Comparison of three different immunoassays in the diagnosis of heparin-induced thrombocytopenia.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is caused by platelet activating antibodies that recognize platelet factor 4/heparin (PF4/H) complexes. Laboratory testing plays a key role in the diagnosis of HIT. As functional assays are unfeasible for most clinical laboratories, antigen binding assays are commonly used in routine testing. However, their low specificity leads to overdiagnosis of HIT. Therefore, it is advisable to improve screening tests in this setting. METHODS: Blood samples from 114 patients in whom HIT was suspected were investigated using a chemiluminescence test (HemosIL® AcuStar HIT-IgG), a PF4/H IgG enzyme immunoassay (Lifecodes PF4 IgG), an IgG-specific lateral flow immunoassay heparin-induced thrombocytopenia (LFI-HIT, STic Expert® HIT) and the heparin-induced platelet aggregation (HIPA) test. RESULTS: Twenty-nine (25.4%) out of 114 subjects with suspected HIT had a positive HIPA test. None of patients with a 4Ts score <4 were positive at HIPA. HemosIL® AcuStar HIT-IgG showed the best performance in term of sensitivity and specificity when used as single test. Receiver operating characteristic (ROC) analysis showed optimization of sensitivity and specificity using a cut-off of 1.13 U/mL (0.95 and 0.98, respectively). As an alternative approach, a strategy based on screening samples by STic Expert® HIT and then retesting positive results by Lifecodes PF4 IgG (cut-off 1 OD) or HemosIL® AcuStar HIT-IgG (cut-off 1.3 U/mL) showed a performance compared to a single test approach by HemosIL® AcuStar HIT-IgG. CONCLUSIONS: The HemosIL® AcuStar HIT or a combinatorial approach with the STic Expert® HIT and the PF4/H IgG enzyme immunoassay provide an accurate diagnosis of immune HIT.

Relevance of antiphospholipid antibody profile in the clinical outcome of ITP: a single-centre study.

OBJECTIVES: The relevance of detecting antibodies against anticardiolipin, ß2-glycoprotein I (ß2gpI) or lupus anticoagulant (LA), collectively called antiphospholipid autoantibodies (APA), in subjects with immune thrombocytopenia (ITP) is still a debated issue. In particular, whether APA profile may affect the clinical course of ITP is unknown. METHODS: In this study, we report our experience in a cohort of ITP patients with APA with specific interest to the relevance of different antiphospholipid antibody profiles in clinical outcome and response to treatment. RESULTS: Thirty-seven out of 159 patients (23.2%) fulfilling ITP criteria had a platelet count ≤50 × 109/L and tested positive at APA at ITP onset. Twenty-three (62.1%) patients received at least one line of treatment for ITP. Fourteen subjects (37.8%) showing triple positivity for APA showed a significantly lower median platelet count compared to other APA patients (p = .006). Among these ITP subjects with triple positivity, 85.7% needed a treatment because of low platelet count compared to 47.8% ITP patients with non-triple-positive APA (p = .0094). ITP/APA subjects who received immunosuppressors had a higher rate of thrombosis (p = .024) as well as thrombosis developed in subjects who were on steroid therapy at a significantly higher dosage than subjects who did not develop thrombotic episodes (p < .001). When considering treatment, CR and SR rate were significantly higher in ITP/triple-positive patients compared to non-triple-positive subjects (p = .021 and p = .005). CONCLUSIONS: The profile of APA may affect the outcome of patients with ITP.

Thrombotic and Hemorrhagic Conditions Due to a Gain of Function of Coagulation Proteins: A Special Type of Clotting Disorders.

Coagulation disorders can be classified into 2 types, namely, type I and type II. In the former, there is a concomitant decrease in factor activity and antigen (activity-antigen ratio is 1), whereas in the latter, there is a discrepancy between factor activity which is always low and antigen which is normal or near normal (activity-antigen ratio is <1, eg, 0.5). Recently, several gain-of-function disorders have been described. These are characterized by an increased activity with respect to the antigen level. The condition involves polymorphisms of factor V and factor II, factor IX, von Willebrand disease, thrombomodulin, tissue factor pathway inhibitor, and thrombin activatable fibrinolysis inhibitor. The conditions could be subdivided into prothrombotic and prohemorrhagic. They should also be distinguished as cases of true gain of function (intrinsic increase activity without concomitant increase in protein level) and of "pseudo" gain of function (increase in both activity and protein level). This is a new concept of coagulation defects that has considerably enhanced our knowledge of blood coagulation and that should be familiar to all those interested in the mechanism of blood clotting and its disorders.

A standardized antenatal class reduces the rate of cesarean section in southern Italy: A retrospective cohort study.

Italy, along with Poland and Hungary, has the highest cesarean section rate (35.7%) in Europe. Among Italian regions, Campania has the highest rate of cesarean section (58.4%).We developed a standardized antenatal class to evaluate whether women who attend this class during pregnancy have a lower cesarean section rate. This antenatal class was developed according to the indication of the Italian Ministry of Health and the World Health Organization. We selected a cohort of women who participated in this antenatal class and a cohort of women who did not participate. We collected information on the mode of delivery, and other characteristics, of these women from certificate of birth assistance form available in 2 hospitals where the women gave birth.Among women who participated in the antenatal class, there were more Italians, the women were more educated, more women were employed and there were more primiparas compared with those who did not participate. Non-participants of antenatal class showed a higher rate of cesarean section than those who participated (56.2% vs 23.1%; relative risk [RR] = 2.43; 95% confidence interval [CI] 1.95-3.03; P < .0001), as well as after adjustment for other variables. This difference was stronger in 1 hospital (RR = 2.88; 95% CI 2.13-3.89; P < .0001) than in the other hospital (RR = 1.86; 95% CI 1.36-2.55; P < .0001).Our standardized antenatal class, which was performed in an area with a high rate of cesarean section, significantly reduced this rate, and this was still significant after adjustment for potential confounders.

A Strange Manifestation of Malaria in a Native Nigerian Boy.

The protective role of Sickle Cell Trait (SCT) in malaria endemic areas has been proved, and prevalence of HbS gene in malaria endemic areas is high. Splenic infarction is a well-known complication of SCT, while the association with malaria is considered rare. A Nigerian boy was admitted to our ward after returning from his country of origin, for P. falciparum malaria. He underwent abdominal ultrasound for upper right abdominal pain, showing cholecystitis and multiple splenic lesions suggestive of abscesses. Empiric antibiotic therapy was undertaken. Bartonella, Echinococcus, Entamoeba serologies, blood cultures, Quantiferon test, copro-parasitologic exam were negative; endocarditis was excluded. He underwent further blood exams and abdomen MRI, confirming the presence of signal alterations areas, with radiographic appearance of recent post-infarction outcomes. Hemoglobin electrophoresis showed a percentage of HbS of 40.6% and a diagnosis of SCT was then made. Splenic infarction should be taken into account in patients with malaria and localized abdominal pain. Moreover, diagnosis of SCT should be considered.

Reduced expression of uncoupling proteins-2 and -3 in adipose tissue in post-obese patients submitted to biliopancreatic diversion.

OBJECTIVE: Little is known about the physiological role and the regulation of uncoupling proteins-2 and -3 (UCP-2 and -3) in adipose tissue. We investigated whether the expression of UCP-2 and -3 in adipose tissue was affected by weight loss due to a biliopancreatic diversion (BPD) and related to the daily energy expenditure (24-h EE). DESIGN: Ten morbidly obese subjects (mean body mass index +/- s.e.m.=49.80 +/- 2.51 kg/m(2)) were studied before and 18+/-2 Months after BPD. METHODS: We determined body composition using tritiated water and 24-h EE in a respiratory chamber. Adipose tissue UCP-2 and -3 mRNA, plasma insulin, glucose, free fatty acids (NEFA), free triiodothyronine (FT3), free thyroxine (FT4) and leptin were assayed before and after BPD. RESULTS: BPD treatment resulted in a marked weight loss (P<0.001) mainly due to a fat mass reduction. A significant decrease in 24-h EE/fat-free mass (FFM) (P<0.05) and in UCP-2 (P<0.05) and UCP-3 (P<0.05) mRNA was observed. A significant reduction in plasma insulin, glucose, NEFA, FT3, FT4 and leptin was seen after BPD. The decline in plasma leptin and FFA was tightly correlated with the decrease in both UCP-2 and -3. A significant correlation was found between changes in FT3 and variations in 24-h EE (r=0.64, P<0.05). In a multiple-regression analysis changes in 24-h EE/FFM after BPD were significantly correlated with changes in UCP-3 expression (P<0.05). CONCLUSION: These findings suggest that UCPs in adipose tissue may play a role in the reduction in 24-h EE observed in post-obese individuals.

Cardiomyopathy in a male patient with neutropenia and growth delay.

Neutropenia encompasses a family of neutropenic disorders, both permanent and intermittent, ranging from severe (<500 neutrophils/mm(3)) to mild (500-1500 neutrophils/mm(3)), which may also affect other organ systems such as the pancreas, central nervous system, heart, muscle and skin. Neutropenia can lead to life-threatening pyogenic infections whose severity is roughly inversely proportional to the circulating neutrophil counts.When neutropenia is detected, an attempt should be made to establish the etiology, and to distinguish acquired forms (the most frequent, including post viral neutropenia and autoimmune neutropenia) and congenital forms (rare disorders) that may be either isolated or part of a complex rare genetic disease. We report on a male patient initially diagnosed with isolated neutropenia who later turned out to be affected with Barth syndrome, a rare complex inherited disorder.