Rheumatology, Musgrave Park Hospital, Belfast, UK
Correspondence to: S. A. Wright, Department of Rheuma-tology, Musgrave Park Hospital, Stockmans Lane, Belfast BT9 7JB, UK. E-mail: stephen{at}wright866.fsnet.co.uk
SIR, TNF- antagonists are an important advance in the treatment of rheumatoid arthritis and other inflammatory arthropathies. There is growing evidence that inhibitors of TNF-
increase susceptibility to infections and also retard the clearing of infections once established [1, 2]. A higher rate of respiratory tract infections was observed with TNF- antagonists than with placebo in clinical trials, and it can be assumed that Streptococcus pneumoniae would be the causative organism in a significant number of these patients, as over 80% of community-acquired respiratory infections are due to pneumococci [3]. There were three deaths in the initial group of 88 patients treated in our region with anti-TNF-
therapy [4]. Two of these deaths were related to infection with S. pneumoniae: lobar pneumonia with pneumococcus isolated in sputum and pneumococcal meningitis following a middle ear infection. Other groups have reported the occurrence of fatal pneumococcal necrotizing fasciitis in patients receiving TNF-
antagonists for rheumatoid arthritis [5, 6]. Pneumococcal necrotizing fasciitis is extremely rare in immunocompetent patients, indicating the effect of TNF-
blockade in comprising host defences.
TNF- has been shown to be increased in the serum and lungs of mice infected with S. pneumoniae, and administration of anti-TNF-
in mouse models resulted in a significant increase in the microbial burden and death rate [7]. These results would suggest that TNF-
helps prevent bacteraemia and death in pneumococcal infections.
Ellerin et al. [6] recently reviewed infections with anti-TNF- and suggested measures aimed at preventing infectious complications in patients treated with anti-TNF-
therapy. One recommendation was the routine use of the polyvalent capsular polysaccharide pneumococcal vaccine in patients on TNF-
antagonists.
The polyvalent capsular polysaccharide pneumococcal vaccine provides prophylactic cover for over 90% of pathogenic pneumococcal strains in the UK, including most antibiotic-resistant pneumococci. The vaccine is effective and provides protection of between 65 and 84% in high-risk patient groups [3], which include rheumatoid arthritis patients. Despite the availability of an effective vaccine, there is clear evidence that it is seriously underused in the community. According to a study of general practitioner prescribing habits, up to 50% of practices did not routinely vaccinate their patients at high risk from pneumococcal infection [8].
Patients should receive the vaccination prior to commencing biological therapy, with re-immunization every 5 yr. Revaccination less than 3 yr after the first injection can produce serious reactions, although revaccination every 5 yr can be considered in those patients in whom antibody response may be suboptimal. Despite vaccination, it is important to remain vigilant to pneumococcal infections, as it has been shown that anti-TNF- therapy impairs the immunogenicity of the pneumococcal vaccination; only 1256% of anti-TNF-
-treated patients respond to the vaccine, compared with 5595% of healthy controls [9].
Pneumococcal vaccination should be a routine procedure in the management of patients treated with TNF- antagonists and it should be the responsibility of the physician prescribing the TNF-
antagonist to ensure each patient receives the vaccine. Due to the significant risk of infections in these patients, we have previously recommended the use of a biological therapy information card for the patients to carry at all times [10]. These measures should help to reduce the risk of infections in this group of patients.
The authors have declared no conflicts of interest.
References