SELECTED ARTICLES FROM THE RECENT LITERATURE 2003

12/18/03

Experience with the Churg-Strauss Syndrome

Summary
One of the vasculitis syndromes in which increased serum levels of anti-neutrophil cytoplasm antibodies (ANCA) are commonly found is the Churg-Strauss Syndrome (CSS). Keogh and Specks of the Mayo Clinic in Rochester, MN reviewed the records of 91 patients who met diagnostic criteria for CSS during evaluation in their institution in the period 1990-2000. Positive p-ANCA tests were found in 73% of untreated patients and in 75% of those tested during a disease flare (with/without ongoing therapy). In comparison, ANCA tests were positive in only 16% of patients tested when their CSS was in remission. Serial measurements suggested a correlation of ANCA levels with CSS clinical activity. Central nervous system involvement was the only organ system involvement that correlated modestly with ANCA status. The majority of the sera that were p-ANCA positive contained anti-myeloperoxidase antibodies. Leukotriene receptor antagonist medications (LTA) had been taken by 23 of the 90 patients in which this information was available of whom the LTA treatment had been started before a diagnosis of CSS in 16 individuals. However, there was no obvious temporal relationship of LTA therapy to CSS onset. The prognosis of CSS in this group was overall better than in other ANCA-associated vasculitides.

Reference
Am J Med 2003;115:284-90

Editor's Comments
Although the authors of this report considered CSS to be present if any one of 3 sets of diagnostic criteria were met, the 73% prevalence of positive ANCA in their untreated CSS patients is similar to the experience reported elsewhere. The correlation of ANCA levels with CSS disease activity is more controversial. It reminds me of the early studies of ANCA in Wegener's Granulomatosis where the Mayo Clinic authors reported a strong correlation of c-ANCA titers with disease activity. However, some other groups found no significant correlation.

It is not surprising that 26% of the CSS patients in this study had taken LTA prior to diagnosis of the CSS since asthma, often prominent, is almost always already present in those who are diagnosed with CSS. Most reports have concluded that LTA use and CSS onset is coincidental, possibly because an attempt is made to reduce the dosage of corticosteroid therapy when the LTA therapy is added. The prior higher doses of corticosteroids employed may have suppressed the non-pulmonary manifestations which would have suggested a diagnosis of CSS.
 

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