Definition of Significant Platelet Clumping: Should We Review All Samples With a Platelet Clumping Flag From Automated Hematology Analyzer?

OBJECTIVES: This study aimed to determine a definition for significant platelet clumping (PC) and evaluate the performance of the Sysmex XN instrument for detecting platelet clumps. METHODS: For part 1, 372 specimens with a 'PLT_clump?' flag in XN-9000 were classified into five groups according to the average number of PCs. We compared the initial platelet count (measured by XN-9000 using impedance method) and corrected platelet count (counted optically or re-analyzed by XN-9000 using vortexed or re-collected sample) of each group. For part 2, 1000 specimens with a PC flag divided into three subgroups {group N (PC = 0), Y (PC ≥ 1), and Z (microscopic fibrin clot)} and additional two groups {group S (PC(+) specimens without any flag and with flags of other categories) and group NC (negative control)} were collected. Positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity of PC detection of XN-9000 were obtained and the platelet counts and four indices (PDW, MPV, P_LCR, and PCT) of groups NC, N, Y, Z, and S were compared to detect PC more precisely. RESULTS: In part 1, all groups showed significant difference between the initial and corrected platelet counts. In part 2, PPV, NPV, prevalence, sensitivity, and specificity were 41.5%, 56.5%, 43.4%, 2.18%, and 98.3%, respectively. The platelet counts and four indices showed statistical differences for detecting PCs, and especially PDW and P_LCR were significantly smaller in group Z than group N or Y. CONCLUSIONS: We suggest the definition of significant PC by the presence of at least three platelets. In addition, utilizing platelet-related indices should be developed to improve the efficiency of the PC detection.

Reliability of the DI-60 Digital Image Analyzer for Detecting Platelet Clumping and Obtaining Accurate Platelet Counts.

Pseudothrombocytopenia caused by platelet clumping (PC) can lead to unnecessary platelet transfusions or underdiagnosis of hematologic neoplasms. To overcome these limitations, we assessed the capacity of the Sysmex DI-60 digital morphology analyzer (Sysmex, Kobe, Japan) for detecting PC and determining an accurate platelet count in the presence of PC. For this purpose, 135 samples with or without PC (groups Y and N, respectively) were processed by an examiner (a hematologic specialist) using both the Sysmex XN-9000 and DI-60 analyzers. Although the platelet aggregate (PA) and giant platelet (GP) counts reported by the DI-60 and the examiner exhibited strong correlations, they proved inadequate as effective indicators for screening samples containing PC. Between the PA and GP counts and four platelet indices (the platelet distribution width [PDW], mean platelet volume [MPV], platelet large cell ratio [P_LCR], and plateletcrit [PCT]) reported by the XN-9000, we observed statistically significant correlations (both overall and with group Y), but they were relatively weak. The platelet counts determined using the DI-60 and light microscopy in group Y showed substantial variations. Although the performance of the DI-60 was reliable for detecting PA and GP in smear images, such fixed areas are not representative of whole samples. Further, in the presence of PC, the resulting platelet counts determined using the DI-60 were not sufficiently accurate to be accepted as the final count.

Establishing 17-Hydroxyprogesterone Cutoff Values for Congenital Adrenal Hyperplasia in Preterm, Low Birth Weight, and Sick Newborns.

BACKGROUND: Newborn screening for congenital adrenal hyperplasia (CAH) has benefits with a high adoption rate worldwide. It also has problems of high false positives, which can cause stress to the patient's family with economic losses and unnecessary visits of newborns to hospitals. Therefore, we investigated the influence of birth weight (BW), gestational age (GA), and GA with sampling time on 17-hydroxyprogesterone (17-OHP) concentration and attempted to establish the 17-OHP cutoff values in preterm, low birth weight (LBW), and sick newborns. METHODS: Newborns (n=1,071) born between October 2020 and January 2022 were screened for CAH. Samples from neonates were collected on filter paper with the heel prick method. 17-OHP concentration was measured by time-resolved immunofluorescence with an AutoDELFIA Neonatal 17-hydroxyprogesteron kit and grouped in relation to BW, GA, and GA with sampling time. RESULTS: The median age of newborns at neonatal sample collection was 6 days. 17-OHP concentration showed a statistically significant negative correlation with BW (r=-0.488, p<0.001) and GA (r=-0.560, p<0.001). Full-term and preterm subgroups had a similar decreasing tendency of 17-OHP concentration with increasing sampling time. Application of newly establishing cutoff criteria significantly reduced recall rates to 1.16%, 0.9%, and 1.75% according to each criterion of BW, GA, and GA with sampling time, respectively. CONCLUSIONS: This study presents new 17-OHP cutoff values for preterm, LBW, and sick newborns. These data in our laboratory can be used as a reference by other laboratories for establishing new cutoff criteria to help lower the high recall rate and reduce unnecessary follow-up tests.

Very severe immune aplastic anemia after mRNA vaccination against COVID-19 responds well to immunosuppressive therapy: clinical characteristics and comparison to previous reports.

OBJECTIVE: Various hematologic side effects of the Coronavirus Disease 2019 (COVID-19) vaccination has been reported, and most of them are thought to be related to autoimmune pathways. To the best of our knowledge, only few cases of post-COVID-19 vaccination aplastic anemia (AA) have been reported and there is no reported Korean case of COVID-19 vaccine-induced AA yet. We present a case of severe immune-mediated AA that developed after the administration of a messenger ribonucleic acid (mRNA) gene-based spike protein vaccine against COVID-19, which responded well to immunosuppressive therapy, and discuss the probable pathogenesis of AA and the implication of vaccination along with a comparison of previous cases reported. METHODS: A 53-year-old Korean man developed sudden pancytopenia three months after COVID-19 vaccination. To evaluate the cause of pancytopenia, a bone marrow study was performed. RESULTS: A diagnosis of AA was made through the bone marrow study and he received triple immunosuppressive therapy (IST). After triple IST for five months, his blood cell count was improved and maintained without transfusion and his follow-up bone marrow examination showed improved cellularity. CONCLUSION: COVID-19 vaccine might be associated with the development of immune-mediated AA. Prompt hematologic evaluation should be performed when there are symptoms or signs suggestive of cytopenia after COVID-19 vaccination. Although the clinical outcome of post-vaccination AA varies, a good prognosis can be possible for patients with COVID-19 vaccination-induced AA.

Association of Lupus Anticoagulant status with Disease Course in SARS-CoV-2 (COVID-19) Infection.

Background: We investigated the importance of lupus anticoagulant (LA) in patients with SARS-CoV-2. Methods: Medical records of 41 SARS-CoV-2 infected patients were reviewed. Patients were classified into two groups according to the frequency of positive LA test results: "LA (-)" and "LA (+) ≥1" (LA positive at least once). Statistical analysis was performed to determine the association between LA presence and change in LA test results and disease course according to both hospital days (HD) and days after diagnosis (DD). Results: The prevalence of LA was 51.2%. Averagely, the first change in LA test result occurred during DD 12-13 and between HD 9-10. The second change occurred on DD 15-16 and HD 13-14. The presence of LA was associated with severe disease (P = .004) but was not associated with thrombotic complications or mortality. The change of results from negative to positive or vice versa or the frequency of the changes was not associated with disease severity, thrombotic complications, or mortality. Conclusions: LA positivity can be regarded as one of the findings suggesting more serious SARS-CoV-2 infection.

An Ethical Issue in Medical Education of Obstetrics and Gynecology.

There are four principles of medical ethics; Beneficence, Respect for autonomy, Non-maleficence, and Justice. It is not easy to apply to principles of medical ethics in the special circumstances of obstetrics and gynecology. Student doctors must learn to be familiar with principles of medical ethics tailored to the special circumstances while the obstetrics and gynecology practice.