Applying a direct aPTT ratio (PlatelinLS/ActinFS) permits to identify rapidly and reliably a bleeding-related factor deficiency or a lupus anticoagulant sequential to an isolated prolongation of aPTT in paediatric pre-operative screening

Objectives: An isolated prolongation of activated partial thromboplastin time (aPTT) found in paediatric pre-operative screening could be due to bleeding or non-bleeding aetiologies. The aim of our study was to evaluate clinical benefits of an additional ActinFS and/or a mixing aPTT study to identify a bleeding-related factor deficiency (BRFD). Methods: Over a 4-yr period, isolated prolongation of aPTT with PlatelinLS was detected in 308 paediatric patients and confirmed in 161 cases by a 2nd sample. ActinFS, a mixing study, FVIII, FIX, FXI, FXII and lupus anticoagulant (LA) were performed. Three different aPTT ratios between PlatelinLS and ActinFS were analysed. Results: We found 17 BRFD, 31 FXII deficiencies and 64 positive LA. A prolonged ActinFS had a significant association with BRFD (P < 0.0001) while a corrected mixing study did not. The direct aPTT ratio had a significant relationship with positive LA (P < 0.05), and with BRFD (P < 0.0001). Using this ratio, the sensitivity of BRFD's and LA's detection could be increased, respectively, to 82% from 59% using ActinFS alone, and to 86% from 55% using mixing study. Conclusions: Applying this direct aPTT ratio allows to quickly and reliably identify both BRFD and LA sequential to an isolated prolongation of aPTT.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

Both IgG and IgM anti-beta2 glycoprotein i antibodies assays are clinically useful to the antiphospholipid syndrome diagnosis

Objectives: The aim of our study was to evaluate the clinical values of anti-beta2 glycoprotein I antibodies (anti-beta2GPI) IgG and IgM comparing with lupus anticoagulant (LA), anticardiolipin antibodies (aCL) in the two clinical groups of antiphospholipid syndrome (APS), vascular thrombosis (VT) and pregnancy morbidity (PM). Methods: Eighty patients who fulfilled the APS clinical criteria, VT n534; PM n540, both VT and PM n56 were included. LA, aCL and three anti-beta2GPI ELISA kits were tested. Results: Sensitivities of LA, aCL and anti-beta2GPI assays were found respectively 62, 26 and 41% in VT, and 28, 28 and 30% in PM. The sensitivity for the APS diagnosis could reach to 63% using triple tests. The presence of LA (P,0.01, OR54.3) or anti-beta2GPI IgG alone (P,0.05, OR58.4) was significantly associated with VT. IgM isotype was found more frequent in PM (92%) than in VT (57%) among all positive anti-beta2GPI cases. Conclusion: Both IgG and IgM anti-beta2GPI assays were useful when clinical features of APS presented, even its standardization is ongoing. A decreased by half sensitivity of LA in PM compared with that in VT underlines the importance of adding anti-beta2GPI in PM of APS, especially IgM isotype although recent review questioned its significance.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An improved method for lupus anticoagulant detection

The diagnosis of lupus anticoagulant (LA) becomes difficult when there is a weak titer of LA antibodies. This study demonstrates that 20 minutes' incubation increases the sensitivity of the mixing test to diagnose LA by 23% and to suspect: the antibodies by 66%.SCOPUS: ar.jinfo:eu-repo/semantics/publishe