Anti-oxidant and anti-inflammatory therapy in hypocomplementemic urticarial vasculitis with pulmonary emphysema

Background

Hypocomplementemic urticarial vasculitis (HUV) with pulmonary emphysema is associated with a poor prognosis, despite high-dose anti-inflammatory treatment including steroids.

Objective

A female former marathon runner, age 47 years, was diagnosed with HUV with skin, renal and pulmonary involvement. Pulmonary arterial pressure was increased during exercise, a novel finding in this disease entity. Complement consumption was associated with the presence of an anti-C1q autoantibody (IgG).

Methods

The initial treatment included high-dose steroids and chloroquine. In analogy to other systemic inflammatory lung diseases, increased oxidant levels were postulated and high-dose acetylcysteine (NAC) was initiated. Later on, dapsone as an inhibitor of pathologically increased neutrophil function was added.

Results

Within 3 months, this therapy resulted in a significant increase of the reduced serum complement levels (CH50, APH50, C4A, and C4B), diffusing capacity, decrease of the anti-C1q autoantibody titer, and normalization of the increased granulocyte count in the broncho-alveolar lavage. Additionally, a stepwise improvement of exercise tolerance (6-min walk test, oxygen consumption during exercise) was seen. Dapsone had no further effect on diffusing capacity or (did not affect) complement serum levels, which remained slightly reduced but stable despite the presence of the anti-C1q autoantibody. The effects have remained stable for the following 36 months. The therapy was well tolerated.

Conclusions

Antioxidant therapy with high-dose NAC might be a potential addition to the conventional anti-inflammatory therapy in patients with HUV and pulmonary involvement. It should be considered for investigation in a larger patient population.