Evaluation of quantitative point-of-care test for measurement of glucose-6-phosphate dehydrogenase enzyme activity in Malaysia.

INTRODUCTION: The treatment of Plasmodium vivax malaria with 8-aminoquinolines is contraindicated in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals due to the risk of acute haemolytic anaemia. Effective G6PD screening is paramount to avoid adverse drug reactions. This study aimed to evaluate the performance of novel quantitative point-of-care (POC) tests as a new screening method for G6PD deficiency in Malaysia. MATERIALS AND METHODS: A total of 153 neonatal cord blood, 99 peripheral blood of older children aged between 1 month to 12-years old, and 62 peripheral adult blood were screened for G6PD deficiency using two quantitative POC tests, CareStartTM biosensor (Carestart) and CareStartTM Biosensor 1 (S1). The results were compared with OSMMR2000D kit as a reference assay. Two statistical analyses were performed in this study to evaluate the POC test performances, the Spearman's correlation test and the Cohen's kappa method. RESULTS: Both Carestart and S1 tests showed significant positive correlations to OSMMRS000D with r2 = 0.7916 and r2 = 0.7467. Their measurement of agreement showed a kappa (κ) value of 0.805 (p<0.001, 95% CI), and 0.795 (p<0.001, 95% CI), respectively. Analysis of the area under the Receiver Operating Curve (ROC) at 60% cut-off illustrated that the Carestart had 90.2% sensitivity, 98.9% specificity, 98.3% positive predictive value (PPV), and 93.8% negative predictive value (NPV). The corresponding values for the S1 were 95.2%, 100%, 100%, and 96.8%, respectively. CONCLUSION: This study showed that the Carestart and S1 biosensors have high-performance reliability for screening of G6PD deficiency, which can guide safe prescriptions of anti-malaria medications and hence, eradication of Plasmodium vivax malaria.

Paraprosthetic leak unmasked by thrombolysis for thrombosed mitral valve.

Prosthetic valve thrombosis (PVT) is classically a cardiothoracic surgical emergency. Case series, however, report thrombolysis as first line management for PVT. A case of mitral PVT treated successfully with thrombolysis is described. Immediately after thrombolysis a trivial paraprosthetic leak noted on pretreatment transoesophageal echocardiography had increased significantly in severity. The paraprosthetic leak subsequently required repeat mitral valve replacement. It is speculated that the thrombolytic treatment interfered with the usual healing process by disrupting the fibrin deposited at the valve ring margin. This suggests that fibrin is important in the formation of the annular seal of the prosthetic valve and that patients receiving thrombolysis should be monitored for this complication.