Use of glucocorticoids and risk of infections

Optimizing immunization in pediatric special risk groups

This article analyzes the current recommended practices and evidence in the immunization of pediatric 'special risk groups'. Special risk group patients are at higher risk of vaccine-preventable diseases and hence require additional strategies to maximize protection against these diseases. The special risk groups include those with an underlying chronic disease, some of whom are on immunosuppressive therapy to treat that condition. The article uses four special risk groups (acute lymphoblastic leukemia; preterm birth; juvenile idiopathic arthritis; and inflammatory bowel disease), to highlight the management considerations and potential vaccination strategies. The risks, benefits and timing of vaccination in the setting of immunosuppression require detailed discussion with treating clinicians, in particular the use of live-attenuated vaccines. The immunogenicity of vaccines in these special risk groups helps provide the evidence base for their immunization guidelines. Protection can include 'cocooning' (i.e., ensuring appropriate immunizations within the immediate family; e.g., varicella, influenza and pertussis vaccination). Improving timeliness and minimizing missed opportunities to vaccinate individuals with these special risk conditions will also optimize protection from vaccine-preventable diseases.

Relapsing polychondritis: An autoimmune disease with many faces

Relapsing polychondritis (RPC) is a rare immune mediated disease which is associated with inflammation in cartilaginous tissue throughout the body. Especially the cartilaginous structures of ear, nose, joints and respiratory tract are affected. In around 30% of the cases an association with other diseases especially systemic vasculitis or myelodysplatic syndrome can be detected. The relative rarity of RPC has not permitted clinical trials to determine the efficacy and safety of therapy strategies. Often the medication in current use is largely empiric and based on case reports. Therefore different immunosuppressants such as cyclophosphamide, azathioprine, cyclosporine, mycophenolate mofetil and also new approaches like tumor necrosis factor alpha blockers (TNF-alpha antagonists) have been used for the treatment of severe manifestations of RPC with varying degrees of efficacy. This review gives a close look to clinical manifestation, diagnosis and also therapy options of RPC.

Glucocorticoid-induced osteoporosis in rheumatic diseases

The aim of this article is to review rheumatological diseases that are associated with glucocorticoid-induced osteoporosis or fractures and to perform a critical analysis of the current guidelines and treatment regimens. The electronic database MEDLINE was searched using the date range of July 1986 to June 2009 and the following search terms: osteoporosis, bone mineral density, fractures, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, vasculitis, juvenile rheumatoid arthritis, juvenile idiopathic arthritis and juvenile dermatomyositis. Osteopenia and osteoporosis respectively account for 1.4 to 68.7% and 5.0 to 61.9% of adult rheumatological diseases. Among juvenile rheumatological disorders, the frequency of low bone mass ranges from 38.7 to 70%. In general, fracture rates vary from 0 to 25%. Although glucocorticoid-induced osteoporosis has a high rate of prevalence among rheumatic diseases, a relatively low number of patients on continuous glucocorticoid treatment receive adequate diagnostic evaluation or preventive therapy. This deficit in patient care may result from a lack of clear understanding of the attributed risks by the patients and physicians, the high complexity of the treatment guidelines and poor patient compliance.

Incidence and nature of infectious disease in patients treated with anti-TNF agents

Tumor necrosis factor alpha (TNF-alpha) inhibitors offer a targeted therapeutic strategy that contrasts with the nonspecific immunosuppressive agents traditionally used to treat most inflammatory diseases. These biologic agents have had a significant impact in ameliorating the signs and symptoms of inflammatory rheumatoid disease and improving patient function. From the onset of clinical trials, a central concern of cytokine blockade has been a potential increase in susceptibility to infections. Not surprisingly, a variety of infections have been reported in association with the use of TNF-alpha inhibitor agents. In particular, there is evidence suggesting an increased rate of granulomatous infections in patients treated with monoclonal TNF-alpha inhibitors. This review provides the incidence and nature of infections in patients treated with TNF-alpha inhibitor agents and reminds the clinician of the required vigilance in monitoring patients.

Immune-mediated adverse drug reactions

Many adverse drug reactions are mediated by the immune system. This can be because the therapeutic effect of the drug targets the immune system. For example, immunosuppressive drugs increase the risk of infections. It is paradoxical that some immunosuppressive drugs can lead to autoimmune reactions. Another mechanism by which drugs can cause an adverse reaction involves an idiosyncratic response to the drug such as an immune-mediated skin rash. These idiosyncratic drug reactions (IDRs) are difficult to study because of the paucity of valid animal models and their unpredictable nature. Therefore, much of our mechanistic knowledge of IDRs is based on inferences from the clinical characteristics of IDRs rather than on controlled mechanistic studies. In general, IDRs are associated with a delay between starting the drug and the onset of the adverse reaction, and the typical delay is different for different types of IDRs. In contrast, on rechallenge, there is usually a rapid onset of the adverse reaction, which is characteristic of an amnestic immune response. The absence of such a rapid response is usually considered evidence that an IDR is not immune-mediated; yet, there are immune-mediated IDRs that do not have an amnestic response. One possible reason for the lack of an amnestic response is if the IDR has a strong autoimmune component leading to deletion of autoimmune memory cells when the drug is withdrawn. Another interesting characteristic of IDRs is that there are many drugs that can cause different types of IDRs in different patients. A possible explanation is that although the immune response is induced by a drug, it is directed against an autoantigen, and interindividual differences in the immune repertoire determine which autoantigen and target organ are affected. Although testing these hypotheses represents a difficult challenge, the importance of these adverse reactions makes it a high priority.