scholarly journals Evaluation of the Diagnostic Performance of a Semi-Quantitative Cryptococcal Antigen Point-of-Care Assay among HIV-infected Persons with Cryptococcal Meningitis

2021 ◽  
Author(s):  
Kiiza Kandole Tadeo ◽  
Audrey Nimwesiga ◽  
Richard Kwizera ◽  
Lucy Apeduno ◽  
Emily Martyn ◽  
...  
Keyword(s):  
Cryptococcal Meningitis ◽  
Diagnostic Performance ◽  
Point Of Care ◽  
False Negative ◽  
Quantitative Result ◽  
Clinical Information ◽  
Step Test ◽  
Cryptococcal Antigen ◽  
Culture Positivity ◽  
One Step

Introduction: A newly developed cryptococcal antigen (CrAg) semi-quantitative (SQ) lateral flow assay (LFA) provides a semi-quantitative result in a rapid, one-step test instead of performing serial dilutions to determine CrAg titer. Methodology: We prospectively compared the diagnostic performance of the CrAgSQ assay (IMMY) with the CrAg LFA (IMMY) on cerebrospinal fluid (CSF) samples collected from persons with HIV-associated meningitis. The CrAgSQ grades (1+ to 5+) were compared with CrAg LFA titers and quantitative CSF fungal cultures. Results: Among 87 participants screened for HIV-associated meningitis, 60 had cryptococcal meningitis (59 CrAg+ by LFA and 1 false negative due to prozone with CrAg LFA titer of 1:1,310,000 and culture positivity), and 27 had no cryptococcal meningitis by CrAg LFA or culture. The CrAgSQ on CSF had 100% (60/60) sensitivity and 100% specificity (27/27). CSF CrAg titers ranged from 1:5 to 1:42 million. CrAgSQ grade of 1+, 2+, 3+, 4+, and 5+ corresponded to median CrAg LFA titers of 1:<10, 1:60, 1:7,680, 1:81,920, and 1:1,474,000, respectively. CSF CrAgSQ 3+ or higher were always CSF culture positive. Mortality at 14 days for those with low CrAgSQ grade (1+ to 3+) was 5% (1/22) versus 21% (8/38) with high CrAgSQ grades (4+ to 5+) (P=.084). Conclusion: The CrAgSQ demonstrates excellent diagnostic performance, maintaining both the sensitivity and specificity of the CrAg LFA, and counters false negative prozone effects. The CrAgSQ assay reading is more complex but does provide useful clinical information about disease burden and probability of culture positivity in a single rapid diagnostic test.

scholarly journals Evaluation of a Novel Point-of-Care Cryptococcal Antigen Test on Serum, Plasma, and Urine From Patients With HIV-Associated Cryptococcal Meningitis

2011 ◽  
Vol 53 (10) ◽  
pp. 1019-1023 ◽  
Author(s):  
J. N. Jarvis ◽  
A. Percival ◽  
S. Bauman ◽  
J. Pelfrey ◽  
G. Meintjes ◽  
...  
Keyword(s):  
Cryptococcal Meningitis ◽  
Point Of Care ◽  
Antigen Test ◽  
Cryptococcal Antigen

scholarly journals High burden of cryptococcal antigenemia and meningitis among patients presenting at an emergency department in Maputo, Mozambique

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250195
Author(s):  
Robert Deiss ◽  
Carolina V. Loreti ◽  
Ana G. Gutierrez ◽  
Eudoxia Filipe ◽  
Milton Tatia ◽  
...  
Keyword(s):  
Emergency Department ◽  
Cryptococcal Meningitis ◽  
Screening Program ◽  
Point Of Care ◽  
Rapid Assessment ◽  
Vital Signs ◽  
Cd4 Count ◽  
Sub Saharan Africa ◽  
Induction Treatment ◽  
Cryptococcal Antigen

Background Cryptococcal meningitis is a leading cause of HIV-related mortality in sub-Saharan Africa, however, screening for cryptococcal antigenemia has not been universally implemented. As a result, data concerning cryptococcal meningitis and antigenemia are sparse, and in Mozambique, the prevalence of both are unknown. Methods We performed a retrospective analysis of routinely collected data from a point-of-care cryptococcal antigen screening program at a public hospital in Maputo, Mozambique. HIV-positive patients admitted to the emergency department underwent CD4 count testing; those with pre-defined abnormal vital signs or CD4 count ≤ 200 cells/μL received cryptococcal antigen testing and lumbar punctures if indicated. Patients with CM were admitted to the hospital and treated with liposomal amphotericin B and flucytosine; their 12-week outcomes were ascertained through review of medical records or telephone contact by program staff made in the routine course of service delivery. Results Among 1,795 patients screened for cryptococcal antigenemia between March 2018—March 2019, 134 (7.5%) were positive. Of patients with cryptococcal antigenemia, 96 (71.6%) were diagnosed with CM, representing 5.4% of all screened patients. Treatment outcomes were available for 87 CM patients: 24 patients (27.6%) died during induction treatment and 63 (72.4%) survived until discharge; of these, 38 (60.3%) remained in care, 9 (14.3%) died, and 16 (25.3%) were lost-to follow-up at 12 weeks. Conclusions We found a high prevalence of cryptococcal antigenemia and meningitis among patients screened at an emergency department in Maputo, Mozambique. High mortality during and after induction therapy demonstrate missed opportunities for earlier detection of cryptococcal antigenemia, even as point-of-care screening and rapid assessment in an emergency room offer potential to improve outcomes.

scholarly journals A comparative study between placental alpha microglobulin-1 rapid immunoassay and standard diagnostic methods for detection of rupture of membranes

2018 ◽  
Vol 7 (5) ◽  
pp. 1813
Author(s):  
Hemant Deshpande ◽  
Umesh Sabale ◽  
C. S. Madkar ◽  
Anuja Bobe
Keyword(s):  
False Negative ◽  
High Sensitivity ◽  
Diagnostic Methods ◽  
Step Test ◽  
Non Invasive ◽  
Emergency Cesarean ◽  
One Step ◽  
Conventional Methods ◽  
Sensitivity Specificity ◽  
Very High

Background: To determine the efficacy of an immunoassay to measure levels of placental alpha-microglobulin-1 in cervico-vaginal secretions.Methods: 100 ANC cases admitted in Dr D. Y. Patil Hospital with symptoms of rupture of membranes during study period. Inclusion criteria-Pregnant women who presented with symptoms of ROM either in labour or not in labour, gestational age from 28 weeks onwards and who have given consent.Results: In 9 cases, the immunoassay test was negative, in 91 cases, it was positive and in one case, the liquor had a lot of meconium, the woman had to undergo an emergency cesarean section. This patient was deemed to have a false negative result by the test. Pooling was positive in 87 cases, nitrazine test in 86 cases and ferning in 88 cases. Hence, in comparison to immunoassay test which had 100% specificity and 98.91% sensitivity due to incomplete evaluation, nitrazine test had 95.58% sensitivity and 100% specificity, Pooling has 97.79% sensitivity and 100% specificity, whereas ferning has 98.34% sensitivity and 100% specificity.Conclusions: The PAMG1 is a non-invasive, rapid, one step test with very high sensitivity, specificity and accuracy as compared to the conventional methods together and also individually. Preforming this test instead of conventional methods can aid the early detection of rupture of membranes and largely affect the outcome of maternal and fetal health as timely decision can be taken once diagnosis is confirmed.

scholarly journals Point-of-Care Diagnosis and Prognostication of Cryptococcal Meningitis With the Cryptococcal Antigen Lateral Flow Assay on Cerebrospinal Fluid

2013 ◽  
Vol 58 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Taseera Kabanda ◽  
Mark J. Siedner ◽  
Jeffrey D. Klausner ◽  
Conrad Muzoora ◽  
David R. Boulware
Keyword(s):  
Cerebrospinal Fluid ◽  
Cryptococcal Meningitis ◽  
Point Of Care ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Cryptococcal Antigen

scholarly journals Evaluation of the Dynamiker Cryptococcal Antigen Lateral Flow Assay for the Diagnosis of HIV-Associated Cryptococcosis

2020 ◽  
Author(s):  
Richard Kwizera ◽  
Denis Omali ◽  
Kiiza Tadeo ◽  
John Kasibante ◽  
Morris K. Rutakingirwa ◽  
...  
Keyword(s):  
Predictive Value ◽  
Diagnostic Performance ◽  
Point Of Care ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Sub Saharan Africa ◽  
Serum Samples ◽  
Cryptococcal Antigen ◽  
Asymptomatic Patients ◽  
Sub Saharan

Background: Cryptococcal meningitis is a leading cause of meningitis in sub-Saharan Africa. Given the need for rapid point of care testing, we evaluated the diagnostic performance of the Dynamiker cryptococcal antigen (CrAg) lateral flow assay (LFA). Methods: We assessed the diagnostic performance of the Dynamiker CrAg-LFA compared to the IMMY CrAg-LFA as the reference standard. We tested 150 serum, 115 plasma, 100 cerebrospinal fluid (CSF) samples from HIV patients with symptomatic meningitis and 113 serum samples from patients with suspected asymptomatic cryptococcal antigenemia. Results: Compared to the IMMY CrAg-LFA, sensitivity of Dynamiker CrAg-LFA was 98% in serum, 100% in plasma, 100% in CSF from symptomatic patients and 96% in serum from asymptomatic patients. Specificity was 66% in serum, 61% in plasma, 91% in CSF from symptomatic patients, and 86% in serum from asymptomatic patients. The positive predictive value was 85% in serum, 82% in plasma, 96% in CSF from symptomatic patients, and 69% in serum from asymptomatic patients. The negative predictive value was 94% in serum, 100% in plasma, 100% in CSF from symptomatic patients, and 99% in serum from asymptomatic patients. The inter-assay reproducibility was 100% across the four sample types with no observed discordant results when Dynamiker CrAg-LFA was tested in duplicate. However, a high number of false positives were observed on serum of symptomatic patients (11%), serum of asymptomatic patients (11%) and plasma of symptomatic patients (14%). Conclusion: The Dynamiker CrAg-LFA had excellent sensitivity but poor specificity, particularly when tested on serum and plasma.

scholarly journals Evaluation of Serum Cryptococcal Antigen Testing Using Two Novel Semiquantitative Lateral Flow Assays in Persons with Cryptococcal Antigenemia

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Caleb Skipper ◽  
Kiiza Tadeo ◽  
Emily Martyn ◽  
Elizabeth Nalintya ◽  
Radha Rajasingham ◽  
...  
Keyword(s):  
False Positive ◽  
Diagnostic Performance ◽  
False Negative ◽  
Lateral Flow ◽  
Reference Standard ◽  
Serum Samples ◽  
Cryptococcal Antigen ◽  
Negative Results ◽  
Lateral Flow Assays ◽  
Positive Results

ABSTRACT Early cryptococcal disease can be detected via circulating antigen in blood before fulminant meningitis develops, when early antifungal therapy improves survival. Two semiquantitative cryptococcal antigen (CrAg) lateral flow assays (LFAs) have been developed, but their diagnostic performance has not been defined. Cryopreserved serum samples from HIV-infected Ugandans obtained as part of a prospective CrAg-screening cohort were tested in duplicate for CrAg by the CrAgSQ (IMMY) and CryptoPS (Biosynex) lateral flow assays. Case-controlled diagnostic performance was measured using the FDA-approved CrAg LFA (IMMY) as a reference standard via McNemar’s test. Of 99 serum samples tested, 57 were CrAg positive (CrAg+) by the CrAg LFA reference standard. By CrAgSQ, 57 were read as positive, with 98% sensitivity (56/57; 95% confidence interval [CI], 0.91 to 0.99) and 98% specificity (41/42; 95% CI, 0.88 to 0.99) (McNemar’s, P = 0.99). The sample with a false-negative result by CrAgSQ (n = 1) had a titer of <1:5, while the sample with a false-positive result (n = 1) yielded a 1+ result. By CryptoPS, 52 samples were read as positive, with 88% sensitivity (50/57; 95% CI, 0.76 to 0.95) and 95% specificity (40/42; 95% CI, 0.84 to 0.99) (McNemar’s, P = 0.18). The CryptoPS false-negative results included samples with titers of <1:5 (n = 1), 1:5 (n = 5), and 1:20 (n = 1), while samples with false-positive results by CryptoPS (n = 2) yielded Positive results. The CryptoPS assay missed 35% (7/20) of samples with CrAg LFA titers of ≤1:20. The new semiquantitative CrAg LFAs allow rapid estimation of titer levels in easy-to-perform platforms. The CrAgSQ demonstrated better qualitative sensitivity and specificity than the CryptoPS compared to the reference standard. The exact grading of the CrAgSQ results has some subjectivity, with interreader variability; however, qualitative reads were generally concordant for both assays.

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