how these distinct antibodies recognized their antigens at the molecular level, leading to the hypothesis that they may target different GXM epitopes. To test this hypothesis, we constructed a microarray containing 26 glycans representative of those found in highly virulent cryptococcal strains and utilized it to study 16 well-characterized monoclonal antibodies. Notably, we found that protective and non-protective antibodies shared conserved reactivity to the M2 motif of GXM, irrespective of the strain used in infection or GXM-isolated to produce a conjugate vaccine. Here, only two antibodies, 12A1 and 18B7, exhibited diverse trivalent GXM motif reactivity. IgG antibodies associated with protective responses showed cross-reactivity to at least two GXM motifs. This molecular understanding of antibody binding epitopes was used to map the antigenic diversity of two Cryptococcus neoformans strains, which revealed the exceptional complexity of fungal capsular polysaccharides. A multi-GXM motif vaccine holds the potential to effectively address this antigenic diversity. Collectively, these findings underscore the context-dependent nature of antibody function and challenge the classification of anti-GXM epitopes as either "protective" or "non-protective".

Prevalence of Anti- Saccharomyces Cerevisiae Antibodies (ASCA) in Patients With Irritable Bowel Syndrome (IBS). A Case-control Study.

BACKGROUND: Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction that affects patients' quality. Recent research has shown variations in the mycobiome of individuals with IBS, particularly involving Saccharomyces cerevisiae , and its association with dysbiosis and visceral hypersensitivity. However, the role of Anti-Saccharomyces cerevisiae antibodies (ASCA) in IBS remains unclear, despite their significance as markers of disease severity in inflammatory bowel disease. OBJECTIVE: This study aimed to investigate the role of ASCA in Mexican IBS patients compared with healthy controls (HCs) and determine whether these antibodies could help differentiate between IBS patients and healthy individuals. METHODS: Serum samples from 400 IBS patients and 400 HC were analyzed. ASCA IgG levels were measured using enzyme-linked immunosorbent assay (ELISA). The IBS patients were further categorized into subtypes: constipation predominant (IBS-C), diarrhea predominant (IBS-D), and mixed (IBS-M). RESULTS: Among the participants, 66 IBS patients (16.5%) and 63 HC (15.75%) tested positive for ASCA IgG. No significant difference was observed in ASCA IgG levels between the 2 groups ( P value: 0.8451). The prevalence of ASCA IgG positivity was 14.5% in IBS-C, 17.8% in IBS-D, and 15.9% in IBS-M. CONCLUSION: Surprisingly, a high prevalence of ASCA IgG was found in the HC group in Mexico. Furthermore, there was no significant difference in ASCA IgG levels between IBS patients and controls. These findings suggest that ASCA is not useful as a discriminatory biomarker for distinguishing IBS patients from healthy individuals and cannot serve as a surrogate marker for visceral hypersensitivity.

Effect of warm and humid days on the positivity rate of anti-Trichosporon asahii antibody test for the diagnosis of summer-type hypersensitivity pneumonitis.

BACKGROUND: Summer-type hypersensitivity pneumonitis (SHP) has been reported to occur during warm and humid summer seasons in Japan; however, the effect of weather conditions on SHP remains unknown. Anti-Trichosporon asahii antibody (TaAb) test is highly specific and useful for the diagnosing SHP. Therefore, we aimed to investigate the impact of weather conditions on SHP by examining the relationship between the positivity rate of TaAb and warm and humid days. METHODS: TaAb test data from June 2013 to June 2020 were obtained from major commercial laboratories to determine the number of samples and positivity rate of TaAb by prefecture. Using the Japan Meteorological Agency database, we counted the warm and humid days (maximum temperature ≥25 °C and average humidity ≥80 %) for each prefecture. Negative binomial regression was employed to examine the relationship between the positivity rate of TaAb and the number of warm and humid days per month. RESULTS: A total of 79,211 samples and 7626 positive samples (9.6 %) were identified. We found that the number of warm and humid days, 1 or 2 months prior to testing for TaAb, was associated with the positivity rate of the test. An increase in the positivity rate by 1.6 % and 2.9 % was observed with every 1-day increase in warm and humid days 1 month and 2 months before the test, respectively. CONCLUSIONS: Our TaAb analysis revealed a significant increase in TaAb positivity 1 or 2 months after periods of warm and humid days.

Radiotracer Development for Fungal-Specific Imaging: Past, Present, and Future.

Invasive fungal infections have become a major challenge for public health, mainly due to the growing numbers of immunocompromised patients, with high morbidity and mortality. Currently, conventional imaging modalities such as computed tomography and magnetic resonance imaging contribute largely to the noninvasive diagnosis and treatment evaluation of those infections. These techniques, however, often fall short when a fast, noninvasive and specific diagnosis of fungal infection is necessary. Molecular imaging, especially using nuclear medicine-based techniques, aims to develop fungal-specific radiotracers that can be tested in preclinical models and eventually translated to human applications. In the last few decades, multiple radioligands have been developed and tested as potential fungal-specific tracers. These include radiolabeled peptides, antifungal drugs, siderophores, fungal-specific antibodies, and sugars. In this review, we provide an overview of the pros and cons of the available radiotracers. We also address the future prospects of fungal-specific imaging.

Comparison of diagnostic efficiency of detecting IgG and IgE with immunoassay method in diagnosing ABPA: a meta-analysis.

BACKGROUND: Hitherto, the bulk of diagnostic criteria regards Aspergillus-specific immunoglobulin E as a key item, and regard IgG as an auxiliary method in diagnose. Nevertheless, there is no conclusive study in summarize the performance of IgG and IgE diagnosing ABPA. METHODS: We conducted a systematic review to identify studies report results of IgE and IgG detection in diagnosing ABPA. QUADAS-2 tool was used to evaluate included studies, and we applied the HSROC model to calculate the pooled sensitivity and specificity. Deeks' funnel was derived to evaluated the public bias of included studies, and Cochrane Q test and I2 statistic were used to test the heterogeneity. RESULTS: Eleven studies were included in this study (1127 subjects and 215 for IgE and IgG). Deeks's test for IgE and IgG were 0.10 and 0.19. The pooled sensitivity and specificity for IgE were 0.83 (95%CI: 0.77, 0.90) and 0.89 (0.83, 0.94), and for IgG were 0.93 (0.87, 0.97) and 0.73 (0.62,0.82), with P value < 0.001. The PLR and NLR for IgE were 7.80 (5.03,12.10) and 0.19 (0.13,0.27), while for IgG were 3.45 (2.40,4.96) and 0.09 (0.05,0.17). The combined diagnostic odds ratio and diagnostic score were 41.49 (26.74,64.36) and3.73 (3.29,4.16) for IgE, respectively, and were 38.42 (19.23,76.79) and 3.65 (2.96,4.34) for IgG. CONCLUSION: The sensitivity for IgG diagnosing ABPA is higher than IgE, while the specificity for IgE is higher. IgG might be able to play a more important role in filtering ABPA patients.

The seroprevalence of anti-Histoplasma capsulatum IgG antibody among pulmonary tuberculosis patients in seven referral tuberculosis hospitals in Indonesia.

BACKGROUND: Histoplasma capsulatum exposure is rarely suspected in Indonesia. Pulmonary histoplasmosis can occur simultaneously with pulmonary tuberculosis (TB) or as an alternative diagnosis in clinically-diagnosed TB patients with no microbiological evidence of TB. This study aimed to determine the seroprevalence of anti-H. capsulatum IgG antibody among pulmonary TB patients. METHODOLOGY: This was a sub-study of 306 participants from a prospective cohort pulmonary TB study conducted at seven TB referral hospitals in Indonesia. The study population was presumptive pulmonary TB adult patients who underwent microbiological TB examinations and were categorized as drug-sensitive (DS), drug-resistant (DR), and clinically-diagnosed TB. Anti-H. capsulatum IgG antibody levels at baseline were measured using MVista Histoplasma Ab enzyme immunoassays. Data were summarized using descriptive statistics. Bivariate and multivariate logistic regression analysis were performed to assess factors associated with anti-H. capsulatum IgG antibody positive result. RESULTS: 12.7% (39/306) of pulmonary TB patients were positive for anti-H. capsulatum IgG antibodies (DR-TB patients (15.9%, 18/114), DS-TB (13.0%, 15/115), and clinically-diagnosed TB (7.8%, 6/77)). The median unit value of anti-H. capsulatum IgG antibody for all positive samples was 15.7 (IQR 10.2-28.9) EU. This median unit value was higher in clinically-diagnosed TB patients compared to DS-TB or DR-TB patients (38.1 (IQR 25.6-46.6) EU, 19.7 (IQR 12.3-28.9) EU, and 10.9 (IQR 9.2-15.4), respectively). There were 10 patients (3.3%) with anti-H. capsulatum IgG antibody levels above 30 EU. Factors associated with the anti-H. capsulatum IgG antibody positive result were malignancies (OR 4.88, 95% CI 1.09-21.69, p = 0.037) and cavitary lesions (OR 2.27, 95% CI 1.09-4.70, p = 0.028). CONCLUSIONS: Our results provide evidence of exposure to H. capsulatum among pulmonary TB patients in Indonesia. Further studies are needed to provide a comprehensive picture of this fungal disease in other populations and regions to enhance awareness among clinicians and public health officials.