Intravenous immunoglobulin therapy in kidney transplant recipients with de novo DSA: Results of an observational study

Background Approximately 25% of kidney transplant recipients develop de novo anti-HLA donor-specific antibodies ( dn DSA) leading to acute antibody-mediated rejection (ABMR) in 30% of patients. Preemptive therapeutic strategies are not available. Methods We conducted a prospective observational study including 11 kidney transplant recipients. Inclusion criteria were dn DSA occurring within the first year after transplant and normal allograft biopsy. All patients were treated with high-dose IVIG (2 g/kg 0, 1 and 2 months post- dn DSA). The primary efficacy outcome was incidence of clinical and subclinical acute ABMR within 12 months after dn DSA detection as compared to a historical control group (IVIG-). Results Acute ABMR occurred in 2 or 11 patients in the IVIG+ group and in 1 of 9 patients in the IVIG- group. IVIG treatment did not affect either class I or class II DSA, as observed at the end of the follow-up. IVIG treatment significantly decreased FcγRIIA mRNA expression in circulating leukocytes, but did not affect the expression of any other markers of B cell activation. Conclusions In this first pilot study including kidney allograft recipients with early dn DSA, preemptive treatment with high-dose IVIG alone did not prevent acute ABMR and had minimal effects on DSA outcome and B cell phenotype.