Galactomannan Lateral Flow Assay Research Articles

Bedside Galactomannan Lateral Flow Assay (GM-LFA) for timely diagnosis of Invasive Pulmonary Aspergillosis In ACLF Patients

Bedside Galactomannan Lateral Flow Assay (GM-LFA) for timely diagnosis of Invasive Pulmonary Aspergillosis In ACLF Patients

P447 Galactomannan lateral flow assay for the diagnosis of invasive Aspergillosis among clinically suspected patients in tertiary care center, Jodhpur, Rajasthan

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM IntroductionInvasive aspergillosis is one of the potentially life-threatening diseases in immunocompromised patients. Early diagnosis and prompt treatment improve patient survival. The gold standard method—conventional microscopy and culture have low sensitivity and a long turnaround time. Serum Galactomannan (GM), a polysaccharide that forms a major component of Aspergillus cell wall and is released by the fungus during invasive growth is established as a reliable biomarker, which is available as Enzyme Linked Immunoassay (ELISA). The limitations of ELISA are high cost, expertise, and difficulty in assay standardization. To overcome these limitations, a qualitative Galactomannan Lateral Flow Assay (GM-LFA) a sandwich immunochromatographic test, recently approved by European CE, is evaluated in our study.ObjectiveTo establish the diagnosis of Invasive Aspergillosis according to EORTC/MSGERC Definitions of Invasive Fungal Diseases 2021 guidelines and comparison of GM-LFA with conventional microscopy and culture.MethodWe performed a retrospective study from October 2021 to March 2022 on serum and bronchoalveolar lavage fluid (BAL) samples. GM-LFA (IMMY sōna Aspergillus Galactomannan LFA) was performed and the results are read after 10 mins with a cube reader according to the manufacturer’s instructions and compared with conventional microscopy and culture.ResultDuring the 6 months study period, 185 samples (14 BAL and 171 Serum) were collected from 148 patients. A total of 17/185 (9.18%) samples from 16 patients were positive by GM-LFA, of those 5 (29.41%) are BAL, and 12 (70.58%) are serum samples. One patient tested positive for Galactomannan on both BAL and serum.Among Assay positive samples, 3/17 (17.64%) samples were positive by microscopy and culture, which grew 2 Aspergillus fumigatus and 1 Aspergillus niger.Treatment details of 5 patients could be traced, of which 4 patients improved clinically and radiologically after Inj. voriconazole and 1 patient died before starting treatment.According to EORTC/MSGERC Definitions of Invasive Fungal Diseases 2021 guidelines, 17 patients belong to the proven and probable Invasive aspergillosis category, in which 16 patients were GM-LFA-positive and the remaining 131 patients had no evidence of invasive aspergillosis disease.ConclusionGM-LFA is a cost-effective, easy, convenient, and rapid procedure. We recommend its use for the diagnosis of invasive Aspergillosis in routine healthcare settings, especially where GM-ELISA is not available or affordable.

P424 Comparative analysis of Galactomannan Lateral Flow Assay, Galactomannan Enzyme Immunoassay and BAL culture for diagnosis of COVID-19-associated pulmonary aspergillosis

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM ObjectivesInvasive pulmonary aspergillosis is a well-known complication in COVID-19 patients. A reliable and early diagnosis is essential for the early initiation of antifungal therapy. On the other hand, conventional Bronchoalveolar lavage (BAL) culture may lack the specificity of differentiating between colonization and infection. Here, we aimed a comparative analysis of Galactomannan Lateral Flow Assay (GM-LFA), Galactomannan Enzyme Immunoassay (GM-EIA), and BAL culture for diagnosis of COVID-19-associated pulmonary aspergillosis (CAPA).MethodsBAL (n = 105) and serum samples (n = 101) from COVID-19 patients who were mechanically ventilated for ≥4 days in intensive care units (ICUs) were evaluated by GM-LFA and GM-EIA. All BAL samples were cultured on Sabouraud-Chloramphenicol dextrose Agar. Diagnostic performance of GM-LFA and GM-EIA in BAL (GM indexes ≥1) and serum (GM indexes >0.5) were evaluated and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and Roc curve compared with BAL culture calculated.ResultsThe Aspergillus GM-LFA for serum and BAL samples showed a sensitivity of 46.9% and 54.5%, specificity of 100% and 91.7%, PPV of 100% and 75%, and NPV of 80.2% and 81.5%, when compared with BAL culture, respectively. GM-EIA showed sensitivities of 56.3% and 60.6%, specificities of 94.2% and 88.9%, PPVs of 81.8% and 71.4%, and NPVs of 82.3% and 83.1% for serum and BAL samples, respectively.ConclusionAccording to our results BAL GM detection using both EIA and LFA may be a promising approach for early diagnosis of CAPA and differentiating between colonization and invasive infection.

P251 Disseminated Histoplasmosis in a Ghanaian HIV Patient: Role of Urine Histoplasma Antigen Testing in Rapid Diagnosis

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackgroundThe inhalation of the thermally dimorphic fungus Histoplasma capsulatum, may result in a wide spectrum of clinical manifestations, ranging from asymptomatic to acute or chronic pulmonary infection to disseminated infection. Symptomatic infections usually occur with high-level exposures or in immunocompromised patients mainly people with HIV. Despite the improved access to antiretroviral therapy, HIV-associated histoplasmosis remains a significant opportunistic infection in endemic regions including Africa. Unfortunately, histoplasmosis is rarely on the diagnostic radar of clinicians in several African countries such as Ghana due to insufficient awareness, inadequate epidemiological data, and poor fungal diagnostic capacity. Herein, we present a case of disseminated histoplasmosis in an HIV/AIDS patient in a tertiary hospital in Ghana.Case PresentationClinical history: A 43-year-old female was referred to the Dermatology Clinic of the Komfo Anokye Teaching Hospital (KATH) with symptoms of fever, cough, and anorexia. She had a history of a skin rash six weeks prior, which initially began on her face and later spread to the trunk and extremities. She was a known HIV/AIDS patient on anti-retroviral drugs (EFV, TFV, 3TC) with no other chronic conditions. She was anemic with a previous hemoglobin level of 7.6 g/dl. Initial diagnostic workup for cutaneous bacterial or viral infection detected no abnormality.ExaminationShe was semi-conscious, and her nostrils were clogged with crust. The patient appeared pale, warm, and anicteric. The face, trunk, and extremities (including palms) were covered with mucocutaneous erosions, ulcers, multiple papule plaques, and nodules. Examination of the cervix revealed the presence of lymph nodes.InvestigationsA fungal diagnostic work-up was done to rule out cutaneous or disseminated mycosis particularly cryptococcosis which was previously captured as a differential diagnosis. Serum cryptococcal antigen lateral flow assay (LFA) (CrAg LFA, IMMY) and Aspergillus galactomannan (GM) (sona Aspergillus GM LFA, IMMY) tests were both negative, but urine Histoplasma GM enzyme immunoassay (EIA) (clarus Histoplasma GM EIA, IMMY) test was positive with a very high optical density indicating high fungal burden was reported. A skin biopsy was also sent for histopathology and fungal culture. Histopathology analysis revealed the presence of yeast cells with round central nuclei and cytoplasmic clearing. Special staining with Periodic acid–Schiff (PAS) confirmed the presence of yeast cells, suggestive of histoplasmosis. Fungal culture was however negative after 8 weeks of incubation. A diagnosis of disseminated histoplasmosis was made.Treatment and outcomeThe patient was administered 200 mg bid of itraconazole. Few weeks after treatment, most of her skin lesions and ulcers were healed. The patient was discharged on itraconazole after the disappearance of some of her lesions. Few weeks later, the patient was admitted but died due to complications of anemia.ConclusionDisseminated histoplasmosis in HIV may be a relatively common but largely unrecognized condition in Ghana. This case report highlights the need to improve awareness of histoplasmosis among clinicians in Ghana and enhance laboratory capacity to provide timely simple contemporary fungal tests for rapid diagnosis and prompt initiation of effective antifungal agents.

Comparative analysis of galactomannan lateral flow assay, galactomannan enzyme immunoassay and BAL culture for diagnosis of COVID-19-associated pulmonary aspergillosis.

BackgroundGalactomannan Enzyme Immunoassay (GM‐EIA) is proved to be a cornerstone in the diagnosis of COVID‐19‐associated pulmonary aspergillosis (CAPA), its use is limited in middle and low‐income countries, where the application of simple and rapid test, including Galactomannan Lateral Flow Assay (GM‐LFA), is highly appreciated. Despite such merits, limited studies directly compared GM‐LFA with GM‐EIA. Herein we compared the diagnostic features of GM‐LFA, GM‐EIA and bronchoalveolar lavage (BAL) culture for CAPA diagnosis in Iran, a developing country.Materials/MethodsDiagnostic performances of GM‐LFA and GM‐EIA in BAL (GM indexes ≥1) and serum (GM indexes >0.5), i.e. sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) and areas under the curve (AUC), were evaluated using BAL (n = 105) and serum (n = 101) samples from mechanically ventilated COVID‐19 patients in intensive care units. Patients were classified based on the presence of host factors, radiological findings and mycological evidences according to 2020 ECMM/ISHAM consensus criteria for CAPA diagnosis.ResultsThe Aspergillus GM‐LFA for serum and BAL samples showed a sensitivity of 56.3% and 60.6%, specificity of 94.2% and 88.9%, PPV of 81.8% and 71.4%, NPV of 82.3% and 83.1%, when compared with BAL culture, respectively. GM‐EIA showed sensitivities of 46.9% and 54.5%, specificities of 100% and 91.7%, PPVs of 100% and 75%, NPVs of 80.2% and 81.5% for serum and BAL samples, respectively.ConclusionOur study found GM‐LFA as a reliable simple and rapid diagnostic tool, which could circumvent the shortcomings of culture and GM‐EIA and be pivotal in timely initiation of antifungal treatment.

The Aspergillus Lateral Flow Assay for the Diagnosis of Invasive Aspergillosis: an Update.

Purpose of ReviewTo review the data on the Aspergillus lateral flow assay for the diagnosis of invasive Aspergillosis.Recent FindingsAspergillus spp. cause a wide spectrum of disease with invasive aspergillosis (IA) as its most severe manifestation. Early and reliable diagnosis of disease is crucial to decrease associated morbidity and mortality, and enable prompt initiation of treatment for IA. Most recently, non-culture-based tests, such as Aspergillus galactomannan (GM), have been useful in early identification and treatment of patients with IA. However, cost, turnaround time, and variable performance indifferent populations at risk for IA remain significant drawbacks to the use of this test. Several diagnostic tests for IA have been developed, including the sōna Aspergillus GM Lateral flow assay (GM-LFA) rapid test.SummaryThe GM-LFA has shown excellent performance for the diagnosis of IA in patients with hematologic malignancy and may be a viable option for settings where ELISA GM testing is not feasible. Further evaluation of the GM-LFA in the non-hematology setting is ongoing, including in solid organ transplant recipients and patients in the intensive care unit.