Low platelet count, female sex, NSAID exposure predict risk of any bleeding

Stephen Padilla
14 Dec 2017

Platelet count thresholds <20 x 109/L and <10 x 109/L are associated with major increased risk for both any and mucosal bleeding. Furthermore, platelet count, female sex and exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) are risk factors for the risk of any bleeding, according to a study presented at the 59th American Society of Hematology (ASH) Annual Meeting and Exposition in Atlanta, Georgia.

However, it appears that severe bleeding is not associated with platelet count but with individual factors, especially exposure to anticoagulant.

“Bleeding is a main cause of morbidity and mortality in adult immune thrombocytopenia (ITP). Treatment is indicated in case of bleeding or of low platelet count. However, the threshold of platelet count associated with bleeding and therefore to initiation of treatment is debated,” researchers said.

“Most of guidelines recommend the threshold of <30 x 109/L. However, some authors recommend other thresholds, as low as 10 x 109/L,” they added.

A total of 302 adults with ITP (median age 66 years; 49.7 percent females) were prospectively included in this study. At the time of diagnosis, 46.8 percent of participants had a Charlson’s score ≥1, 3.7 percent had a history or current symptoms of gastroduodenal ulcer, 16.0 percent had secondary ITP, 19.5 percent were exposed to antiplatelet drugs, 7.6 percent to anticoagulant drugs, 7.6 percent to NSAIDs and 6.6 percent to serotonin reuptake inhibitors (SRIs). Median platelet count was 18 x 109/L.

At diagnosis, more than half of the patients (57.9 percent) had any bleeding symptom, while 30.1 and 6.6 percent experienced mucosal and severe bleeding, respectively (including four central nervous system bleedings). [ASH 2017, abstract 1041]

If platelet count was <20 x 109/L, the rate of any bleeding was >50 percent, while the rate of mucosal bleeding was >40 percent if platelet count was <10 x 109/L. On the other hand, there was a comparable risk of severe bleeding with all platelet count categories.

Only slight differences in other subgroups were seen, but there was an increased frequency of any bleeding in case of exposure to NSAIDs and an elevated rate of severe bleeding in elderly and patients exposed to anticoagulants and SRIs.

Multivariate analysis revealed that low platelet count (<10 x 109/L vs >20 x 109/L: odds ratio [OR], 46.3; 95 percent CI, 19.4 to 110.6; between 10 and 19 x 109/L vs >20 x 109/L: OR, 5.1; 2.3 to 11.2), female sex (OR for males, 0.4; 0.2 to 0.8) and exposure to NSAIDs (OR, 4.4; 1.1 to 18.7) correlated with any bleeding at ITP diagnosis.

Moreover, only a low platelet count predicted mucosal bleeding (<10 x 109/L vs >20 x 109/L: OR, 6.2; 3.4 to 11.6; between 10 and 19 x 109/L vs >20 x 109/L: OR, 2.6; 1.1 to 6.1), and only exposure to anticoagulants was a risk factor for severe bleeding (OR, 4.5; 1.4 to 14.4). Analyses restricted to primary ITPs resulted in comparable outcomes.

Researchers analysed all patients included between June 2013 and December 2016 in the CARMEN (Cytopénies Auto-immunes: Registre Midi-PyréneEN) registry. Also included were all adult patients newly diagnosed for ITP at the French National Referral Center for autoimmune cytopaenias from November 2015 to December 2016 where data were prospectively recorded in the same database.

ITP was defined by platelet count <100 x 109/L and exclusion of other causes of thrombocytopaenia, according to researchers.

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