Urine Lipoarabinomannan Research Articles

Urine lipoarabinomannan concentrations among HIV-negative adults with pulmonary or extrapulmonary tuberculosis disease in Vietnam.

Lipoarabinomannan (LAM) is a promising target biomarker for diagnosing subclinical and clinical tuberculosis (TB). Urine LAM (uLAM) testing using rapid diagnostic tests (RDTs) has been approved for people living with HIV (PLWH), however there is limited data regarding uLAM levels in HIV-negative (HIV-ve) adults with clinical TB. We conducted a clinical study of adults presenting with clinical TB-related symptoms at the National Lung Hospital in Hanoi, Vietnam. The uLAM concentrations were measured using electrochemiluminescent (ECL) immunoassays and compared to a microbiological reference standard (MRS) using GeneXpert Ultra and TB culture testing. Estimated uLAM concentrations above plate specific calculated limit of detection (LOD) were considered uLAM positive. Additional microbiological testing was conducted for possible extrapulmonary TB (EPTB). Among 745 participants enrolled, 335 (44.9%) participants with presumptive pulmonary TB (PTB) and 6 (11.3%) participants with presumptive EPTB had confirmed TB disease. Overall, the S/A antibody pair had a sensitivity of 39% (95% Confidence Interval [CI] 0.33, 0.44) and a specificity of 97% (95% CI 0.96, 0.99) compared to the MRS. The F/A antibody pair had a sensitivity of 41% (95% CI 0.35, 0.47) and a specificity of 79% (95% CI 0.75, 0.84). S/A provided greater discriminatory ability compared to F/A for both individuals with presumptive PTB (AUROC: 0.74 vs 0.63, p<0.0001) and presumptive EPTB (0.76 vs 0.54, p = 0.045) when using the MRS. Among HIV-ve participants in an adult cohort in Vietnam, the concentrations of uLAM remained relatively low for people with clinical TB, which may present challenges for improving RDT sensitivity.

Real-world diagnostic accuracy of lipoarabinomannan in three non-sputum biospecimens for pulmonary tuberculosis disease

Development of a non-sputum test using readily-obtainable biospecimens remains a global priority for tuberculosis (TB) control. We quantified lipoarabinomannan (LAM) concentrations, a pathogen biomarker for Mycobacterium tuberculosis, in urine, plasma and serum for real-world diagnostic accuracy of pulmonary TB among people living with and without HIV. We conducted a prospective diagnostic study among adults with TB symptoms in South Africa. We measured LAM concentrations in time-matched urine, plasma and serum with an electrochemiluminescence immunoassay using two capture antibodies (FIND 28 and S4-20). From the completed cohort, we randomly selected 210 participants (2 cases: 1 control) based on sensitivity estimates, and we compared diagnostic accuracy of LAM measurements against the microbiological reference standard. Urine and blood specimens from 210 of 684 adults enrolled were tested for LAM. Among 138TB-positive adults (41% female), median urine LAM was 137pg/mL and 52pg/mL by FIND 28 and S4-20, respectively. Average LAM concentrations were highest in HIV-positive participants with CD4+ T cells <200cells/mm3. Urine LAM by S4-20 achieved diagnostic sensitivity of 62% (95% CI: 53%-70%) and specificity of 99% (95% CI: 96%-100%). Plasma and serum LAM by FIND 28 showed similar sensitivity (70%, 95% CI: 62%-78%) and comparable specificities (90%, 95% CI: 82%-97%; 94%, 95% CI: 88%-99%). Diagnostic sensitivity of urine LAM by S4-20 was higher among participants without HIV (41%, 95% CI: 24%-61%) compared to HIV-positive participants with CD4 ≥200cells/mm3 (20%, 95% CI: 8%-39%). Detection of LAM was achievable in non-sputum specimens for pulmonary TB, but additional analyte concentration or signal amplification may be required to achieve diagnostic accuracy targets. Bill and Melinda Gates Foundation.

Expanding Xpert MTB/RIF Ultra® and LF-LAM testing for diagnosis of tuberculosis among HIV-positive adults admitted to hospitals in Tanzania and Mozambique: a randomized controlled trial (the EXULTANT trial)

IntroductionTuberculosis (TB) is an important cause of morbidity and mortality among people living with HIV (PLHIV). Current WHO-recommended strategies for diagnosing TB among hospitalized PLHIV rely on symptom screening and disease severity to assess eligibility for urine lipoarabinomannan lateral flow (LF-LAM) and molecular testing. Despite these recommendations, autopsy studies show a large burden of undiagnosed TB among admitted PLHIV. The EXULTANT trial aims to assess the impact of an expanded screening strategy using three specimens (sputum, stool, and urine) for TB diagnosis among PLHIV admitted to hospitals in two high HIV and TB burden African countries.MethodsThis is a multicenter, pragmatic, individually randomized controlled trial conducted across eleven hospitals in Tanzania and Mozambique. Participants in the intervention arm will be tested with Xpert MTB/RIF Ultra® from expectorated sputum, stool, and urine samples, with additional urine LF-LAM testing in the first 24 h after hospital admission, irrespective of the presence of the symptoms. The control arm will implement the WHO standard of care recommendations. Hospitalized adults (≥ 18 years) with a confirmed HIV-diagnosis, irrespective of antiretroviral (ART) therapy status or presence of TB symptoms will be assessed for eligibility at admission. Patients with a pre-existing TB diagnosis, those receiving anti-tuberculosis therapy or tuberculosis preventive treatment in the 6 months prior to enrolment, and those transferred from other hospitals will not be eligible. Also, participants admitted for traumatic reasons such as acute abdomen, maternal conditions, scheduled surgery, having a positive SARS-CoV2 test will be ineligible. The primary endpoint is the proportion of participants with microbiologically confirmed TB starting treatment within 3 days of enrolment.DiscussionThe EXULTANT trial investigates rapid implementation after admission of a new diagnostic algorithm using Xpert MTB/RIF Ultra® in several non-invasive specimens, in addition to LF-LAM, in hospitalized PLHIV regardless of TB symptoms. This enhanced strategy is anticipated to detect frequently missed TB cases in this population and is being evaluated as an implementable and scalable intervention.Trial registrationTrial reference number: NCT04568967 (ClinicalTrials.gov) registered on 2020–09-29.

Prospective Analysis of urINe LAM to Eliminate NTM Sputum Screening (PAINLESS) study: Rationale and trial design for testing urine lipoarabinomannan as a marker of NTM lung infection in cystic fibrosis.

Routine screening for nontuberculous mycobacterial (NTM) lung disease is dependent on sputum cultures. This is particularly challenging in the cystic fibrosis (CF) population due to reduced sputum production and low culture sensitivity. Biomarkers of infection that do not rely on sputum may lead to earlier diagnosis, but validation trials require a unique prospective design. The rationale of this trial is to investigate the utility of urine lipoarabinomannan (LAM) as a test to identify people with CF with a new positive NTM culture. We hypothesize that urine LAM is a sensitive, non-invasive screening test with a high negative predictive value to identify individuals with a relatively low risk of having positive NTM sputum culture. This is a prospective, single-center, non-randomized observational study in adults with CF, 3 years of negative NTM cultures, and no known history of NTM positive cultures. Patients are followed for two year-long observational periods with the primary endpoint being a positive NTM sputum culture within a year of a positive urine LAM result and a secondary endpoint of a positive NTM sputum culture within 3 years of a positive urine LAM result. Study implementation includes remote consent and sample collection to accommodate changes from the COVID-19 pandemic. This report describes the study design of an observational study aimed at using a urine biomarker to assist in the diagnosis of NTM lung infection in pwCF. If successful, urine LAM could be used as an adjunct to traditional sputum cultures for routine NTM screening.

Enhanced tuberculosis diagnosis with computer-aided chest X-ray and urine LAM in adults with HIV admitted to hospital (CASTLE study): A cluster randomised trial.

People with HIV (PHIV) admitted to hospital have high mortality, with tuberculosis (TB) being the major cause of death. Systematic use of new TB diagnostics could improve TB diagnosis and might improve outcomes. We conducted a cluster randomised trial among adult PHIV admitted to Zomba Central Hospital, Malawi. Admission-days were randomly assigned to: enhanced TB diagnostics using urine lipoarabinomannan (LAM) antigen tests (SILVAMP-LAM, Fujifilm, Japan and Determine-LAM, Alere/Abbot, USA), digital chest X-ray with computer aided diagnosis (dCXR-CAD, CAD4TBv6, Delft, Netherlands), plus usual care ("enhanced TB diagnostics"); or usual care alone ("usual care"). The primary outcome was TB treatment initiation during admission. Secondary outcomes were 56-day mortality, TB diagnosis within 24-hours, and undiagnosed TB at discharge, ascertained by culture of one admission sputum sample. Between 2 September 2020 and 15 February 2022, we recruited 419 people. Four people were excluded post-recruitment, leaving 415 adults recruited during 207 randomly assigned admission-days in modified intention-to-treat analysis. At admission, 90.8% (377/415) were taking antiretroviral therapy (ART) with median (IQR) CD4 cell count 240 cells/mm3. In the enhanced diagnostic arm, median CAD4TBv6 score was 60 (IQR: 51-71), 4.4% (9/207) had SILVAMP-LAM-positive and 14.4% (29/201) had Determine-LAM positive urine with three samples positive by both urine tests. TB treatment was initiated in 46/208 (22%) in enhanced TB diagnostics arm and 24/207 (12%) in usual care arm (risk ratio [RR] 1.92, 95% CI 1.20-3.08). There was no difference in mortality by 56 days (enhanced TB diagnosis: 54/208, 26%; usual care: 52/207, 25%; hazard ratio 1.05, 95% CI 0.72-1.53); TB treatment initiation within 24 hours (enhanced TB diagnosis: 8/207, 3.9%; usual care: 5/208, 2.4%; RR 1.61, 95% CI 0.53-4.71); or undiagnosed microbiological-confirmed TB at discharge (enhanced TB diagnosis, 0/207 (0.0%), usual care arm 2/208 (1.0%) (p = 0.50). Urine SILVAMP-LAM/Determine-LAM plus dCXR-CAD diagnostics identified more hospitalised PHIV with TB than usual care. The increase in TB treatment appeared mainly due to greater use of Determine-LAM, rather than SILVAMP-LAM or dCXR-CAD. Poor concordance between Determine-LAM and SILVAMP-LAM urine tests requires further investigation. Inpatient mortality for adults with HIV remains unacceptability high.

Parallel use of low-complexity automated nucleic acid amplification tests and lateral flow urine lipoarabinomannan assays to detect tuberculosis disease in adults and adolescents living with HIV

Parallel use of low-complexity automated nucleic acid amplification tests and lateral flow urine lipoarabinomannan assays to detect tuberculosis disease in adults and adolescents living with HIV

Improving the diagnosis of active tuberculosis: a novel approach using magnetic particle-based chemiluminescence LAM assay

ObjectivesTuberculosis (TB) is a significant global health concern, given its high rates of morbidity and mortality. The diagnosis using urine lipoarabinomannan (LAM) primarily benefits HIV co-infected TB patients with low CD4 counts. The focus of this study was to develop an ultra-sensitive LAM assay intended for diagnosing tuberculosis across a wider spectrum of TB patients.Design & MethodsTo heighten the sensitivity of the LAM assay, we employed high-affinity rabbit monoclonal antibodies and selected a highly sensitive chemiluminescence LAM assay (CLIA-LAM) for development. The clinical diagnostic criteria for active TB (ATB) were used as a control. A two-step sample collection process was implemented, with the cutoff determined initially through a ROC curve. Subsequently, additional clinical samples were utilized for the validation of the assay.ResultsIn the assay validation phase, a total of 87 confirmed active TB patients, 19 latent TB infection (LTBI) patients, and 104 healthy control samples were included. Applying a cutoff of 1.043 (pg/mL), the CLIA-LAM assay demonstrated a sensitivity of 55.2% [95%CI (44.13%~65.85%)], and a specificity of 100% [95%CI (96.52%~100.00%)], validated against clinical diagnostic results using the Mann-Whitney U test. Among 11 hematogenous disseminated TB patients, the positive rate was 81.8%. Importantly, the CLIA-LAM assay consistently yielded negative results in the 19 LTBI patients.ConclusionOverall, the combination of high-affinity antibodies and the CLIA method significantly improved the sensitivity and specificity of the LAM assay. It can be used for the diagnosis of active TB, particularly hematogenous disseminated TB.

Advancements in LAM-based diagnostic kit for tuberculosis detection: enhancing TB diagnosis in HIV-negative individuals.

The purpose of this study was to investigate the diagnostic value of urine lipoarabinomannan (LAM) detection based on chemiluminescence assay for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) in HIV-negative individuals. A total of 215 patients and 37 healthy individuals were included according to inclusion and exclusion criteria, including 173 cases of PTB and 42 cases of EPTB. Sputum smears, sputum culture, TB-RNA, GeneXpert, and urine LAM results were obtained from all patients before treatment. Using the composite reference standard as the reference, the diagnostic performance of these methods for PTB and EPTB was evaluated, and the diagnostic performance and cost-effectiveness of different combinations were analyzed. In PTB, LAM exhibited the highest sensitivity (55.49%), followed by GeneXpert (44.51%). In EPTB, LAM also had the highest sensitivity (40.48%), followed by GeneXpert (33.33%). When combined with one method, LAM combined with GeneXpert showed the highest sensitivity for both PTB (68.79%) and EPTB (61.9%). When combined with two methods, culture, GeneXpert, and LAM showed the highest sensitivity for both PTB (73.99%) and EPTB (69.05%). In terms of cost-effectiveness analysis, the price of LAM was significantly lower than that of GeneXpert ($129.82 vs. $275.79 in PTB and 275.79 vs. 502.33 in EPTB). Among all combinations, the combination of LAM and sputum smear had the lowest cost, with prices of $124.94 for PTB and $263.72 for EPTB. Urine LAM detection based on chemiluminescence assay can be used as an adjunct diagnostic tool for PTB and EPTB in HIV-negative individuals. This facilitates expanding the current application of urine LAM from solely HIV-positive populations to the general population. LAM detection can overcome the limitations of obtaining clinical samples, and its ease of sample acquisition will be beneficial for its broader application in a larger scope. For economically better-off areas, we recommend using a combination of LAM + GeneXpert+culture for higher sensitivity; for economically disadvantaged areas, LAM + smear microscopy combination can provide a quick and accurate diagnosis of tuberculosis at a lower cost.

Evaluation of the efficacy of urine-based lipoarabinomannan antigen test in the diagnosis of pulmonary tuberculosis

Objective: To analyze the diagnostic efficacy of urinary lipoarabinomannan (LAM) antigen detection method in tuberculosis patients, and to provide an experimental basis for the clinical application of urinary LAM kit in China. Methods: From March to May 2023, 228 patients with lung diseases [134 male, 94 female, age 20-82 (44.8±16.7) years] were prospectively collected in Beijing Chest Hospital, Capital Medical University, including 143 pulmonary tuberculosis patients and 85 non-tuberculosis patients. Urine and sputum samples from patients were collected for traditional etiological detection and urinary LAM antigen detection. The screening results of each positive detection combination were analyzed, and the difference analysis and regression analysis were performed. Results: The detection sensitivity and specificity of the urinary LAM kit were 46.2% (95%CI: 37.9%-54.7%) and 96.5% (95%CI: 89.3%-99.1%), respectively, with an overall coincidence rate of 64.9%. The detection rate of LAM antigen detection and GeneXpert MTB/RIF (Xpert) combined (60.8%, 87/143) was significantly higher than that of Xpert alone (49.7%, 71/143), and the difference was statistically significant (P<0.05). The results of risk factor analysis showed that the risk of negative urinary LAM antigen test results increased significantly as the bacterial load decreased. Conclusions: Urine LAM antigen detection method has a high specificity and can be combined with traditional methods to effectively improve the detection rate. Urinary LAM antigen detection method still has limitations, such as the influence of bacterial load and the inability to distinguish nontuberculosis mycobacteria samples, which needs further experimental verification.

Urinary lipoarabinomannan in individuals with sputum-negative pulmonary tuberculosis.

Tuberculosis (TB) is a major global cause of ill health. Sputum microscopy for confirmation of presumptive pulmonary TB (PTB) has a reportedly low sensitivity of 22-43 per cent for single smear and up to 60 per cent under optimal conditions. National TB Elimination Programme in India recommends the use of cartridge-based nucleic acid amplification test (CBNAAT) and culture for microbiological confirmation in presumptive PTB individuals with sputum smear negative test. The use of lateral flow urine lipoarabinomannan (LF-LAM) is usually recommended for the diagnosis of TB in HIV-positive individuals with low CD4 counts or those who are seriously ill. The objective of this study was to detect urinary LAM using cage nanotechnology that does not require a physiologic or immunologic consequence of HIV infection for LAM quantification in human urine in 50 HIV-seronegative sputum smear-negative PTB individuals. To study the diagnostic value of urinary LAM in sputum smear negative PTB individuals, a cage based nanotechnology ELISA technique was used for urinary LAM in three different groups of participants. Fifty smears negative PTB clinically diagnosed, 15 smear positive PTB and 15 post TB sequel individuals. Sputum was tested by smear, CBNAAT, and culture along with urine LAM before treatment. The results were interpreted by ROC curve in comparison to the standard tests like CBNAAT and culture. The mean urinary LAM value was 0.84 ng/ml in 37 culture-positive [Mycobacterium tuberculosis (M.tb)] and 0.49 ng/ml in 13 culture-negative (M.tb) smear-negative individuals with PTB, respectively. In 47 smear-negative PTB cases with microbiologically confirmed TB by CBNAAT, the mean urinary LAM was 0.76 ng/ml. The mean urinary LAM in post-TB sequel individuals was 0.47 ng/ml. As per the receiver operating characteristic curve, cut-off value of urinary LAM in individuals with smear-negative PTB microbiologically confirmed by: (i) CBNAAT was 0.695 ng/ml and (ii) culture was 0.615 ng/ml. The findings of this study suggest that individuals with smear-negative PTB and a urinary LAM value of >0.615 ng/ml were most likely to have microbiological confirmed TB while those with a LAM value <0.615 ng/ml >0.478 ng/ml are less likely and those with a value <0.478 ng/ml are unlikely to have microbiological confirmed TB.

What is New in the Diagnosis of Childhood Tuberculosis?

The fact that almost half of the 1 million cases of childhood tuberculosis (TB)globally remain undiagnosed jeopardizes the TB elimination goal. Fortunately, there are new advances in this fieldwhich have the potential to bridge this diagnostic gap. Advances in imaging include computer assisted interpretation of chest X-rays (CXRs), point of care ultrasound (POCUS) and faster and superior computed tomography/ magnetic resonance imaging (CT/ MRI) protocols. The urine lipoarabinomannan test has proved to be a good point of care test for diagnosing TB in Human immunodeficiency virus (HIV) infected children. Stool and nasopharyngeal aspirates are emerging as acceptable alternatives for gastric lavage and induced sputum for diagnosing intrathoracic tuberculosis. Xpert MTB/RIF Ultra has improved sensitivitycompared to Xpert MTB/RIF for diagnosing both pulmonary/ extrapulmonary TB. Xpert XDR is another commercially available accurate point of care test for detecting resistance to drugs other than rifampicin in smear positive samples. Other molecular methods including new line probe assays, pyrosequencing, whole genome sequencing, and targeted next generation sequencing are extremely promising but not available commercially at present. The C-Tb skin test isan acceptable alternative to the tuberculin skin test and interferon gamma release assays for diagnosis of latent infection. There is an urgent need to incorporate some of these advances in the existingdiagnostic algorithms of childhood TB.

The use of urine lipoarabinomannan for establishing pulmonary TB in HIV patient: case report and systematic review

Introduction: Indonesia is still the country that provides the second-largest estimated number of TB cases worldwide. Several patients had TB with HIV-positive. HIV-positive patients with symptoms suggestive of pulmonary tuberculosis often difficult to produce sputum of sufficient quality. Lateral flow lipoarabinomannan examination with urine specimens is expected to be easy, inexpensive, fast, and accurate point-of-care testing. The aim of this research was to assess the sensitivity and specificity of the lateral flow method in detecting lipoarabinomannan (LAM) from urine specimens in HIV-positive patients with suspected pulmonary tuberculosis. Sputum cultures were utilised as a reference standard. Case Description: A 21-year-old male patient came to the clinic complaining of a cough that had not subsided since the previous month. Cough felt throughout the day with a little white phlegm. The patient admitted to having high-risk sexual behavior and had been tested positive for HIV but had not started antiretroviral therapy. The laboratory examination results showed that the leukocyte count was 3600/mm3 and the radiological examination revealed a chest X-ray within normal limits. The patient had been tested for sputum smears with negative results but was still advised to start TB treatment. The patient has not started treatment because he feels that his sputum smear test results are negative. Currently, the patient is not willing to have his sputum checked again. The polyclinic doctor knows the lipoarabinomannan (LAM) examination that uses urine specimens to diagnose TB but does not yet know its effectiveness for this patient. Conclusion: In this case report, the patient was unwilling to do a diagnostic test related to the TB. The systematic review was that the Alere Determine™ TB LAM Ag may not be clinically applicable for diagnosing tuberculosis infection in patients living with HIV at this time. However, Fujifilm SILVAMP TB LAM® could be regarded as a supplementary tool to the established diagnostic protocol for tuberculosis in HIV-positive patients.

Diagnostic value of chemiluminescence for urinary lipoarabinomannan antigen assay in active tuberculosis: insights from a retrospective study.

This study aimed to assess the efficacy of chemiluminescence-based urinary lipoarabinomannan (LAM) antigen assay as a diagnostic tool for identifying active tuberculosis. A retrospective study was conducted on 166 Tuberculosis (TB), 22 Non-Tuberculous Mycobacteria (NTM), 69 Non-TB cases, and 73 healthy controls from Zhangjiagang First Peoples Hospital between July 2022 and November 2022. Clinical and laboratory data were collected, including urine samples for LAM antigen detection, sputum samples and pleural effusion for GeneXpert, TB-DNA, and culture. TB group exhibited a higher LAM positivity rate (P < 0.001). CD4 count and diabetes as independent factors influencing the diagnostic accuracy of LAM. The LAM assay showed a sensitivity of 50.6% and a specificity of 95.65%. Notably, LAM's sensitivity was superior to TB-DNA (50.60% vs. 38.16%, P < 0.05). LAM's PTB detection rate was 51.7%, superior to TB-DNA (P = 0.047). Moreover, in EPTB cases, the LAM detection rate was 42.11%, surpassing Gene Xpert (P = 0.042), as well as exceeding the detection rates of TB-DNA and sputum culture. LAM antigen detection using chemiluminescence has demonstrated outstanding clinical diagnostic value for active TB, especially in the diagnosis of extrapulmonary TB. The convenience of sample collection in this diagnostic approach allows for widespread application in the clinical diagnosis of active tuberculosis, particularly in cases of EPTB and sputum-negative patients.

Breakthrough of chemiluminescence-based LAM urine test beyond HIV-positive individuals: Clinical diagnostic value of pulmonary tuberculosis in the general population.

To investigate the diagnostic value of a novel high-sensitivity urine lipoarabinomannan (LAM) test (chemiluminescence-based) for active tuberculosis in the general population. A retrospective study was conducted on 250 clinical suspected tuberculosis patients who were HIV-negative and visited the Fourth People's Hospital of Foshan from January 2022 to December 2022. Among them, there were 135 cases of pulmonary tuberculosis, 34 cases of extrapulmonary tuberculosis, and 81 cases of non-tuberculosis. Urine samples were collected for LAM antigen detection before treatment, and laboratory data of sputum smear acid-fast staining (smear method), sputum culture, and GeneXpert method were collected. Using clinical diagnosis as the reference standard, the diagnostic efficacy of 4 methods for detecting active tuberculosis was evaluated. For the 135 cases of pulmonary tuberculosis, the sensitivity of sputum smears, sputm culture, sputm GeneXpert method, and urine LAM were 29.6% (40/135), 45.9% (62/135), 59.3% (80/135), and 51.9% (70/135), respectively. The combination of LAM + GeneXpert and LAM + culture had the highest sensitivity for detecting active pulmonary tuberculosis, which were 71.0% and 78.2%, respectively. For the detection of sputum culture-negative pulmonary tuberculosis, the positive rates of smear, GeneXpert, and LAM were 0.0% (0/73), 53.4% (39/73), and 52.1% (38/73), respectively. LAM + smear and LAM + Genexpert could detect 52.1% and 68.5% of sputum culture-negative patients, respectively. The high-sensitivity urine LAM test holds promise for tuberculosis diagnosis in the general population. It demonstrates high-sensitivity, enabling the detection of sputum culture-negative pulmonary tuberculosis patients. Furthermore, when combined with existing methods, it can enhance the overall detection rate.

1506. Prevalence of Histoplasma Antigenuria among an outpatient Advanced HIV cohort in Kampala,Uganda

Abstract Background Histoplasmosis is a major cause of mortality in persons with advanced HIV disease (CD4&amp;lt; 200 cells/mcL) and areas of endemicity are evolving. Presenting symptoms of histoplasmosis may overlap with that of tuberculosis (TB). The true burden of histoplasmosis remains unknown in persons with advanced HIV disease, in part due to poor diagnostic capacity. We sought to evaluate the prevalence of Histoplasma antigenuria among outpatients with advanced HIV disease in Kampala, Uganda. Methods This prospective cohort study of outpatients with advanced HIV in Kampala, Uganda was nested within the ongoing ENCORE trial evaluating preemptive therapy and prophylaxis among outpatients with advanced HIV disease. Urine samples were obtained from participants at the time of enrollment and a Histoplasma galactomannan enzyme immunoassay (EIA) (Immy, Norman OK) was run on urine per manufacturer’s instructions. We obtained baseline characteristics and laboratory values, a statistical comparison by antigen status was not done due to a low number of positives. We calculated the prevalence of histoplasmosis in our cohort using EIA results. We obtained information on symptoms, TB diagnostics, and TB treatment for those with Histoplasma antigenuria. Results We tested 388 urine samples among participants with advanced HIV disease. Four samples were positive for Histoplasma antigen (1%). Baseline characteristics of participants are summarized in Table 1. Histoplasma antigen prevalence among participants with CD4&amp;lt; 100 cells/mcL was 2.5% (4/158). Of those that tested positive for histoplasmosis, the median CD4 count was 39 cells/mcL (interquartile range (IQR): 16–54), and median CRP was elevated at 29 (IQR 14-46). All four participants with Histoplasma antigenuria had a positive TB urine lipoarabinomannan (LAM, AlereLAM, Abbott, Palatine, IL, USA), though only two of four participants reported symptoms of cough, weight loss, and/or physical weakness. Three of four participants with positive Histoplasma antigen were started on anti-TB treatment. Patient symptoms resolved with no intervention. Conclusion Among outpatients with severe advanced HIV disease with CD4&amp;lt; 100 cells/mcL in Kampala, Uganda Histoplasma antigen prevalence was 2.5%. Disclosures All Authors: No reported disclosures

1496. Utility of Urinary Lipoarabinomannan (LAM) for Diagnosis of Tuberculosis in HIV-infected Hospitalized Patients – A Prospective Observational Study.

Abstract Background Lipoarabinomannan (LAM) is an essential component of the cell wall of mycobacterium tuberculosis. LAM causes anti-inflammatory effects on the human immune system by reducing innate and acquired cellular activity and increasing IL-10 production. Increased LAM in body fluid is a marker of active infection, with maximum concentration in sputum followed by urine. WHO has endorsed the urine LAM for diagnosis of tuberculosis in HIV infection. The study aimed to find the utility of urinary LAM assay in diagnosing tuberculosis in hospitalized patients with HIV Infection. Methods All Adult (≥18-year-old) patients with HIV infection and hospitalised and regardless of their presenting symptoms or CD4 count, were included for urinary LAM assay (Alere) for diagnosis of tuberculosis. Patients who had taken antituberculosis drugs (first or second line) the month prior were excluded. With molecular and culture methods, best practices were done to find opportunistic infections, including tuberculosis. Results A total of 60 patients were enrolled, and urinary LAM was positive in 18 (30%) cases. Among culture or GeneXpert-confirmed tuberculosis, urinary LAM was positive in 55.6% of cases. None of the patients who were not eligible for the LAM test as per 2019 WHO guidelines were found positive (Table 1). The sensitivity, specificity, and negative and positive predictive values of urinary LAM were 62.5%, 91.8%, 76.3% and 85.1%, respectively. In-hospital mortality was significantly high in LAM-positive cases (38.8% vs 16.7%; p-value=0.03). Conclusion Urinary LAM may greatly help diagnose tuberculosis in Patients with HIV-TB co-infection with critically ill, with low CD4, or presented by multiple system affection with high specificity. LAM positivity was also associated with increased mortality in HIV infection. Disclosures All Authors: No reported disclosures

Rearranging fluorescence‐magneto spatiality for “win‐win” dual functions to enhance point‐of‐care diagnosis

AbstractFluorescent‐magneto nanoemitters have gained considerable attention for their applications in mechanical controlling‐assisted optical signaling. However, the incompatibility between magnetic and fluorescent components often leads to functional limitations in traditional magneto@fluorescence nanostructure. Herein, we introduce a new compact‐discrete spatial arrangement on a “fluorescence@magneto” core–shell nanostructure consisting of a close‐packed aggregation‐induced emission luminogen (AIEgen) core and a discrete magnetic shell. This structural design effectively eliminates the optical and magnetic interferences between the dual components by facilitating AIEgens loading in core region and reducing the magnetic feeding amount through effective exposure of the magnetic units. Thereby, the resulting magneto‐AIEgen nanoparticle (MANP) demonstrates “win‐win” performances: (i) high fluorescent intensity contributed by AIEgens stacking‐enhanced photoluminescence and reduced photons loss from the meager magnetic shell; (ii) marked magnetic activity due to magneto extraposition‐minimized magnetic shielding. Accordingly, the dual functions‐retained MANP provides a proof of concept for construction of an immunochromatographic sensing platform, where it enables bright fluorescent labeling after magnetically enriching and separating procalcitonin and lipoarabinomannan in clinical human serum and urine, respectively, for the clinical diagnosis of bacterial infections‐caused inflammation and tuberculosis. This study not only inspires the rational design of magnetic‐fluorescent nanoemitter but also highlights promising potential in magneto‐assisted point‐of‐care test and biomedicine applications.

Prevalence and predictors of tuberculosis among HIV patients who completed isoniazid preventive therapy (IPT) at Reach out Mbuya community health initiative

Tuberculosis (TB) continues to be the leading cause of morbidity and mortality among human immunodeficiency virus (HIV) infected individuals in Sub Saharan Africa, including Uganda. Isoniazid prophylaxis therapy (IPT) is a major public health intervention to limit tuberculosis disease among people living with HIV. However, there is limited information about the influence of IPT on TB disease incidence and its associated risk factors among HIV positive patients in Uganda especially at Reach out-Mbuya community health initiative hence the study. A cross sectional study was conducted among HIV positive adult patients who completed a 6-months long daily treatment of Isoniazid preventive therapy. Sputum samples and urine samples were collected and analysed using Gene Xpert and lateral flow urine Lipoarabinomannan (LF-LAM) tests respectively for presence of Tuberculosis disease. Data analysis was performed using STATA (version 14). Bivariate and multivariate logistic regression were performed to assess the risk factors associated with tuberculosis among the study population and significance estimated at 95% confidence level. A total of 103 HIV positive adults was studied. The mean age of the participants was 42.1 (10.5) and median age was 43 (IQR = 16). The prevalence of tuberculosis disease among HIV positive adult patients who completed Isoniazid preventive therapy was 5.8% (6/103). Counselling, the only significant factor, reduced the likelihood of occurrence of TB disease among HIV patients on IPT treatment (aOR:0.028, P-value < 0.001). A low prevalence of TB disease was observed among HIV patients on IPT treatment. Counselling is a protective factor of TB disease among HIV patients on IPT treatment.

Etiology of Fever and Associated Outcomes Among Adults Receiving Chemotherapy for the Treatment of Solid Tumors in Uganda.

Little is known about the microbiology and outcomes of chemotherapy-associated febrile illness among patients in sub-Saharan Africa. Understanding the microbiology of febrile illness could improve antibiotic selection and infection-related outcomes. From September 2019 through June 2022, we prospectively enrolled adult inpatients at the Uganda Cancer Institute who had solid tumors and developed fever within 30 days of receiving chemotherapy. Evaluation included blood cultures, malaria rapid diagnostic tests, and urinary lipoarabinomannan testing for tuberculosis. Serum cryptococcal antigen was evaluated in participants with human immunodeficiency virus (HIV). The primary outcome was the mortality rate 40 days after fever onset, which we estimated using Cox proportional hazards models. A total of 104 febrile episodes occurred among 99 participants. Thirty febrile episodes (29%) had ≥1 positive microbiologic result. The most frequently identified causes of infection were tuberculosis (19%) and bacteremia (12%). The prevalence of tuberculosis did not differ by HIV status. The 40-day case fatality ratio was 25%. There was no difference in all-cause mortality based on HIV serostatus, presence of neutropenia, or positive microbiologic results. A universal vital assessment score of >4 was associated with all-cause mortality (hazard ratio, 14.5 [95% confidence interval, 5-42.7]). The 40-day mortality rate among Ugandan patients with solid tumors who developed chemotherapy-associated febrile illness was high, and few had an identified source of infection. Tuberculosis and bacterial bloodstream infections were the leading diagnoses associated with fever. Tuberculosis should be included in the differential diagnosis for patients who develop fever after receiving chemotherapy in tuberculosis-endemic settings, regardless of HIV serostatus.

Evidence for Tuberculosis in Individuals With Xpert Ultra "Trace" Sputum During Screening of High-Burden Communities.

"Trace" results on Xpert MTB/RIF Ultra ("Ultra"; Cepheid) -a molecular diagnostic test for tuberculosis (TB)-are often interpreted as an indication for TB treatment, but may also represent detection of nonviable bacilli or analytical error. In community-screening settings where individual TB risk is low, there is limited guidance on how to interpret Ultra-trace results. We conducted systematic Ultra TB screening of adults and adolescents (≥15 years) in Kampala, Uganda, through door-to-door and event-based sputum collection. We enrolled individuals with trace-positive sputum for detailed clinical, radiographic, and microbiological (including 2 sputum cultures, repeat Ultra, and for people with HIV, urine lipoarabinomannan) evaluation, and compared those findings with similar evaluations in controls with Ultra-negative and Ultra-positive (non-trace) sputum. Of 21 957 people screened with Ultra, 211 (1.0%) tested positive, including 96 (46% of positives) with trace results. Of 92 people enrolled with trace-positive sputum; 12% (11/92) were HIV-positive and 14% (13/92) had prior TB. The prevalence of TB among participants with trace-positive sputum results was 14% (13/92) by culture, 24% (22/92) using broader microbiological criteria, and 26% (24/92) after accounting for clinical diagnosis. The prevalence of cough and of abnormal chest computed tomography (CT) findings were 32% and 26%, respectively, if Ultra-negative; 34% and 54% if trace-positive/non-microbiologically confirmed; 72% and 95% if trace-positive/microbiologically confirmed; and 71% and 93% if Ultra-positive (more than trace). Most individuals with trace-positive sputum in Ugandan communities did not have microbiologically confirmed TB but had more symptoms and chest CT abnormalities than people with Ultra-negative sputum.