To cite this article: Pouplard C, Gueret P, Fouassier M, Ternisien C, Trossaert M, Ré gina S, Gruel Y. Prospective evaluation of the Ô4TsÕ score and particle gel immunoassay specific to heparin/PF4 for the diagnosis of heparin-induced thrombocytopenia. J Thromb Haemost 2007; 5: 1373-9.See also Arnold DM, Kelton JG. Testing for heparin-induced thrombocytopenia: are we there yet? This issue, pp 1371-2.Summary. Background: Heparin-induced thrombocytopenia (HIT) is a severe disease that is often difficult to diagnose. A clinical scoring system, the Ô4TsÕ score, has been proposed to estimate its probability before laboratory testing, and a particle gel immunoassay (H/PF4 PaGIA Ò ) has also been developed for rapid detection of HIT antibodies. Aim: To evaluate the performance of both methods when HIT is suspected clinically. Methods: Two hundred thirteen consecutive patients were included in four centers. The probability of HIT was evaluated using the 4Ts score blind to antibody test results. HIT was confirmed only when the serotonin release assay (SRA) was positive. Results: The risk of HIT was evaluated by the 4Ts score as low (LowR), intermediate (IR) or high (HR) in 34.7%, 60.6% and 4.7% of patients, respectively. The negative predictive value (NPV) of the 4Ts score was 100%, as the SRA was negative in all LowR patients. PaGIA Ò was negative in 176 patients without HIT (99.4%, NPV) and the negative likelihood ratio (LR-) was 0.05. PaGIA Ò was positive in 37 patients, including 21 with HIT (positive predictive value = 56.8%), with a positive LR of 11.4. A negative PaGIA Ò result decreased the probability of HIT in IR patients from 10.9% before assay to 0.6%, whereas a positive result did not substantially increase the likelihood for HIT. Conclusion: The use of the 4Ts score with PaGIA Ò appears to be a reliable strategy to rule out HIT.

Summary Cardiopulmonary bypass (CPB) induces the release of platelet factor 4 (PF4) and patients are at risk of heparin‐induced thrombocytopenia (HIT). This study was aimed to determine whether an abnormal evolution in platelet count (PC) after CPB is predictive of the development of HIT antibodies. Two abnormal PC patterns were defined: pattern P1, characterized by a decrease in PC following previous correction of thrombocytopenia occurring during CPB, and pattern P2, defined as a persistent low PC in the days following CPB. PC was evaluated for 10 d in 305 consecutive patients before and after CPB. Serotonin release assay (SRA) was carried out between days 8 and 10 to detect pathogenic heparin‐dependent antibodies. Moreover, antibodies to heparin–PF4 (H–PF4) complexes were assayed by enzyme‐linked immunosorbent assay. PC evolution after CPB was normal in 300 patients although antibodies to H–PF4 were frequently present (53·4%). Changes in PC were abnormal in five patients with pattern P1 (n = 4) or P2 (n = 1). As SRA was positive in four of the five cases, the positive predictive value of abnormal PC pattern for pathogenic HIT antibodies was 80%. Careful follow‐up of PC after CPB makes it possible to predict with high specificity (99%) for those patients who develop pathogenic HIT antibodies.

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Tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine proteinase inhibitor that inhibits plasmin-dependent activation of several metalloproteinases. Downregulation of TFPI-2 could thus enhance the invasive potential of neoplastic cells in several cancers, including lung cancer. In this study, TFPI-2 mRNA was measured using a real-time PCR method in tumours of 59 patients with nonsmall-cell lung cancer (NSCLC). Tumour TFPI-2 mRNA levels appeared well correlated with protein expression evaluated by immunohistochemistry and were 4 -120 times lower compared to those of nonaffected lung tissue in 22 cases (37%). Hypermethylation of the TFPI-2 gene promoter was demonstrated by restriction enzyme-polymerase chain reaction in 12 of 40 cases of NSCLC (30%), including nine of 17 for whom tumour TFPI-2 gene expression was lower than in noncancerous tissue. In contrast, this epigenetic modification was shown in only three of 23 tumours in which no decrease in TFPI-2 synthesis was found (P ¼ 0.016). Decreased TFPI-2 gene expression and hypermethylation were more frequently associated with stages III or IV NSCLC (eight out of 10, P ¼ 0.02) and the TFPI-2 gene promoter was more frequently hypermethylated in patients with lymph node metastases (eight out of 16, P ¼ 0.02). These results suggest that silencing of the TFPI-2 gene by hypermethylation might contribute to tumour progression in NSCLC.

Background: Tissue factor (TF), the main initiator of blood coagulation, is also a signaling protein that regulates cancer progression. TF synthesis was recently shown to be affected by tumor suppressor genes (TSGs) in tumor cell lines. We therefore studied TF gene (F3) expression and the status of genes coding for tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), and serine/threonine kinase 11 (STK11) in non–small cell lung cancer (NSCLC). Heparanase (HPSE) gene expression was also measured because this endo-β-D-glucuronidase was recently shown to enhance TF gene expression. Methods: TF and heparanase mRNA expression was measured by real-time PCR in 53 NSCLC tumors. Exons 5–8 of TP53 were sequenced from genomic DNA. Mutations of PTEN and STK11 were screened by multiplex ligation-dependent probe amplification. Results: TF mRNA levels were significantly higher in T3–T4 tumors (P = 0.04) and in stages III–IV of NSCLC (P = 0.03). Mutations of TP53, STK11, and PTEN were identified in 20 (37.7%), 21 (39%), and 20 (37.7%) of tumors, respectively. TF expression was higher in mutated TP53 (TP53Mut) (P = 0.02) and PTENMut (P = 0.03) samples. Moreover, TF mRNA increased from 2700 copies (no mutation) to 11 6415 when 3 TSG were mutated. Heparanase gene expression did not differ according to TF gene (F3) expression or TSG mutation. The median survival time was shorter in patients with tumor TF mRNA levels above median values (relative risk 2.2; P = 0.03, multivariate analysis) and when TP53 was mutated (relative risk 1.8; P = 0.02). Conclusions: These results provide clear evidence that combined oncogene events affecting TSG dramatically increase TF gene expression in lung tumors. Moreover, this study suggests that TF gene expression could be used as a prognostic marker in NSCLC. .

These results suggest that high TF expression in lung tumors may result from K-ras mutation and contribute to NSCLC progression, probably via mechanisms other than angiogenesis.

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PurposeIschemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality. There are several causes of stroke, affecting prognosis, outcomes, and management, but in many cases, the etiology remains undetermined. We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by standard methods. The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months. The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation.Methods and resultsWe prospectively enrolled 24 patients under 75 years of age, 15 men and 9 women of mean age 49 years, who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism. All causes of stroke were excluded by normal 12-lead ECG, 24-h Holter monitoring, echocardiography, cervical Doppler, hematological, and inflammatory tests. All patients underwent electrophysiological study. Of the patients, 37.5% had latent atrial vulnerability, and 33.3% had inducible sustained arrhythmia. Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months. No sustained arrhythmia was found. Only one patient had non-significant episodes of atrial fibrillation.ConclusionIn this study, symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder in patients under 75 years with unexplained cerebral ischemia. The use of this device should not be generalized in the systematic evaluation of these patients. In addition, this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients.