Aetiology and clinical significance of thrombocytosis: analysis of 732 patients with an elevated platelet count

PROGNOSTIC IMPLICATIONS OF CHANGES IN PLATELET TRAJECTORIES IN PATIENTS WITH SEPSIS: A RETROSPECTIVE ANALYSIS USING THE MEDICAL INFORMATION MART FOR INTENSIVE CARE IV DATABASE

ABSTRACT

Objective: Patients with sepsis often experience reductions or increases in platelet counts, but the implications of these temporal patterns on prognosis remain unclear. The aim of this study was to investigate the impact of changes in platelet trajectories on the clinical prognosis of sepsis. Methods: This study was a retrospective analysis using data from the Medical Information Mart for Intensive Care IV database. Patients with sepsis were identified from the database, and their platelet trajectories were categorized into four distinct models based on the changes in platelet counts over a period of 14 days after diagnosis of sepsis. The effect of these trajectories on patient prognosis was subsequently evaluated. Results: A total of 15,250 patients with sepsis were included to construct a model, and the following four distinct platelet count trajectories were identified: normal platelet levels (phenotype 1); persistently low platelet levels (phenotype 2); gradually increasing platelet levels exceeding the normal range (phenotype 3); and consistently significantly elevated platelet levels (phenotype 4). Statistically significant differences were found in the 28-day mortality, in-hospital mortality, and 90-day mortality among the four phenotypes. Multivariate regression analysis showed that compared to the group with normal platelet levels (phenotype 1), the group with persistently low platelet levels (phenotype 2) had higher in-hospital mortality (odds ratio [OR] = 1.34, 95% confidence interval [CI]: 1.16-1.54), 28-day mortality (OR = 1.69, 95% CI: 1.47-1.94), and 90-day mortality (OR = 1.50, 95% CI: 1.32-1.69). There was no difference in in-hospital mortality between phenotypes 3 and 4 compared to phenotype 1, although phenotype 4 showed an increase in 28-day mortality ( P < 0.05), and phenotype 3 showed a decreasing trend in 90-day mortality ( P < 0.05). The results of inverse probability weighting adjusted by regression were basically consistent with the above findings, except that there was no statistical difference in 28-day mortality between phenotype 4 and phenotype 1. In the subgroups based on age, weight, and antiplatelet drugs or therapies, there was an interaction between platelet levels and these factors. Conclusions: In patients with sepsis, a decrease in platelet count is associated with increased mortality, while a moderate increase in platelet count can reduce 90-day mortality. However, for patients with persistently elevated platelet counts, caution is advised when using antiplatelet drugs or therapies, as it may increase mortality.

Assessment of platelet-to-white blood cell ratio on short-term mortality events in patients hospitalized with acute decompensated heart failure: evidence from a cohort study from Jiangxi, China

Objective

Platelet-to-white blood cell ratio (PWR) as a comprehensive indicator of inflammatory response has been widely used to assess the prognosis of various diseases. However, the relationship between PWR and adverse outcomes in patients with acute decompensated heart failure (ADHF) remains unclear. This study aimed to evaluate the association between PWR and all-cause mortality within 30 days of hospitalization in ADHF patients from Jiangxi, China.

Methods

A total of 1,453 ADHF patients from the Jiangxi-ADHF study1 cohort were included. The primary outcome measure was all-cause mortality within 30 days of hospitalization. Multivariable Cox proportional hazards regression, restricted cubic spline regression, and receiver operating characteristic curve analysis were employed to explore the association between the inflammatory marker PWR and all-cause mortality in ADHF patients within 30 days of hospitalization.

Results

During the 30-day observation period, a total of 53 subjects experienced mortality events. Multivariable Cox regression showed a negative correlation between PWR and all-cause mortality within 30 days of hospitalization in ADHF patients. Restricted cubic spline regression demonstrated an L-shaped association between PWR and 30-day mortality risk (p for nonlinear = 0.038). Further threshold analysis revealed a threshold point for PWR at 15.88, where a decrease in PWR below this threshold was significantly associated with increased risk of all-cause mortality (p for log-likelihood ratio test = 0.046). Additionally, the results of receiver operating characteristic curve analysis indicated that PWR had high predictive accuracy for mortality events within 30 days of hospitalization in ADHF patients and is significantly better than the traditional HF marker N-Terminal Pro-Brain Natriuretic Peptide (AUC: NT-proBNP 0.69, PWR 0.76; Delong test P < 0.05). Subgroup analysis showed that compared to subjects with reduced or moderately reduced ejection fraction, ADHF patients with preserved ejection fraction had a lower risk of short-term mortality associated with PWR (HR:0.99 vs. 0.98 vs. 0.87, P for interaction = 0.0067).

Conclusion

This study reveals, for the first time, a negative correlation between the inflammatory marker PWR and all-cause mortality within 30 days of hospitalization in ADHF patients. Based on the threshold analysis findings, patients with ADHF and a PWR below 15.88 had a significantly higher risk of death within 30 days.

Etiology and clinical course of severe and extreme thrombocytosis in children: a retrospective single-center study

The aim of this study was to describe the etiology and clinical course in children with severe thrombocytosis (ST, platelet counts > 900 × 109/L) and extreme thrombocytosis (ET, platelet counts > 1000 × 109/L) in a tertiary pediatric hospital. Patients aged 0-18 years with platelet counts over 900 × 109/L who were admitted to our hospital were analyzed. Thrombocytosis was defined as a platelet count exceeding 450 × 109/L. Thrombosis was diagnosed based on computed tomography scans or ultrasound findings. Potential factors associated with the development of extreme thrombocytosis were identified using logistic regression models. Only one (0.8%) out of the 120 patients identified with ST (n = 61) and ET (n = 59) had primary thrombocytosis. The most common underlying condition was congenital heart disease (26.7%), followed by Kawasaki disease (16.7%). With the exception of the hemoglobin level, no major differences were found for the baseline characteristics between the ST and ET groups. A lower hemoglobin level (< 10.0 g/dL) at the onset of thrombocytosis was identified as a predictor for ET development (adjusted odds ratio 2.73, 95% confidence interval 1.18-6.28). Overall, 56 of 120 (46.7%) patients received aspirin therapy. Venous thrombosis occurred in one (0.8%) patient.

CONCLUSIONS

We found a low proportion of primary thrombocytosis and a low incidence of thrombosis in children with ST and ET. Our results suggest that pediatric ST and ET may share common characteristics and may have features that are distinct from those in adults.

WHAT IS KNOWN

• Secondary thrombocytosis is a frequent finding in children. • Adult extreme thrombocytosis has been found to be associated with primary thrombocytosis.

WHAT IS NEW

• There were no major differences in the baseline characteristics between children with severe and extreme thrombocytosis. • The incidence of thrombosis was markedly low in both severe and extreme thrombocytosis groups.

Higher Platelet Count Mostly in the Normal Range Is Associated with the First Episode of Peritonitis Risk in Incident Peritoneal Dialysis Patients

INTRODUCTION

Platelets play parts in infection and immune processes. However, the association between platelet count and the risk of peritoneal dialysis (PD)-associated peritonitis is unclear.

METHODS

This was a retrospective, observational, single-center cohort study. A Cox regression analysis was used to evaluate the independent association of platelet count with the occurrence of first PD-associated peritonitis. Models were adjusted for gender, age, body mass index, cardiovascular disease, diabetes mellitus, white blood cell count, neutrophil-lymphocyte ratio, hemoglobin level, albumin level, potassium level, and anti-platelet medication usage.

RESULTS

A total of 2,374 patients were enrolled in this study (59% men; mean age 47.40 ± 12.12). The average platelet count was 229.30 ± 82.12 × 109/L. 467 (20%) patients suffered from PD-associated peritonitis at least once. In the multivariable model, the adjusted hazard ratios (HRs) for quartiles 2, 3 and 4 versus quartile 1 were 1.428 (95% CI 1.060-1.924, p = 0.019), 1.663 (95% CI 1.240-2.229, p < 0.001) and 1.843 (95% CI 1.363-2.492, p < 0.001) with baseline data. A nonlinear relationship between platelet count and first PD-associated peritonitis was observed. Further, the association between platelet and first PD-associated peritonitis was significant in the patients with hypokalemia (P for interaction = 0.040).

CONCLUSION

In PD patients, elevated platelet counts were significantly associated with an increased risk of the first onset of PD-associated peritonitis.

Successful management of postpartum venous thrombosis following splenectomy for traumatic splenic rupture: a case report

Traumatic splenic rupture is rare in pregnant women; and multiple venous thromboses of the portal vein system, inferior vena cava and ovarian vein after caesarean section and splenectomy for splenic rupture has not been previously reported. This case report describes a case of multiple venous thromboses after caesarean section and splenectomy for traumatic splenic rupture in late pregnancy. A 34-year-old G3P1 female presented with abdominal trauma at 33+1 weeks of gestation. After diagnosis of splenic rupture, she underwent an emergency caesarean section and splenectomy. Multiple venous thromboses developed during the recovery period. The patient eventually recovered after anticoagulation therapy with low-molecular-weight heparin and warfarin. These findings suggest that in patients that have had a caesarean section and a splenectomy, which together might further increase the risk of venous thrombosis, any abdominal pain should be thoroughly investigated and thrombosis should be ruled out, including the possibility of multiple venous thromboses. Anticoagulant therapy could be extended after the surgery.

Reactive Thrombocytosis: A Bizarre Consequence of Splenectomy

Platelets are blood components produced in the bone marrow and are essential in forming blood clots. Thrombocytosis refers to a condition that causes the excess production of platelets in the body. When it develops as a reaction to an infection, trauma, or surgery, it is known as secondary or reactive thrombocytosis. Although thrombocytosis is typically a self-limiting disorder, it can frequently result in hemorrhagic or thrombotic events. Extreme thrombocytosis may trigger thrombotic events. Therefore, clinicians must be aware of the complications of thrombocytosis. In this case report, a 35-year-old female, known to have portal hypertension and Budd-Chiari syndrome, presented with complaints of weakness and tingling in her hands persisting for eight days. She disclosed that she had undergone an elective splenectomy as part of her management for portal hypertension and Budd-Chiari syndrome eight days prior.

Red Blood Cell Contribution to Thrombosis in Polycythemia Vera and Essential Thrombocythemia

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) characterized by clonal erythrocytosis and thrombocytosis, respectively. The main goal of therapy in PV and ET is to prevent thrombohemorrhagic complications. Despite a debated notion that red blood cells (RBCs) play a passive and minor role in thrombosis, there has been increasing evidence over the past decades that RBCs may play a biological and clinical role in PV and ET pathophysiology. This review summarizes the main mechanisms that suggest the involvement of PV and ET RBCs in thrombosis, including quantitative and qualitative RBC abnormalities reported in these pathologies. Among these abnormalities, we discuss increased RBC counts and hematocrit, that modulate blood rheology by increasing viscosity, as well as qualitative changes, such as deformability, aggregation, expression of adhesion proteins and phosphatidylserine and release of extracellular microvesicles. While the direct relationship between a high red cell count and thrombosis is well-known, the intrinsic defects of RBCs from PV and ET patients are new contributors that need to be investigated in depth in order to elucidate their role and pave the way for new therapeutical strategies.

Risk factors of portal vein system thrombosis after splenectomy: a meta-analysis

BACKGROUND

The primary aim of the present study was to explore risk factors for portal vein system thrombosis following splenectomy.

METHODS

A systematic search of PubMed, Embase and Cochrane libraries was conducted to identify original studies that fulfilled the inclusion criteria. Raw data on potential risk factors for portal vein system thrombosis after splenectomy were extracted for meta-analysis. Subsequently, a sensitivity analysis was conducted to verify the stability of the results.

RESULTS

Eighteen studies with 626 thrombosis events from 1807 splenectomy met the inclusion criteria. Larger spleen volume (SMD 0.44, P = 0.000), broader splenic vein diameter (WMD 2.30, P = 0.000), broader portal vein diameter (WMD 2.08, P = 0.000), a lower velocity of portal blood flow (WMD -0.91, P = 0.001), decreased platelet count (WMD -5.14, P = 0.007), decreased white blood cell (WMD -0.40, P = 0.027), decreased haemoglobin (WMD -9.14, P = 0.002), ascites (OR 1.81, P = 0.003) and bleeding history before surgery (OR 1.88, P = 0.002) were identified to be factors that exacerbated the risk of portal vein system thrombosis after splenectomy. Sex, age, preoperative prothrombin time, postoperative platelet count, postoperative D-dimer, operation time and intraoperative blood loss, did not increase the risk of thrombosis.

CONCLUSION

Larger spleen volume, broader splenic vein diameter, broader portal vein diameter, a lower velocity of portal blood flow, ascites, bleeding history before surgery, decreased platelet count, white blood cell and haemoglobin may increase the risk of portal vein system thrombosis.

Development and external validation of a nomogram for predicting postoperative pneumonia in aneurysmal subarachnoid hemorrhage

Background

Postoperative pneumonia (POP) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) associated with increased mortality rates, prolonged hospitalization, and high medical costs. It is currently understood that identifying pneumonia early and implementing aggressive treatment can significantly improve patients' outcomes. The primary objective of this study was to explore risk factors and develop a logistic regression model that assesses the risks of POP.

Methods

An internal cohort of 613 inpatients with aSAH who underwent surgery at the Neurosurgical Department of First Affiliated Hospital of Wenzhou Medical University was retrospectively analyzed to develop a nomogram for predicting POP. We assessed the discriminative power, accuracy, and clinical validity of the predictions by using the area under the receiver operating characteristic curve (AUC), the calibration curve, and decision curve analysis (DCA). The final model was validated using an external validation set of 97 samples from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database.

Results

Among patients in our internal cohort, 15.66% (n = 96/613) of patients had POP. The least absolute shrinkage and selection operator (LASSO) regression analysis identified the Glasgow Coma Scale (GCS), mechanical ventilation time (MVT), albumin, C-reactive protein (CRP), smoking, and delayed cerebral ischemia (DCI) as potential predictors of POP. We then used multivariable logistic regression analysis to evaluate the effects of these predictors and create a final model. Eighty percentage of patients in the internal cohort were randomly assigned to the training set for model development, while the remaining 20% of patients were allocated to the internal validation set. The AUC values for the training, internal, and external validation sets were 0.914, 0.856, and 0.851, and the corresponding Brier scores were 0.084, 0.098, and 0.143, respectively.

Conclusion

We found that GCS, MVT, albumin, CRP, smoking, and DCI are independent predictors for the development of POP in patients with aSAH. Overall, our nomogram represents a reliable and convenient approach to predict POP in the patient population.

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.

Thrombocytosis in 158 cats (2011-2018)

OBJECTIVES

Thrombocytosis is an uncommon hematologic abnormality that is associated with various physiologic, metabolic, inflammatory and neoplastic conditions in people and dogs. Thrombocytosis is not a well-described abnormality in cats. The objective of this study was to classify thrombocytosis in cats based on underlying disease processes and severity, and to compare this with a control population of cats.

METHODS

A retrospective study was conducted by reviewing the medical records of cats with increased (>600 × 103/µl; thrombocytosis group) and normal (200-600 × 103/µl; 2:1 age-matched control group) platelet counts between 2011 and 2018. Platelet counts were estimated based on blood smear assessment in all cats. Cats were classified by the severity (mild, moderate or marked) of thrombocytosis. Diagnoses were recorded for all cases, and were classified broadly into either neoplasia, endocrine or inflammatory disease.

RESULTS

In total, 158 cats were identified with thrombocytosis, with 315 cats in the control group. Non-neoplastic inflammatory disease was the most common diagnosis in both groups (54.4% in cats with thrombocytosis and 56.2% in controls; P = 0.77); however, gastrointestinal diseases were more common in cats with thrombocytosis (75.6%) when compared with controls (34.5%; P <0.0001). Neoplasia was diagnosed more frequently in cats with thrombocytosis (44.3%) compared with the control group (25.4%; P <0.0001). Round cell tumor was the most common neoplasia diagnosis in both groups, but gastrointestinal and multicentric lymphoma were diagnosed more frequently in cats with thrombocytosis compared with control cats. No association between the severity of thrombocytosis and etiology was identified.

CONCLUSIONS AND RELEVANCE

Thrombocytosis in cats is more commonly associated with gastrointestinal, hepatobiliary or immune-mediated diseases when compared with a control population. Neoplasia, especially multicentric and gastrointestinal lymphoma, was more commonly diagnosed in cats with thrombocytosis when compared with control cats.

Clinical prediction rule for bacterial arthritis: Chi-squared automatic interaction detector decision tree analysis model

Objectives:

Differences in demographic factors, symptoms, and laboratory data between bacterial and non-bacterial arthritis have not been defined. We aimed to identify predictors of bacterial arthritis, excluding synovial testing.

Methods:

This retrospective cross-sectional survey was performed at a university hospital. All patients included received arthrocentesis from January 1, 2010, to December 31, 2020. Clinical information was gathered from medical charts from the time of synovial fluid sample collection. Factors potentially predictive of bacterial arthritis were analyzed using the Student’s t-test or chi-squared test, and the chi-squared automatic interaction detector decision tree analysis. The resulting subgroups were divided into three groups according to the risk of bacterial arthritis: low-risk, intermediate-risk, or high-risk groups.

Results:

A total of 460 patients (male/female = 229/231; mean ± standard deviation age, 70.26 ± 17.66 years) were included, of whom 68 patients (14.8%) had bacterial arthritis. The chi-squared automatic interaction detector decision tree analysis revealed that patients with C-reactive protein > 21.09 mg/dL (incidence of septic arthritis: 48.7%) and C-reactive protein ⩽ 21.09 mg/dL plus 27.70 < platelet count ⩽ 30.70 × 10⁴/μL (incidence: 36.1%) were high-risk groups.

Conclusions:

Our results emphasize that patients categorized as high risk of bacterial arthritis, and appropriate treatment could be initiated as soon as possible.

Effect of iron supplementation on platelet count in adult patients with iron deficiency anemia

Iron deficiency anemia (IDA) affects more than 1.2 billion individuals globally. In addition to anemia, reactive thrombocytosis is also a common clinical hematological condition in patients with IDA. However, some case reports have described the thrombotic complications in association with IDA-induced thrombocytosis. Patients with a high risk of thrombosis need prompt identification and effective treatment to prevent thrombotic complications. While iron replacement treatment has been shown to decrease platelet count in this context, there is limited published evidence on how iron supplementation affects the thrombocytosis caused by IDA. We retrospectively examined the clinical records of 440 patients with IDA from an RCT completed from 1 January 2016, to 30 December 2017, and data obtained from this study was used for post hoc analysis to examine the effect of iron on platelet count in IDA-induced thrombocytosis.The mean ± standard deviation (SD) platelet counts of the 440 patients with IDA was 310.23 ± 98.72 × 10⁹/L. With baseline platelet counts>450 × 10⁹ /L as the cutoff for thrombocytosis, patients were divided into 2 groups: 36 (8.1%) in the IDA with thrombocytosis group (mean ± SD platelet count, 521.67 ± 73.85 × 10⁹/L) and the remaining 404 in the IDA without thrombocytosis group (mean ± SD platelet count, 291.39 ± 76.11 × 10⁹/L).Differences were found in baseline characteristics including white blood cell (WBC) count, hemoglobin (Hb) level, mean corpuscular volume (MCV), transferrin saturation (TSAT), serum iron (SI) level, and total iron-binding capacity (TIBC) between the two groups (P < .05). From baseline to 8 weeks of continuous iron supplementation treatment, the mean platelet counts in both groups were decreased at 2-week treatment intervals. And in the IDA with thrombocytosis group, half of the patients resolved thrombocytosis after 2 weeks of iron supplementation, and the counts of all patients with thrombocytosis decreased below 450 × 10⁹ /L within 6 weeks.In conclusion, the rate of reactive thrombocytosis in patients with IDA was 8.1%. IDA patients with thrombocytosis showed more severe anemia, lower ferritin, and more advanced iron deficiency than those without thrombocytosis. Platelet counts of half of the patients with thrombocytosis reduced below cut off of 450 × 10⁹/L for thrombocytosis after 2 weeks of treatment, and all patients resolved thrombocytosis after 6 weeks. Our study provided clinical evidence for more effective and individualized iron management in the future. IDA patients with thrombocytosis should take active iron treatment and increase follow-up frequency to prevent thrombotic events. For patients with persistent thrombocytosis, a concomitant clonal process should be considered.

Platelets accumulate in lung lesions of tuberculosis patients and inhibit T-cell responses and Mycobacterium tuberculosis replication in macrophages

Platelets regulate human inflammatory responses that lead to disease. However, the role of platelets in tuberculosis (TB) pathogenesis is still unclear. Here, we show that patients with active TB have a high number of platelets in peripheral blood and a low number of lymphocytes leading to a high platelets to lymphocytes ratio (PL ratio). Moreover, the serum concentration of different mediators promoting platelet differentiation or associated with platelet activation is increased in active TB.

Immunohistochemistry analysis shows that platelets localise around the lung granuloma lesions in close contact with T lymphocytes and macrophages. Transcriptomic analysis of caseous tissue of human pulmonary TB granulomas, followed by Gene Ontology analysis, shows that 53 platelet activation‐associated genes are highly expressed compared to the normal lung tissue.

In vitro activated platelets (or their supernatants) inhibit BCG‐induced T‐ lymphocyte proliferation and IFN‐γ production. Likewise, platelets inhibit the growth of intracellular macrophages of Mycobacterium (M.) tuberculosis. Soluble factors released by activated platelets mediate both immunological and M. tuberculosis replication activities. Furthermore, proteomic and neutralisation studies (by mAbs) identify TGF‐β and PF4 as the factors responsible for inhibiting T‐cell response and enhancing the mycobactericidal activity of macrophages, respectively. Altogether these results highlight the importance of platelets in TB pathogenesis.

A Rare Case of Recurrent Arterial Thrombosis Secondary to Iron Deficiency Anemia

Iron deficiency anemia is the leading cause of anemia all over the world. Iron deficiency is known to cause reactive thrombocytosis. However, arterial thrombosis secondary to reactive thrombocytosis is a rare entity. In this article, we present a case of a 37-year-old female with recurrent arterial thrombosis due to severe thrombocytosis caused by iron deficiency anemia. The patient developed spleen and kidney infractions, as well as abdominal aortic thrombosis. She was subsequently treated with iron and aspirin with an improvement of the anemia and thrombocytosis, with no further thrombotic complications. Arterial thrombosis is a very serious condition as the thrombus can embolize to carotid arteries leading to stroke or to peripheral blood vessels causing peripheral ischemia and gangrene. Iron deficiency anemia is a reversible cause of thrombocytosis that can be treated very easily to avoid thrombotic complications.

Extreme Thrombocytosis in Refractory ITP Post-Splenectomy With Associated Fatal Thromboembolism

Thrombopoietin (TPO)-receptor agonists have heralded a paradigm shift in the treatment of refractory immune thrombocytopenia (ITP). Reactive thrombocytosis has been described as a secondary effect of such therapies. However, the phenomenon of extreme thrombocytosis with morphology mimicking a myeloproliferative neoplasm (MPN) followed by fatal thromboembolism is unusual in this setting. Caution is required in the diagnosis of refractory ITP as well as TPO-receptor agonist dosing in such cases.

Causes of Thrombocytosis: A Single-center Retrospective Study of 1,202 Patients

Objective Thrombocytosis can occur as a primary event accompanying hematological diseases or as a secondary event. Since the publication of the World Health Organization classification in 2008, thrombocytosis is now generally defined as a platelet count above 450×10⁹/L. Furthermore, the discovery of driver-gene mutations in myeloproliferative neoplasms (MPNs) has simplified the diagnostic approach for thrombocytosis. To identify the causes of thrombocytosis using this new definition, we conducted a retrospective study. Methods We identified outpatients and inpatients aged 20 years or older with platelet counts >450×10⁹/L in a half-year period at a single institute and analyzed the causes of thrombocytosis and associated clinical characteristics. Results Among 1,202 patients with thrombocytosis, 150 (12.5%) had primary and 999 (83.1%) had secondary thrombocytosis. Of these patients with primary thrombocytosis, 129 (86%) had at least 1 molecular marker indicative of MPNs. The major causes of secondary thrombocytosis were tissue injury (32.2%), infection (17.1%), chronic inflammatory disorders (11.7%) and iron deficiency anemia (11.1%). The median platelet count and the incidence of thrombosis were significantly higher in patients with primary thrombocytosis than in those with secondary thrombocytosis. Conclusion Thrombocytosis mainly occurs as a secondary event; however, it is important to determine the cause of and prevent thrombosis, particularly in cases of primary thrombocytosis.

Is It Possible to Predict Clonal Thrombocytosis in Triple-Negative Patients with Isolated Thrombocytosis Based Only on Clinical or Blood Findings?

JAK2, MPL, and CALR mutations define clonal thrombocytosis in about 90% of patients with sustained isolated thrombocytosis. In the remainder of patients (triple-negative patients) diagnosing clonal thrombocytosis is especially difficult due to the different underlying conditions and possible inconclusive bone marrow biopsy results. The ability to predict patients with sustained isolated thrombocytosis with a potential clonal origin has a prognostic value and warrants further examination. The aim of our study was to define a non-invasive clinical or blood parameter that could help predict clonal thrombocytosis in triple-negative patients. We studied 237 JAK2 V617-negative patients who were diagnosed with isolated thrombocytosis and referred to the haematology service. Sixteen routine clinical and blood parameters were included in the logistic regression model which was used to predict the type of thrombocytosis (reactive/clonal). Platelet count and lactate dehydrogenase (LDH) were the only statistically significant predictors of clonal thrombocytosis. The platelet count threshold for the most accurate prediction of clonal or reactive thrombocytosis was 449 × 10⁹/L. Other tested clinical and blood parameters were not statistically significant predictors of clonal thrombocytosis. The level of LDH was significantly higher in CALR-positive patients compared to CALR-negative patients. We did not identify any new clinical or blood parameters that could distinguish clonal from reactive thrombocytosis. When diagnosing clonal thrombocytosis triple-negative patients are most likely to be misdiagnosed. Treatment in patients with suspected triple negative clonal thrombocytosis should not be delayed if cardiovascular risk factors or pregnancy coexist, even in the absence of firm diagnostic criteria. In those cases the approach “better treat more than less” should be followed.

Clinical and Prognostic Features of Essential Thrombocythemia: Comparison of 2001 WHO Versus 2008/2016 WHO Criteria in a Large Single-center Cohort

BACKGROUND

According to 2008/2016 classification of the World Health Organization (WHO), a platelet (PLT) count ≥ 450 × 10⁹/L, reduced from the previously published WHO 2001 indicated level ≥ 600 × 10⁹/L, was considered the new PLT threshold for the diagnosis of essential thrombocythemia (ET).

PATIENTS AND METHODS

To validate this important diagnostic change in a setting of current clinical practice, we retrospectively analyzed clinical and hematologic features at diagnosis and during follow-up of 162 patients with ET, diagnosed in our center from January 2008 to December 2017. We subdivided patients according to PLT value at baseline into Group A (PLT ≥ 600 × 10⁹/L) (124 patients; 76.5%) and Group B (PLT ≥ 450 × 10⁹/L < 600 × 10⁹/L) (38 patients; 23.5%).

RESULTS

Among clinical features, only the median value of leukocytes (P < .001) was significantly higher in Group A. Cytostatic treatment was administered in 103 patients, with a significantly higher rate in patients of group A (P < .001). After a median follow-up of 42.4 months (interquartile range, 22.1-70.6 months), 8 thrombotic events were recorded in the entire cohort, without differences between the 2 groups (P = .336). The 5-year overall survival (OS) of the entire cohort was 96.9% (95% confidence interval, 92.6%-100%), without differences between the 2 groups (P = .255).

CONCLUSIONS

Our data indicate a substantial homogeneity among patients with ET regardless of the PLT count at diagnosis, thus confirming the usefulness of the 2008/2016 WHO diagnostic criteria.

Thrombocytosis and Thrombosis: Is There Really a Correlation?

PURPOSE OF REVIEW

Thrombocytosis is common to all myeloproliferative neoplasms (MPN), including essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis. Despite the traditionally held belief amongst many clinicians that thrombocytosis correlates with thrombosis risk, there is little evidence in the literature to support that claim. Herein we critically analyze the literature to better understand the relationship between thrombocytosis and risk of thrombosis in MPN.

RECENT FINDINGS

Both retrospective and prospective studies argue against associations between thrombocytosis and risk of thrombosis in patients with ET and PV. Rather, most studies suggest that the presence of extreme thrombocytosis is instead associated with an increased risk of hemorrhagic events, a paradoxical phenomenon with important clinical implications. Thrombosis risk has a multifactorial set of etiologies in MPNs. While qualitative abnormalities of the platelets may contribute, associations between platelet quantity and thrombosis risk are weak in MPN patients.

Micro-Rheological Changes of Red Blood Cells in the Presence of an Arterio-Venous Fistula or a Loop-Shaped Venous Graft in the Rat

Introduction: In case of kidney failure, hemodialysis is the primary kidney replacement technique. Several vascular access methods used for the therapy, one of which is the arterio-venous fistula (AVF). In the AVF, the blood flow is altered, which can elevate the mechanical stress on the red blood cells (RBCs). This can affect the RBC hemorheological properties, and it can further cause systemic changes. To lower the turbulence and shear stress, we performed a loop-shaped arterio-arterial venous interposition graft (loop-shaped graft) to compare its effect to the conventional AVF. Materials and Methods: Thirty male Wistar were used (permission registration Nr.: 25/2016/UDCAW). The animals were randomly divided into sham-operated, AVF, and loop groups (n = 10/each). The superficial inferior epigastric vein (SIEV) was used to create the AVF and the loop-shaped graft. Blood samples were taken before/after the surgery and at the 1st, 3rd, and 5th postoperative weeks. We measured hemorhelogical, hematological, and blood gas parameters. The microcirculation of the hind limbs was also monitored using Laser Doppler fluxmetry. Results: Hematocrit, RBC count, and hemoglobin decreased by the 1st postoperative week. The erythrocyte aggregation values significantly increased in the fistula group by the 5th week (6.43 ± 2.31 vs. 13.60; p < 0.0001; vs. before operation). At the postoperative 1st week in the loop group, the values showed a significant decrease in RBC deformability. During the maturation period, dominantly at the 5th week, all values were normalized. The operated hind limb's skin microcirculation significantly increased in the sham and loop group by the 1st week (39 ± 10.57 vs. 73.93 ± 1.97 BFU, p < 0.01). This increase wasn't observed in the fistula group probably due to a steal-effect. Conclusion: Unlike in the loop group, in the presence of the fistula, several rheological parameters have changed. The loop-shaped graft had only minimal impact on micro-rheological parameters.

An Improved Scoring System Based on Platelet-Albumin-Bilirubin in Predicting Posthepatectomy Liver Failure Outcomes

BACKGROUND

Posthepatectomy liver failure (PHLF) is one of the major complications of liver resection that causes perioperative mortality. Accurate preoperative assessment of PHLF is of great significance to reduce the complication rate after hepatectomy and improve the survival rate.

METHODS

A retrospective study of patients who received hepatectomy from January 2016 to October 2019 at Tang Du Hospital was performed. The area under the receiver operating characteristic (ROC) curve was used to compare the predictive effects of various scoring models on PHLF.

RESULTS

The area under the ROC curve of platelet-albumin-bilirubin (PALBI) score, new platelet-albumin-bilirubin (I-PALBI) score, ALBI score, and MELD score was, respectively, 0.647, 0.772, 0.677, and 0.686 (p < 0.01). The I-PALBI score was significantly better than the other scores.

CONCLUSIONS

I-PALBI score can be used as a predictive score of PHLF, and its prediction accuracy is better than other scoring systems.

Extreme Thrombocytosis after Pediatric Pancreatectomy with Islet Autotransplantation Is Unique Compared to Other Postsplenectomy States

BACKGROUND

Hematologic trends after pancreatectomy with islet autotransplantation (IAT), which involves splenectomy, have been rarely studied. Reactive thrombocytosis (RT, platelets ≥500 K/μL) often occurs postoperatively, similar to other postsplenectomy states, but the degree of similarities and true incidence are unknown.

STUDY DESIGN

A single-site, retrospective, observational cohort study of patients who underwent total splenectomy between 2010 and 2018 was performed. Thrombocytosis incidence and pharmacologic management strategies were evaluated, including cohort-based analyses for IAT versus other splenectomy indications.

RESULTS

Analyses included 112 patients overall, 42 of whom underwent IAT. RT occurred frequently (93.8%) despite most patients having normal preoperative platelet counts. IAT patients had significantly higher peak platelet counts compared to non-IAT patients and the rate of platelet rise for IAT patients was significantly faster. IAT was uniquely predictive of developing extreme thrombocytosis (ExT, platelets ≥1000 K/μL, 90% vs. 15.7%, risk ratio 4.11, P < 0.0001) despite standardized hydroxyurea use. Thrombotic events were infrequent and did not differ between groups.

CONCLUSIONS

RT was common regardless of splenectomy indication but ExT was uniquely associated with IAT despite cytoreductive pharmacotherapy. These results strongly suggest that splenectomy is unlikely to be the sole contributor to post-IAT RT but further investigations into this phenomenon are needed.

LEVEL-OF-EVIDENCE RATING

Treatment study, Level III (retrospective comparative study).

Platelet count and risk of major bleeding in venous thromboembolism

The relationship between platelet count and risk of major bleeding in patients with venous thromboembolism (VTE) during anticoagulation remains unclear. We therefore investigated the association between platelet count, measured at VTE diagnosis and before the thrombotic event, and risk of major bleeding. Participants comprised 744 patients with incident VTE derived from the Tromsø Study. Major bleedings were recorded during the first year after VTE. Cox-regression was used to calculate hazard ratios (HRs) for major bleeding across platelet count quartiles.There were 55 major bleedings (incidence rate 9.1/100 person-years, 95% confidence interval [CI] 7.0-11.8). The major bleeding risk increased across quartiles of platelet count measured at VTE diagnosis (P for trend<0.02). In the age- and sex-adjusted model, subjects with platelet count in the highest quartile (≥300x10⁹/L) had a 4.3-fold (95% CI 1.7-10.9) higher risk of major bleeding compared to those with platelet count in the lowest quartile (≤192x10⁹/L), and exclusion of patients with cancer yielded similar results. When platelet count was measured on average 7 years before a VTE, the corresponding HR was 2.5 (95% CI 0.9-6.7). Our results suggest that increasing platelet count, assessed several years before and at VTE diagnosis, is associated with a higher risk of major bleeding, and could be a stable individual marker of major bleeding risk in VTE-patients.

The "Janus Face" of Platelets in Cancer

Besides their vital role in hemostasis and thrombosis, platelets are also recognized to be involved in cancer, where they play an unexpected central role: They actively influence cancer cell behavior, but, on the other hand, platelet physiology and phenotype are impacted by tumor cells. The existence of this platelet-cancer loop is supported by a large number of experimental and human studies reporting an association between alterations in platelet number and functions and cancer, often in a way dependent on patient, cancer type and treatment. Herein, we shall report on an update on platelet-cancer relationships, with a particular emphasis on how platelets might exert either a protective or a deleterious action in all steps of cancer progression. To this end, we will describe the impact of (i) platelet count, (ii) bioactive molecules secreted upon platelet activation, and (iii) microvesicle-derived miRNAs on cancer behavior. Potential explanations of conflicting results are also reported: Both intrinsic (heterogeneity in platelet-derived bioactive molecules with either inhibitory or stimulatory properties; features of cancer cell types, such as aggressiveness and/or tumour stage) and extrinsic (heterogeneous characteristics of cancer patients, study design and sample preparation) factors, together with other confounding elements, contribute to “the Janus face” of platelets in cancer. Given the difficulty to establish the univocal role of platelets in a tumor, a better understanding of their exact contribution is warranted, in order to identify an efficient therapeutic strategy for cancer management, as well as for better prevention, screening and risk assessment protocols.

An unusual case of extreme thrombocytosis caused by iron deficiency

Iron deficiency is a common cause of reactive thrombocytosis resulting in usually mild to moderately increased but sometimes even in extreme thrombocytosis (ie, >1000×10⁹/L). We report a case of a 34-year-old woman who developed an increased platelet count of 1953×10⁹/L. Upon admission, cytoreductive therapy was initiated until an underlying chronic myeloproliferative neoplasia was ruled out. The patient had undergone bariatric surgery 5 years previously, and surprisingly, a diagnosis of reactive thrombocytosis due to iron deficiency secondary to iron malabsorption was made. It is concluded that the degree of extreme thrombocytosis may be even fourfold to fivefold increased in patients with severe iron deficiency. Our finding emphasises the importance of regular control of possible need for iron supplementation following bariatric surgery.

Could there be a relation between Steven-Johnson syndrome and ST-segment elevation myocardial infarction?

Steven-Johnson syndrome (SJS) is a rare but serious mucocutaneous reaction to medications. We present a rare case of SJS developing after antibiotic administration for a lower respiratory tract infection and whose inpatient course was complicated with an acute ST-segment elevation myocardial infarction (MI). The laboratory findings revealed thrombocytosis which was possibly reactive and explained the underlying pathophysiology of the thrombus formation seen in the coronary artery. Stenting and aspiration of thrombus was performed. This case illustrates a possibly rare association between SJS and MI.

Late Presentation of Uterine Rupture: A Case Report

Uterine rupture is a rare disease, which usually presents in the form of a life-threatening emergency. It occurs most commonly after a vaginal birth after cesarean (VBAC) and is characterized by complete separation of the uterine incision throughout most of its length, involving all layers of the uterus. We present the case of uterine rupture in which the patient had no acute signs of rupture; instead, she presented with symptoms of generalized peritonitis. She presented 23 days after VBAC, with complaints of slight vaginal bleeding and a palpable abdominal mass. Leukocyte and platelet counts were raised, suggesting infection, which occurred due to the spread of fluid from the uterus to the abdomen through the scar defect. A total abdominal hysterectomy was performed due to widespread adhesions and a non-viable uterus. Our case was unusual as the presentation was delayed, with no acute symptoms of either uterine rupture or peritonitis. Uterine rupture can be fatal if not recognized and managed promptly.

A case of simultaneous acute cardio-cerebral infarction in a woman with essential thrombocythemia

Essential thrombocythemia (ET) can cause arterial embolism. Patients with arterial thrombosis usually have additional risk factors, such as smoking and hypertension. We report a 70-year-old woman with ET who had no risk factors, except for age. Cranial magnetic resonance imaging showed fresh lacunar infarction in several lobes. Electrocardiography showed ST-segment elevation in leads II, III, and aVF. Coronary angioplasty and stenting were successfully performed. We checked the bone marrow and performed genetic testing. The Janus kinase 2 (JAK2) V617F gene mutation was found. This case was a rare initial presentation of previously undiagnosed ET with embolism of cardiovascular and cerebral vessels. Anti-platelet drugs and hydroxyurea were used to prevent further thrombosis in the coronary and cerebral arteries.

Etiologies of Extreme Thrombocytosis: A Contemporary Series

OBJECTIVE

To describe the multifactorial etiologies of extreme thrombocytosis (EXT) in different care settings and the frequency of finding an occult malignancy.

PATIENTS AND METHODS

We conducted a retrospective chart review at Mayo Clinic from January 1, 2011, through December 31, 2016. Adult patients who had at least 2 readings of platelet counts greater than 1000×10⁹/L within 30 days of each other were included. We determined the causes of EXT on the basis of preset definitions of precipitating factors and identified the dominant causes on the basis of the trend of platelet counts.

RESULTS

A total of 44,490 patients had thrombocytosis, and 305 patients (0.7%) had EXT. In 242 patients (79.3%), EXT was multifactorial. Surgical complications (54.1%) and hematologic malignancies (27.9%) were the 2 most dominant causes. Thirty-eight patients (12.5%) had new diagnoses of malignancies, mostly myeloproliferative neoplasms. In inpatients, surgical complications (71.9%), concurrent/previous splenectomy (50.5%), and infections (44.9%) were the most common causes, whereas hematologic malignancies (56.9%), iron deficiency (36.7%), and previous splenectomy (28.4%) were the most common causes in outpatients. Hematologic malignancy was 3.4 times more likely to be the cause of EXT in outpatients than in inpatients (56.9% vs 16.8%), and a new diagnosis of hematologic malignancy was 1.9 times more likely to be made in outpatients (15.6% vs 8.2%). Eighty-four percent of patients had resolution of EXT within 30 days. One patient died during the period of EXT. Nonsurgical patients with hematologic malignancies had the most prolonged period of EXT.

CONCLUSION

Extreme thrombocytosis is a multifactorial hematologic condition, and its etiology differs substantially between inpatients and outpatients. Occult hematologic malignancies are uncommon in EXT when other major causes are present.

Thrombocytosis as a prognostic factor in polymyalgia rheumatica: characteristics determined from cluster analysis

Background:

This study aimed to identify the clinical subgroups of polymyalgia rheumatica (PMR) using cluster analysis and compare the outcomes among the identified subgroups.

Methods:

We enrolled patients with PMR who were diagnosed at Okayama University Hospital, Japan between 2006 and 2017, met the 2012 European League Against Rheumatism/American College of Rheumatology provisional classification criteria for PMR, and were treated with glucocorticoids. Hierarchical cluster analysis using variables selected by principal component analysis was performed to identify the clusters. Subsequently, the outcomes among the identified clusters were compared in the study. The primary outcome was treatment response at 1 month after commencement of treatment. The secondary outcome was refractory clinical course, which was defined as the requirement of additional treatments or relapse during a 2-year observational period.

Results:

A total of 61 consecutive patients with PMR were enrolled in the study. Their mean age was 71 years, and 67% were female. Hierarchical cluster analysis revealed three distinct subgroups: cluster 1 (n = 14) was characterized by patients with thrombocytosis (all patients showed a platelet count of >45 × 10⁴/µl), cluster 2 (n = 38), by patients without peripheral arthritis, and cluster 3 (n = 9), by patients with peripheral arthritis. The patients in cluster 1 achieved treatment response less frequently than those in cluster 2 (14% versus 47%, p = 0.030). Refractory cases were more frequent in cluster 1 than in cluster 2; however, no significant difference was noted (71% versus 42%, p = 0.06).

Conclusions:

Thrombocytosis could predict the clinical course in patients with PMR.

Prognostic Impact of Increased Perioperative Platelet Count in Gastric Cancer Patients

BACKGROUND

Solid tumors are a common cause of secondary (reactive) thrombocytosis, a paraneoplastic syndrome that is also a prognostic factor for various cancers. However, cutoff values for platelet count specific to gastric cancer and their prognostic roles are unknown.

METHODS

We retrospectively analyzed records of 4643 patients with gastric cancer who underwent radical surgery from 2007 to 2010. The minimum P-value approach was used with the log-rank test to determine the optimal prognosis predicting threshold for preoperative platelet count. Change in perioperative platelet count over time was evaluated with a generalized estimating equation. Clinicopathologic features and prognostic significance were analyzed according to platelet count.

RESULTS

Thrombocytosis prevalence (platelet count ≥40 × 10⁴/μL) was 1.6% (75 of 4643 patients). The platelet count cutoff value with the lowest P-value was ≥25.5 × 10⁴/μL, and patients with higher platelet count had more advanced disease. Multivariate analysis showed that cutoff value was an independent prognostic factor of overall survival (hazard ratio 1.19, 95% confidence interval 1.03-1.37, P = 0.017). Patients who underwent adjuvant chemotherapy (n = 1300) and had a greater than 10% increase in platelet count at postoperative 1 y compared to before surgery had significantly poorer overall survival (hazard ratio 1.65, 95% confidence interval 1.11-2.45, P = 0.013).

CONCLUSIONS

Elevated preoperative platelet count (≥25.5 × 10⁴/μL) and increased platelet count (≥10%) at postoperative 1 y in an adjuvant chemotherapy group were unfavorable prognostic factors. Platelet count could be a cost-effective biomarker for screening and monitoring patients with unfavorable survival outcomes.

An overlooked fact: thrombocytopenia following bioprosthetic aortic valve replacement

Introduction

Thrombocytopenia observed after bioprosthetic aortic valve replacement has remained a puzzle to solve.

Aim

To analyze thrombocytopenia occurring after bioprosthetic aortic valve replacement by comparison to mechanical aortic valve replacement and coronary artery bypass grafting procedures.

Material and methods

The study was conducted retrospectively on a total of 297 patients who underwent bioprosthetic aortic valve replacement, mechanical prosthetic aortic valve replacement and coronary artery bypass grafting at the cardiovascular surgery department of our clinical center between January 2013 and September 2017. Preoperative and postoperative first 14-day thrombocyte levels of the patients were analyzed.

Results

The postoperative blood thrombocyte level decrease was found to be more significant in patients who underwent bioprosthetic aortic valve replacement than in patients who underwent mechanical aortic valve replacement and coronary artery bypass grafting (p < 0.01). There was also a statistically significant difference in the time to reach the lowest postoperative platelet levels according to type of surgery (p = 0.001; p < 0.01).

Conclusions

When compared to the patients who underwent coronary artery bypass grafting and mechanical prosthetic aortic valve replacement, postoperative thrombocytopenia was found to be more severe in patients who underwent bioprosthetic aortic valve replacement, with a dramatic decrease in thrombocyte count being observed on the postoperative second day. It was found that the thrombocytopenia recovers without causing any problem. We think that the shear forces may play a role in this recovery through washout of chemicals responsible for thrombocytopenia from the glutaraldehyde treated bioprostheses.

Reactive thrombocytosis in acute infectious diseases: Prevalence, characteristics and timing

BACKGROUND

Reactive thrombocytosis is known to occur in infectious, inflammatory and neoplastic diseases. However, the characteristics of its association with acute infections (ID) has not been systematically studied.

SETTING

A department of internal medicine in a general teaching hospital.

METHODS

Retrospective chart review of admitted patients with a confirmed diagnosis of community-acquired pneumonia (CAP), urinary tract infection (UTI) or skin and soft tissue infection (SSTI). Key clinical and laboratory data were retrieved and patients with platelet counts >400 × 10⁹/L who had no alternative cause of thrombocytosis were studied longitudinally and compared to patients with acute infections who had no thrombocytosis.

RESULTS

Thirty two of 421 patients with acute infections (ID) had infection-associated thrombocytosis (7.6%): 11/125 patients with CAP (8.8%), 13/205 patients with UTI (6.3%) and 8/91 (8.8%) patients with SSTI. Their median ages (77-78 years), gender (48% males), admission temperature, Hb, and WBC were not significantly different from ID patients without thrombocytosis. However, patients with thrombocytosis had longer hospital stays (P = 0.001), more bacteremias (P = 0.048) and in 4/32 (12/5% vs. 2%) significantly increased combined mortality or suppurative complications (P = 0.0006). The ESR (median 70 vs. 40 mm/h, P = 0.000) and CRP (median 214 vs. 114 mg/dL, P < 0.0001) were found to be increased in ID-associated thrombocytosis patients, similarly for each ID. Platelets increase was already found on admission in 18 patients (56%), was mild in most cases (median 492.5 × 10⁹/L, range 401-917 × 10⁹/L) and resolved after recovery in all survivors. The median time to thrombocytosis was 1 day in patients with CAP, 4 days in UTI and 7.5 days in SSTI. No thrombotic complications were found.

CONCLUSIONS

Approximately 8% of patients with acute ID examined had thrombocytosis which was mostly mild, transient, and not usually indicative of an infectious complication. However, these patients had enhanced acute-phase response, increased length of hospital stay, more bacteremia and increased mortality/suppurative complications albeit affecting a minority of patients.

Thrombocytosis as an Initial Presentation of Plasma Cell Neoplasm: A Case Report

Plasma cell neoplasms are usually associated with normal or decreased platelet count. The association of thrombocytosis and multiple myeloma is exceedingly rare, with only six such cases reported in the literature until now. Differentiating clonal from secondary causes of thrombocytosis can be extremely difficult, yet the distinction has important therapeutic implications. We report the case of a woman presenting with thrombocytosis that led to the diagnosis of multiple myeloma. The possible etiological link between both these entities is also discussed.

The Birth and Death of Platelets in Health and Disease

Blood platelets are involved in a wide range of physiological responses and pathological processes. Recent studies have considerably advanced our understanding of the mechanisms of platelet production and clearance, revealing new connections between the birth and death of these tiny, abundant cells. Key insights have also been gained into how physiological challenges such as inflammation, infection, and chemotherapy can affect megakaryocytes, the cells that produce platelets.

A Review and Assessment of Drug-Induced Thrombocytosis

OBJECTIVES

The purpose of this article is to review the current literature on drug-induced thrombocytosis with the goal of critically assessing causality and providing a comprehensive review of the topic. Thrombopoietic growth factors, such as thrombopoietin-receptor agonists (romiplostim and eltrombopag) and erythropoietin are not included in our review.

DATA SOURCES

The literature search included published articles limited to the English language and humans in MEDLINE, EMBASE, and Web of Science databases. MEDLINE/PubMed (1966 to September 2018) was searched using the MeSH terms thrombocytosis/chemically-induced and thrombocytosis/etiology. EMBASE (1980 to September 2018) was searched using the EMTAGS thrombocytosis/side effect. Web of Science (1970 to September 2018) was searched using the search term thrombocytosis. References of all relevant articles were reviewed for additional citations and information.

STUDY SELECTION AND DATA EXTRACTION

Review articles, clinical trials, background data, case series, and case reports of drug-induced thrombocytosis were collected, and case reports were assessed for causality using a modified Naranjo nomogram.

DATA SYNTHESIS

Drug-induced thrombocytosis, a form of reactive thrombocytosis cannot be easily differentiated from more common etiologies of reactive thrombocytosis. In all, 43 case reports of drug-induced thrombocytosis from a wide variety of drugs and drug classes were reviewed using a modified Naranjo probability scale that included criteria specific for thrombocytosis.

CONCLUSIONS

Drug-induced thrombocytosis is a relatively rare adverse drug reaction. The strongest evidence of causality supports low-molecular-weight heparins and neonatal drug withdrawal. Weaker evidence exists for all-trans retinoic acid, antibiotics, clozapine, epinephrine, gemcitabine, and vinca alkaloids.

Thromboembolic Events Following Splenectomy: Risk Factors, Prevention, Management and Outcomes

BACKGROUND

Thromboembolic events following splenectomy are not uncommon. However, the role of thromboprophylaxis and risk factors for thrombosis, as well as the clinical course and outcomes, are not well characterized.

METHODS

A retrospective review of individuals who underwent splenectomy between January 2006 and December 2015 in two university hospitals.

RESULTS

Overall, 297 patients underwent splenectomy [open splenectomy (n = 199), laparoscopic splenectomy (n = 98)]. Mechanical (thigh-length pneumatic compression stockings) and pharmacologic thromboprophylaxis (40 mg enoxaparin daily, starting 12 h after surgery until discharge) was provided for all patients. One hundred and sixteen patients (39%) also received an extended thromboprophylaxis course of enoxaparin for 2-4 weeks after discharge. Twenty-three patients (7.7%) experienced thrombotic complications following splenectomy, including 16 cases (5.4%) of portal-splenic mesenteric venous thrombosis (PSMVT), 5 (1.7%) pulmonary embolism and 2 (0.7%) deep vein thrombosis. Longer operative time (mean operative time of 405 vs. 273 min, P = 0.03) was independently associated with PSMVT. Post-splenectomy thrombocytosis was not associated with thrombosis (P = 0.41). The overall thrombosis rate was significantly lower in patients who received an extended thromboprophylaxis course following splenectomy (3.4 vs. 10.5%, P = 0.02). Complete resolution of thrombosis was observed in most cases (n = 20, 87.0%), with no recurrent thrombosis during a mean follow-up of 38 ± 25 months.

CONCLUSIONS

Thromboembolic complications, mainly PSMVT, are common following splenectomy. Longer operative time was associated with thrombosis. Significantly lower rates of thrombosis were found in patients who received an extended thromboprophylaxis course.

Thrombocytosis as a Marker for Postoperative Complications in Colorectal Surgery

BACKGROUND

Blood platelet measurement is a widely available and inexpensive test that is performed routinely. Platelets are thought to act by inducing inflammation and play a role in clotting and antimicrobial defence. A postoperative rise in the platelet count (thrombocytosis) is often dismissed as an incidental finding, but there is growing evidence to suggest that it may act as an indicator to underlying pathology. It correlates with significant pyogenic infections as well as multiple malignancies. In addition to this, recent research indicates that thrombocytosis may be a useful prognostic indicator for postoperative outcomes in patients with malignancies. In patients undergoing surgery for gastric cancer, a combination of platelet count and neutrophil-to-lymphocyte (NLR) ratio collected preoperatively was shown to correlate with postoperative survival.

OBJECTIVE

To evaluate whether there is a positive correlation between pre- and postoperative thrombocytosis and the risk of complications following colorectal surgery.

METHODS

This was a retrospective observational study based in Morriston Hospital, Swansea. Patients undergoing elective colorectal surgery for an 18-month period between 2014 and 2016 were included. Data on patient demographics, pre- and postoperative platelet count, the first date at which the highest platelet count was recorded, length of stay, type of operation, and postoperative complications using the Clavien-Dindo classification was obtained from the theatre booking software (TOMS) and Welsh Clinical Portal. Pearson's chi-square test was used for the analysis of the categorical variables.

RESULTS

Of the 201 patients studied, 75 (37%) had postoperative thrombocytosis (platelets ≥ 500 × 109/L, range 501-1136), 120 (59%) had postoperative normocytosis (platelets < 500 × 109/L, range 107-499), and 6 (2.9%) patients were excluded due to insufficient data. Peak platelet level was seen at a median of 8 days postoperatively but ranged from days 1 to 49. In patients with thrombocytosis, the mean time to peak platelet count was 9.5 days and ranged 1 to 49 days. 101/195 (52%) patients had a Clavien-Dindo III/V postoperative complication: 63% patients with postoperative normocytosis and 24% with postoperative thrombocytosis. In the thrombocytosis group, 16/75 (21%) were found to have postoperative pelvic collections compared to 1/120 (0.8%) of the normocytic patients. The total percentage of medical complications (44% versus 20%, p = 0.006) and surgical complications (64% versus 15.8%, p = 0.0001) was higher in the thrombocytosis group compared to the normocytosis group.

CONCLUSION

In this retrospective study, thrombocytosis was shown to have a positive correlation with postoperative medical and surgical complications. An elevated platelet count in the postoperative period should alert the clinician to a developing complication. We recommend that further studies with a larger sample size would test the specific associations with individual complications.

Bilateral visual loss and cerebral infarction after spleen embolization in a trauma patient with idiopathic thrombocytopenic purpura: A case report

RATIONALE

Splenic artery embolization (SAE) is a common procedure in trauma patients with blunt splenic injuries. We report a case of acute ischemic stroke following orthopedic surgery in a patient with post-SAE reactive thrombocytosis.

PATIENT CONCERNS

A 37-year-old woman with idiopathic thrombocytopenic purpura (ITP) suffered from multiple trauma scheduled for open reduction and internal fixation for right tibial and left radius fracture five days after SAE. The patient did not have any thromboembolic complications, although the platelet counts increased from 43 × 10/L to 568 × 10/L within two days after SAE. Surgery was completed under general anesthesia with tracheal intubation without complications. The patient complained of visual loss followed by limb weakness on the fourth and eighth hour postoperatively.

DIAGNOSES

Magnetic resonance imaging (MRI) of head demonstrated ischemic change over bilateral basal ganglia, and occipital areas, suggesting the diagnosis of cortical blindness.

INTERVENTIONS

To suppress platelet count and avoid platelet hyper-aggregation, anti-platelet drug (i.e., oral aspirin 100 mg daily), hydration, and hydroxyurea (i.e., 20 mg/kg daily) were used for the treatment of reactive thrombocytosis.

OUTCOMES

Although right-sided hemiparesis persisted, the patient reported mild visual recovery. She was discharged four months after SAE with active rehabilitation.

LESSONS

Our report highlights an increased risk of acute arterial thromboembolic events in patients with reactive thrombocytosis, especially those undergoing surgery.

Acute myocardial infarction and antiphospholipid antibody syndrome: a systematic review

BACKGROUND

Antiphospholipid antibody syndrome (APS) is a disorder associated with both arterial and venous thromboembolic disease, including acute myocardial infarction (AMI). Given that management with anticoagulants is critical and differs from usual AMI care, identification of key discriminators of patients with AMI with APS is important.

METHODS

We performed an English-language systematic review of the literature of cases and case series of patients with AMI and APS from inception until 20 March 2016, collecting demographics, investigations, and outcomes.

RESULTS

Forty cases of AMI because of APS were identified from 27 articles. Patients were younger than typical AMI patients (41.10±13.61 years) and 45% were women. STelevation myocardial infarction was the presentation in 45% (18/40) of cases. The average platelet count was 130 000±138 912 c/mm in the 10 cases reporting it and partial thromboplastin time was elevated in all four reporting it. Coronary arteries were described as normal or with acute thrombosis in 75%. Three died during hospitalization and six had recurrence of myocardial infarction within 3 months after admission.

CONCLUSION

APS should be considered in young patients with AMI, especially if previous unprovoked thromboses, lower platelet counts, high partial thromboplastin times, and normal coronary arteries or coronary thromboses are identified.