Impact of different immunosuppressive regimens on antigen-presenting blood cells in kidney transplant patients.

BACKGROUND: Alloantigen-specific and unspecific immune processes contribute to chronic renal graft dysfunction. Despite 'optimized immunosuppressive therapy' (IS), the role of chronic cell activation still remains open. METHODS: 69 kidney transplant recipients (NTX) were assessed for monocyte surface antigens CD14 (LPS receptor) and CD16 (Fc-gamma-III receptor) by flow cytometry including the percentage amount of the proinflammatory CD14+CD16+ subset. 14 non-dialysis patients with chronic renal failure (CRF) and 24 healthy persons served as controls. RESULTS: All 14 patients suffering from CRF revealed higher CRP serum levels compared to healthy controls (p = 0.01). NTX patients had a (not significant) tendency to higher CRP concentrations (p > 0.05). The mean expression of CD14 on monocytes (mCD14) was lower in patients with CRF and in NTX patients (p = 0.024-p = 0.026). NTX patients revealed low expression of monocytic CD14 with no difference between the single IS therapy groups. The proinflammatory monocyte subpopulation positive for CD14 and CD16 was elevated both in uremic and NTX patients (p < 0.002), despite long-lasting IS therapy. CONCLUSIONS: Continuing IS therapy, even under 'optimized' drug-monitoring conditions, does not sufficiently prevent or suppress a microinflammatory (and potential fibrotic growth-promoting) status in NTX patients.