Mimic of massive pulmonary embolism: heparin-induced thrombocytopaenia (HIT)-associated anaphylactoid reactions following subcutaneous low molecular weight heparin.

A female in her 60s was admitted via the emergency department following a respiratory collapse at home. She was profoundly hypoxic and hypertensive. For 1 week prior, she had been self-administering subcutaneous (SC) low molecular weight heparin (LMWH) for a small postoperative pulmonary embolism (PE) and reported worsening, self-resolving episodes of breathlessness 1 hour post-injection. Repeat imaging revealed a new small PE and blood tests showed a significant platelet drop. Her heparin-induced thrombocytopaenia (HIT) antibody test was positive. A diagnosis of HIT-associated anaphylactoid reaction was made. She was switched to a direct oral anticoagulant and fully recovered. This condition is well described, often presenting with profound respiratory compromise that can be misdiagnosed as 'massive PE'. A key differentiation is that there is often hypertension instead of hypotension. This case, however, is unusual as it was triggered by SC LMWH not intravenous heparin as previously described in the literature.

A rare occurrence of Vancomycin-induced gastrointestinal hemorrhage without thrombocytopenia: a case report and literature review.

BACKGROUND: Vancomycin-induced bleeding has been reported, attributed to the mechanism of immune thrombocytopenia. A rare case of vancomycin-induced gastrointestinal hemorrhage in a young patient with no underlying disease, receiving intravenous vancomycin for methicillin-resistant Staphylococcus aureus (MRSA) infection, is presented. This occurrence occurred without thrombocytopenia. Relevant cases reported in the literature were also reviewed. CASE PRESENTATION: A 34-year-old male patient presented with maxillofacial multiple spaces infection accompanying left temporal abscess, bilateral lung abscesses. Culture results from both blood and secretion indicated that the infection was caused by MRSA. The patient received standard-dose vancomycin (1 g q12h intravenously guttae) for treatment. On the 5th day of therapy, he presented with bright red blood in his stool; however, vancomycin treatment was continued. By the 9th day, a decrease in hemoglobin level to 76 g/L and a platelet (PLT) count of 424 × 109/L raised concerns about gastrointestinal hemorrhage. The hemoglobin level decreased to 62 g/L on day 12. Due to the high tissue concentration of linezolid, administration of linezolid at a dose of 600 mg q12h intravenously guttae commenced on the 13th day as an alternative to vancomycin(D13-D17). Subsequently, on the 17th day, there was an improvement in hemoglobin level to 78 g/L. However, despite treatment with linezolid, the patient's fever showed no significant improvement, prompting a switch back to vancomycin at a dosage of 1 g q12h intravenously guttae(D18-D22). On the 21st day, there was a recurrence of gastrointestinal hemorrhage, accompanied by a hemoglobin level of 42 g/L and a PLT count of 224 × 109/L. Gastroscopy revealed the presence of a gastroduodenal ulcer. The patient had no prior history of hemorrhoids, gastrointestinal ulcers, liver cirrhosis, or purpura. Prior to admission, he had not been administered non-steroidal anti-inflammatory drugs (NSAIDs) or steroids. During hospitalization, the only medications given were vancomycin, ambroxol and lidocaine. Additional tests ruled out immunological disorders as the cause of gastrointestinal ulcers, and a positive vancomycin rechallenge test indicated an association between vancomycin and bleeding. After discontinuation of vancomycin, no further bleeding occurred. This case highlights a rare occurrence of vancomycin-induced bleeding without thrombocytopenia, classified as "Certain" according to the World Health Organization-Uppsala Monitoring Centre (WHO-UMC) scale for standardized case causality assessment. CONCLUSION: This case represents the first documented instance of vancomycin-induced bleeding without thrombocytopenia, as confirmed by a positive rechallenge test. This discovery will aid in the early detection of this rare adverse reaction in future cases.

[Chinese expert consensus on the diagnosis and treatment of Evans syndrome (2024)].

Evans syndrome (ES) is a rare autoimmune disorder characterized by the presence of at least two autoimmune cytopenias (AIC), including immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and autoimmune neutropenia (AIN). Secondary ES accounts for 21%-50% of cases. ES is characterized by recurrent relapses, serious complications such as thrombosis and infection, and high mortality. The management of ES is highly heterogeneous, necessitating treatment for AIC, the primary disease, as well as associated complications. However, there remains a lack of prospective evidence, randomized clinical trials for ES. To standardize the diagnosis and management of ES in China effectively, this consensus was developed by the Red Blood Cell Diseases (Anemia) Group under the Chinese Society of Hematology within the Chinese Medical Association. It aims to provide valuable guidance for diagnosing and managing ES in clinical practice based on international consensus and comprehensive review of both domestic and international literature.

Immune or inherited thrombocytopenia? A population-based cohort study on children and adolescents presenting with a low platelet count.

BACKGROUND: Thrombocytopenia is a common hematologic finding in children and adolescents. Immune thrombocytopenia (ITP) is the most common cause of this finding, but the differential diagnosis includes a growing list of genetic disorders. We aimed to report differences in phenotypes of patients with ITP, inherited platelet disorder (IPD)/primary immunodeficiency disorder (PID), and other causes, with a focus on differentiating ITP from inherited thrombocytopenia. PROCEDURE: This retrospective, population-based observational cohort from 2006 to 2020 involved 506 Finnish children under 16 years of age presenting with isolated thrombocytopenia. RESULTS: Of the 506 participants, 79.7% had ITP, 6.7% had IPD/PID, and 13.6% had other causes of thrombocytopenia. A platelet count of ≤12 × 109/L best distinguished between ITP and other reasons with a sensitivity of 60% and a specificity of 80%. Among patients with the lowest platelet count of less than 10 × 109/L, 95.9% had ITP, 3.3% had IPD/PID, and 0.8% had other causes. Severe bleeding events were reported in 20 patients (4.0%), but there were no cases of intracranial or fatal bleeding due to thrombocytopenia. Up to 50% of patients with a high suspicion of inherited thrombocytopenia remained without a specific diagnosis despite genetic testing. CONCLUSIONS: ITP remains the most common cause of thrombocytopenia. A platelet count of ≤12 × 109/L often leads to an ITP diagnosis. Genetic disorders are rare but should be suspected in patients with persisting thrombocytopenia, especially with platelet counts constantly above 12 × 109/L, a positive family history, or atypical clinical features.

Prediction model for early diagnosis of late-onset sepsis in preterm newborns.

AIM: Late-onset neonatal sepsis has a high mortality rate in premature infants. To date, no single test in the evaluation of neonatal sepsis has been demonstrated to be both sensitive and specific enough to assist in timely decision making. The aim of our study is to develop a predictive model that can be applied to all premature babies, using clinical and laboratory findings in premature babies, to recognize late-onset neonatal sepsis. STUDY DESIGN: 65 premature patients diagnosed with culture-proven late-onset neonatal sepsis and hospitalized in Dr. Behcet Uz Pediatric Diseases and Surgery Training and Research Hospital neonatal intensive care unit between January 2018 and December 2020, and 65 premature newborns of similar age and gender who did not have sepsis were included in the study retrospectively. RESULTS: In our study, feeding difficulties, worsening in clinical appearance and fever were found to be significant among clinical findings, while thrombocytopenia and high C-reactive protein among laboratory findings are the strongest data supporting late-onset neonatal sepsis. In multiple regression analysis, thrombocytopenia, mean platelet volume, C-reactive protein, lymphocyte count and feeding difficulties had the highest odds ratio (p < 0.05). By converting these data into a scoring system, a nomogram was created that can be easily used by all clinicians. CONCLUSION: In our study, we developed a scoring system that can be easily applied to all premature patients by evaluating the clinical and laboratory findings in late-onset neonatal sepsis. We think that it will help in recognizing late-onset neonatal sepsis and strengthening the treatment decision. Predicting the individual probability of sepsis in preterm newborns may provide benefits for uninfected newborns to be exposed to less antibiotics, not to be separated from mother and baby, and to reduce healthcare system expenditures. The nomogram can be used to assess the likelihood of sepsis and guide treatment decision.

Disseminated Tuberculosis: Rare Presentation.

India contributes to 26% of the global tuberculosis (TB) burden, with very high mortality and morbidity. The exact incidence of disseminated TB cannot be established among the general population but accounts for <2% of cases among immunocompromised hosts and constitutes 20% of all extrapulmonary TB cases. Disseminated TB has a very high mortality rate of around 25-30%. Miliary TB, a disseminated form, is another entity of TB that poses a health burden due to its difficulty in diagnosis. This entity usually presents with subclinical symptoms and poses a diagnostic challenge in the absence of specific diagnostic tests. We present a case of a young female with epistaxis and thrombocytopenia who was diagnosed with disseminated TB [miliary, bone cyst, bone marrow (BM) involvement].

A nomogram incorporating linezolid and metabolite concentrations for predicting linezolid induced thrombocytopenia in patients with renal impairment.

A nomogram to estimate the risk of linezolid-induced thrombocytopenia in patients with renal impairment is not available. The aim of the study is to develop a nomogram for predicting linezolid-induced thrombocytopenia in patients with renal impairment and to investigate the incremental value of PNU-142300 concentration beyond clinical factors and linezolid trough concentration (Cmin) for risk prediction. Logistic regression was used to identify independent risk factors for linezolid-induced thrombocytopenia in patients with renal impairment and nomograms were established. The performance of the nomograms was assessed in terms of area under the receiver operating characteristic curve (AUROC), net reclassification improvement (NRI), integrated discrimination improvement (IDI) , decision curve analysis (DCA) and calibration. Internal validation and external validation of the nomograms were also performed. Four nomograms were created: nomogram A including total bilirubin, creatinine clearance and concomitant mannitol use; nomogram B containing linezolid Cmin additionally; nomogram C containing total bilirubin, concomitant mannitol use, linezolid Cmin, and PNU142300 concentration; nomogram D including total bilirubin, concomitant mannitol use, and PNU142300 concentration. Nomogram C improved the prediction performance than nomogram A (AUROC 0.881 vs. 0.749; NRI 0.290; IDI 0.226) and nomogram B (AUROC 0.881 vs. 0.812; NRI 0.152; IDI 0.130) in the training cohort. DCA analysis showed that nomogram C yielded a greater net benefit. Compared with nomogram A and nomogram B, nomogram C also showed superior discriminatory efficacy, good calibration and clinical usefulness in the external validation cohort. The nomogram containing PNU-142300 concentration and linezolid Cmin had better predictive capability than that containing linezolid Cmin for predicting linezolid-induced thrombocytopenia in patients with renal impairment.

Pediatric Severe Febrile Thrombocytopenia Syndrome: A Case Report and Literature Review.

Severe febrile thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease that is endemic in parts of eastern Asia. Few pediatric cases have been reported. We describe a case of SFTS in a seven-year-old girl who presented with prolonged fever and gastrointestinal symptoms. Leukopenia and thrombocytopenia on hematology, and a history of outdoor activity led us to diagnose SFTS, although the patient had no tick bite marks. We also review the literature and discuss the characteristics of pediatric SFTS. Physicians should consider SFTS in the differential diagnosis of fever with thrombocytopenia in children living in endemic areas.

National recommendations of the Croatian Chamber of Medical Biochemists and Working group for Laboratory hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine: Management of samples with suspected EDTA-induced pseudothrombocytopenia.

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions (i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management (i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions (i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results.

[Developments of high-throughput sequencing-based diagnosis of congenital thrombocytopenia/platelet disorders in a registry study].

Congenital thrombocytopenia/platelet disorders are heterogeneous disorders of platelet number and/or function. Pathogenic variants in the genes implicated in megakaryocyte differentiation and platelet formation cause thrombocytopenia in these patients. Recent advances have elucidated several causative genes for these disorders, but identifying the underlying causative genes remains challenging. Patients with these disorders often receive inappropriate treatments, including glucocorticoids and splenectomy, for chronic immune thrombocytopenia (ITP). In Japan, we have developed a diagnostic system using high-throughput DNA sequencing with a multigene panel and established a registry. Between 2018 and 2023, 245 patients were enrolled and analyzed. Pathogenic variants in 17 genes (42 MYH9, 19 ANKRD26, 17 ITGA2B/ITGB3, 8 ACTN1, 8 WAS, 6 ETV6, 6 VWF, 5 CYCS, and 14 others) were identified in 125 patients (51.0%). An additional 29 patients (11.8%) had suspected pathogenic variants under investigation. We also found that immature platelet fraction (IPF%) is useful in the differential diagnosis because the median IPF% in MYH9 disorders, 48.7%, was significantly higher than in all other groups (chronic ITP, 13.4%; controls, 2.6%). The results of this study provide new insight into congenital thrombocytopenia/platelet disorders.

Limitations of a platelet count-based clinical decision support system to facilitate diagnosis of heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a rare complication of heparin exposure with potential for significant morbidity and mortality. Early identification and treatment can prevent catastrophic thrombosis. Herein, we report the performance of a platelet count-based clinical decision support system (CDSS) where providers received a notification when a patient had a platelet count decline of ≥50 %. In the 90-day study period, the CDSS sent 302 notifications on 270 patients. Notifications were frequently inappropriate; 25 % had an expected platelet count decline (organ donation, stem cell transplant), an inaccurate count, or no heparin exposure. Patient testing for HIT prompted by the CDSS was not in accordance with best practice guidelines in most circumstances. For example, 36 % had a low probability 4Ts score, while 42 % with an intermediate or high probability 4Ts score were not tested. Due to concern for lack of efficacy, the CDSS was discontinued. Analysis of an 8-month period before and after discontinuation showed a significant decrease in the number of enzyme immunoassays ordered (547 vs. 386) without a change in the number of patients with HIT identified (13 vs. 13) or the rate of thrombosis in those with confirmed HIT (62 % vs. 62 %). In conclusion, a CDSS based on platelet count decline contributed to "alert fatigue" via inappropriate notification and did not improve evidence-based HIT testing. In addition, its removal did not decrease or delay HIT identification. Additional efforts are needed to better define how CDSS can support the rapid diagnosis and appropriate treatment of patients with HIT.

Refractory Thrombocytopenia is the Earliest Diagnostic Criterion for Sinusoidal Obstruction Syndrome in Children.

Sinusoidal obstruction syndrome (SOS) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT), whose diagnostic criteria changed over time to achieve a timelier diagnosis. Recently, pediatric-specific criteria presented by the European Society for Blood and Marrow Transplantation (pEBMT) incorporated transfusion-refractory thrombocytopenia (RT) as an early indicator of SOS in children. However, a comparison of all individual diagnostic parameters belonging to pEBMT and former SOS diagnostic criteria has never been performed. This retrospective study conducted at a pediatric tertiary care hospital analyzed all pediatric HSCT cases diagnosed with SOS among 170 children transplanted from 2009 to 2023. Eleven patients developed SOS during this period (incidence: 11/170, 6.5%). pEBMT, Seattle, and Baltimore criteria were retrospectively applied to the 11 cases and compared, showing that RT was the earliest fulfilled parameter (median onset: 6 d post-HSCT). pEBMT and Seattle criteria identified 11/11 SOS cases, with pEBMT leading to an earlier diagnosis. RT typically manifested before diagnosis, with significantly higher platelet transfusion requirements before diagnosis than after. RT is the earliest satisfied criterion in pediatric SOS and typically occurs in the initial stages of the disease before diagnosis. Further research is needed to identify additional early indicators of pediatric SOS.

DNA damage repair in megakaryopoiesis: molecular and clinical aspects.

INTRODUCTION: Endogenous DNA damage is a significant factor in the damage of hematopoietic cells. Megakaryopoiesis is one of the pathways of hematopoiesis that ends with the production of platelets and plays the most crucial role in hemostasis. Despite the presence of efficient DNA repair mechanisms, some endogenous lesions can lead to mutagenic alterations, disruption of pathways of hematopoiesis including megakaryopoiesis and potentially result in human diseases. AREAS COVERED: The complex regulation of DNA repair mechanisms plays a central role in maintaining genomic integrity during megakaryopoiesis and influences platelet production efficiency and quality. Moreover, anomalies in DNA repair processes are involved in several diseases associated with megakaryopoiesis, including myeloproliferative disorders and thrombocytopenia. EXPERT OPINION: In the era of personalized medicine, diagnosing diseases related to megakaryopoiesis can only be made with a complete assessment of their molecular aspects to provide physicians with critical molecular data for patient management and to identify the subset of patients who could benefit from targeted therapy.

Two delayed-diagnosis case reports of long-lasting thrombocytopenia with splenomegaly.

RATIONALE: Gaucher disease (GD) is a rare hereditary lysosomal storage disorder disease progression and inappropriate treatment. However, not all patients with GD receive timely diagnosis and treatment. PATIENT CONCERNS: Early diagnosis is important for initiating proper treatment and preventing complications. DIAGNOSES: Two patients were diagnosed as GD in this study. INTERVENTIONS AND OUTCOMES: These 2 patients received the imiglucerase enzyme replacement and symptoms significantly improved by the follow-up. LESSONS: Herein, we report 2 patients with a delayed diagnosis of GD to increase awareness and improve education regarding rare diseases. However, noninvasive ß-glucocerebrosidase activity or GBA gene testing had not been done before bone marrow aspiration, which are the noninvasive and reliable tests that indicate the diagnosis of GD.

Heparin Induced Thrombocytopenia Testing.

This article provides a comprehensive overview of Heparin-Induced Thrombocytopenia (HIT) with an emphasis on laboratory testing and advantages of automation. HIT is a critical condition arising from heparin exposure, leading to a contradictory combination of thrombocytopenia with an increased thrombosis risk. The article discusses HIT's history, clinical presentation, laboratory diagnosis, and management strategies. It highlights the importance of interdisciplinary collaboration for effective diagnosis and treatment, underscoring advancements in technology and targeted therapies that are shaping future approaches to HIT management.

Delayed diagnosis of TAFRO syndrome: A case report.

RATIONALE: TAFRO syndrome is a systemic inflammatory disorder, manifesting as thrombocytopenia (t), anasarca (a), fever (f), reticulin myelofibrosis/renal insufficiency (r), and organomegaly (o), and considered as a unique clinical subtype of idiopathic multicentric Castleman disease (iMCD). Such syndrome gave rise to a clinical picture similar to that of either a connective tissue disease or an autoimmune disease. PATIENT CONCERNS: A Chinese young female initially presenting with arthralgia, Raynaud phenomenon, generalized edema, and a positive anti-small nuclear ribonucleoprotein particle antibody was diagnosed as mixed connective tissue disease. The kidney biopsy showed thrombotic microangiopathy. Bone marrow smear showed bone marrow hyperplasia and biopsy revealed suspected light chain restricted expression, megakaryocyte proliferation, and moderate to severe bone marrow fibrosis. A lymph node biopsy was conducted and the histopathological findings were consistent with the subtype of mixed Castleman disease. The clinical symptoms were relieved after regular chemotherapy. DIAGNOSES: After above examination results and clinical manifestations, the final diagnoses was TAFRO syndrome. INTERVENTION: The she was started on chemotherapy with bortezomib, cyclophosphamide, and dexamethasone. OUTCOME: After chemotherapy, symptoms such as thrombocytopenia, hematuria and proteinuria disappeared, lymphadenopathy and VEGF level decreased, and bone marrow fibrosis relieved. LESSONS: Our case illustrated the first cases of shared characteristics of mixed connective tissue disease and iMCD-TAFRO syndrome. Cytokines may play a role in the shared pathogenicity of the iMCD-TAFRO syndrome and systemic autoimmune diseases. Therapy directly against inflammatory factors such as corticosteroids or chemotherapy have an important therapeutic implication.

Pediatric TAFRO syndrome: A multi-institution case series illustrating clinical challenges and excellent outcomes.

A rare lymphoproliferative disorder involving thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), renal dysfunction (R), and organomegaly (O), called TAFRO syndrome, was first reported in 2010. Considered a variant of idiopathic multicentric Castleman's disease, the recent discovery and rarity of this syndrome pose challenges to diagnosis and management. Herein, we review three pediatric cases, including an infant, that illustrate the heterogeneity of TAFRO syndrome. Despite differences in presentation and treatment responses, all patients experienced excellent outcomes. This multi-institutional case series highlights the need to work toward earlier diagnosis and improved long-term management recommendations for patients with TAFRO syndrome.

Safety of Antiplatelet Therapy in Noncardioembolic Ischemic Stroke With Thrombocytopenia: The CASE II Study.

BACKGROUND: There is scant evidence regarding the safety of antiplatelet therapy in acute ischemic stroke (AIS) patients with thrombocytopenia. Our study aims to address this concern by examining AIS patients with thrombocytopenia from a large database in real-world settings. METHODS AND RESULTS: We included patients with AIS with a platelet count <100×109/L who had complete records of antiplatelet drug use. Those requiring anticoagulation or having contraindications to antiplatelet therapy were excluded. Short-term safety outcomes were in-hospital bleeding events, while the long-term safety outcome was 1-year all-cause mortality. A good clinical outcome was defined as functional independence, indicated by a modified Rankin Scale score of 0 to 2 at discharge. Propensity score matched analyses were used. We screened 169 423 patients with AIS from 90 stroke centers in the CASE II register, ultimately enrolling 2808 noncardioembolic patients with thrombocytopenia. In the propensity score matched analyses, no significant difference was observed between the antiplatelet and nonantiplatelet groups in terms of intracranial hemorrhage (odds ratio=0.855 [95% CI, 0.284-5.478]; P=0.160) or gastrointestinal bleeding (odds ratio=2.034 [95% CI, 0.755-5.478]; P=0.160). Antiplatelet therapy was associated with improved functional outcomes at discharge (odds ratio=1.405 [95% CI, 1.028-1.920]; P=0.033), and showed a trend towards reducing 1-year mortality (odds ratio=0.395 [95% CI, 0.152-1.031]; P=0.058). CONCLUSIONS: The use of antiplatelet therapy lessened as platelet count decreased in patients with AIS with thrombocytopenia. However, our findings suggest that antiplatelet medications remain safe and effective for this population.