A Review and Assessment of Drug-Induced Thrombocytosis

An Approach to the Investigation of Thrombocytosis: Differentiating between Essential Thrombocythemia and Secondary Thrombocytosis

Background

Thrombocytosis is a common reason for referral to Hematology. Differentiating between secondary causes of thrombocytosis and essential thrombocythemia (ET) is often clinically challenging. A practical diagnostic approach to identify secondary thrombocytosis could reduce overinvestigation such as next generation sequencing (NGS) panel.

Methods and Results

All adult patients with thrombocytosis (≥450 × 109/L) who underwent molecular testing at a single tertiary care centre between January 1, 2018 and May 31, 2021 were evaluated. Clinical and laboratory variables were compared between patients with secondary thrombocytosis vs. ET. Clinical variables included smoking, thrombosis, splenectomy, active malignancy, chronic inflammatory disease, and iron deficiency anemia. Laboratory variables included complete blood count (CBC), ferritin, and myeloid mutations detected by NGS. The overall yield of molecular testing was 52.4%; 92.1% of which were mutations in JAK2, CALR, and/or MPL. Clinical factors predictive of ET included history of arterial thrombosis (p < 0.05); active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency were associated with secondary thrombocytosis (p < 0.05). A diagnosis of ET was associated with higher hemoglobin, mean corpuscular volume (MCV), red cell distribution width (RDW), and mean platelet volume (MPV), while secondary thrombocytosis was associated with higher body mass index, white blood cells, and neutrophils (p < 0.01).

Conclusion

A practical approach to investigating patients with persistent thrombocytosis based on clinical characteristics such as active malignancy, chronic inflammatory disease, splenectomy, and iron deficiency may assist in accurately identifying patients more likely to have secondary causes of thrombocytosis and reduce overinvestigation, particularly costly molecular testing.

Predictive factors for severe outcomes in substance abuse-related emergency visits: A 5-year retrospective analysis at a medical center in Taiwan

BACKGROUND

Substance abuse is a considerable medical issue worldwide, yet current surveillance systems in Taiwan offer limited insights into the clinical characteristics and outcomes of substance abuse patients. This study aimed to delineate the epidemiology of emergency department visits related to substance abuse at a hospital in Taiwan and to identify factors predictive of severe complications or mortality.

METHODS

A retrospective analysis was conducted on substance abuse-related emergency department visits at a medical center in Taiwan between 2009 and 2013. Eligible participants were individuals aged 20 or older who had confirmed substance abuse through urinalysis. Variables such as patient demographics, substances abused, clinical characteristics, and outcomes were collected. Severe outcomes were defined as admission to the intensive care unit, requirement for endotracheal intubation, or in-hospital death. Logistic regression models were employed to identify factors contributing to severe outcomes.

RESULTS

The cohort consisted of 623 patients, of whom 64.0% were female and 67.1% were aged between 20 and 49 years. Benzodiazepines were detected in 75.3% of patients, while z-drugs (specifically zopiclone, zolpidem, or zaleplon) were found in 27.8%. Depressants, stimulants, and hallucinogens were present in 14.9%, 10.6%, and 0.6% of the cases, respectively. Of the patient, 121 (19.4%) experienced severe outcomes, including 116 (18.6%) intensive care unit admissions, 73 (11.7%) intubations, and 11 (1.8%) in-hospital deaths. Multivariable logistic regression analysis revealed multiple predictors of severe outcomes, such as emergency department triage level, aspiration pneumonia, leukocytosis, abnormal hepatic function, abnormal renal function, hypernatremia, and hypocalcemia.

CONCLUSION

In Taiwan, benzodiazepines emerged as the most prevalent substance of abuse among emergency department visitors, and a significant proportion of these patients experienced severe outcomes. Continuous monitoring of severe outcome predictors is essential for enhanced understanding and management.

Secondary thrombocythemia with ST-segment elevation myocardial infarction as the first manifestation: a case report

Secondary thrombocythemia (ST), also called reactive thrombocytosis, is caused by a disorder that triggers increased production by normal platelet-forming cells and is characterized by the abnormally increased number of platelet and megakaryocytes in the bone marrow. Previous reports have found complications from malignant tumors, chronic inflammation, acute inflammation, acute hemorrhage, splenectomy, etc. to be the common causes of ST. However, reports of secondary thrombocytosis caused by antibiotics are limited and there are no reports of secondary thrombocytosis with acute myocardial infarction as the first presentation. If the patient is at high risk of thrombosis, intensive antithrombotic therapy is required. To raise clinicians' awareness of drug-induced secondary thrombocytosis and to enhance antithrombotic therapy for high-risk patients, this article presented a case of drug-induced secondary thrombocytosis with acute ST-segment elevation myocardial infarction as the primary manifestation.

CASE PRESENTATION

An 80-year-old woman was admitted with cardiogenic shock due to post-activity chest pain. She was started on aspirin and clopidogrel antiplatelet therapy, then replaced aspirin with indolibuprofen, which has relatively few side effects. There was no significant decrease in platelet counts during treatment.

CLINICAL DISCUSSION

Secondary thrombocythemia, characterized by nonspecific symptoms, is difficult to diagnose. Secondary thrombocytosis with acute myocardial infarction as the first symptom is uncommon, but is very urgent and associated with a poor prognosis. What's more, cause-specific treatment counts for secondary thrombocythemia. Therefore it is important to search for the causal factor of secondary thrombocytosis. Secondary thrombocytosis caused by cephalosporins is rare. There is a need to arouse the attention of clinicians to the ST caused by cephalosporins and to provide a guide of treatment to these patients.

CONCLUSION

After a thorough analysis of the pertinent literature, we discovered that several retrospective studies demonstrated the effectiveness of cytoreductive therapy in significantly reducing platelet counts. Based on this finding, we prescribed hydroxyurea to our patient, which led to a gradual decrease in platelet count and ultimately resulted in a return to normal levels.

Study of the acute and repeated dose 28-day oral toxicity in mice treated with PT-31, a molecule with potential antipsychotic profile

Schizophrenia is a psychiatric disorder that affects 1% of the world population and is treated with antipsychotics, which may induce important biochemical and hematological alterations. Since it is necessary to verify the safety of new molecules with antipsychotic potential, the present study aimed to evaluate the oral toxicity of PT-31, a putative α₂-adrenoreceptor agonist, after acute (2000 mg/kg) and repeated doses (28 days) gavage treatment, in three different doses: minimum effective dose in animal models (10 mg/kg), twice the dose (20 mg/kg), and four times the dose (40 mg/kg), as recommended by the OECD guidelines. Balb/C female adult mice were used, and biochemical, hematological, and histopathological analyses were performed. PT-31 10 and 20 mg/kg did not cause biochemical alterations related to hepatic and renal toxicity, and neither altered glycemic and lipid profiles. The preclinical dose of PT-31 also did not promote mice histopathological changes in the liver, kidney, and brain. In the hematimetric parameters, PT-31 only increased HGB at 20 mg/kg, and MCH and MCHC at 40 mg/kg. However, all the tested doses of PT-31 showed platelet increase, which must be better investigated. Therefore, further studies are needed to investigate the safety of PT-31 as a potential antipsychotic drug.

[Effect of ethanol on platelet biology]

In recent years, interest in the study of platelets, significantly increased due to recent discoveries providing convincing evidence that their functions by are not limited to their participation in the blood coagulation mechanism. Many works are devoted to the study of the functional state of platelets under conditions of acute and chronic alcohol exposure. The results of such studies can be useful for the development of new markers of the degree of alcohol intoxication of the body for the subsequent choice of the method drug correction of disorders caused by acute or chronic alcohol effects. The review summarizes results in vivo and in vitro of studies performed during more than 60 years on the effect of ethanol on the biogenesis, number, morphology and biochemistry of platelets.

Imipenem–cilastatin-induced thrombocytosis: A probable rare case report

Drug-induced thrombocytosis is difficult to identify and is rarely reported. Here, we report a probable rare case of imipenem–cilastatin-induced thrombocytosis in a 51-year-old female. The patient received imipenem–cilastatin treatment because of an intra-abdominal infection, following which the platelet count increased to a peak value of 1058×109 cells/L in 14 days. When imipenem–cilastatin was replaced by levofloxacin and amikacin, the platelet count decreased progressively and remained within the normal range until the 6-month follow-up. Moreover, platelet counts were independent of the infection. Thrombocytosis was probably attributable to imipenem–cilastatin with a Naranjo score of seven. This is a probable rare case in which the thrombocytosis was likely an adverse reaction induced by imipenem–cilastatin. We suggest that clinicians need to be vigilant concerning the impact of imipenem–cilastatin on platelet count in patients with thrombocytosis.

Clinical course involving thrombocytosis and thrombocytopenia in a patient with bladder cancer treated with gemcitabine and cisplatin

Gemcitabine induce thrombocytopenia and thrombocytosis as toxicity. In this report, we show detailed time-course for platelet fluctuation. Our case emphasis attention to monitor see-saw-like toxicity on platelet count.

Isotretinoin-Induced Thrombocytosis in a Patient With Acne Vulgaris: A Case Report

Isotretinoin is one of the first-line medications for the treatment of acne. One of the reported side effects of isotretinoin is thrombocytopenia, in addition to other abnormalities such as incomplete blood count. However, reports on thrombocytosis associated with isotretinoin are controversial. The present report discusses the case of a patient with acne vulgaris who was treated with isotretinoin and consequently suffered from isotretinoin-induced thrombocytosis.

A 20-year-old female patient was diagnosed with acne vulgaris and started treatment with systemic isotretinoin (20 mg once daily) for one month. A baseline complete blood count was performed, as well as another blood count after one month of medication administration. Platelet count was recorded at each visit. The baseline platelet count was within the normal range; however, it was found to be elevated after one month of treatment. Accordingly, the medication was discontinued, and the platelet count returned to normal levels after one month, as measured during the monthly visit. The patient also experienced seizure episodes during treatment, which did not cease with the treatment discontinuation. Although isotretinoin-induced thrombocytosis is considered a rare side-effect for isotretinoin, it should be routinely monitored in high-risk patients and those undergoing surgeries. Further prospective studies on isotretinoin-induced thrombocytosis need to be conducted to gain a deeper insight into the various aspects related to the condition.

Enoxaparin-induced reactive thrombocytosis: a case report

Background

Enoxaparin is an anticoagulant that falls in the class of medications called low molecular weight heparins (LMWHs), and is used to prevent or treat patients with deep vein thrombosis (DVT) and pulmonary embolism. Enoxaparin is the most widely used LMWH for DVT prophylaxis following knee or hip replacement surgery. Common side effects of enoxaparin include bleeding, petechiae at the injection site, and thrombocytopenia. However, reactive thrombocytosis is a rarely reported adverse reaction. We managed a patient who developed enoxaparin-associated thrombocytosis, which was completely resolved after treatment cessation.

Case presentation

A 78-year-old female was hospitalized for post-hip replacement rehabilitation. Low molecular weight heparin 40 mg/day was administered subcutaneously to prevent deep venous thrombosis (DVT). At admission, her platelet count was normal (228 × 10⁹/L) and her white blood cell count was slightly elevated (12.91 × 10⁹/L). Seven days after admission, the patient developed thrombocytosis, which peaked on the 14th day (836 × 10⁹/L), while her white blood cell count had returned to normal (8.86 × 10⁹/L). Her therapeutic regimen was reviewed, and enoxaparin was identified as a potentially reversible cause of reactive thrombocytosis. Switching from enoxaparin to rivaroxaban lead to a gradual decrease in the patient’s platelet count, which eventually returned to normal levels 16 days after enoxaparin was discontinued. No complications secondary to thrombocytosis was observed, and no conclusion was reached on the use of small doses of aspirin for antithrombotic therapy under these circumstances.

Conclusion

Enoxaparin-induced reactive thrombocytosis should be suspected in patients with thrombocytosis following enoxaparin administration as an anticoagulant to prevent certain complications.

Unfractionated heparin as a safe alternative in a case of low molecular weight heparin-induced thrombocytosis: A case report

Introduction and importance

Low molecular weight heparins are rarely associated with thrombocytosis. However, the safety of transitioning to unfractionated heparin is unknown.

Case presentation

We report a case of a 47-year-old South Asian male who presented to the hospital after ingestion of a caustic liquid. He received subcutaneous enoxaparin 40 mg once daily for prophylaxis against venous thromboembolism. His platelet count increased from the baseline of 748 × 10⁹/L to a peak of 1213 × 10⁹/L, after which enoxaparin was changed to unfractionated heparin. His platelet count returned to normal within seven days. The modified Naranjo scale with thrombocytosis-specific criteria was 6, indicating a probable association with enoxaparin.

Clinical discussion

In this case, the patient developed thrombocytosis after initiation of low-molecular weight heparin and platelet count normalized after shifting to unfractionated heparin.

Conclusion

Clinicians should suspect LMWH-induced thrombocytosis when platelet count elevation cannot be explained by other causes. Unfractionated heparin might be a safe alternative in case of low molecular weight heparin-induced thrombocytosis.

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Low molecular weight heparin-induced thrombocytosis is a rare adverse drug reaction.

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Clinicians should anticipate low molecular weight induced thrombocytosis when other causes of thrombocytosis are excluded.

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Unfractionated heparin may be a safe therapeutic alternative in case of low molecular weight induced thrombocytosis.

Alcohol-induced thrombocytopenia: Current review

Thrombocytopenia is a decrease in the platelet count below 150,000 in a microliter of blood, i.e., below the lower limit of the reference range, which is 150,000-400,000/μL. The phenomenon of thrombocytopenia related to heavy drinking began to arouse interest in the 1960s and 1970s. It was initially described in case reports and clinical studies on small groups. In the following years, the phenomenon itself and the significance of alcohol-induced thrombocytopenia was studied. Many methodological difficulties inhibiting objective conclusions from research were encountered. Model pathological mechanisms of alcohol thrombocytopenia and the effects of alcohol on the structure and function of platelets were described. Furthermore, the phenomenon of rapid normalization of the number of platelets in people who stopped drinking was described. Relationships between alcohol use, its intensity and occurrence, and intensity of thrombocytopenia have been demonstrated. Predictive platelet counts for alcohol withdrawal syndrome complications have been proven and calculated. The risk of occurrence of withdrawal seizures or delirium tremens in alcohol withdrawal syndrome increases significantly when the platelet count is less than 119,000/μL. The knowledge of the nature of the phenomenon of alcohol-induced thrombocytopenia in a clinical environment allows decisions that are more rational. The attention of clinicians should be drawn to the importance of results of blood tests routinely collected on admission.

Enoxaparin induced reactive thrombocytosis: a rare adverse drug reaction

Objectives Enoxaparin is a low molecular weight heparin (LMWH), which belongs to the class of anticoagulants. The drug is administered as subcutaneous injection to prevent or treat deep vein thrombosis (DVT), pulmonary embolism and ischemic complications. Case Presentation A 57-year-old women diagnosed with acute coronary syndrome developed reactive thrombocytosis following the administration of enoxaparin subcutaneously. The blood test reports of the patient showed that there is a gradual elevation of platelet count day by day following enoxaparin administration. On an assessment using both World Health Organization-Uppsala Monitoring Centre (WHO-UMC) scale and Naranjo Causality Assessment Scale indicated that enoxaparin is the "probable" cause for the reaction. Conclusions We conclude that reactive thrombocytosis is a probable adverse drug reaction and close monitoring of blood counts is essential, following enoxaparin injection. More studies are to be conducted to identify further complications.

Toxicity study of separase inhibitor-Sepin-1 in Sprague-Dawley rats

Sepin-1 is a small compound that inhibits enzymatic activity of Separase and growth of cancer cells. As part of the IND-enabling studies to develop Sepin-1 as a chemotherapeutic agent, herein we have profiled the toxicity of Sepin-1 in Sprague-Dawley rats in a good laboratory practice (GLP) setting. The maximum tolerated dose (MTD) of Sepin-1 in rats is 40 mg/kg in single dose study and 20 mg/kg in the study dosed for 7 consecutive days. The toxicity study consists of two parts-Main Study and Recovery Study. Sepin-1 with 0 (control), 5 (low dose), 10 (median dose), and 20 (high dose) mg/kg was administered by bolus intravenous injection to rats once daily for 28 consecutive days. The animals in the Main Study were euthanized on Day 29, whereas animals in the Recovery Study were allowed to recover for 28 days following the 28-day Sepin-1 dose before they were euthanized on Day 29 of the off-dose period. Although the effects of Sepin-1 at low and median doses are minimal, hematological analysis shows that high-dose Sepin-1 is associated with decrease of red blood cells and hemoglobin, and increase in the number of reticulocytes and platelets as well as mean corpuscular volume. Clinical chemistry indicates that Sepin-1 causes increase of total bilirubin and decrease of creatine kinase. Histopathology analysis indicates Sepin-1 results in minimal bone marrow erythroid hyperplasia, minimal to moderate splenic extramedullary hematopoiesis, minimal splenic lymphoid depletion, minimal to mild thymic lymphoid depletion, and minimal to mild mandibular lymph node lymphoid hyperplasia in male and female rats in the Main Study. Those abnormal changes are Sepin-1 dose-dependent and mostly reversible after a 28-day recovery period in animals from the Recovery Study. Based on our results, we conclude that Sepin-1 at pharmacologic doses (5-10 mg/kg) is well tolerable, with no significant rates of mortality or morbidity, and can further be developed as a potential new drug to treat Separase-overexpressed tumors.