A man in his fifties with recurrent urticaria, fever and joint pain. / En mann i 50-årene med tilbakevendende urtikaria, feber og leddsmerter.

BACKGROUND: Schnitzler's syndrome is a rare, acquired and probably underdiagnosed disorder. It is a type of autoinflammatory condition with late onset. CASE PRESENTATION: A man in his fifties had had recurrent urticaria, fever and chronic joint pain during the previous year. After an extensive investigation, no evidence of infection, autoimmune disease or malignancy was found. Blood samples showed moderately elevated SR and CRP, mild thrombocytosis and presence of monoclonal IgM in low concentration (MGUS). The combination of sterile inflammation, joint/muscle pain, urticaria and M-component was consistent with Schnitzler's syndrome. He was placed on a treatment trial with anakinra (interleukin [IL]-1 receptor antagonist) 100 mg x 1 daily, given as a subcutaneous injection. His condition was excellent until one week after the first injection. The initial treatment indicated a good clinical effect of IL-1 blockade, but due to the very unpleasant localised side effects (extensive dermatitis), treatment with anakinra was withdrawn, and canakinumab (monoclonal antibody against IL-1ß) was chosen instead. He responded very well to this treatment and experienced no adverse effects. One year after starting treatment, the patient still has an excellent treatment response. INTERPRETATION: Anakinra is the treatment of first choice for this condition, but this case history illustrates that canakinumab can be tried if anakinra is not tolerated by the patient.

Cold agglutinin disease revisited: a multinational, observational study of 232 patients.

We retrospectively studied 232 patients with cold agglutinin disease (CAD) at 24 centers in 5 countries. In Norway and a northern region of Italy, the study was close to being population-based. For the first time, we demonstrate fourfold differences between cold and warmer climates regarding prevalence (20 vs 5 cases/million) and incidence (1.9 vs 0.48 cases/million per year). Mean baseline hemoglobin level was 9.3 g/dL, but 27% had hemoglobin <8 g/dL. Identification of typical features of CAD-associated lymphoproliferative disorder in the bone marrow was greatly increased by centralized biopsy assessment. CAD seems to be associated with a slightly increased risk of venous thrombosis. This work includes a follow-up study of therapies, focusing on the long-term outcomes of the rituximab plus bendamustine and rituximab plus fludarabine regimens. Rituximab plus bendamustine therapy resulted in responses in 35 (78%) of 45 patients; 24 (53%) achieved complete response. Interestingly, these rates were still higher than observed in the original (2017) prospective trial, and we also found a shift toward deeper responses with time. This is explained by the prolonged time to response seen in many patients, probably related to long-lived plasma cells. In patients responding to rituximab-bendamustine, median response duration was not reached after 88 months, and estimated 5-year sustained remission was 77%. The regimen appeared safe regarding late-occurring malignancies. Rituximab plus fludarabine therapy seems to carry a higher risk of long-term adverse effects.

Eculizumab treatment during pregnancy does not affect the complement system activity of the newborn.

Eculizumab is a humanized IgG2/4 chimeric anti-complement C5 antibody used to treat patients with paroxysmal nocturnal hemoglobinuria (PNH) or atypical hemolytic uremic syndrome. The aim of this study was to evaluate whether or not the complement activity in newborns from pregnant women who receive eculizumab is impaired. A novel eculizumab-C5 complex (E-C5) specific assay was developed and revealed that two newborns carried only 6-7% of the E-C5 detected in their eculizumab-treated PNH mothers. Serum from the pregnant women completely lacked terminal complement pathway activity, whereas the complement activity in the serum of the newborns was completely normal. Data from the pregnant women and their newborns were compared with that of healthy age-matched female controls and healthy newborns, as well as a non-treated pregnant woman with PNH and her newborn. These all showed normal complement activity without detectable E-C5 complexes. Furthermore, absence of eculizumab or E-C5 in the newborn could not be explained by lack of eculizumab binding to the neonatal Fc receptor (FcRn), as eculizumab bound strongly to the receptor in vitro. In conclusion, despite binding to FcRn neither eculizumab nor E-C5 accumulates in fetal plasma, and eculizumab treatment during pregnancy does not impair the complement function in the newborn.