Institut J. Bordet Normal with Actin-FS avoids intrinsic pathway factors assays in the presence of an isolated prolongation of (Platelin-LS) without hemorrhagic history R.Li, C.Swaelens, F.Vandermijnsbrugge, B.Cantinieaux BSTH Laboratory of haematology, Porte de Hal, Antwerp Institut Jules Bordet and CHU Saint-Pierre, ULB 23/11/2012
Introduction Coagulometer MDA II Reagent Platelin-LS assays Sensitivity Intrinsic pathway factor deficiency Lupus anticoagulant LA Heparin therapy
Introduction An isolated prolonged paediatric Pre-operative screening Bleeding related Non-bleeding related FVIII, FIX, FXI deficiency FXII or contact factor deficiency, Inhibitor like LA
Introduction An isolated prolonged with Platelin LS with Actin FS A mixing study Prolonged Normal Non corrected Corrected FVIII, FIX, FXI FXII deficiency LA FXII deficiency LA FVIII, FIX, FXI, FXII deficiency
Aim An isolated prolonged with Platelin LS with Actin FS A mixing study Differential diagnosis FVIII, FIX, FXI deficiency Bleeding related Non-bleeding related FXII or contact factor deficiency, Inhibitor like LA
An algorithm for a prolonged At first time a prolonged with Platelin LS with Actin FS and A mixing (1:1 without incubation) Prothrombin time, Fibrinogen and Thrombin time Abnormal PT, Fibrinogen and TT Follow other algorithms Normal PT, Fibrinogen and TT New sample to confirm this prolonged and to continue further investigations
Materials and Methods The quantitative determinations of FVIII, FIX, FXI and FXII were performed in using one stage factor clotting assay in the week. - firstly with Platelin LS in two dilutions, - secondly with Actin FS if a suspicion of a nonspecific inhibitor detected by Platelin LS with a non-parallel curve. LA assays (PTT-LA and drvvt) were done in the week.
Materials and Methods During 4 years, from 2008 to 2011, among 9048 paediatric patients: an isolated prolonged in 308 (3.4%) outpatients in their haemostasis screening before surgical intervention 156 pateints with 161 samples: confirmed this prolongation of Median age: 3 years-old, 1 to 15 years-old including 13 neonatal samples (age < 6 months) Further investigations including :FVIII, FIX, FXI, FXII and LA with the limitation of the plasma volume -- in 140 samples: FVIII, FIX and FXI were performed -- in 131 samples : FVIII, FIX, FXI and FXII were performed -- in 88 samples: LA assays were performed
Materials and Methods cut-off values -- with Platelin LS, with Actin FS and mixing cut-off values were established locally (N=50). -- FVIII, FIX, FXI and F XII 50 % 200% -- LA cut-off values were established according to the international recommendation Statistics Sensitivity, Specificity, Postive Predicitive Value, Negative Predictive Value and p value were analysed by Fisher s exact test
Results With the further investigation of factor clotting and LA assays : Explanation of the prolonged : 101/161 (63%) Factor deficiencies: 43 -- for FVIII, FIX and FXI: 17/140 (12%) -- isolated : 10 -- multiple deficiencies: 7 (5 neonatal cases) -- for FVIII, FIX, FXI and FXII: 31/131 (24%) -- isolated FXII: 26 -- multiple deficiencies : 5 (3 neonatal cases) LA: 88 -- Positive: 64 /88 (73%) -- Negative: 24
Results N=140 (FVIII, FIX and FXI ) N=17 FVIII, FIX, FXI deficiencies N=123 FVIII, FIX, FXI normal Bleeding related Non-bleeding related Table 1 The statistical values of an with Actin FS and a mixing study for the detection of FVIII, FIX or FXI deficiencies by Fisher s exact test. N=140 (FVIII, FIX and FXI ) Factor Deficiencies (N=17) % Sensitivity Specificity PPV NPV P value Prolonged Actin-FS 59 93 53 94 <0,0001 Corrected mixing 59 29 10 84 0,2328 Prolonged Actin-FS and Corrected mixing 29 96 50 91 0,0025
Results N=131 (FVIII, FIX, FXI and FXII) N=43 FVIII, FIX, FXI, FXII deficiencies N=88 FVIII, FIX, FXI, FXII normal Table 2 The statistical values of an with Actin FS and a mixing study for the detection of FVIII, FIX, FXI or FXII deficiencies by Fisher s exact test. N=131 (F VIII, IX, FXI and XII ) Factor Deficiencies (N=43) % Sensitivity Specificity PPV NPV P value Prolonged ActinFS 28 92 63 72 0,0034 Corrected mixing 74 38 37 75 0,1225 Prolonged ActinFS and Corrected mixing 14 95 60 69 0,0634
Results Table 3. The levels of intrinsic pathway factor deficiencies with normal Actin FS Normal Actin FS Factor Deficiencies 16,4-36,2 F VIII F IX F XI F XII secondes % % % % Case 1 33,8 48 Case 2 30,4 41 Case 3 32,7 46 Case 4 33,1 37 Case 5 32,1 38 Case 6 35,4 43 Case 7 34,1 32 24 of 26 cases (92%) normal 22-48
Results N=88 (LA) N=64 Positive LA N=24 Negative LA Table 4. The statistical values of an with Actin-FS and a mixing study for the LA detection. N= 88 (LA) Positive LA (N=64) % Sensitivity Specificity PPV NPV P value Non-corrected mixing 55 88 92 42 0,0003 Normal Actin-FS 94 21 76 56 0,0584 Non-corrected mixing and normal Actin-FS 50 96 97 42 <0,0001 A prolonged with Actin FS was found in 4 of 64 positive LA samples.
Conclusions Face to an isolated prolongation of without hemorrhagic or family history, A normal with Actin-FS permitted: -- to exclude a FVIII, FIX or FXI deficiency lower than 30%, -- to explain an isolated prolonged (Platelin-LS) by either a FXII deficiency or the presence of LA, so it was not necessary to perform the factor clotting assays in this case. A mixing study -- a non-corrected mixing was useful to suggest the presence of LA, -- a corrected mixing was useless to detect a factor deficiency.