Fungal Lung Disease.

Fungal lung disease encompasses a wide spectrum of organisms and associated clinical conditions presenting a significant global health challenge with type and severity determined by underlying host immunity and infecting fungal strain. The most common group of diseases are associated with the filamentous fungus Aspergillus spp. and include allergic bronchopulmonary aspergillosis (ABPA), sensitization, aspergilloma, and chronic and invasive pulmonary aspergillosis. Fungal lung disease remains epidemiologically heterogenous and is influenced by geography, environment, and host comorbidities. Diagnostic modalities continue to evolve and now include novel molecular assays and biomarkers, however, persisting challenges include achieving rapid and accurate diagnosis, particularly in resource-limited settings and in differentiating fungal infection from other pulmonary conditions. Treatment strategies for fungal lung diseases rely mainly on antifungal agents, however, the emergence of drug-resistant strains poses a substantial global threat and adds complexity to existing therapeutic challenges. Emerging antifungal agents and increasing insight into lung mycobiome via may offer fresh and personalized approaches to diagnosis and treatment, while innovative methodologies are required to mitigate drug resistance and adverse effects of treatment. This state-of-the-art review describes the current landscape of fungal lung disease, highlighting key clinical insights, current challenges, and emerging approaches for its diagnosis and treatment.

Predicting post-lung transplant survival in systemic sclerosis using CT-derived features from preoperative chest CT scans.

OBJECTIVES: The current understanding of survival prediction of lung transplant (LTx) patients with systemic sclerosis (SSc) is limited. This study aims to identify novel image features from preoperative chest CT scans associated with post-LTx survival in SSc patients and integrate them into comprehensive prediction models. MATERIALS AND METHODS: We conducted a retrospective study based on a cohort of SSc patients with demographic information, clinical data, and preoperative chest CT scans who underwent LTx between 2004 and 2020. This cohort consists of 102 patients (mean age, 50 years ± 10, 61% (62/102) females). Five CT-derived body composition features (bone, skeletal muscle, visceral, subcutaneous, and intramuscular adipose tissues) and three CT-derived cardiopulmonary features (heart, arteries, and veins) were automatically computed using 3-D convolutional neural networks. Cox regression was used to identify post-LTx survival factors, generate composite prediction models, and stratify patients based on mortality risk. Model performance was assessed using the area under the receiver operating characteristics curve (ROC-AUC). RESULTS: Muscle mass ratio, bone density, artery-vein volume ratio, muscle volume, and heart volume ratio computed from CT images were significantly associated with post-LTx survival. Models using only CT-derived features outperformed all state-of-the-art clinical models in predicting post-LTx survival. The addition of CT-derived features improved the performance of traditional models at 1-year, 3-year, and 5-year survival prediction with maximum AUC scores of 0.77 (0.67-0.86), 0.85 (0.77-0.93), and 0.90 (95% CI: 0.83-0.97), respectively. CONCLUSION: The integration of CT-derived features with demographic and clinical features can significantly improve t post-LTx survival prediction and identify high-risk SSc patients. KEY POINTS: Question What CT features can predict post-lung-transplant survival for SSc patients? Finding CT body composition features such as muscle mass, bone density, and cardiopulmonary volumes significantly predict survival. Clinical relevance Our individualized risk assessment tool can better guide clinicians in choosing and managing patients requiring lung transplant for systemic sclerosis.

Performance status at the time of lung retransplant predicts long-term function.

BACKGROUND: Lung retransplantation is offered to select patients with chronic allograft dysfunction. Given the increased risk of morbidity and mortality conferred by retransplantation, post-transplant function should be considered in the decision of who and when to list. The aim of this study is to identify predictors of post-operative disability in patients undergoing lung retransplantation. METHODS: Data were collected from the UNOS national dataset and included all patients who underwent lung retransplant from May 2005-March 2023. Pre- and post-operative function was reported by the Karnofsky Performance Status (KPS) and patients were stratified based on their needs. Cumulative link mixed effects models identified associations between pre-transplant variables and post-transplant function. RESULTS: A total of 1275 lung retransplant patients were included. After adjusting for between-group differences, pre-operative functional status was predictive of post-transplant function; patients requiring Total Assistance ( n = 740) were 74% more likely than No/Some Assistance patients (n = 535) to require more assistance in follow-up (OR 1.74, 95% CI 1.13-2.68, p = .012). Estimated one year survival of Total Assistance patients is lower than No/Some Assistance Recipients (72% vs. 82%, CI 69%-75%; 79%-86%) but similar to overall re-transplant survival (76%, CI 74%-79%). CONCLUSION: Both survival and regain of function in patients requiring Total Assistance prior to retransplant may be higher than previously reported. Pre-operative functional status is predictive of post-operative function and should weigh in the selection, timing and post-operative care of patients considered for lung retransplantation.

Lung transplantation in HIV seropositive recipients: An analysis of the UNOS registry.

BACKGROUND: Experience with lung transplantation (LT) in patients with human immunodeficiency virus (HIV) is limited. Many studies have demonstrated the success of kidney and liver transplantation in HIV-seropositive (HIV+) patients. Our objective was to conduct a national registry analysis comparing LT outcomes in HIV+ to HIV-seronegative (HIV-) recipients. METHODS: The United Network for Organ Sharing database was queried to identify LTs performed in adult HIV+ patients between 2016 and 2023. Patients with unknown HIV status, multiorgan transplants, and redo transplants were excluded. The primary endpoints were mortality and graft rejection. Survival time was analyzed using Kaplan-Meier analysis. RESULTS: The study included 17 487 patients, 67 of whom were HIV+. HIV+ recipients were younger (59 vs. 62 years, p = .02), had higher pulmonary arterial pressure (28 vs. 25 mm Hg, p = .04), and higher lung allocation scores (47 vs. 41, p = .01) relative to HIV- recipients. There were no differences in graft/recipient survival time between groups. HIV+ recipients had higher rates of post-transplant dialysis (18% vs. 8.4%, p = .01), but otherwise had similar post-transplant outcomes to HIV-recipients. CONCLUSIONS: This national registry analysis suggests LT outcomes in HIV+ patients are not inferior to outcomes in HIV- patients and that well-selected HIV+ recipients can achieve comparable patient and graft survival rates relative to HIV- recipients.

Associations between the stanford integrated psychosocial assessment for transplant and one-year lung transplant medical and psychosocial outcomes.

The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) is a standardized measure of the psychosocial risk profile of solid organ transplant candidates. While studies have found associations between this measure and transplant outcomes, to date this has not been examined in lung transplant recipients. We examined relations between pre-transplant SIPAT scores and 1-year lung transplant medical and psychosocial outcomes in a sample of 45 lung transplant recipients. The SIPAT was significantly associated with 6-minute walk test (χ2(1) = 6.47, p = .010), number of readmissions (χ2(1) = 6.47, p = .011), and mental health services utilization (χ2(1) = 18.15, p < .001). It was not a significantly associated with the presence of organ rejection or mortality (ps > 0.10). Results suggest that the SIPAT can help identify patients who are at an elevated risk for transplant complications and thus would benefit from services to mitigate risk factors and improve outcomes.

Lung Transplantation Outcomes in Recipients Aged 70 Years or Older and the Impact of Center Volume.

OBJECTIVE: To evaluate trends and outcomes of lung transplants (LTx) in recipients ≥ 70 years. METHODS: We performed a retrospective analysis of the UNOS database identifying all patients undergoing LTx (May 2005-December 2022). Baseline characteristics and postoperative outcomes were compared by age (<70 years, ≥70 years) and center volume. Kaplan-Meier analyses were performed with pairwise comparisons between subgroups. RESULTS: 34,957 patients underwent LTx, of which 3236 (9.3%) were ≥70 years. The rate of LTx in recipients ≥ 70 has increased over time, particularly in low-volume centers (LVCs); consequently, high-volume centers (HVCs) and LVCs perform similar rates of LTx for recipients ≥ 70. Recipients ≥ 70 had higher rates of receiving from donor after circulatory death lungs and of extended donor criteria. Recipients ≥ 70 were more likely to die of cardiovascular diseases or malignancy, while recipients < 70 of chronic primary graft failure. Survival time was shorter for recipients ≥ 70 compared to recipients < 70 old (hazard ratio (HR): 1.36, 95% confidence interval (CI): 1.28-1.44, p < 0.001). HVCs were associated with a survival advantage in recipients < 70 (HR: 0.91, 95% CI: 0.88-0.94, p < 0.001); however, in recipients ≥ 70, survival was similar between HVCs and LVCs (HR: 1.11, 95% CI: 0.99-1.25, p < 0.08). HVCs were more likely to perform a bilateral LTx (BLT) for obstructive lung diseases compared to LVCs, but there was no difference in BLT and single LTx likelihood for restrictive lung diseases. CONCLUSIONS: Careful consideration is needed for recipient ≥ 70 selection, donor assessment, and post-transplant care to improve outcomes. Further research should explore strategies that advance perioperative care in centers with low long-term survival for recipients ≥ 70.

Lung transplant recipients with telomere-mediated pulmonary fibrosis have increased risk for hematologic complications.

Idiopathic pulmonary fibrosis lung transplant recipients (IPF-LTRs) are enriched for short telomere length (TL) and telomere gene rare variants. A subset of patients with nontransplant short-TL are at increased risk for bone marrow (BM) dysfunction. We hypothesized that IPF-LTRs with short-TL and/or rare variants would be at increased risk for posttransplant hematologic complications. Data were extracted from a retrospective cohort of 72 IPF-LTRs and 72 age-matched non-IPF-LTR controls. Genetic assessment was done using whole genome sequencing or targeted sequence panel. TL was measured using flow cytometry and fluorescence in-situ hybridization (FlowFISH) and TelSeq software. The majority of the IPF-LTR cohort had short-TL, and 26% of IPF-LTRs had rare variants. Compared to non-IPF controls, short-TL IPF-LTRs were more likely to have immunosuppression agents discontinued due to cytopenias (P = .0375), and BM dysfunction requiring BM biopsy was more prevalent (29% vs 4%, P = .0003). IPF-LTRs with short-TL and rare variants had increased requirements for transfusion and growth factor support. Multivariable logistic regression demonstrated that short-TL, rare variants, and lower pretransplant platelet counts were associated with BM dysfunction. Pretransplant TL measurement and genetic testing for rare telomere gene variants identified IPF-LTRs at increased risk for hematologic complications. Our findings support stratification for telomere-mediated pulmonary fibrosis in lung transplant candidates.

Immunocompromised Host Pneumonia: Definitions and Diagnostic Criteria: An Official American Thoracic Society Workshop Report.

Pneumonia imposes a significant clinical burden on people with immunocompromising conditions. Millions of individuals live with compromised immunity because of cytotoxic cancer treatments, biological therapies, organ transplants, inherited and acquired immunodeficiencies, and other immune disorders. Despite broad awareness among clinicians that these patients are at increased risk for developing infectious pneumonia, immunocompromised people are often excluded from pneumonia clinical guidelines and treatment trials. The absence of a widely accepted definition for immunocompromised host pneumonia is a significant knowledge gap that hampers consistent clinical care and research for infectious pneumonia in these vulnerable populations. To address this gap, the American Thoracic Society convened a workshop whose participants had expertise in pulmonary disease, infectious diseases, immunology, genetics, and laboratory medicine, with the goal of defining the entity of immunocompromised host pneumonia and its diagnostic criteria.

Contemporary trends in PGD incidence, outcomes, and therapies.

BACKGROUND: We sought to describe trends in extracorporeal membrane oxygenation (ECMO) use, and define the impact on PGD incidence and early mortality in lung transplantation. METHODS: Patients were enrolled from August 2011 to June 2018 at 10 transplant centers in the multi-center Lung Transplant Outcomes Group prospective cohort study. PGD was defined as Grade 3 at 48 or 72 hours, based on the 2016 PGD ISHLT guidelines. Logistic regression and survival models were used to contrast between group effects for event (i.e., PGD and Death) and time-to-event (i.e., death, extubation, discharge) outcomes respectively. Both modeling frameworks accommodate the inclusion of potential confounders. RESULTS: A total of 1,528 subjects were enrolled with a 25.7% incidence of PGD. Annual PGD incidence (14.3%-38.2%, p = .0002), median LAS (38.0-47.7 p = .009) and the use of ECMO salvage for PGD (5.7%-20.9%, p = .007) increased over the course of the study. PGD was associated with increased 1 year mortality (OR 1.7 [95% C.I. 1.2, 2.3], p = .0001). Bridging strategies were not associated with increased mortality compared to non-bridged patients (p = .66); however, salvage ECMO for PGD was significantly associated with increased mortality (OR 1.9 [1.3, 2.7], p = .0007). Restricted mean survival time comparison at 1-year demonstrated 84.1 days lost in venoarterial salvaged recipients with PGD when compared to those without PGD (ratio 1.3 [1.1, 1.5]) and 27.2 days for venovenous with PGD (ratio 1.1 [1.0, 1.4]). CONCLUSIONS: PGD incidence continues to rise in modern transplant practice paralleled by significant increases in recipient severity of illness. Bridging strategies have increased but did not affect PGD incidence or mortality. PGD remains highly associated with mortality and is increasingly treated with salvage ECMO.

The kidney protects against sepsis by producing systemic uromodulin.

Sepsis is a significant cause of mortality in hospitalized patients. Concomitant development of acute kidney injury (AKI) increases sepsis mortality through unclear mechanisms. Although electrolyte disturbances and toxic metabolite buildup during AKI could be important, it is possible that the kidney produces a protective molecule lost during sepsis with AKI. We have previously demonstrated that systemic Tamm-Horsfall protein (THP; uromodulin), a kidney-derived protein with immunomodulatory properties, falls in AKI. Using a mouse sepsis model without severe kidney injury, we showed that the kidney increases circulating THP by enhancing the basolateral release of THP from medullary thick ascending limb cells. In patients with sepsis, changes in circulating THP were positively associated with a critical illness. THP was also found de novo in injured lungs. Genetic ablation of THP in mice led to increased mortality and bacterial burden during sepsis. Consistent with the increased bacterial burden, the presence of THP in vitro and in vivo led macrophages and monocytes to upregulate a transcriptional program promoting cell migration, phagocytosis, and chemotaxis, and treatment of macrophages with purified THP increases phagocytosis. Rescue of septic THP-/- mice with exogenous systemic THP improved survival. Together, these findings suggest that through releasing THP, the kidney modulates the immune response in sepsis by enhancing mononuclear phagocyte function, and systemic THP has therapeutic potential in sepsis.NEW & NOTEWORTHY Specific therapies to improve outcomes in sepsis with kidney injury have been limited by an unclear understanding of how kidney injury increases sepsis mortality. Here, we identified Tamm-Horsfall protein, known to protect in ischemic acute kidney injury, as protective in preclinical sepsis models. Tamm-Horsfall protein also increased in clinical sepsis without severe kidney injury and concentrated in injured organs. Further study could lead to novel sepsis therapeutics.

Characterization of the Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) in Lung Transplant Candidates.

The SIPAT is a standardized measure for pre-transplant psychosocial evaluation. Previous SIPAT studies utilized a relatively small lung transplant sample and only included listed patients. This study characterized the SIPAT in 147 lung transplant candidates to better elucidate its utility. The average score corresponded to a minimally acceptable rating and nearly half of the patients had relative or absolute contraindications. Interstitial Lung Disease (ILD) patients scored more favorably than non-ILD patients (U = 7.69, p < .05). The Total (ß = - .05, SE = .018, p < .01), Social Support Subscale (ß = - .133, SE = .058, p < .05), and Psychosocial Stability and Psychopathology Subscale (ß = - .103, SE = .040, p < .05) significantly predicted listing status. The SIPAT has a unique profile in lung transplant candidates and demonstrated utility for guiding transplant decisions. Future research should examine which lung transplant outcomes are significantly associated with SIPAT scores.

Diagnosis of Histoplasmosis Using the MVista Histoplasma Galactomannan Antigen Qualitative Lateral Flow-Based Immunoassay: A Multicenter Study.

BACKGROUND: Accurate and timely methods for the diagnosis of histoplasmosis in resource-limited countries are lacking. Histoplasma antigen detection by enzyme immunoassay (EIA) is widely used in the United States (US) but not in resource-limited countries, leading to missed or delayed diagnoses and poor outcomes. Lateral flow assays (LFAs) can be used in this setting. METHODS: Frozen urine specimens were submitted to MiraVista diagnostics for antigen testing from 3 medical centers in endemic areas of the US. They were blinded and tested for the MVista Histoplasma LFA. Patients were classified as controls or cases of histoplasmosis. Cases were divided into proven or probable; pulmonary or disseminated; immunocompetent or immunosuppressed; and mild, moderate, or severe. RESULTS: Three hundred fifty-two subjects were enrolled, including 66 cases (44 proven, 22 probable) and 286 controls. Most of the cases were immunocompromised (71%), and 46 had disseminated and 20 had pulmonary histoplasmosis. Four cases were mild, 42 moderate, and 20 severe. LFA and EIA were highly concordant (κ = 0.84). Sensitivity and specificity of the LFA were 78.8% and 99.3%, respectively. LFA sensitivity was higher in proven cases (93.2%), patients with disseminated (91.3%), moderate (78.6%), and severe disease (80%), and those with galactomannan levels >1.8 ng/mL (97.8%). Specificity was 99.3% in proven cases, 99.3% in patients with moderate or severe disease, and 96.8% in those with galactomannan levels >1.8 ng/mL. Cross-reactivity was noted with other endemic mycoses. CONCLUSIONS: The MVista Histoplasma LFA meets the need for accurate rapid diagnosis of histoplasmosis in resource-limited countries, especially in patients with high disease burden, potentially reducing morbidity and mortality.

Extracorporeal photopheresis to attenuate decline in lung function due to refractory obstructive allograft dysfunction.

BACKGROUND: This study was designed to prospectively evaluate the efficacy of extracorporeal photopheresis (ECP) to attenuate the rate of decline of FEV1 in lung transplant recipients with refractory bronchiolitis obliterans. Due to an observed higher than expected early mortality, a preliminary analysis was performed. STUDY DESIGN AND METHODS: Subjects from 10 lung transplant centres were assigned to ECP treatment or to observation based on spirometric criteria, with potential crossover for those under observation. The primary endpoint of this study was to assess response to ECP (i.e., greater than a 50% decrease in the rate of FEV1 decline) before and 6 months after initiation of ECP. Mortality was also evaluated 6 and 12 months after enrolment as a secondary endpoint. RESULTS: Of 44 enrolled subjects, 31 were assigned to ECP treatment while 13 were initially assigned to observation on a non-random basis using specific spirometric inclusion criteria (seven of the observation patients subsequently crossed over to receive ECP). Of evaluable patients, 95% of patients initially assigned to treatment responded to ECP with rates of FEV1 decline that were reduced by 93% in evaluable ECP-treated patients. Mortality rates (percentages) at 6 and 12 months after enrolment was 32% and 41%, respectively. The most common (92%) primary cause of death was respiratory or graft failure. Significantly (p = 0.002) higher rates of FEV1 decline were observed in the non-survivors (-212 ± 177 ml/month) when compared to the survivors (-95 ± 117 ml/month) 12 months after enrolment. In addition, 18 patients with bronchiolitis obliterans syndrome (BOS) diagnosis within 6 months of enrolment had lost 38% of their baseline lung function at BOS diagnosis and 50% of their lung function at enrolment. CONCLUSIONS: These analyses suggest that earlier detection and treatment of BOS should be considered to appreciate improved outcomes with ECP.

Risk of primary graft dysfunction following lung transplantation in selected adults with connective tissue disease-associated interstitial lung disease.

BACKGROUND: Previous studies have reported similarities in long-term outcomes following lung transplantation for connective tissue disease-associated interstitial lung disease (CTD-ILD) and idiopathic pulmonary fibrosis (IPF). However, it is unknown whether CTD-ILD patients are at increased risk of primary graft dysfunction (PGD), delays in extubation, or longer index hospitalizations following transplant compared to IPF patients. METHODS: We performed a multicenter retrospective cohort study of CTD-ILD and IPF patients enrolled in the Lung Transplant Outcomes Group registry who underwent lung transplantation between 2012 and 2018. We utilized mixed effects logistic regression and stratified Cox proportional hazards regression to determine whether CTD-ILD was independently associated with increased risk for grade 3 PGD or delays in post-transplant extubation and hospital discharge compared to IPF. RESULTS: A total of 32.7% (33/101) of patients with CTD-ILD and 28.9% (145/501) of patients with IPF developed grade 3 PGD 48-72 hours after transplant. There were no significant differences in odds of grade 3 PGD among patients with CTD-ILD compared to those with IPF (adjusted OR 1.12, 95% CI 0.64-1.97, p = 0.69), nor was CTD-ILD independently associated with a longer post-transplant time to extubation (adjusted HR for first extubation 0.87, 95% CI 0.66-1.13, p = 0.30). However, CTD-ILD was independently associated with a longer post-transplant hospital length of stay (median 23 days [IQR 14-35 days] vs17 days [IQR 12-28 days], adjusted HR for hospital discharge 0.68, 95% CI 0.51-0.90, p = 0.008). CONCLUSION: Patients with CTD-ILD experienced significantly longer postoperative hospitalizations compared to IPF patients without an increased risk of grade 3 PGD.

Blastomycosis in the Capital District of New York State: A Newly Identified Emerging Endemic Area.

BACKGROUND: The Centers for Disease Control and Prevention and New York State Department of Health recently identified the Capital District of New York (CDNY) as an emerging endemic area for blastomycosis. However, no clinical or epidemiological description of blastomycosis in the CDNY has been published. METHODS: We performed a retrospective analysis of blastomycosis cases at Albany Medical Center (AMC) and Albany Stratton Veterans Affairs Medical Center (VAMC) from January 1, 2000, through June 1, 2019. Patients were identified via an institution-approved informatics system at the hospital's microbiology laboratory. RESULTS: We identified 20 patients diagnosed with blastomycosis over the past 2 decades. There was a nearly 9-fold increase in the annual number of cases in 2016-2019 compared with 2000-2015. The majority of patients resided in the CDNY (90%), and 65% lived within the Mohawk River valley. Most cases (85%) were assumed to be malignancies or non-mycotic infections prior to diagnosis, with median time between presentation and diagnosis of 53 days. CONCLUSIONS: Our data support recent reports that blastomycosis is an emerging disease in the CDNY. Most patients were misdiagnosed as malignancy or non-mycotic infection, which led to treatment delays.

Endemic Fungi Presenting as Community-Acquired Pneumonia: A Review.

In endemic areas, dimorphic fungal infections due to Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides posadasii/immitis account for up to 30% of cases of community-acquired pneumonia. Because respiratory manifestations are often indistinguishable from common bacterial causes of pneumonia, the diagnosis of pulmonary histoplasmosis, blastomycosis, and coccidioidomycosis is often delayed and associated with antibiotics overuse. In addition to being highly endemic to certain regions of North America, dimorphic fungi have global significance due to established areas of endemicity in all six inhabited continents, an increasingly interconnected world of travelers and transported goods, and a changing epidemiology as a result of global heating and anthropomorphic land utilization. In this review, we discuss the epidemiology, pathogenesis, clinical presentation, diagnostic modalities, and treatment strategies for histoplasmosis, blastomycosis, and coccidioidomycosis.

Treatment of Community-Acquired Pneumonia in Immunocompromised Adults: A Consensus Statement Regarding Initial Strategies.

BACKGROUND: Community-acquired pneumonia (CAP) guidelines have improved the treatment and outcomes of patients with CAP, primarily by standardization of initial empirical therapy. But current society-published guidelines exclude immunocompromised patients. RESEARCH QUESTION: There is no consensus regarding the initial treatment of immunocompromised patients with suspected CAP. STUDY DESIGN AND METHODS: This consensus document was created by a multidisciplinary panel of 45 physicians with experience in the treatment of CAP in immunocompromised patients. The Delphi survey methodology was used to reach consensus. RESULTS: The panel focused on 21 questions addressing initial management strategies. The panel achieved consensus in defining the population, site of care, likely pathogens, microbiologic workup, general principles of empirical therapy, and empirical therapy for specific pathogens. INTERPRETATION: This document offers general suggestions for the initial treatment of the immunocompromised patient who arrives at the hospital with pneumonia.

Current Concepts in the Epidemiology, Diagnosis, and Management of Histoplasmosis Syndromes.

Histoplasmosis is a global disease endemic to regions of all six inhabited continents. The areas of highest endemicity lie within the Mississippi and Ohio River Valleys of North America and parts of Central and South America. As a result of climate change and anthropogenic land utilization, the conditions suitable for Histoplasma capsulatum are changing, leading to a corresponding change in epidemiology. The clinical manifestations of histoplasmosis are protean, variably resembling other common conditions such as community-acquired pneumonia, tuberculosis, sarcoidosis, Crohn's disease, or malignancy. Making a successful diagnosis is contingent on a thorough understanding of epidemiology, common clinical presentations, and best testing practices for histoplasmosis. While most subclinical or self-limited diseases do not require treatment in immunocompetent patients, all immunocompromised patients and those with progressive disseminated disease or chronic pulmonary disease should be treated. Liposomal amphotericin B is the preferred agent for severe or disseminated disease, while itraconazole is adequate for milder cases and "step-down" therapy following response to amphotericin B. In this review, we discuss the current evidence-based approaches to the epidemiology, diagnosis, and management of histoplasmosis.