Successful induction of tolerance to infliximab in patients with Crohn's disease and prior severe infusion reactions

Review article: managing the adverse events caused by anti-TNF therapy in inflammatory bowel disease

BACKGROUND

Biological therapy is currently widely used to treat IBD. Infliximab, adalimumab and golimumab are currently licensed anti-TNF therapies. Biosimilar anti-TNF monoclonal antibodies are increasingly used. Anti-TNF therapies are widely used and their adverse effects are well characterised, and may cause significant morbidity and mortality in a small proportion of exposed patients. Gastroenterologists need to understand the mechanisms for these effects, recognise these swiftly and manage such events appropriately.

AIM

To cover the range of potential adverse reactions as a result of biologic therapy and specifically management of these events.

METHODS

A Medline and Pubmed search was undertaken. Search terms included were "anti-TNF," "infliximab" or "adalimumab" or "golimumab" combined with the keywords "ulcerative colitis" or "Crohn's disease" or "inflammatory bowel disease" and then narrowed to articles containing the keywords "complications," "side effects" or "adverse events" or "safety profile." International guidelines were also reviewed where relevant.

RESULTS

Adverse events discussed in this review include infusion reactions, blood disorders and infections (including bacterial, viral, fungal and opportunistic infections) as well as autoimmune, dermatological disorders, cardiac and neurological conditions. Malignancies including solid organ, haematological and those linked to viral disease are discussed.

CONCLUSIONS

Anti-TNF therapy has wide-ranging effects on the immune system resulting in a spectrum of potential adverse events in a small proportion of patients. Research advances are improving the understanding, recognition and management of these adverse events.

Hypersensitivity to intravenous iron: classification, terminology, mechanisms and management

Intravenous (IV) iron therapy is widely used in iron deficiency anaemias when oral iron is not tolerated or ineffective. Administration of IV-iron is considered a safe procedure, but severe hypersensitivity reactions (HSRs) can occur at a very low frequency. Recently, new guidelines have been published by the European Medicines Agency with the intention of making IV-iron therapy safer; however, the current protocols are still non-specific, non-evidence-based empirical measures which neglect the fact that the majority of IV-iron reactions are not IgE-mediated anaphylactic reactions. The field would benefit from new specific and effective methods for the prevention and treatment of these HSRs, and the main goal of this review was to highlight a possible new approach based on the assumption that IV-iron reactions represent complement activation-related pseudo-allergy (CARPA), at least in part. The review compares the features of IV-iron reactions to those of immune and non-immune HSRs caused by a variety of other infused drugs and thus make indirect inferences on IV-iron reactions. The process of comparison highlights many unresolved issues in allergy research, such as the unsettled terminology, multiple redundant classifications and a lack of validated animal models and lege artis clinical studies. Facts and arguments are listed in support of the involvement of CARPA in IV-iron reactions, and the review addresses the mechanism of low reactogenic administration protocols (LRPs) based on slow infusion. It is suggested that consideration of CARPA and the use of LRPs might lead to useful new additions to the management of high-risk IV-iron patients.

IgE antibodies and skin tests in immediate hypersensitivity reactions to infliximab in inflammatory bowel disease: impact on infliximab retreatment

BACKGROUND

Infliximab (IFX) is used for the treatment of inflammatory bowel diseases (IBD). Immediate hypersensitivity reactions (HR) to IFX are frequently reported.

OBJECTIVES

We investigated immunoglobulin E (IgE)-mediated mechanisms underlying immediate HR to IFX. We also evaluated the clinical utility of allergological tests as well as the tolerability of IFX retreatment in these patients.

METHODS

This was a prospective single-center study including IBD patients with previous immediate HR to IFX. Skin tests to IFX, including prick tests and intradermal tests, and measurement of anti-IFX IgE antibodies were performed at least 4 weeks after HR. In case of negative skin tests and absence of IgE antibodies, readministration of IFX was performed with a twice-reduced infusion rate. In case of positive tests or recurrence of HR during readministration of IFX, a 12-step desensitization or induction of tolerance protocol was proposed.

RESULTS

A total of 24 IBD patients were included (Crohn's disease: n=20). Prick tests to IFX were all negative. Intradermal test was positive in one patient. Anti-IFX IgE antibodies were not detected in 21 patients and were detected in three patients (significant level in one patient and intermediate level in two patients). No relationship was observed between positive skin tests and the presence of anti-IFX IgE antibodies. Switch to adalimumab was well tolerated in 10/11 patients. The readministration of IFX was well tolerated in 4/11 patients. Desensitization to IFX was successful in three out of four patients.

CONCLUSION

The vast majority of immediate HR to IFX is not IgE-mediated. Allergological tests are of poor clinical utility. Desensitization or induction of tolerance protocol may allow continuation of IFX therapy in IBD patients with a history of immediate HR.

Infliximab-Related Infusion Reactions: Systematic Review

OBJECTIVE

Administration of infliximab is associated with a well-recognised risk of infusion reactions. Lack of a mechanism-based rationale for their prevention, and absence of adequate and well-controlled studies, has led to the use of diverse empirical administration protocols. The aim of this study is to perform a systematic review of the evidence behind the strategies for preventing infusion reactions to infliximab, and for controlling the reactions once they occur.

METHODS

We conducted extensive search of electronic databases of MEDLINE [PubMed] for reports that communicate various aspects of infusion reactions to infliximab in IBD patients.

RESULTS

We examined full texts of 105 potentially eligible articles. No randomised controlled trials that pre-defined infusion reaction as a primary outcome were found. Three RCTs evaluated infusion reactions as a secondary outcome; another four RCTs included infusion reactions in the safety evaluation analysis; and 62 additional studies focused on various aspects of mechanism/s, risk, primary and secondary preventive measures, and management algorithms. Seven studies were added by a manual search of reference lists of the relevant articles. A total of 76 original studies were included in quantitative analysis of the existing strategies.

CONCLUSIONS

There is still paucity of systematic and controlled data on the risk, prevention, and management of infusion reactions to infliximab. We present working algorithms based on systematic and extensive review of the available data. More randomised controlled trials are needed in order to investigate the efficacy of the proposed preventive and management algorithms.

Adverse reactions to infliximab and the outcome of desensitization

BACKGROUND

Infliximab is a highly effective monoclonal antibody against tumor necrosis factor, which is a major inflammatory mediator in certain gastrointestinal, rheumatic, and skin diseases. In some patients, infliximab infusion causes systemic adverse reactions that often lead to discontinuation of therapy even in responsive patients.

OBJECTIVE

To investigate the frequency and characteristics of adverse reactions to infliximab at the authors' institution and the outcome of their management, including desensitization.

METHODS

This was a single-center retrospective study of patients who were treated with infliximab, primarily for inflammatory bowel disease, from January 1, 2000 to March 31, 2014. Data included age, sex, underlying disease, infliximab therapy duration before the first reaction, manifestation of reaction, onset, and management.

RESULTS

There were 336 patients with inflammatory bowel disease who were treated with infliximab during the study period. Thirty patients (8.9%) developed a systemic adverse reaction to infliximab, which was discontinued in 15 patients (50%) and was continued in 3 patients after premedication and/or decreased infusion rate. Twelve patients (40%) underwent infliximab desensitization with gradually increasing doses starting at a dilution of 0.1 mg/mL to reach the full treatment dose over approximately 4 to 6 hours. It was successful in all 12 patients, who continued to receive up to 26 infliximab infusions, mostly without premedication.

CONCLUSION

Infliximab can trigger systemic reactions that hinder its administration. The present desensitization protocol appears to be safe and effective and it can be considered in patients whose inflammatory bowel disease responds well to infliximab but who develop systemic adverse reactions.

Factors influencing acute infusion reactions in inflammatory bowel disease patients treated with infliximab in the era of scheduled maintenance therapy

BACKGROUND

An acute infusion reaction during infliximab infusions could lead to drug withdrawal and limit the therapeutic armamentarium in inflammatory bowel diseases.

AIM

To determine the risk and protective factors of an acute infusion reaction.

MATERIALS AND METHODS

Data were retrieved retrospectively from electronic charts of patients from the 'Clermont-Ferrand IBD cohort'.

RESULTS

Among 80 patients, including 51 (63.8%) patients with Crohn's disease, 23 (28.8%) experienced an acute infusion reaction. In multivariate analysis, the Crohn's disease nonstricturing nonfistulizing phenotype predicted an acute infusion reaction (odds ratio=11.40, 95% confidence interval 1.5-87.6; P=0.019).Among 1107 infusions, we observed 38 acute infusion reactions (3.4%). In multivariate analysis, only resumption of infliximab after drug holiday was a major risk factor (odds ratio=24.87, 95% confidence interval 4.4-140.0; P<0.001). Concomitant premedication or immunosuppressant therapies did not prevent an acute infusion reaction.The patients who experienced an acute infusion reaction had a trend toward a higher rate of infliximab discontinuation (69.6 vs. 50.9%, P=0.14).

CONCLUSION

An acute infusion reaction is a major event in the history of inflammatory bowel diseases patients treated with infliximab as it could lead to drug discontinuation and thus limits the therapeutic armamentarium considerably. The resumption of infliximab after drug holiday is a major risk factor for an acute infusion reaction. Premedication efficacy remains questionable and should be limited to these high-risk patients.

Biologics in paediatric Crohn's disease

Crohn's disease affects increasing numbers of children worldwide. Generally, childhood-onset disease runs a more severe course than in adults and has a greater impact on quality of life. Therapy in children must take account of a different set of risks for toxicity compared to adults, but also to their longevity. Biologic drugs present remarkable advantages in terms of disease control for children, especially in those whose disease cannot be controlled with conventional therapies, but their long-term risks are still being assessed. Data regarding biologic use in children is limited and mostly amounts to case series, but results have been promising, both in terms of controlling disease activity and improving growth parameters. Adverse reactions are infrequent in the short term, but loss of response is a long-term problem, particularly in children. More information is needed about very long term risks. Infliximab and adalimumab are the most studied agents in children, while there is relatively limited data on certolizumab and natalizumab. Further collection of data on these agents is still needed, but this should not restrict access to these agents for children in whom no other agent is effective.

Severe infusion reactions to infliximab: aetiology, immunogenicity and risk factors in patients with inflammatory bowel disease

BACKGROUND

Infliximab (IFX) elicits acute severe infusion reactions in about 5% of patients with inflammatory bowel disease (IBD).

AIM

To investigate the role of anti-IFX antibodies (Ab) and other risk factors.

METHODS

The study included all IBD patients treated with IFX at a Danish university hospital until 2010 either continuously (IFX every 4-12 weeks) or episodically (reinitiation after >12 weeks). Anti-IFX Ab were measured using radioimmunoassay.

RESULTS

Twenty-five (8%) of 315 patients experienced acute severe infusion reactions. Univariate analysis showed that patients who reacted were younger at the time of diagnosis (19 vs. 26 years, P=0.013) and at first IFX infusion (28 vs. 35 years, P=0.012). Furthermore, they more often received episodic therapy (72% vs. 31%, P<0.001) and logistic regression revealed this as the only significant predictor of reactions (OR 5 [2-13]; P<0.001). IFX reinitiation after 6 months intermission further increased the risk (OR 8 [3-20], P<0.001). Most reactions (n=14, 88%) occurred at 2nd infusion in the 2nd treatment series (P=0.006). Anti-IFX IgG Ab were highly positive in 19 of 20 patients (95%) shortly after the reactions (median 84 U/mL). Anti-IFX IgG Ab measured prior to the retreatment series were negative in 7 of 11 patients tested (64%). Anti-IFX IgE Ab were negative in all patients with reactions.

CONCLUSIONS

Acute severe infusion reactions were strongly associated with development of anti-IFX IgG Ab, but not with anti-IFX IgE Ab. The risk was particularly high at the 2nd infusion in retreatment series. Negative anti-IFX Ab before reinitiation did not rule out reactions.

A decade of infliximab: The Austrian evidence based consensus on the safe use of infliximab in inflammatory bowel disease

Infliximab (IFX) has tremendously enriched the therapy of inflammatory bowel diseases (IBD) and other immune mediated diseases. Although the efficacy of IFX was undoubtedly proven during the last decade numerous publications have also caused various safety concerns. To summarize the immense information concerning adverse events and safety issues the Austrian Society of Gastroenterology and Hepatology launched this evidence based consensus on the safe use of IFX which covers the following topics: infusion reactions and immunogenicity, skin reactions, opportunistic infections (including tuberculosis), non-opportunistic infections (bacterial and viral), vaccination, neurological complications, hepatotoxicity, congestive heart failure, haematological side effects, intestinal strictures, stenosis and bowel obstruction (SSO), concomitant medication, malignancy and lymphoma, IFX in the elderly and the young, mortality, fertility, pregnancy and breast feeding. To make the vast amount of information practicable for routine application the consensus was finally condensed into a checklist for a safe use of IFX which consists of two parts: issues to be addressed prior to anti-TNF therapy and issues to be addressed during maintenance. Both parts are further divided into obligatory and facultative items.

The complex clinical picture of side effects to biologicals

Biologicals are proteins used as drugs. Biologicals target clearly defined molecular structures, being part of established pathogenetic pathways. Therefore, their focused mode of action seems to render them superior to classic small molecular drugs regarding "off-target" adverse drug reactions (ADR). Nevertheless, the increasing use of biologicals for the treatment of different diseases has revealed partially unexpected adverse reactions. The often direct interaction of a biological with the immune system provides a clue to most side effects, which have consequently been subclassified, based on pathogenetic principles, into 5 subtypes named alpha, beta, gamma, delta, and epsilon, reflecting overstimulation (high cytokine values, type alpha), hypersensitivity (type beta), immune deviation (including immunodeficiency, type gamma), cross-reactivity (type delta), and nonimmune mediated side effects (type epsilon). This article presents typical clinical manifestations of these subtypes of ADR to biologicals, proposes general rules for treating them, and provides a scheme for a thorough allergological workup. This approach should help in future handling of these often very efficient drugs.

Prevention of acute adverse events related to infliximab infusions in pediatric patients

OBJECTIVE

To study whether premedication with an oral antifebrile agent (acetaminophen) and antihistamine (cetirizine) could decrease the frequency of acute infusion reactions in pediatric patients.

METHODS

All pediatric patients scheduled for infliximab infusions at the Helsinki University Central Hospital, a tertiary care center, were prospectively introduced to a standard oral premedication of acetaminophen (20 mg/kg) and cetirizine (10 mg) prior to infliximab infusions for a period of 1 year. All acute adverse events related to infliximab infusions given according to the guidelines of pediatric rheumatologists or gastroenterologists were registered for this time period and retrospectively during the preceding year.

RESULTS

During the study period, infliximab infusions with premedication were given to 64 pediatric patients (48 with rheumatic disease and l6 with inflammatory bowel disease, mean age 13 years, n = 34 boys, and n = 30 girls). Infliximab was introduced to 14 children; the rest were on maintenance therapy. Twelve infusion reactions, 4 mild and 8 severe, were observed in 8 (12.5%) of the 64 subjects, and in 1 subject 4 times. During the preceding year, 60 pediatric patients had received infliximab infusions without premedication. In this latter group, infusion reactions occurred in 5 children (8.3%; P > 0.05). The presentation of an acute infusion reaction was not related to the sex or diagnosis of the patient.

CONCLUSION

In pediatric patients, acute infusion reactions related to infliximab could not be prevented with premedication with oral acetaminophen and cetirizine.

Infliximab safety profile and long-term applicability in inflammatory bowel disease: 9-year experience in clinical practice

BACKGROUND

Most available data on infliximab therapy come from large, short-term, pivotal RCTs and concerns about long-term safety profile still remain.

AIM

To evaluate the long-term safety profile of infliximab in inflammatory bowel disease (IBD) in a clinical practice setting.

METHODS

Since 1999, all IBD patients treated with infliximab were registered and clinical outcomes prospectively recorded up to March 2008, loss of follow-up or patient's death. Infliximab regimens and preventive measures were in accordance with the prevalent guidelines or with the manufacturer's recommendations.

RESULTS

One hundred fifty-two patients were included (121 Crohn's disease, 24 ulcerative colitis, 7 indeterminate colitis), with a median of 5 infliximab infusions (IQR 3-8) and 87% of patients received at least three infusions. Seventy-nine per cent of them received concomitant immunomodulators and 70% were pre-medicated with hydrocortisone from the first infusion. After a median follow-up of 142 weeks, 13% presented infusion reactions, 13% viral or bacterial infections and two patients developed neoplasia. The mortality rate was 2.6% (four patients).

CONCLUSIONS

Infliximab therapy is safe when the recommended preventive measures are implemented, with a rate of serious adverse events less than 10%. No new safety signals were found.

Hypersensitivity reactions to mAbs: 105 desensitizations in 23 patients, from evaluation to treatment

BACKGROUND

Rapid desensitization, a procedure for graded drug administration, allows for the safe readministration of a medication after certain types of hypersensitivity reactions (HSRs) and is indicated in cases in which there are no reasonable therapeutic alternatives. The use of rapid desensitization for HSRs to mAbs has not been validated.

OBJECTIVE

We sought to describe our experience with rapid desensitization to mAbs, including rituximab, infliximab, and trastuzumab.

METHODS

One hundred five rapid desensitizations were performed in 23 patients with a standardized 12-step, 6-hour protocol. Our approach to patient evaluation before desensitization is described. The severity, characteristics, and timing of both initial HSRs and HSRs during desensitization were determined by means of retrospective review of medical records. After a reaction during desensitization, patient-specific protocol modifications were made before each subsequent desensitization.

RESULTS

104 of 105 desensitizations undertaken were successfully completed. We observed HSRs during 29% of desensitizations, including 27 mild reactions, 1 moderate reaction, and 2 severe reactions. Overall, reactions during desensitization were markedly less severe than initial HSRs, but reactions did recur in a minority of successive desensitizations.

CONCLUSIONS

Rapid desensitization is a promising method for the delivery of monoclonal therapeutics after an HSR, but the possibility of a reaction remains with each desensitization.

Infliximab reintroduction is not associated to a higher rate of immune-related adverse effects in patients with inflammatory bowel disease initially treated with a three-infusion induction regimen

BACKGROUND

Episodic infliximab (IFX) treatment is associated with a higher risk for acute infusion reactions (AIR) and secondary loss of response (SLR), but this has not been evaluated in patients initially treated with an induction regimen with 3 IFX infusions.

AIMS

To evaluate whether IFX reintroduction after > or = 4 months in patients treated with a 3-infusion induction regimen is associated with a higher incidence of AIR or SLR.

METHODS

Incidence of immunogenic adverse effects was assessed in patients with inflammatory bowel disease who received > or = 4 consecutive IFX infusions (3 infusions at weeks 0, 2, and 6, plus > or = 1 maintenance infusion) (Continuous, n=47) and patients who were treated with a successful initial 3-infusion induction scheme and in whom IFX was then discontinued because of a complete response but reintroduced > or = 4 months later (Reintro, n=29).

RESULTS

AIR rate was 17% in both groups, and SLR rate was 26% in the Continuous group and 15% in the Reintro group (not significant). The lack of concomitant immunomodulators and/or pretreatment with hydrocortisone were associated with AIR development (P=0.002).

CONCLUSIONS

In patients who completed a 3-infusion induction regimen, IFX can be safely reintroduced even after a long time from discontinuation.

Efficacy and safety of infliximab induction therapy in Crohn's Disease in Central Europe--a Hungarian nationwide observational study

Background

Infliximab (IFX) has proven to be an effective addition to the therapeutic arsenal for refractory, fistulizing, and steroid dependent Crohn's disease (CD), with efficacy in the induction and maintenance of clinical remission of CD. Our objective in this study is to report the nationwide, multicenter experience with IFX induction therapy for CD in Hungary.

Methods

During a 6-year-period, beginning in 2000, a total of 363 CD patients were treated with IFX as induction therapy (5 mg/kg IFX infusions given at week 0, 2 and 6) at eleven centers in Hungary in this observational study. Data analysis included patient demographics, important disease parameters and the outcome of IFX induction therapy.

Results

Three hundred and sixty three patients (183 women and 180 men) were treated with IFX since 2000. Mean age was 33.5 ± 11.2 years and the mean duration of disease was 6.7 ± 6.1 years. The population included 114 patients (31.4%) with therapy-refractory CD, 195 patients (53.7%) with fistulas, 16 patients (4.4%) with both therapy-refractory CD and fistulas, and 26 patients (7.2%) with steroid dependent CD. Overall response rate was 86.2% (313/363). A higher response rate was observed in patients with shorter disease duration (p = 0.05, OR:0.54, 95%CI:0.29-0.99) and concomitant immunosuppressant therapy (p = 0.05, OR: 2.03, 95%CI:0.165-0.596). Concomitant steroid treatment did not enhance the efficacy of IFX induction therapy. Adverse events included 34 allergic reactions (9.4%), 17 delayed type hypersensitivity (4.7%), 16 infections (4.4%), and 3 malignancies (0.8%).

Conclusion

IFX was safe and effective treatment in this cohort of Hungarian CD patients. Based on our experience co-administration of immunosuppressant therapy is suggested in patients receiving IFX induction therapy. However, concomitant steroid treatment did not enhanced the efficacy of IFX induction therapy.

Infliximab in the treatment of plaque type psoriasis

Psoriasis is a chronic and immunomediated skin disease characterized by erythematous scaly plaques. Psoriasis affects approximately 1% to 3% of the Caucasian population. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-α drug widely used for the treatment of plaque type psoriasis and psoriatic arthritis. Controlled clinical trials demonstrated that infliximab is characterized by a high degree of clinical response in moderate to severe plaque psoriasis. Moreover infliximab showed rapid efficacy in nail psoriasis which represents a therapeutic challenge for dermatologists and a relevant source of distress for patients with plaque psoriasis. This anti-TNF-α has an encouraging safety profile, especially as long as physicians are watchful in prevention and early diagnosis of infections and infuse reactions. The efficacy, tolerability and safety profiles suggest infliximab as a suitable anti-psoriatic drug in the long-term treatment of a chronic disease such as plaque-type psoriasis.

Canadian Association of Gastroenterology Clinical Practice Guidelines: The use of tumour necrosis factor-alpha antagonist therapy in Crohn's disease

BACKGROUND

Guidelines regarding the use of infliximab in Crohn's disease were previously published by the Canadian Association of Gastroenterology in 2004. However, recent clinical findings and drug developments warrant a review and update of these guidelines.

OBJECTIVE

To review and update Canadian guidelines regarding the use of tumour necrosis factor-alpha antibody therapy in both luminal and fistulizing Crohn's disease.

METHODS

A consensus group of 25 voting participants developed a series of recommendation statements that addressed pertinent clinical questions and gaps in existing knowledge. An iterative voting and feedback process was used in advance of the consensus meeting in conjunction with a systematic literature review to refine the voting statements. These statements were brought to a formal consensus meeting held in Montreal, Quebec (March 2008), wherein each statement underwent discussion, reformulation, voting and subsequent revision until group consensus was obtained (at least 80% agreement).

OUTCOME

The 47 voting statements addressed three themes: induction therapy, maintenance therapy and safety issues. As a result of the iterative process, 23 statements achieved consensus and were submitted for publication.

CONCLUSION

In the past five years, tumour necrosis factor-alpha antagonist therapy has become a cornerstone in the management of moderate-to-severe Crohn's disease refractory to conventional treatment algorithms. The evidentiary base supporting the use of these drugs in Crohn's disease is substantial and strengthened by results from longterm clinical and molecular studies. However, significant gaps in knowledge exist, particularly with regard to treatment failure. Confidence in the safety of these drugs is increasing, provided that therapy is administered in a clinical setting in which potential complications can be readily recognized and treated.

Review and expert opinion on prevention and treatment of infliximab-related infusion reactions

Infliximab (Remicade; Schering-Plough, Kenilworth, NJ, U.S.A.) is a chimeric monoclonal antibody that acts as a tumour necrosis factor-alpha inhibitor. Infliximab is registered for the treatment of rheumatoid arthritis, psoriatic arthritis, Crohn disease, ulcerative colitis, ankylosing spondylitis and plaque-type psoriasis. Like other foreign protein-derived agents, infliximab may lead to infusion reactions during and after infusion. Infusion reactions occur in 3-22% of patients with psoriasis treated with infliximab. Most of these reactions are mild or moderate and only few are severe. Nevertheless, they may lead to discontinuation of treatment. As infliximab for psoriasis is prescribed as a last resort and is in most cases very effective, discontinuation of treatment is undesirable. With proper care and prevention of the infusion reactions the need to discontinue treatment with infliximab can be diminished. The objective of this article is to present a guideline for the management of infliximab-related infusion reactions, based on the best available evidence. This guideline can be used in patients with psoriasis as well as in dermatology patients receiving infliximab for off-label indications such as hidradenitis suppurativa or pyoderma gangrenosum.

Hypersensitivity reactions to biological agents with special emphasis on tumor necrosis factor-alpha antagonists

PURPOSE OF REVIEW

Several biological agents have been introduced into the drug market and more are emerging. Adverse reactions to these agents have recently been classified into five different subtypes. Some of these reactions are frequent but without consequences for the patients. Others are less frequent but potentially life-threatening, and they include allergic reactions.

RECENT FINDINGS

Hypersensitivity reactions are well described adverse drug reactions, corresponding to the ss-type of the newly proposed classification of adverse reactions induced by biological agents. We focus our search on tumor necrosis factor-alpha antagonists, as they represent a dramatic improvement in the therapy of both rheumatic and inflammatory bowel diseases and because adverse reactions have been closely scrutinized. We also add cases from our own experience. We found very few properly documented allergic reactions.

SUMMARY

Hypersensitivity reactions to tumor necrosis factor-alpha antagonists are not rare. Whether these manifestations have to be considered type beta or type gamma reactions is still a matter of debate. There is a need for allergological tests in vivo and in vitro.