Comparison of HIT Tests in Patients with COVID-19 and Thrombocytopenia.

Thrombosis and coagulopathy have been found to be the most prevalent complications in patients with COVID-19. Thromboprophylaxis to prevent thromboembolic events is recommended for hospitalized COVID-19 patients. Heparin-induced thrombocytopenia (HIT) is a known complication of heparin use. This study aimed to determine the incidence of HIT among admitted patients with confirmed COVID-19 by PCR. In this study, two different HIT assays, rapid immunoassay (STic Expert HIT, Stago) and H-PF4 specific enzyme-linked immunosorbent assay (Asserachrom® HPIA - IgG), were performed. Of 200 patients with confirmed COVID-19, we identified 49 patients who met the possibility of HIT (low platelet count and high D-Dimer level). Only five (10.2%) had a positive HIT rapid test. However, none of the tested samples tested positive by ELISA. Thrombosis was reported in two of five (40%) patients. Further extensive studies are required to determine the prevalence and clinical significance of a positive HIT test among patients with COVID-19.

Hematologic reference intervals for healthy adult Saudis in Riyadh.

BACKGROUND: Laboratory hematological tests are widely used in clinical practice to assess health and disease conditions. Reference ranges provided by laboratory reports are considered the most authoritative medical tools to assist in the decision-making phase. International standards institutes recommend that reference ranges be established for each region. OBJECTIVES: Provide reference values of routine hematological parameters in Saudi adults according to age and gender. DESIGN: Cross-sectional SETTING: Central province of Saudi Arabia. PATIENTS AND METHODS: Apparently healthy Saudi adults were subjected to laboratory testing of routine hematological parameters (full blood count, hemostatic profile, and serum hematinics), after completing a detailed health medical questionnaire. MAIN OUTCOME MEASURES: Hematological reference values based on the local population. SAMPLE SIZE AND CHARACTERISTICS: 637 after screening 827 potentially healthy Saudi adults with ages ranging from 15 to 65 years. RESULTS: The reference values of routine hematological parameters for the full population and by gender are presented with 90% CI as the lower and upper limits. Reference ranges mostly differed from universal established ranges shown in textbooks. CONCLUSION: The reference ranges of routine hematologic parameters for accurate assessment and appropriate management will help improve the routine clinical care of the adult Saudi population. LIMITATIONS: Difficulty in assessing health status of participants, who could have subclinical illnesses not reflected in the evaluated blood measurement. Lack of ability to eliminate individuals who might be carriers for haemoglobinopathies. Studies with larger sample sizes from different areas of the country are required to achieve a more accurate representation of the whole Saudi population. CONFLICT OF INTEREST: None.

Incidence of lupus anticoagulant in hospitalized covid-19 patients.

BACKGROUND: Procoagulant profile of 2019-nCoV/SARS-CoV-2 has been well documented over the last year. Perturbance in coagulating factors has also been reported in Covid-19 patients, including increased d-dimers and reports of lupus anticoagulant (LA). METHODS: The current study aimed to identify the incidence of positivity of lupus anticoagulant in Covid-19 patients and analyze the association between LA and D-dimer in predicting thrombosis and mortality in one-hundred and five hospitalized adult (age >14 years) patients and forty-three hospitalized pediatric (age <14 years) patients with a confirmed diagnosis of Covid-19 between June 2020 and September 2020. RESULTS: Twenty-one (20%) adult patients were tested positive for PTT LA, of which nine (8.6%) turned out to be confirmed positive for LA through StaClot and DRVVT Ratio tests. Six (14%) pediatric patients were positive for PTT LA, and only one (2.3%) had positive StaClot. Median D-dimer at admission was positively correlated with age and CRP among adult patients and was significantly higher in expired cases (P=0.001). No association between any of the coagulation tests and thrombosis or mortality was observed in the pediatric cohort. CONCLUSION: We report an increased incidence of LA in Covid-19 patients, yet we didn't find any association between thrombotic events or mortality, probably due to the small sample size.

Assessing the Performance of Extended Half-Life Coagulation Factor VIII, FC Fusion Protein by Using Chromogenic and One-Stage Assays in Saudi Hemophilia A Patients.

BACKGROUND: The one-stage assay is the most common method to measure factor VIII activity (FVIII : C) in hemophilia A patients. The chromogenic assay is another two-stage test involving purified coagulation factors followed by factor Xa-specific chromogenic substrate. AIM: This study aimed to assess the discrepancy and correlation between the chromogenic and one-stage assays in measuring FVIII : C levels in hemophilia patients receiving Extended Half-Life Elocta® as a recombinant extended half-life coagulation factor. METHODS: We performed a study comparing the measurements of FVIII : C levels by the chromogenic versus the one-stage assays at different drug levels. Data of FVIII : C levels, dosage, and the time interval from administration to measurement were retrieved from the hospital records. The correlation, mean differences, and discrepancy between the two assays were calculated. The linear regression analysis was used to predict the time interval till reaching 1% FVIII : C. RESULTS: Fourteen patients with 56 samples were included in the study. Of them, 13 patients were receiving Elocta® as a prophylactic, while one was receiving Elocta® on demand. One-third of these samples showed a discrepancy between the chromogenic and one-stage assays. The two assays were well correlated. Mean differences were significant at the individual and the time interval level. The time since the last Elocta® injection could significantly predict FVIII : C levels (ß = 0.366, P < 0.001). CONCLUSION: Our findings suggested a significant difference between both methods; the FVIII : C levels measured by the one-stage assay were less than those estimated by the chromogenic assay. However, the measurements of FVIII levels by the two assays were well correlated but discrepant in one-third of the samples. The levels of FVIII : C reach 1% after 5.4 days since the last Elocta® administration.