Childhood idiopathic thrombocytopenic purpura in the Nordic countries: Epidemiology and predictors of chronic disease

Abstract

Aim: To describe the epidemiology of idiopathic thrombocytopenic purpura (ITP) in the Nordic countries, to define clinical subgroups and to investigate factors predicting chronic disease. Methods: A prospective registration was done from 1998 to 2000, including all children with newly diagnosed ITP aged 0–14 y and at least one platelet count <30×109/l. Results: 506 children were registered and 423 followed for 6 mo. The incidence was 4.8/105 per year. Most children were aged 0–7 y (78%), with a predominance of boys, while patients aged 8–14 y had equal representation of the two sexes. There were seasonal variations determined by variations in postinfectious cases with sudden onset. The platelet count was <10×109/l in 58%, but bleeding manifestations were mild or moderate in 97%. The insidious form (symptoms for more than 2 wk) was more frequent in older children and girls, showed little seasonal variation, had milder manifestations and ran a chronic course in more than half the cases. Intracranial haemorrhages did not occur in the first 6 mo after diagnosis. Chronic ITP developed in 25%. The strongest predictor of chronic disease was insidious onset of symptoms (OR 5.97). Conclusion: In the Nordic countries, ITP mainly affects children aged 0–7 y, with a winter bulk of postinfectious cases superimposed on a steady occurrence of non‐infectious cases. Clinically, it may be useful to distinguish between children with sudden versus insidious onset of symptoms rather than between different age groups.

Epidemiology of immune thrombocytopenic purpura in the General Practice Research Database

“…Most studies use a threshold of 150 · 10 9 /l (Cortelazzo et al, 1991;McMillan & Durette, 2004;Fogarty & Segal, 2007), but other values have also been used (e.g. Simpson et al, 1998;Frederiksen & Schmidt, 1999;Sutor et al, 2001;Neylon et al, 2003;Zeller et al, 2005). A normal platelet count ranges from 150 to 450 · 10 9 /l (Kaushansky & Roth, 2004); the platelet counts of adult ITP patients are often <20 · 10 9 /l at diagnosis.…”

Quantification of specific T and B cells immunological markers in children with chronic and transient ITP

“…Several clinical factors have been previously investigated aiming to identify patients who are more susceptible to becoming chronic. [12][13][14][15][16][17]22 In addition, two genetic biomarkers have been sug- gested as predictors of a chronic course: overexpression of vanin-1 and the Q63R missense variant of the gene encoding the cannabinoid receptor type 2. 16 We found that age and gender were positive predictors for disease course, similar to previous reports.…”

“…These include among others, sudden appearance of the disease, viral disease preceding the presentation, lower platelets count, age younger than 10 years, male gender, and lack of mucosal bleeding at diagnosis. 4,[11][12][13][14][15][16] Predicting which patients are more susceptible to become chronic will determine the treatment and the search for an underlying etiology.…”

Interferon‐γ +874A/T and interleukin‐4 intron3 VNTR gene polymorphisms in Chinese patients with idiopathic thrombocytopenic purpura

“…The hospitalbased ethics committee approved the study. Based on the previous reports on childhood ITP (18,19), we divided the patients into two groups: childhood ITP with age of first onset at 0-14 yr and adult ITP with age of first onset at more than 14 yr. This age is also the age limit for referring a patient to adult clinic in China.…”