Rituximab Administration in Patients with Hypoalbuminemia and Significant Proteinuria

Risk Assessment and Treatment Decision

The Kidney International guidelines suggest that serum albumin of 1.5 g/dL and 4+ proteinuria indicate high-risk nephrotic syndrome, which is a risk factor for disease progression in membranous nephropathy (MN) 1
Low serum albumin (<30 g/L) is considered a risk factor for disease progression and may warrant immunosuppressive therapy, according to the Kidney International guidelines 3
The decision to use rituximab should consider eGFR stability, previous treatments and response, and risk of disease progression, as recommended by the Kidney International guidelines 2, 4, 5

High-risk patients with severe hypoalbuminemia and significant proteinuria may be treated with rituximab if eGFR is stable, as suggested by the Kidney International guidelines 1, 4
If eGFR is decreasing, cyclophosphamide with glucocorticoids may be preferred over rituximab for high-risk patients, according to the Kidney International guidelines 2
Very high-risk patients with life-threatening nephrotic syndrome or rapidly deteriorating kidney function may be treated with cyclophosphamide with glucocorticoids, as recommended by the Kidney International guidelines 5

The Kidney International guidelines recommend monitoring anti-PLA2R antibody levels at 3-6 months after starting therapy to evaluate treatment response, and evaluating proteinuria and serum albumin response after 3 months of treatment 1, 4
Additional doses of rituximab may be considered if B-cell depletion is insufficient, as suggested by the Kidney International guidelines 4
If resistance to rituximab occurs, compliance should be checked and efficacy markers monitored, and persistent proteinuria alone is not sufficient to define resistance, according to the Kidney International guidelines 2

Patients should receive optimal supportive care, including RAS blockade, blood pressure control, and management of nephrotic syndrome complications, as recommended by the Kidney International guidelines 1, 6
Prophylactic anticoagulation should be considered in patients with severe hypoalbuminemia due to increased thromboembolism risk, according to the Kidney International guidelines 6, 7
Prophylactic trimethoprim-sulfamethoxazole should be considered in patients receiving rituximab to prevent infections, as suggested by the Kidney International guidelines 7