Angiœdèmes à évolution ecchymotique révélant un lupus érythémateux systémique de l’enfant avec anticorps anti-C1q

Comorbidity and pathogenic links of chronic spontaneous urticaria and systemic lupus erythematosus--a systematic review

Chronic spontaneous urticaria (CSU) is a common mast cell-driven disease characterized by the development of wheals (hives), angioedema (AE), or both for > 6 weeks. It is thought that autoimmunity is a common cause of CSU, which is often associated with autoimmune thyroiditis, whereas the link to other autoimmune disorders such as systemic lupus erythematosus (SLE) has not been carefully explored. Here, we systematically reviewed the existing literature for information on the prevalence of CSU in SLE (and vice versa) and we examined the possible clinical and pathogenetic relationship between CSU and SLE. The prevalence of CSU and CSU-like rash in SLE was investigated by 42 independent studies and comorbidity in adult patients reportedly ranged from 0% to 21.9% and 0.4% to 27.5%, respectively (urticarial vasculitis: 0-20%). In children with SLE, CSU was reported in 0-1.2% and CSU-like rash in 4.5-12% (urticarial vasculitis: 0-2.2%). In contrast, little information is available on the prevalence of SLE in patients with CSU, and more studies are needed to determine the rate of comorbidity. Recent insights on IgG- and IgE-mediated autoreactivity suggest similarities in the pathogenesis of CSU and SLE linking inflammation and autoimmunity with the activation of the complement and coagulation system. Future studies of patients with either or both conditions could help to better define common pathomechanisms in CSU and SLE and to develop novel targeted treatment options for patients with CSU and SLE.

The effect of anti-Anisakis simplexantibody levels on C3 and C4 complement components in human sera

Previously, anin vitroeffect was observed on the complement system not only of the excretory-secretory products but also of somatic antigens from L3Anisakis simplexlarvae. In the present work the effect of anti-A. simplexspecific antibodies on C3 and C4 levels in human sera was investigated. Up to 309 samples of sera were tested to determine levels of C3 and C4 and anti-A. simplexantibodies, including immunoglobulins IgG, IgM, IgA and IgE. Significant differences were observed between levels of C3 and C4 and all immunoglobulins except for IgE. In the case of immunoglobulins, the probability that an anti-A. simplexpositive subject has a C3 deficiency was 3.8 times higher than a subject without specific antibodies. In conclusion, an association between elevated levels of anti-A. simplexantibodies and C3 and C4 deficiency was demonstrated.

[Hypocomplementemic vasculitis treated with dapsone]

BACKGROUND

Hypocomplementemic urticarial vasculitis, described by MacDuffie in 1973, is rare. Some doubt surrounds its classification. We report a case of hypocomplementemic urticarial vasculitis (MacDuffie syndrome) treated with dapsone with a favorable outcome.

CASE REPORT

Over a number of years, a 43-year-old man presented urticarial vasculitis attacks with palpebral oedema and systemic symptoms such as fever and arthralgia. In 2006, MacDuffie syndrome was diagnosed on the grounds of positive anti-C1q antibodies. Treatment with dapsone was started and resulted in considerable improvement.

DISCUSSION

Hypocomplementemic urticarial vasculitis is characterized by urticarial vasculitis lesions, leucocytoclastic vasculitis and systemic symptoms. The latter symptoms are similar to those of systemic lupus erythematosus (SLE), and some authors have suggested that MacDuffie syndrome may in fact belong to SLE. Diagnosis is based on clinical appearance, histology and the presence of anti-C1q antibodies. There is no specific treatment for hypocomplementemic urticarial vasculitis. Immunosuppressant therapy can be used for lesions refractory to systemic corticosteroids.