Frequency, clinical, and laboratory findings of platelet secretion disorders in patients referred to the specialized coagulation laboratory of the Iranian Blood Transfusion Organization.

OBJECTIVES: Platelet secretion disorders (PSDs) are a subgroup of platelet function disorders (PFDs) caused by defects in the content or release of platelet granules. These patients have a variable degree of mucocutaneous bleeding tendency. The diagnostic facilities of PSDs are imitated in Iran, even in specialized coagulation laboratories. The present study aims to estimate the frequency of PSDs among patients referred to the Iranian Blood Transfusion Organization (IBTO). METHODS: The research population includes all patients referred to the specialized coagulation laboratory of IBTO and requested platelet function and von Willebrand testing by their physicians. They were recruited between May 2022 and October 2022 if they were not diagnosed as having procoagulant defects, von Willebrand disease (VWD), Glanzmann thrombasthenia (GT), Bernard-Soulier syndrome (BSS), and platelet count <100 × 10 9 (except in the syndromic forms). Patients with a defect in response to at least two agonists in Light transmission aggregometry (LTA), one agonist in the ATP-secretion study, and/or impairment in the expression of CD62P are considered PSDs. RESULTS: Among 121 cases referred to our center over 6 months, 40 patients fulfilled the inclusion and exclusion criteria. Ten patients were diagnosed with PSDs. Six were classified as δ-platelet secretion disorders (δ-PSD), two α-platelet secretion disorders (α-PSD), and two αδ-platelet secretion disorders (αδ-PSD). CONCLUSIONS: The prevalence of PSDs in our population study was 25% (10/40), which seems highly prevalent. Therefore, expanding laboratory approaches to platelet function defects is necessary as a routine in our country.

Utility of the international society on thrombosis and hemostasis-bleeding assessment tool in the diagnosis of patients who suspected of platelet function disorders.

The ISTH-BAT is a structured bleeding assessment tool to record and help diagnose patients with possible bleeding disorders. However, a few studies evaluated the utility of ISTH-BAT in diagnosing patients with platelet function defects (PFDs). In this study, we evaluated the diagnostic utility of ISTH-BAT in predicting PFDs among patients suspected of PFDs. Forty patients suspected of PFDs and 21 normal healthy controls were evaluated by the ISTH-BAT scoring system, light transmission aggregometry (LTA), ATP-releasing assays (lumi-aggregometry), and expression of CD62P for diagnosis of PFDs. Among 40 patients suspected of PFDs, 10 were diagnosed as PFDs using lumiaggregometry and CD62P. The ISTH-BAT score in patients suspected of PFDs [(6, interquartile range (IQR) 1-8] and patients with PFDs was significantly higher than the control group (0; IQR 0-0) ( P  < 0.001). Receiver operating characteristic curves indicate that ISTH-BAT is not able to discriminate patients with PFDs from those without PFDs (areas under the curve of 0.620 (95% confidence interval 0.415-0.825). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the ISTH-BAT in predicting the presence of PFDs, respectively, were 40, 73.3, 33.3, and 78.6% in the cut-off ISTH-BAT at least 4 in adult men, at least 6 in adult women, and at least 3 in children (age < 18). The ISTH-BAT scoring system has good discriminatory power in diagnosing patients with PFDs from healthy controls but is ineffective in differentiating them from those without PFDs.

Severe Prekallikrein Deficiency Associated with Low Level of Factor XII: A Case Report.

Hereditary deficiency of plasma prekallikrein (PPK) is a rare autosomal recessive disease. The affected patients are often asymptomatic and diagnosed incidentally during preoperative investigations or during hospitalization by isolated prolongation of activated partial thromboplastin time (aPTT). In this article, we report, a 46-year-old woman who was candidate for two invasive procedures (thyroid FNA and hysterectomy) and underwent preoperative evaluation. Due to prolonged aPTT with normal PT she was referred to the IBTO reference coagulation laboratory for specific coagulation assays. Ultimately, the examinations revealed severe PPK deficiency (<1%) with partial deficiency of factor XII level (25%).

Heparin-Induced Thrombocytopenia in Iranian Cardiac Surgery Patients Using the 4Ts Clinical Scoring System and Laboratory Methods.

Background: Heparin-induced thrombocytopenia (HIT) is a serious adverse drug reaction. HIT diagnosis needs an algorithmic approach including clinical evaluation and laboratory tests (screening and confirmatory). Few studies have been conducted on HIT in Iran, and most existing research has been general and based on clinical evaluations alone. The present study was conducted to determine the prevalence of HIT among cardiac surgery patients using an algorithmic approach. Materials and Methods: A cross-sectional study was carried out over a period of 10 months, at Modares Hospital (Tehran, Iran) on 92 patients who were candidates for cardiac surgery. For the clinical evaluation, the 4Ts scoring system was used; in cases with 4Ts scores ≥4, a laboratory evaluation of anti-PF4/heparin antibody (Ab) was performed by enzyme-linked immunosorbent assay (ELISA) and a HIPA test too as a functional confirmatory method. The patients with 4Ts scores ≥4 who were ELISA positive (OD ≥0.2) and HIPA positive were taken as a definite case of HIT. Results: Of the 92 patients who had undergone cardiac surgery, 14 (15%) had 4Ts scores ≥4. Anti- PF4/heparin Ab was detected in eight patients using the ELISA and in six patients using the HIPA. Ultimately, definite HIT was confirmed in five of the patients. Conclusion: The prevalence of HIT was 5.4% among the cardiac surgery patients assessed in the present study. To the researchers' knowledge, this is the first time that HIT has been evaluated in Iran using a comprehensive algorithmic approach including clinical history-taking and both immunological and functional laboratory tests, and the findings showed a slightly higher HIT frequency in this single-center study in comparison with the other studies carried out in other countries.