Long-Term Outcome of Otherwise Healthy Individuals with Incidentally Discovered Borderline Thrombocytopenia

Abstract:  With extensive automation in laboratories, an ever increasing number of asymptomatic individuals with platelet counts ranging between 100 × 109/l and 150 × 109/l are now being recognized. However, both the clinical features of these individuals, as well as the natural history of their thrombocytopenia, have not been systematically studied. An undetermined number may go on to develop an overt disease associated with a low platelet count, others may maintain normal or borderline platelet counts indefinitely, but to date no consistent figures concerning these events are available. Althou gh the differential diagnosis is fairly broad, most asymptomatic adults who have a low platelet count as the sole laboratory abnormality are likely to have an immune thrombocytopenia, either primary (idiopathic) or secondary to an autoimmune disorder. In fact, thrombocytopenia may often be the initial manifestation of a systemic autoimmune disease; thus, it may not be possible to differentiate secondary immune thrombocytopenia at the time of initial presentation from idiopathic thrombocytopenic purpura (ITP). Information about these patients has a potential clinical impact because many systemic autoimmune diseases can be treated and controlled if detected in the early stages. Patients often have symptoms for several years before the correct diagnosis is made, and this delay in treatment may cause damage to major organs and result in permanent disability. This study was designed with the aim of elucidating the natural history of apparently healthy adults who were diagnosed with a platelet count between 100 × 109/l and 150 × 109/l, cases that in this study were defined as having “borderline thrombocytopenia.” Citation: Stasi R, Amadori S, Osborn J, Newland AC, Provan D (2006) Long-Term Outcome of Otherwise Healthy Individuals with Incidentally Discovered Borderline Thrombocytopenia. PLoS Med 3(3): e24. doi:10.1371/journal. pmed.0030024