Etiology of Thrombocytosis in a General Medicine Population: Analysis of 801 Cases With Emphasis on Infectious Causes

Abstract

BackgroundThe clinical importance of an elevated platelet count is often overlooked, particularly as a diagnostic clue to the presence of an underlying infection. We sought to better describe the relationship between thrombocytosis and inflammatory conditions, with a focus on infectious causes.MethodsWe retrospectively reviewed 801 sequential cases of thrombocytosis (platelet count > 500 × 109/L) at a tertiary care hospital.ResultsEssential thrombocythemia was the most common cause of primary thrombocytosis, and these patients were more likely to have extreme (> 800 × 109/L) and prolonged (> 1 month) thrombocytosis. Secondary thrombocytosis was more common than primary, with infectious causes accounting for nearly half the cases. Demographic factors associated with an infectious etiology included inpatient status, quadriplegia/paraplegia, an indwelling prosthesis, dementia and diabetes. Clinical and laboratory characteristics associated with an infectious cause of thrombocytosis included fever, tachycardia, weight loss, hypoalbuminemia, neutrophilia, leukocytosis and anemia. Patients with thrombocytosis secondary to infection had a more rapid normalization of platelet count, but higher risk of dying, than those with secondary, non-infectious causes.ConclusionsInfection is a common cause of thrombocytosis and should be considered in patients with comorbidities that increase risk of infection and when clinical and/or laboratory data support an infectious etiology. Thrombocytosis may have prognostic implications as a clinical parameter.

Reference intervals of complete blood count constituents are highly correlated to waist circumference: Should obese patients have their own “normal values?”

“…Shah et al showed that increased mean platelet volume, possibly a measure of platelet metabolism, is strongly associated with the presence and severity of diabetes . Platelet counts are also increased in the setting of acute and chronic inflammation and may be influenced by a similar cytokine milieu as that implicated in increased WBC count .…”

Predicting Discontinuation of Pegylated Interferon as a Result of Lack of Efficacy in United States Veterans With Chronic Hepatitis C on Dual Therapy

“…High platelet count may be an indicator for other conditions such as inflammatory bowel disease or serious infection. [52][53][54] The high correlation between behavioral-type factors and LOE discontinuation suggests several potential hypotheses. The first is that patients with these characteristics were less adherent in the weeks prior to their LOE discontinuation, diminishing viral response, and the consequence was LOE discontinuation.…”

Platelet Function Tests and Inflammatory Markers for the Differentiation of Primary Thrombocytosis and Secondary Thrombocytosis

“…Since in cases of non-mutated JAK2V617F, CALR and myeloproliferative leukemia (MPL), according to the 2016 World Health Organization diagnostic criteria, the diagnosis of ET is still based on the absence of reactive thrombocytosis (Arber et al, 2016). The diagnosis of ST is straightforward in patients who have a clinically apparent underlying disorder such as autoimmune disease, concurrent infection and active malignancy (Schafer, 2004;Rose et al, 2012). However, the diagnosis is challenging in the cases of unclear causes of thrombocytosis.…”