Researchers found an approximately 19-fold greater risk of progression to immune thrombocytopenia (ITP) or hematologic neoplasia in adults with persistent, isolated mild thrombocytopenia (PIMT), compared with healthy individuals, in an adjusted analysis. Results of this analysis were presented at the 2022 ASH Annual Meeting by Nardeen Ayad, MD, of Harvard Medical School in Boston, Massachusetts, and colleagues.

For patients with PIMT, specific guidelines are lacking that may aid in diagnostic workup or surveillance of this condition. There also has been little information regarding prognosis with PIMT, and management of the condition varies.

In this retrospective cohort study, the research team evaluated 91 patients who had presented with PIMT during the period from 1995 through 2004 in order to estimate the long-term risk of ITP or hematologic neoplasia developing in this population. In analyses, patients with PIMT were compared with 364 healthy individuals, with matching at a 1:4 ratio and involving characteristics such as age, sex, and ethnicity. Median follow-up durations spanned approximately 20 years for each group.

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Among patients with PIMT, hematologic disease developed in 28 individuals (30.8%), while it occurred in only 7 (1.9%) of the healthy individuals. ITP developed in 17 of the patients in the PIMT group and in 1 of the healthy individuals. Hematologic neoplasia developed in 13 of the patients in the PIMT group and in 6 of the healthy individuals.

For patients with PIMT, the 15-year cumulative incidence of development of any hematologic disease was 15.5% (95% CI, 8.9%-23.6%). The 25-year cumulative incidence of hematologic disease in the PIMT group was 37.0% (95% CI, 25.2%-48.8%). The 15-year cumulative incidence of ITP in the PIMT group was 10.0%, and the 25-year cumulative incidence of this was 26.0%. For hematologic neoplasia in the PIMT group, 15- and 25-year cumulative incidences were 6.7% and 15.7%, respectively.

The researchers performed a competing-risk analysis between the study groups that was controlled for age. In this analysis, the risk of hematologic disease was approximately 19 times higher in the PIMT group than among the healthy individuals (subhazard ratio, 18.99; 95% CI, 8.39-42.96; P <.001).

Deaths were reported among 21% of patients in the PIMT group and in approximately 6% of the healthy individuals. Major bleeding was reported among 4 patients in the PIMT group, compared with 0 patients among the healthy individuals. Overall, bleeding events that were considered major, clinically relevant nonmajor, or minor were reported in 24 individuals of the PIMT group and in 6 of the healthy individuals.

In this study, the researchers concluded that in adjusted analyses PIMT was associated with a greater risk of progression to ITP or hematologic neoplasia than seen in healthy individuals, as well as high rates of other outcomes, such as clinically significant bleeding or death.

Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.


Ayad N, Grace RF, Kuter DJ, Al-Samkari H. Long-term risk of developing immune thrombocytopenia and hematologic neoplasia in adults with persistent, isolated mild thrombocytopenia. Presented at ASH 2022. December 10-13, 2022. Abstract 19.