Thrombocytopenia: Case definition and guidelines for collection, analysis, and presentation of immunization safety data

University of Oulu, Uleoborg, Northern Ostrobothnia, Finland
Vaccine (Impact Factor: 3.62). 09/2007; 25(31):5717-24. DOI: 10.1016/j.vaccine.2007.02.067
Source: PubMed
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    ABSTRACT: Demographics, outcome, and management of idiopathic thrombocytopenic purpura (ITP) in children present differences between countries. Although several factors influence outcome, it is impossible to predict at diagnosis which patients will have acute or chronic disease. High rates of spontaneous remission in chronic ITP have been reported. Data concerning 1,683 patients with ITP diagnosed from 1981 to date are presented; outcome was evaluated in 1,418 children. Remarkable presenting features were an incidence peak in the first 2 years of age and male predominance in patients <24 months of age. Three age groups with different recovery rates (P < 0.001) were established (2-12 months: 89.8%; 1-8 years: 71.3%; 9-18 years: 49.0%). Platelet count <10 x 10(9)/L and history of previous illness were associated with higher remission rates only in patients >12 months of age. The score developed by the NOPHO Group showed a predictive value of 83.9% for acute ITP. Spontaneous remission between 6 months and 11 years from diagnosis was achieved by 107 of 325 (32.9%) non-splenectomized children with chronic ITP, and in 44.9% of them between 6 and 12 months from diagnosis. Age and score were main prognostic factors. Infants <1 year of age are a special group with a brief course and very high recovery rate that are not influenced by other prognostic factors. Definition of groups based on age and scoring could be useful to establish differential management guidelines. The cut-off value to define chronic ITP should be changed to 12 months.
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    ABSTRACT: Active surveillance data from 12 Canadian tertiary-care hospitals on children hospitalized with postvaccination thrombocytopenia were analyzed. Since 1992, there have been 107 cases reported; while 96% of the children were symptomatic, only 2 had severe bleeding. With treatment, 28 children (26%) had normal platelet counts on discharge from hospital and 93% had documented recovery within 3 months.
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    ABSTRACT: To determine the incidence of immune thrombocytopenic purpura (ITP) after measles-mumps-rubella (MMR) immunization compared with natural measles and rubella, its clinical course and outcome, and the risk of recurrence after repeat MMR vaccination. We performed a systematic review of the Ovid MEDLINE (1950 to present) bibliographic database. We selected studies that reported cases of thrombocytopenia in a known number of children who were immunized with MMR vaccine before development of ITP. We also extracted data from the same and other studies regarding bleeding manifestations and the resolution of MMR-associated thrombocytopenia or thrombocytopenic purpura within 6 months. Finally, we studied the risk of ITP recurrence after MMR immunization or reimmunization. On the basis of 12 studies, the incidence of MMR-associated ITP ranged from 0.087 to 4 (median 2.6) cases per 100,000 vaccine doses. Severe bleeding manifestations were rare, and MMR-associated thrombocytopenia resolved within 6 months from diagnosis in 93% of the children. MMR vaccination of unimmunized patients with ITP and revaccination of patients with prior ITP did not lead to recurrence of thrombocytopenia. MMR-associated ITP is rare, self-limited, and non-life threatening, and susceptible children with ITP should be immunized with MMR at the recommended ages.
    The Journal of pediatrics 04/2010; 156(4):623-8. DOI:10.1016/j.jpeds.2009.10.015 · 3.79 Impact Factor
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