Progressive Disseminated Histoplasmosis Research Articles

Histoplasmosis in patients living with HIV in Europe: review of literature.

Histoplasma capsulatum (var. capsulatum Hcc and duboisii Hcd), is a dimorphic fungus that causes histoplasmosis. It usually affects people coming from endemic areas, causing a variety of clinical manifestations up to progressive disseminated histoplasmosis (PDH), especially among people living with HIV (PLWH). We conducted a systematic review to assess histoplasmosis burden of PLWH in Europe. The review follows PRISMA guidelines, with protocol registered in PROSPERO (CRD42023429779). Seventy-eight articles were selected, including 109 patients (32 women). On overall, median age was 37 years. Forty-six patients were Americans, 39 Africans, 17 Europeans, 5 Asians, in 2 cases nationality was not specified. Cases were mainly diagnosed in Italy (28.4%), France (17.3%) and Spain (17.4%), with a north-south gradient. Six cases lacked epidemiologic links with endemic areas. Concerning CDC HIV staging at diagnosis, the information was available for 60 PLWH (55%) and all subjects were at stage C3 except for two subjects at stage B3. PDH was the AIDS-presenting illness in 39 patients. Most patients had a PDH (80.7%); other common extrapulmonary forms were isolated cutaneous histoplasmosis (7.3%), or lymphatic localization (2.7%). In 30 cases, the diagnosis was made by analyzing only one sample. For the remaining 79 cases, multiple samples were collected from each patient. Regarding the biological sample more frequently used for the diagnosis of histoplasmosis, bronchoalveolar lavage sample was taken from 39 patients, and tested positive in 51.3% of cases; 36 patients underwent a skin biopsy which was positive in 86.1% of cases and 28 patients performed bone-marrow biopsy, which led to the diagnosis of histoplasmosis in 92.9% of cases. The identification of Histoplasma capsulatum was available in 97 PLWH through examination of different samples: Hcc and Hcd were identified in 89 and 8 PLWH, respectively. Concerning therapies, 67.9% were treated with liposomal amphotericin B, 18.3% with itraconazole, 10 died pre-treatment. The overall mortality rate was 23.6%. Non-survivors exhibited more frequently gastrointestinal symptoms (p = 0.017), while cutaneous signs correlated with better survival (p = 0.05). Untreated patients faced higher mortality (p < 0.001). Histoplasmosis should be considered amongst opportunistic infection in PLWH, even in Europe, especially if patients originate from or have travelled to endemic areas. Systematic review registration: The registration number is CRD42023429779.

Progressive disseminated histoplasmosis: The experience in one non-endemic medical center.

Histoplasmosis, the most common endemic mycosis in North America, presents in a myriad of ways, spanning the spectrum from self-limiting pneumonia to progressive disseminated histoplasmosis (PDH). Toward better describing contemporary histoplasmosis syndromes, risks, and outcomes, this single-center retrospective cohort study was performed (2009-2019). The population who developed PDH was similar to that with other forms of histoplasmosis (OFH) except for higher rates of preexisting immunocompromising conditions (91.3% vs. 40%, P<.001) and a trend toward receiving more chronic immunosuppression (65.2% vs. 33.3%, P=.054) compared to those with OFH. Diagnosis was most frequently achieved by urinary or serum antigen positivity. People with PDH more frequently tested positive compared to those with OFH, but negative tests did not rule out histoplasmosis. Median time to diagnosis was prolonged among people with both PDH and OFH (32 vs. 31 days, respectively). Following diagnosis, people with PDH received more liposomal amphotericin (78.3% vs. 20%, P<.001). Subsequent survival at 90 and 365 days and treatment response were similar in both groups. Patients with PDH were more often hospitalized (95.7% vs. 60%, P=.006); however, once admitted, there were no differences in hospital length of stay or intensive care unit admission rate. The challenges of diagnosing histoplasmosis based on clinical presentation alone highlight the need for heightened awareness of these entities especially given the recent reports on expanded endemicity and delays in diagnosis.

Closing the Gap in Proteomic Identification of Histoplasma capsulatum: A Case Report and Review of Literature.

Histoplasmosis is a globally distributed systemic infection caused by the dimorphic fungus Histoplasma capsulatum (H. capsulatum). This fungus can cause a wide spectrum of clinical manifestations, and the diagnosis of progressive disseminated histoplasmosis is often a challenge for clinicians. Although microscopy and culture remain the gold standard diagnostic tests for Histoplasma identification, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has emerged as a method of microbial identification suitable for the confirmation of dimorphic fungi. However, to our knowledge, there are no entries for H. capsulatum spectra in most commercial databases. In this review, we describe the case of disseminated histoplasmosis in a patient living with HIV admitted to our university hospital that we failed to identify by the MALDI-TOF method due to the limited reference spectrum of the instrument database. Furthermore, we highlight the utility of molecular approaches, such as conventional polymerase chain reaction (PCR) and DNA sequencing, as alternative confirmatory tests to MALDI-TOF technology for identifying H. capsulatum from positive cultures. An overview of current evidence and limitations of MALDI-TOF-based characterization of H. capsulatum is also presented.

Evaluation of the Histoplasma capsulatum 100-kilodalton antigen dot blot for the rapid diagnosis of progressive histoplasmosis in HIV/AIDS patients

Among people living with HIV (PLHIV), progressive disseminated histoplasmosis (PDH) represents an important cause of mortality. Since antigen detection allows a rapid diagnosis and the instauration of a specific treatment this study aimed to evaluate the analytical performance of the Hcp100 dot blot, an in-house assay that detects the Histoplasma capsulatum 100-kilodalton antigen in urine and compare it with 2 commercially available assays the Histoplasma Urine Antigen Lateral Flow Assay (MVD-LFA) (MiraVista® Diagnostics) and the Clarus Histoplasma Galactomannan EIA (Clarus HGM) (IMMY). Urine specimens from 23 PLHIV with PDH, 13 patients with other infectious diseases, and 20 healthy individuals were tested. The Hcp100 dot blot showed higher sensitivity (87.0%), specificity (97.0%) and accuracy (92.9%) than the MVD-LFA (73.9%, 78.8%, and 76.8%, respectively) and the Clarus HGM (78.3%, 90.9%, and 85.7%, respectively). The Hcp100 dot blot had high analytical performance and would be a valuable screening tool for diagnosing PDH among PLHIV.

Role of recombinant Histoplasma capsulatum 100-kilodalton antigen in the diagnosis of histoplasmosis among HIV/AIDS patients: Antigenuria and antibodies detection.

Diagnosing progressive disseminated histoplasmosis (PDH) is still challenging in many countries where this disease is highly endemic. Definitive diagnosis is established by culture and/or by cytology/histopathology but both procedures have limited sensitivity and cultures are time-consuming. Antibodies detection by immunodiffusion has a low sensitivity in immunocompromised individuals. Commercially available antigen detection assays have high sensitivity in PDH cases; however, they are expensive and only performed in few laboratories. To describe the potential use of a novel ELISA for antibodies testing and a dot blot assay for antigen testing for diagnosing PDH using the recombinant 100 kDa protein of Histoplasma capsulatum (Hcp100) and their polyclonal antibodies as novel reagents, respectively. Serum and urine samples from a cohort of patients with HIV/AIDS and proven PDH were studied for the detection of anti-Hcp100 antibodies by ELISA and Hcp100 antigen by dot blot, respectively. Sensitivity, specificity and cross-reactions with other diseases were estimated for each assay and compared with those obtained using histoplasmin (HMN) as a reagent for antibodies detection by ELISA and immunodiffusion, and using a commercial antigenuria test. Antibodies detection by the Hcp100 ELISA demonstrated 78.6% sensitivity and 88.4% specificity, versus 85.7% sensitivity and 81.0% specificity for the HMN ELISA and 26.1% sensitivity and 100% specificity for the immunodiffusion assay. Antigen detection by the Hcp100 dot blot demonstrated 89.3% sensitivity and 97.0% specificity versus 82.1% sensitivity and 90.9% specificity for the commercial test. The immunoassays described herein based on Hcp100 would be a valuable screening tool for diagnosing PDH.

Establishing the proportion of severe/moderately severe vs mild cases of progressive disseminated histoplasmosis in patients with HIV.

Progressive disseminated histoplasmosis remains a major but neglected cause of death among patients with advanced HIV. Recently, aiming to reduce avoidable deaths, the Pan American Health Organization issued the first diagnosis and treatment guidelines for HIV-associated histoplasmosis. But what proportion of progressive disseminated histoplasmosis in HIV-infected patients is severe is currently not known. Because this proportion influences treatment needs, we aimed to estimate this in a cohort of 416 patients in French Guiana. We used the definition in the recent PAHO/WHO guidelines for severity. We used regression modelling to predict the impact of CD4 count on the proportion of severe cases. In a territory where treatment cost is not a limiting factor and where histoplasmosis is well known, we assumed that clinicians' initial treatment reflected their perception about the severity of the case and therefore, the needs for different treatments. Using these definitions, since the beginning, there were 274 (65.9%) severe/moderately severe cases and 142 (34.1%) mild cases. In practice 186 cases were treated with deoxycholate or liposomal amphotericin B (44.7%) and 230 (55.3%) cases treated with itraconazole as first line treatment. The Kappa concordance measure between the guideline definition and the actual treatment given was 0.22. There was a 9% risk difference for death within 30 days of antifungal treatment initiation between severe/moderately severe and mild cases. Over threequarters (77%) of early deaths were attributed to severe/moderately severe cases. This is the only rigorous estimate of the proportion of severe/moderately severe cases of progressive disseminated histoplasmosis in symptomatic HIV patients on the largest published cohort. These numbers may help defend budget needs for rapid diagnostic tests and liposomal amphotericin B.

Thrombotic Microangiopathy Due to Progressive Disseminated Histoplasmosis in a Child With Down Syndrome and Acute Lymphoblastic Leukemia.

Histoplasmosis, a common mycosis in the south-central United States, may be life threatening in immunocompromised patients. We describe a 4-year-old female with Down syndrome and acute lymphoblastic leukemia who developed hemolytic anemia, thrombocytopenia, and renal failure, consistent with thrombotic microangiopathy. Bone marrow biopsy revealed non-necrotizing granulomas with GMS staining demonstrating budding yeast. Serum Histoplasma antigen testing was positive, providing further evidence for the diagnosis of progressive disseminated histoplasmosis. Treatment with amphotericin B, plasma exchange, and ventilator, vasopressor, and renal replacement support led to a full recovery. Providers should have a low threshold for histoplasmosis testing in ill immunocompromised patients, who are at greater risk for infection-related morbidity.

P302 Disseminated histoplasmosis: Rare entity in immunocompromised individuals in India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMInvasive mycoses kill more than one million people every year. The disease burden of mycoses has increased over the last 20 years and the importance of fungal disease is expected to keep increasing in the years to come. One of these mycoses, histoplasmosis, a disease caused by species of dimorphic genera, Histoplasma and is endemic in the USA, Asia, and Africa with sporadic cases reported from India. In the United States alone, 3.4 cases/100 000 people occur yearly. In India, prevalence of histoplasmosis is seen in the eastern part of the country and few cases are reported from north India. Here, we present four cases of classic progressive disseminated histoplasmosis from non-endemic central and northern parts of India.Cases I and II: Two cases, firstly a 51-year-old male resident of Delhi, came with complaints of fever, generalized weakness and weight loss for the past 6 months, and another a 55-year-old in an apparently immunocompetent female from a non-endemic state in central India. The disease was diagnosed by bone marrow aspirate incidentally.Cases III and IV: A 25-year-old female and a 29-year-old HIV-infected female, with chief complaints of multiple skins colored swellings on her face, neck, chest, and back and also on both limbs. Physical examination revealed multiple skin-colored papules and nodules coalescing to form large plaques on the face, neck, upper back, and chest which had overlying yellowish-brown crusting (Fig.1). Her entire face was involved with depression of the nasal bridge and madarosis. Multiple discrete 0.1-0.5 mm papules and nodules on bilateral upper and lower limbs. Patient was started on the treatment of cutaneous histoplasmosis with injection of liposomal amphotericin-B 100 mg intravenous (around 3 mg/kg/day) after pre-medication for 10 days. For both cases, capsule itraconazole 200 mg BD started for 4 days. Patient responded well to the treatment and follow-up showed improvement in the condition of the patient.ResultsIn all the cases, fine needle aspirate cytology of the lesions showed plenty of inflammatory cells and macrophages in pathological microscopic examination. Microscopic examination of skin tissue revealed that macrophages comprising of yeast forms of Histoplasma have pericellular halo around them. Moreover, on long incubation of biopsy sample on SDA media plate at 27˚C, white/buff colonies with yellow-tan on the back were observed. Furthermore, microscopic examination of grown fungal culture showed mycelial septate hyphae bearing round to pear-shaped, smooth-walled broadly elliptical microconidia, or tuberculate macroconidia. In all the cases, clinical suspicion, histopathological and mycological findings (microscopy, culture and post-culture sequencing) led to a confirmatory diagnosis of progressive disseminated Histoplasmosis by H. capsulatum var. capsulatum was made.ConclusionIn all, 3 of these cases are of progressive disseminated histoplasmosis in apparently immunocompetent patients from the non-endemic states of north India. On the contrary, one of the cases was HIV positive with mucocutaneous lesions. Disseminated histoplasmosis in immunocompetent individuals is not a rare entity, in India. High clinical suspicion and awareness regarding the pathogen are required. From the point of good patient care, an accurate diagnosis, and timely management in cases of histoplasmosis are warranted.

837. Performance of Blood (1- &amp;gt;3)-β-D-Glucan in People with AIDS Presenting with Respiratory Symptoms

Abstract Background The gold standard for diagnosis of Pneumocystis jirovecii pneumonia (PCP) is direct visualization of the microorganism in respiratory samples, usually obtained via bronchoalveolar lavage (BAL). Blood β-D-glucan (BDG) is used as a non-invasive adjunctive diagnostic test for PCP, but specificity is only modest, in part because other opportunistic fungal infections cause high BDG. We previously showed BDG-positivity in 94% of people with AIDS (PWA), progressive disseminated histoplasmosis (PDH), and respiratory symptoms in our hospital. In this study, we aim to assess the performance of BDG as a diagnostic test for PCP in PWA who have respiratory symptoms. Methods We retrospectively identified PWA who had a BDG result between 2014 and 2019. AIDS was defined as past or current absolute CD4 count &amp;lt; 200 cells/µL, or a past or current AIDS-defining condition. Positive cytological or histological evidence of P. jirovecii in bronchoalveolar lavage (BAL) fluid or lung biopsy, or positive Pneumocystis PCR on sputum or BAL confirmed PCP. The Fungitell Assay (Associates of Cape Cod, East Falmouth, MA) determined BDG levels as follows: negative, &amp;lt; 60 pg/mL; indeterminate, 60-79 pg/mL, and positive, ≥ 80 pg/mL. Values &amp;lt; 31 pg/mL and those &amp;gt;500 pg/mL were censored at 30 pg/mL and 500 pg/mL, respectively. Respiratory symptoms were defined as cough, dyspnea, chest pain, or hypoxia. We compared BDG results for participants with proven PCP and participants without proven PCP. Results We identified 260 PWA with a BDG result, of whom 183 had at least one respiratory symptom. 84 (45.9%) of these participants had a positive BDG. BDG results among participants with and without PCP are shown in Table 1. Of the 44 participants with a positive BDG who did not have PCP, 29 (65.9%) had PDH. Other diagnoses included cryptococcosis and candidemia. The test performance of BDG for the diagnosis of PCP is shown in Table 2. Exclusion of participants with PDH increased the specificity of BDG for PCP to 86.4%. Table 1. Results of (1-&amp;gt;3)-β-D-glucan Testing by Pneumocystis jirovecii Pneumonia Diagnosis Among Participants with AIDS and Respiratory Symptoms Table 2. Test Performance of (1-&amp;gt;3)-β-D-glucan for the Diagnosis of Pneumocystis jirovecii Pneumonia* Conclusion At our center where histoplasmosis is endemic, a positive BDG should not be attributed to PCP among PWA with respiratory symptoms because of low specificity and low positive predictive value. However, a negative BDG can exclude PCP in this population. Disclosures All Authors: No reported disclosures

A case report of progressive disseminated histoplasmosis in Vietnam

A case report of progressive disseminated histoplasmosis in Vietnam

Comparison of Blood (1->3)-β-d-Glucan Levels in AIDS-Related Pneumocystis jirovecii Pneumonia and AIDS-Related Progressive Disseminated Histoplasmosis.

In this retrospective study, (1->3)-β-d-glucan (B-glucan) was an unreliable marker for AIDS-related Pneumocystis jirovecii pneumonia (PCP) because a high percentage of participants with progressive disseminated histoplasmosis and respiratory symptoms had a positive B-glucan result. Where histoplasmosis is common, attributing B-glucan positivity to PCP without further testing risks misdiagnosis.

Diagnostic accuracy of antigen detection in urine and molecular assays testing in different clinical samples for the diagnosis of progressive disseminated histoplasmosis in patients living with HIV/AIDS: A prospective multicenter study in Mexico.

The progressive disseminated histoplasmosis (PDH) has been associated with severe disease and high risk of death among people living with HIV (PLWHIV). Therefore, the purpose of this multicenter, prospective, double-blinded study done in ten Mexican hospitals was to determine the diagnostic accuracy of detecting Histoplasma capsulatum antigen in urine using the IMMY ALPHA Histoplasma EIA kit (IAHE), clarus Histoplasma GM Enzyme Immunoassay (cHGEI IMMY) and MiraVista Histoplasma Urine Antigen LFA (MVHUALFA); as well as the Hcp100 and 1281-1283220SCAR nested PCRs in blood, bone-marrow, tissue biopsies and urine. We included 415 PLWHIV older than 18 years of age with suspicion of PDH. Using as diagnostic standard recovery of H. capsulatum in blood, bone marrow or tissue cultures, or histopathological exam compatible, detected 108 patients (26%, [95%CI, 21.78-30.22]) with proven-PDH. We analyzed 391 urine samples by the IAHE, cHGEI IMMY and MVHUALFA; the sensitivity/specificity values obtained were 67.3% (95% CI, 57.4-76.2) / 96.2% (95% CI, 93.2-98.0) for IAHE, 91.3% (95% CI, 84.2-96.0) / 90.9% (95% CI, 87.0-94.0) for cHGEI IMMY and 90.4% (95% CI, 83.0-95.3) / 92.3% (95% CI, 88.6-95.1) for MVHUALFA. The Hcp100 nested PCR was performed on 393, 343, 75 and 297, blood, bone marrow, tissue and urine samples respectively; the sensitivity/specificity values obtained were 62.9% (95%CI, 53.3-72.5)/ 89.5% (95%CI, 86.0-93.0), 65.9% (95%CI, 56.0-75.8)/ 89.0% (95%CI, 85.2-92.9), 62.1% (95%CI, 44.4-79.7)/ 82.6% (95%CI, 71.7-93.6) and 34.9% (95%CI, 24.8-46.2)/ 67.3% (95%CI, 60.6-73.5) respectively; and 1281-1283220SCAR nested PCR was performed on 392, 344, 75 and 291, respectively; the sensitivity/specificity values obtained were 65.3% (95% CI, 55.9-74.7)/ 58.8% (95%CI, 53.2-64.5), 70.8% (95%CI, 61.3-80.2)/ 52.9% (95%CI, 46.8-59.1), 71.4% (95%CI, 54.7-88.2)/ 40.4% (95%CI, 26.4-54.5) and 18.1% (95%CI, 10.5-28.1)/ 90.4% (95%CI, 85.5-94.0), respectively. The cHGEI IMMY and MVHUALFA tests showed excellent performance for the diagnosis of PDH in PLWHIV. The integration of these tests in clinical laboratories will certainly impact on early diagnosis and treatment.

Diagnosis of histoplasmosis: current status and perspectives.

Histoplasmosis is a worldwide-distributed systemic mycosis caused by the dimorphic fungus Histoplasma capsulatum. Its clinical manifestations range from subclinical or mild respiratory illness to progressive disseminated histoplasmosis (PDH), a life-threatening disease, whose accurate diagnosis is still challenging and limited in many countries, where this disease is highly endemic. In this regard, Histoplasma antigen testing is now included in the WHO Essential Diagnostics List. The final diagnosis of histoplasmosis is established by culture and/or visualization of the yeast cells by cytology or histopathology using specific stains. However, both procedures have limited sensitivity to detect the disease and cultures are time-consuming. Antibody detection assays are effective for the subacute and chronic clinical forms of histoplasmosis. However, their sensitivity is low in the immunocompromised host. Several molecular "in-house" tests were also developed and showed promising results, but none of these tests are commercially available and their standardization and validation are still pending. Antigen detection assays have high sensitivity in PDH cases and are of great value for the follow-up of patients with histoplasmosis; however, cross-reactivity with other related fungi are common. In addition, this assay is expensive and only performed in few laboratories. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques in order to obtain standardized and specific reagents for the diagnosis of histoplasmosis, as opposed to the unspecific antigens or crude extracts currently used. This review describes the currently available assays, highlighting their strengths and limitations and reports the latest approaches to achieve reliable and rapid diagnostic tests for histoplasmosis. KEY POINTS: • PDH causes thousands of deaths per year globally. • Rapid accurate diagnosis of PDH is unfeasible in many regions. • Fast, accurate, and low-cost diagnostic alternatives are currently under development.

Progressive disseminated histoplasmosis in children living with HIV: a case series study.

Progressive disseminated histoplasmosis (PDH) is thought to be on the top of the list of AIDS-defining illnesses in South America. Reported experience in children is very scarce. The aim of this study was to describe the clinical characteristics, management, and outcomes of children living with HIV presenting with PDH in Ecuador. We did a retrospective study using collected data on medical records of children living with HIV attended in Francisco Icaza Bustamante Children's Hospital (Guayaquil) between 1997 and 2019. The inclusion criteria consisted of patients under 18 years of age at admission with documented HIV infection and laboratory-confirmed diagnosis of PDH. Twenty-four children living with HIV were attended due to laboratory-confirmed PDH. Median CD4 cell count was 39 cells/mm³ (p25-p75 21-155) between 1 and 5 years and 22 cells/mm³ (p25-p75 10-57) for those aged 6 years and over. Fever (96%) was the most common clinical manifestation, followed by hepatomegaly (75%), cough (67%), weight loss (63%), diarrhea (63%), and abdominal distension (58%). Most significant laboratory findings were hypoalbuminemia (90%), hypertransaminasemia (78%), and pancytopenia (46%). Intravenous treatment with amphotericin B deoxycholate was started in all but one case in which diagnosis was postmortem. All these 23 patients were discharged after being hospitalized for a median of 68 days (p25-p75 48-90). Two children showed relapse during follow-up, one of whom died during the hospitalization of this second episode of PDH.Conclusion: Clinical manifestations and laboratory findings of PDH in children living with HIV seem similar to those seen in adults, and low CD4 cell count appears to be the most important risk factor. What is Known: • Since 1987, progressive disseminated histoplasmosis has been considered an AIDS-defining illness and, although underdiagnosis is frequent, is thought to be on the top of the list of AIDS-defining illnesses in South America. • Reported experience in children is very scarce. What is New: • Clinical manifestations and laboratory findings of progressive disseminated histoplasmosis in children living with HIVseem similar to those seen in adults. • Low CD4 cell count to be the most important risk factor.

934. Diagnostic Utility of Blood (1- &amp;gt;3)-β-D-Glucan Testing in Patients with HIV in Arkansas

BackgroundBlood (1- > 3)-β-D-Glucan (BDG) is a sensitive marker for Pneumocystis jirovecii pneumonia (PJP) in patients with AIDS (PWA). However, other fungal infections, including progressive disseminated histoplasmosis (PDH), cause high levels of BDG. At our hospital, PDH is a common diagnosis in PWA with fever and respiratory complaints, making it difficult to differentiate PJP from PDH based on clinical features alone. The objective of this study was to assess BDG as a diagnostic test for PJP in Arkansas where histoplasmosis is endemic.MethodsWe performed a retrospective review of patients with confirmed PJP and confirmed PDH who had BDG testing between 2014-2020. Positive cytological or histological evidence of P. jirovecii in bronchoalveolar lavage (BAL) or lung biopsy, or positive PCR on sputum or BAL confirmed PJP. Identification of Histoplasma capsulatum in culture of blood or other normally sterile site, histology showing typical yeast forms, or a positive urine H. capsulatum antigen assay (MiraVista Diagnostics) confirmed PDH. The Fungitell Assay determined BDG levels as follows: negative, < 60 pg/mL; indeterminate, 60-79 pg/mL, and positive > 80 pg/mL. Values below 31 pg/mL and those above 500 pg/mL were censored at 30 and 500, respectively. Respiratory symptoms were defined as the presence of cough, shortness of breath, or dyspnea on exertion.Results53 episodes of PDH occurred in 46 patients. 42 were accompanied by a BDG result. Of these, 38 (90%) were positive; 3 (7%) were negative; and 1 (2%) was indeterminate. 44 (83%) of the PDH episodes were associated with respiratory symptoms. 36 of these had a BDG result. 34 (94%) were positive; 1 (3%) was negative; and 1 (3%) was indeterminate. 44 episodes of PJP occurred in 40 patients. All had a BDG result. 43 (98%) were positive.10 (23%) episodes of PJP were accompanied by a concomitant infection.The mean BDG level was significantly higher in the PJP group compared to those with PDH and respiratory symptoms (P=.002). However, values overlapped substantially, and BDG positivity was not significantly more frequent in the PJP group (P=.586). Box-and-Whisker Display of (1->3)-β-D-Glucan Results ConclusionIn Arkansas, BDG positivity is not a reliable marker of PJP because it cannot distinguish between PJP and PDH. Attributing an elevated BDG to PJP without additional evaluation risks misdiagnosis.Disclosures All Authors: No reported disclosures

Histoplasma capsulatum 100-kilodalton antigen: recombinant production, characterization, and evaluation of its possible application in the diagnosis of histoplasmosis.

The goal of the present work was to develop a novel reagent with potential for histoplasmosis diagnosis. For this purpose, the genetic sequence of the 100kDa protein of Histoplasma capsulatum (Hcp100) was cloned and expressed as a secretory protein in Pichia pastoris. After optimizing the culture conditions and purifying by immobilized metal ion affinity chromatography, the highest yield of Hcp100 reached approximately 1.3mg/l with > 90% purity in shake flasks using basal salt medium supplemented with casamino acids after 72h of methanol induction. To investigate its potential for diagnosis, its detection in urine samples using specific polyclonal antibodies as reagent was evaluated by dot blot in 6 patients with progressive disseminated histoplasmosis (PDH), of whom all had AIDS. Antigen was detected in urine from all 6 (100%) PDH patients. Urine samples from a pool of 20 healthy individuals did not react with the anti-Hcp100 antibodies. The dot blot assay performed in this study provides preliminary data of a simple technology that can be performed in medical institutions with limited resources to facilitate the rapid diagnosis of histoplasmosis, particularly the disseminated forms. Hence, use of these assays may provide a rapid diagnostic tool of PDH in endemic areas for histoplasmosis where PDH-related mortality is high, hastening treatment and improving patient survival. Finally, this novel antigen and its specific antibodies may provide an alternative diagnostic reagent to the largely unknown and poorly characterized polysaccharide antigens (HPA, galactomannan, histoplasmin) frequently used in the diagnostic tests. KEY POINTS: Few antigens are used as laboratory tools for the immunodiagnosis of histoplasmosis. P. pastoris was an excellent system for recombinant Hcp100 expression. Maximum expression levels of rHcp100 were achieved in BSM with 1% casamino acids. Dot blot assays with anti-rHcp100 antisera can be successfully used for diagnosing PHD.

Treating progressive disseminated histoplasmosis in people living with HIV.

BackgroundProgressive disseminated histoplasmosis (PDH) is a serious fungal infection that affects people living with HIV. The best way to treat the condition is unclear.ObjectivesWe assessed evidence in three areas of equipoise.1. Induction. To compare efficacy and safety of initial therapy with liposomal amphotericin B versus initial therapy with alternative antifungals.2. Maintenance. To compare efficacy and safety of maintenance therapy with 12 months of oral antifungal treatment with shorter durations of maintenance therapy.3. Antiretroviral therapy (ART). To compare the outcomes of early initiation versus delayed initiation of ART.Search methodsWe searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane CENTRAL; MEDLINE (PubMed); Embase (Ovid); Science Citation Index Expanded, Conference Proceedings Citation Index‐Science, and BIOSIS Previews (all three in the Web of Science); the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and the ISRCTN registry, all up to 20 March 2020.Selection criteriaWe evaluated studies assessing the use of liposomal amphotericin B and alternative antifungals for induction therapy; studies assessing the duration of antifungals for maintenance therapy; and studies assessing the timing of ART. We included randomized controlled trials (RCT), single‐arm trials, prospective cohort studies, and single‐arm cohort studies.Data collection and analysisTwo review authors assessed eligibility and risk of bias, extracted data, and assessed certainty of evidence. We used the Cochrane 'Risk of bias' tool to assess risk of bias in randomized studies, and ROBINS‐I tool to assess risk of bias in non‐randomized studies. We summarized dichotomous outcomes using risk ratios (RRs), with 95% confidence intervals (CI).Main resultsWe identified 17 individual studies. We judged eight studies to be at critical risk of bias, and removed these from the analysis.1. InductionWe found one RCT which compared liposomal amphotericin B to deoxycholate amphotericin B. Compared to deoxycholate amphotericin B, liposomal amphotericin B may have higher clinical success rates (RR 1.46, 95% CI 1.01 to 2.11; 1 study, 80 participants; low‐certainty evidence). Compared to deoxycholate amphotericin B, liposomal amphotericin B has lower rates of nephrotoxicity (RR 0.25, 95% CI 0.09 to 0.67; 1 study, 77 participants; high‐certainty evidence). We found very low‐certainty evidence to inform comparisons between amphotericin B formulations and azoles for induction therapy.2. MaintenanceWe found no eligible study that compared less than 12 months of oral antifungal treatment to 12 months or greater for maintenance therapy.For both induction and maintenance, fluconazole performed poorly in comparison to other azoles.3. ARTWe found one study, in which one out of seven participants in the 'early' arm and none of the three participants in the 'late' arm died.Authors' conclusionsLiposomal amphotericin B appears to be a better choice compared to deoxycholate amphotericin B for treating PDH in people with HIV; and fluconazole performed poorly compared to other azoles. Other treatment choices for induction, maintenance, and when to start ART have no evidence, or very low certainty evidence. PDH needs prospective comparative trials to help inform clinical decisions.

Histoplasmosis diseminada progresiva en una cohorte de pacientes coinfectados con el VIH

Objetivo: identificar manifestaciones clínicas y métodos de laboratorio conducentes al diagnóstico de histoplasmosis diseminada progresiva (HDP), en una cohorte de pacientes coinfectados con el VIH. &#x0D; Diseño: análisis retrospectivo de historias clínicas. No intervención adicional. &#x0D; Pacientes: cuarenta pacientes con HDP e infección por VIH del Hospital La María, enero de 1992 a diciembre de 2008. &#x0D; Mediciones: datos demográficos, signos, síntomas y exámenes de laboratorio que permitieron el diagnóstico de HDP. &#x0D; Resultados: cuarenta pacientes, 34 hombres (85%), y seis mujeres (15%), con edades promedio de 33.4 y 27 años, respectivamente. En éstos predominaron: tos (77.5%), fiebre (90%) y anorexia con pérdida de peso en 92.5% y 77.4%, respectivamente. Lesiones en piel en 55% y en mucosa en 50%, crecimiento ganglionar en 62.5% y hepatomegalia en 52.5%. Menos frecuentes fueron disnea, esplenomegalia, vómito, diarrea y cefalea. Presentaron anemia el 85%, leucopenia el 52.5% y trombocitopenia el 30% de los pacientes. Exámenes micológicos: directo positivo en 21 muestras, de lavado broncoalveolar siete, piel seis, ganglio 12, biopsia transbronquial una y lesión de mucosa una. Se aisló H. capsulatum en todos los pacientes a partir de muestras de piel 10, ganglio 18, sangre tres, médula ósea una, lavado broncoalveolar (LBA) 10, y mucosa tres. Además, en siete pacientes, el hongo se aisló de más de un sitio anatómico. La serología realizada en 13 pacientes, se mostró reactiva en la inmunodifusión en gel de agar (IDGA) en 11 y en la fijación del complemento (FC) en 10. &#x0D; Conclusión: ante un cuadro clínico compatible con HDP en paciente con infección por VIH que presenta fiebre, pérdida del estado general, crecimiento ganglionar, compromiso medular y piel y mucosas, el laboratorio permitirá confirmar fácilmente el diagnóstico de la sospecha clínica de la entidad

Loop-mediated Isothermal Amplification and nested PCR of the Internal Transcribed Spacer (ITS) for Histoplasma capsulatum detection

BackgroundHistoplasmosis is a neglected disease that affects mainly immunocompromised patients, presenting a progressive dissemination pattern and a high mortality rate, mainly due to delayed diagnosis, caused by slow fungal growth in culture. Therefore, a fast, suitable and cost-effective assay is required for the diagnosis of histoplasmosis in resource-limited laboratories. This study aimed to develop and evaluate two new molecular approaches for a more cost-effective diagnosis of histoplasmosis.MethodologySeeking a fast, suitable, sensitive, specific and low-cost molecular detection technique, we developed a new Loop-mediated Isothermal Amplification (LAMP) assay and nested PCR, both targeting the Internal Transcribed Spacer (ITS) multicopy region of Histoplasma capsulatum. The sensitivity was evaluated using 26 bone marrow and 1 whole blood specimens from patients suspected to have histoplasmosis and 5 whole blood samples from healthy subjects. All specimens were evaluated in culture, as a reference standard test, and Hcp100 nPCR, as a molecular reference test. A heparin-containing whole blood sample from a heathy subject was spiked with H. capsulatum cells and directly assayed with no previous DNA extraction.ResultsBoth assays were able to detect down to 1 fg/μL of H. capsulatum DNA, and ITS LAMP results could also be revealed to the naked-eye by adding SYBR green to the reaction tube. In addition, both assays were able to detect all clades of Histoplasma capsulatum cryptic species complex. No cross-reaction with other fungal pathogens was presented. In comparison with Hcp100 nPCR, both assays reached 83% sensitivity and 92% specificity. Furthermore, ITS LAMP assay showed no need for DNA extraction, since it could be directly applied to crude whole blood specimens, with a limit of detection of 10 yeasts/μL.ConclusionITS LAMP and nPCR assays have the potential to be used in conjunction with culture for early diagnosis of progressive disseminated histoplasmosis, allowing earlier, appropriate treatment of the patient. The possibility of applying ITS LAMP, as a direct assay, with no DNA extraction and purification steps, makes it suitable for resource-limited laboratories. However, more studies are necessary to validate ITS LAMP and nPCR as direct assay in other types of clinical specimens.

Diagnosis of Progressive Disseminated Histoplasmosis in Advanced HIV: A Meta-Analysis of Assay Analytical Performance.

Histoplasmosis is an important cause of mortality in people with advanced HIV, especially in countries with limited access to diagnostic assays. Histoplasmosis can be diagnosed using culture, histopathology, and antibody, antigen, and molecular assays. Several factors may affect the analytical performance of these laboratory assays, including sample type, clinical stage of the disease, and previous use of antifungal treatment, among others. Here we describe the results of a systematic literature review, followed by a meta-analysis of the analytical performances of the diagnostic laboratory assays employed. Our initial search identified 1631 references, of which 1559 references were excluded after title and abstract screening, leaving 72 references identified as studies relevant to the validation of histoplasmosis diagnostic assays. After evaluating the full text, 30 studies were selected for final review, including one paper not identified in the initial search. The meta-analysis for assay analytical performance shows the following results for the overall sensitivity (Sen) and specificity (Spe) of the various methods evaluated: Culture, Sen 77% (no data for specificity calculation); antibody detection assays, Sen 58%/Spe 100%; antigen detection assays, Sen 95%/Spe 97%; and DNA detection assays (molecular), Sen 95%/Spe 99%. Of the 30 studies reviewed, nearly half (n = 13) evaluated Histoplasma antigen assays, which were determined to be the most accurate methodology for diagnosis of progressive disseminated histoplasmosis in advanced HIV (inverse of the negative likelihood ratio was 13.2). Molecular assays appear promising for accurate diagnosis of histoplasmosis, but consensus on exact techniques is needed. Cultures showed variable sensitivity related to sample type and laboratory handling. Finally, antibody assays presented high specificity but low sensitivity. This poor sensitivity is most likely due the highly immunosuppressed state of this patient population. Diagnostic assays are crucial for accurate diagnosis of progressive disseminated histoplasmosis (PDH) with advanced HIV disease.