Leukotriene antagonists: bystanders or causes of Churg-Strauss syndrome?

Elderly cases of Churg-Strauss syndrome: case report and review of Japanese cases

Churg-Strauss syndrome (CSS) is a vasculitis usually thought to affect comparatively young individuals, however, elderly cases of CSS are being reported increasingly. We report two elderly cases of CSS and review 123 cases of CSS reported in Japan between 2003 and 2010. The two patients showed typical features of CSS such as asthma, chronic sinusitis, purpura and mononeuritis multiplex. The biopsy specimens demonstrated leukocytoclastic vasculitis with infiltration of eosinophils. Both patients responded well to oral prednisolone. The age of the CSS cases we reviewed ranged from the teens to the 80s, with 47.2% of the patients aged 60 years or older. These patients tended more frequently to have complications such as gastrointestinal involvement, and a higher mortality rate. Elderly cases of CSS are not rare. Correct diagnosis at an earlier stage and careful, long-term follow up are of particular importance in preventing a fatal outcome.

Leukotriene receptor antagonists and Churg-Strauss syndrome: cause, trigger or merely an association?

Concern has been raised in the medical literature that the use of leukotriene receptor antagonists for the treatment of asthma may be associated with an increased incidence of Churg-Strauss syndrome, a rare small-vessel vasculitic syndrome. This review provides a critical appraisal of the literature to address this question. The incidence of Churg-Strauss syndrome in the general population is one to four cases per million. In patients with asthma it is 20-60 cases per million patient-years, which is similar to that seen in a population receiving leukotriene receptor antagonists. There is no evidence for a direct causative role of leukotriene receptor antagonists in the development of Churg-Strauss syndrome. There may be multiple other non-causative reasons for an association, including the fact that these agents may be initiated in patients who are already in the process of developing Churg-Strauss syndrome, or that the use of leukotriene receptor antagonists leads to a reduction in corticosteroid use, which in turn allows the Churg-Strauss syndrome to be 'unmasked'.

Pharmacotherapy of asthma

The pharmacotherapy of asthma is a complex and evolving topic. A detailed understanding of the pathophysiologic processes involved in the asthmatic response forms the basis for understanding the actions of drugs used to treat this condition. Likewise, a solid comprehension of the medicinal chemistry and pharmacologic properties of the numerous agents involved in the treatment of asthma is critical for rationalizing drug choices and understanding potential side effects. Asthma is addressed at several points in the PharmD curriculum at South University including in the Pathophysiology (quarter 2), Integrated Sequence III (quarter 6), and Critical Care (quarter 9) courses. Various teaching strategies are employed throughout, along with weekly case-based recitations. The content presented here includes a synopsis of the pathophysiology and pharmacology from our Integrated Sequence III block on inflammatory diseases and asthma. A short review of pertinent pathophysiology is followed by a detailed presentation on the various classes of asthma drugs which includes their chemistry, mechanism of action, pharmacokinetics, toxicity, and interactions. This presentation is designed to prepare students for asthma therapeutics, which follows next in the schedule. The complexities of asthma pharmacotherapy are stressed along with current controversies and future drug development.

The linkage between Churg-Strauss syndrome and leukotriene receptor antagonists: fact or fiction?

Epidemiologic evidence has shown that the worldwide prevalence of asthma is increasing. The leukotriene receptor antagonists (LTRAs) represent a new class of therapy for asthma. They have been developed in the last decade and play a pivotal steroid-sparing role in treating the inflammatory component of asthma. Consequently, reports of Churg-Strauss syndrome (CSS), a rare form of systemic vasculitis, have been recognized as a potential side effect in individuals with moderate to severe asthma on LTRA therapy. The serious nature of this disorder is worthy of prompt recognition by clinicians and aggressive therapy to avoid the subsequent longstanding effects of vasculitis. To validate the postulated linkage between the LTRAs and CSS, this review comprehensively evaluates reported cases in the literature and supports a pathophysiological relationship between the LTRAs and the development of CSS.

Churg-Strauss Syndrome Development during Asthma Therapy with Leukotriene Receptor Antagonists: Just a Coincidental Association?

A report on our clinical experience based on 3 male patients who developed Churg-Strauss syndrome (CSS) after standard oral montelukast use. All patients affected by moderate asthma and chronic hyperplastic rhinosinusitis were treated with inhaled corticosteroids and ß2 agonists. Systemic corticosteroid treatment consisted in oral daily prednisone in case 1, in short courses of oral betamethasone in case 2, and in remote and isolated administrations of oral betamethasone and intramuscular methylprednisolone in case 3. Because of the improvement of the asthma symptoms after montelukast use, patient 1 decided to take half the dose of prednisone for 10 days and patient 2 decided to discontinue systemic and inhaled corticosteroids for 45 days. Overt CSS was heralded by vasculitic skin lesions and developed in each patient with severe organ damage, consisting in renal, myocardial and gastrointestinal involvement. Remission was obtained by standard CSS therapy after montelukast withdrawal.

According to the unmasking hypothesis, antileukotriene treatment, by enabling the reduction in systemic corticosteroid therapy in case 1 and its discontinuation in case 2, might have only permitted the precipitation of the vasculitis. However antileukotriene-associated CSS reportedly occurred in systemic corticosteroid-naïve patients and relapsed in one patient after antileukotriene treatment. These observations lend support to the concept that the precipitation of the vasculitic phase may be associated with leukotriene modifier deleterious effects. In conclusion there is not enough evidence to prove that antileukotriene treatment plays a direct causative role in the pathogenesis of CSS. Further clinical and experimental research is required to clarify the antileukotriene associated CSS controversy.

Churg-Strauss syndrome: clinical presentation, antineutrophil cytoplasmic antibodies, and leukotriene receptor antagonists

PURPOSE

To determine the association of antineutrophil cytoplasmic antibodies (ANCA) and leukotriene receptor antagonists with disease activity in a large series of patients with Churg-Strauss syndrome.

METHODS

Potential subjects were identified by a computerized search of the Mayo Clinic Rochester database for the years 1990 to 2000. Patients meeting one of three classification schemes for Churg-Strauss syndrome were included.

RESULTS

Ninety-one patients met the inclusion criteria. Clinical manifestations were similar to those in previous reports. Mortality was similar to that in the general population. ANCA testing was performed in 74 patients. Seventy-three percent (n = 22) of the 30 patients tested before therapy were ANCA positive, as were 75% (n = 12) of the 16 patients tested during a disease flare. In comparison, 16% (n = 8) of the 49 tested during remission were ANCA positive. Serial measurements indicated a correlation of ANCA levels with disease activity. Central nervous system involvement was the only clinical manifestation that correlated with ANCA status (P = 0.05). Twenty-three patients received leukotriene receptor antagonists, of whom 16 (70%) began treatment before diagnosis and 6 (27%) began during remission. Two of those treated after diagnosis relapsed. In 1 patient the relation between disease and leukotriene receptor antagonist use could not be determined. Use of leukotriene receptor antagonists did not affect the time between onset of asthma and manifestations of vasculitis, and was not correlated with organ manifestations, except sinus disease.

CONCLUSION

No one classification scheme identified all patients. Churg-Strauss syndrome has a better prognosis than other ANCA-associated vasculitides. ANCA status correlates with disease activity, whereas a pathogenic role for leukotriene receptor antagonists in the development of Churg-Strauss syndrome was not noted.

Leukotriene antagonists

Hepatotoxicity is the most common cause of fulminant hepatic failure in the United States and the main indication for market withdrawal of drugs. This condition has been increasingly recognized as a problem of enormous medical, financial legal, and regulatory importance. It is in context of this heightened awareness of hepatotoxicity, particularly associated with new high profile drugs, that the authors reviews the published data regarding liver injury related to a novel group of asthma drugs.