Need for an improved vaccination rate in primary immune thrombocytopenia patients exposed to rituximab or splenectomy. A nationwide population-based study in France

Abstract

International guidelines on immune thrombocytopenia (ITP) management recommend vaccination against Streptococcus pneumoniae (S.p.), Haemophilus influenza b (Hib) and Neisseiria meningitidis (N.m.) before splenectomy. French guidelines also recommend these vaccinations before rituximab. The aim of this study was to assess the application of these recommendations. The French Adult ITP: a French pHarmacoepidemiological study (FAITH, n°ENCEPP 4574) is aimed at following in the French national health insurance system database (SNIIRAM) the cohort of all incident and persistent or chronic primary ITP adults treated in France. We assessed vaccine exposure in the 1,106 patients who entered the FAITH cohort between 2009 and 2011. Vaccination was said "recommended" if performed at least 2 weeks before rituximab or splenectomy accordingly with French guidelines. Among the 423 non-splenectomized patients exposed to rituximab, vaccination rates against S.p., Hib and N.m. were respectively 32.4%, 18.9%, and 3.8%. It was recommended in 12.8%, 6.6%, and 1.2% of the patients, respectively. Among the 178 splenectomized patients, vaccination rates were 70.2%, 47.0%, and 11.9%, respectively (recommended: 60.1%, 35.7%, and 9.5%). Among the splenectomized patients previously exposed to rituximab (n=67), 53.3% of the vaccinations occurred during the semester following a rituximab infusion that is during the maximal B-cell depletion period. In multivariate analyses, a disease duration exceeding 3 months was the sole factor associated to recommended vaccination in rituximab-treated patients as well as in splenectomized patients. This study stresses the need of better and earlier vaccination of ITP patients.