Pediatric Rheumatology Unit of Faculdade de Medicina da Universidade de São Paulo, Brazil. email@example.com
The aim of the present paper is to assess the influence of demographic, muscle enzymes, JDM scores and treatment on non-adjuvanted influenza A H1N1/2009 vaccine immunogenicity in juvenile dermatomyositis (JDM) patients.
Thirty JDM patients and 81 healthy age-matched controls were vaccinated. All participants were evaluated pre- and 21 days post-vaccination and serology for anti-H1N1 was performed by haemagglutination inhibition assay. Muscle enzymes, JDM scores and treatment were evaluated before and after vaccination. Adverse events were reported.
After immunisation, seroconversion rates were significantly lower in JDM patients compared to age-matched controls (86.7 vs. 97.5%, p=0.044), whereas seroprotection (p=0.121), geometric mean titres (GMT) (p=0.992) and factor increase (FI) in GMT (p=0.827) were similar in both groups. Clinical and laboratorial evaluations revealed that JDM scores and muscle enzymes remained stable throughout the study (p>0.05). A higher frequency of chronic course was observed in non-seroconverted compared to seroconverted (100% vs. 27%, p=0.012). Regarding treatment, a lower rate of seroconversion was observed in patients under prednisone>20mg/day (50% vs. 4%, p=0.039), and in those treated with a combination of prednisone, methotrexate and cyclosporine (50% vs. 4%, p=0.039). Local and systemic vaccine adverse events were mild and similar in patients and controls (p>0.05).
This study identified that chronic course and immunosuppressive therapy are the major factors hampering seroconversion in JDM, suggesting that a specific protocol may be required for this subgroup of patients. In spite of that, a single dose of non-adjuvanted influenza A/H1N1 2009 vaccine was generally seroprotective in this disease with no evident deleterious effect in disease itself (ClinicalTrials.gov, no. NCT01151644).
PMID: 22931582 [PubMed]
Received: 27/12/2011 - Accepted : 14/03/2012 - In Press: 29/08/2012 - Published: 29/08/2012