Application of ELISA in Detecting Heparin-Induced Thrombocytopenia Antibodies / 现代检验医学杂志

Objective To develop an ELISA method for determination of heparin-induced thrombocytopenia (HIT)antibody. Methods The compound formed between human platelet factor 4 (PF4)and heparin was used as the coating antigen,incu-bating the patients plasma with the coating antigen in the well,after washing,the second antibody labeled HRP was added in the well to incubate and washing again,the chromogenic substrates was added in the well to incubate,when the stop reaction was finished,the absorbance A450/A630 was detected,and the test results were judged according to standard,this method was compared with IBL method and was optimized and evaluated the performance.Results An indirect ELISA method was de-velop with the purified human PF4,the optimal dilution of sample and second antibody were 1∶100 and 1∶1 500 which de-tected by the orthogonal test,the intra-and inter-assay average coefficients of variation were 7.66% and 7.76%(<10%) respectively that detected by repeated measurement the three positive standard plasma.Through measureing the 100 healthy human plasm with no history of using heparin,the positive and negative predictive reference values were 0.304 and 0.456. IBL and this method detected 100 hemodialysis patients samples at the same time,and the result of statistical analysis was that,the sensitivity,speciality and accuracy of this method were 90%,97.78% and 90%,respectively.The negative and posi-tive predictive value were 81.8% and 98.88% respectively,and the difference was statistically significant [K=0.84(0.81~1)and Pexac=0.012<0.05].The difference was statistically significant,consistency was optimal,95% confidence interval was 92.59%~92.59%.Conclusion Comparing with the IBL,the method reported by this article had the similar perform-ance and good consistency,and it could satisfy the clinical detection and diagnosis of HIT patients.

Heparin Anticoagulation during Cardiopulmonary Bypass for Thoracoabdominal Aorta Replacement in a Patient with a History of Heparin-Induced Thrombocytopenia / 日本心臓血管外科学会雑誌

Immune heparin-induced thrombocytopenia (HIT) is a crucial side effect of heparin therapy. We report the case of a 52-year-old man who was strongly suspected of having HIT after urgent descending aorta replacement. This case required continuous hemodiafiltration (CHDF) anticoagulated with unfractionated heparin (UFH) for acute renal failure after the operation. The patient developed thrombocytopenia and thrombus emphraxis in the circuit on the seventh day and was suspected of having HIT. UFH was ceased and replaced with argatroban. After then, thrombus emphraxis was not seen in the circuit and the platelet count was recovered promptly. He tested positive in an enzyme-linked immunosorbent assay for anti-platelet factor 4/heparin antibodies (anti-PF4/H Abs). Six months later, we found, an expanding thoracoabdominal aortic aneurysm and performed thoracoabdominal aorta replacement. We selected heparin anticoagulation for cardiopulmonary bypass because anti-PF4/H Abs were negative at that time. Thrombus emphraxis was not found during the operation. The patient developed neither thrombocytopenia nor thrombosis in the perioperative period.

The pharmacotherapy of heparin-induced thrombocytopenia (HIT): A review of contemporary therapeutic challenges in clinical practice

Our objectives were to discuss a general overview on the description and recognition of heparin–induced thrombocytopenia (HIT) and present a critical review of the traditional and most recent advances in its pharmacotherapy. Computerized searches were done on MEDLINE and Iowa Drug Information Service (IDIS) databases from June 2001 until June 2007 and from May 2005 until May 2007, respectively. Search terms used included ‘heparin-induced thrombocytopenia’, ‘heparin-associated thrombocytopenia’, therapeutics, HIT, HAT. We largely selected publications within the timeframe above, but did not exclude commonly referenced and highly regarded older publications. The commonly referenced published articles were obtained through manual searches derived from bibliographic citations and retrievals from the authors’ personal files. Pertinent literatures (89 key articles) that were thought to have substantially contributed new information to the therapeutics of HIT within the last 6 years were identified, reviewed and presented. The following limits were used for the MEDLINE and IDIS searches: ‘human’, drug therapy’, ‘review’, ‘meta-analysis’, ‘clinical trial’, and case reports. The therapeutics of HIT is rapidly evolving and needs to consider an evidence – based approach. It is imperative that practitioners be aware of the associated risk and be up-to-date with the current advances in the management of this fatal clinical condition.