BACKGROUND: We previously reported that rituximab (RIT) and intravenous immunoglobulin (IVIg) combination therapy is effective in deterring the progression of chronic active antibody-mediated rejection (CAMR), but that report was based on the assessment of a small number of cases for a short period.

MATERIAL AND METHODS: Forty-three patients with CAMR were recruited during the study period after 2010. The patients were divided into high (n=17, 39.5%) and low proteinuria groups (n=26, 60.5%) based on spot urine protein-to-creatinine ratio of > or <3.5 g/g. We compared clinical outcomes between the two groups in terms of allograft survival rate, decrease in estimated glomerular filtration rate (ΔeGFR), change in proteinuria level, and infectious complications. We also evaluated the risk factors of allograft failure.

RESULTS: The 3-year allograft survival rate after combination treatment was 60.5% overall, but was higher in the low proteinuria group than in the high proteinuria group (69.2% versus 47.1%; log rank p<0.05). The combination treatment reduced the eGFR slope in both groups, and this effect was more definite in the low proteinuria group. No significant differences in the amount of proteinuria and infectious complication rate were found between the two groups. Proteinuria and eGFR at treatment were independent predictive factors of allograft failure (p<0.01 and p<0.001, respectively).

CONCLUSIONS: RIT and IVIg combination therapy was effective in reducing the progression of CAMR, and this effect was more definite in the patients with low proteinuria.

Keywords: Proteinuria, Graft Rejection, Kidney Transplantation, Glomerular Filtration Rate