Rituximab

Anti-CD20 monoclonal antibody; depletes B cells

Response rate
Promising in refractory cases
Onset
Weeks–months
Route
IV 375 mg/m² x4 or 1000 mg x2
Line
3rd
IgM effect
Reduces anti-C1q antibody production via B-cell depletion

Evidence summary

B-cell depletion with rituximab reduces anti-C1q autoantibody production. Shown effective in refractory HUVS, especially with renal involvement. Long-term follow-up of pediatric DNASE1L3-mutant siblings showed rituximab was the most effective treatment. Emerging as a key option for severe/refractory disease.