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33-63% of all adult meningitis in southern Africa 1-3

Evaluation of a Novel Point of Care Cryptococcal Antigen (CRAG) Test on Serum, Plasma and Urine from Patients with HIV-associated Cryptococcal Meningitis. Joseph N Jarvis, Ann Percival, Sean Bauman, Graeme Meintjes, G. Ntombomzi Williams, Nicky Longley, Thomas S Harrison, Thomas R Kozel.

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33-63% of all adult meningitis in southern Africa 1-3

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  1. Evaluation of a Novel Point of Care Cryptococcal Antigen (CRAG) Test on Serum, Plasma and Urine from Patients with HIV-associated Cryptococcal Meningitis Joseph N Jarvis, Ann Percival, Sean Bauman, Graeme Meintjes, G. Ntombomzi Williams, Nicky Longley, Thomas S Harrison, Thomas R Kozel

  2. Cryptococcal Meningitis 33-63% of all adult meningitis in southern Africa 1-3 Acute mortality with Amphotericin 24-43% 4-7 Acute mortality with Fluconazole 54-96% 8-10 * References on final slide

  3. Diagnosis? Lumbar puncture and India-ink Immunodiagnosis (CRAG)

  4. Diagnosis? Lumbar puncture and India-ink Immunodiagnosis (CRAG) A Point-of Care Assay? Earlier diagnosis Antigen screening Serum, plasma and urine

  5. Study aims To evaluate a quantitative antigen-capture ELISA for GXM and a novel point of care lateral flow immunoassay (LFA) Using paired serum, plasma and urine from patients with active or prior CM we: - defined the relationship of CRAG levels in serum, plasma and urine - tested the sensitivity of the novel lateral flow assay in serum, plasma and urine

  6. GF Jooste Hospital, Cape Town • Paired blood and urine samples • HIV +ve adults with a history of laboratory confirmed cryptococcal meningitis • Tested in parallel using: • Quantitative sandwich ELISA • - Lateral flow assay Study design

  7. Methods Quantitative sandwich ELISA GXM concentrations were determined in each sample by use of a quantitative sandwich ELISA that was constructed using the GXM mAbs F12D2 and 339 Lateral flow assay A novel LFA was constructed from the same mAbs F12D2 and 339 utilized in the quantitative sandwich ELISA

  8. Test strips were read after 10 minutes by four different observers Positive if all four observers read the strip as positive and equivocal if some but not all observers read the strip as positive Titers were determined by serially diluting patient samples and assessing reactivity as described above. The highest sample dilution that produced a positive result when read by four observers was recorded as the LFA titer.

  9. Patient demographics 62 patients Median age 34 years, 40% male, median CD4 count 45 cells/mL 61% acute episode 39% during follow-up, median 189 days (98-376)

  10. Results 1 - Quantitative ELISA for GXM All 62 patients had detectable GXM in serum, plasma and urine The mean (95% CI) GXM concentrations were: Serum 3800 (2100-6600) ng/ml Plasma 3600 (2100-6300) ng/ml Urine 170 (100-280) ng/ml

  11. p < 0.001 for all pairings

  12. Results 2 - Lateral flow assay

  13. Results 2 - Lateral flow assay

  14. p < 0.001 for all pairings

  15. Conclusions Serum and plasma can be used interchangeably for CRAG testing CRAG testing of urine is of potential value There are close correlations between GXM levels on ELISA and LFA titers in serum, plasma and urine This point of care test has the potential to markedly improve the early diagnosis of CM in many settings

  16. 1. Bekondi Int J Infect Dis 2006 2. Scarborough NEJM 2007 3. Jarvis BMC Infect Dis 2010 4. Bicanic Clin Infect Dis 2007 5. Bicanic Clin Infect Dis 2008 6. Kambugu Clin Infect Dis 2008 7. Jarvis J Infect 2010 8. Mwaba Postgrad Med J 2001 9. Mayanja-Kizza Clin Infect Dis 1998 10. Longley Clin Infect Dis 2009

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