The

study was a prospective investigation of the changes in immunoregulatory markers in the blood, bone marrow, and liver allograft in recipients converted from TAC monotherapy to SRL monotherapy for clinical indications (e.g., TAC toxicity). Inclusion criteria were as follows: age ≥18 years; ≥6 months post-LT; TAC monotherapy ≥1 month before SRL monotherapy conversion for nephrotoxicity (glomular filtration rate [GFR] 30-60 cc/min by modified diet in renal disease [MDRD]) or other indication; ≥6 months without a rejection episode; Tanespimycin mouse no lymphocyte depletion therapy for ≥1 year; normal liver-function tests; and no rejection or fibrosis on preconversion liver biopsy. Exclusion criteria were as follows: previous liver or multiorgan transplant; previous immune or viral liver disease unless hepatitis C virus (HCV) RNA was undetectable; proteinuria (≥0.5 g/day); estimated glomerular filtration rate (eGFR) ≤30 cc/min; ≥2 rejections

post-LT; history of hepatic artery thrombosis; hematological abnormalities or severe hypertriglyceridemia; active infection or malignancy; and inadequacy for follow-up. All patients signed informed consent and were followed for 7 months after SRL conversion. The protocol conformed to the Declaration of Helsinki guidelines and was approved by the Northwestern Institutional this website Review Board (Northwestern University Feinberg School of Medicine, Chicago, IL). History and physical exams, complete blood counts, comprehensive metabolic panels, fasting lipids, hemoglobin A1C tests (HgA1C), and spot urine protein:creatinine ratios were performed before and 3 and 6 months after conversion. Bone marrow aspirations and percutaneous liver biopsies were performed once before and 6 months after conversion. For conversion, SRL at 2 or 3 mg (< or ≥100 kg body weight) daily was initiated with subsequent weekly SRL trough-level monitoring. When these reached ≥5 ng/mL, TAC was discontinued followed by weekly laboratory tests and SRL trough levels (goal, 5-8 ng/mL) for 1 month,

then monthly. Prospective liver- and renal-function tests, lipid levels, urine protein:creatinine Smoothened ratios, and any new SRL toxicities were recorded. Treg immunophenotyping (twice before conversion and 3, 4, 6, and 7 months after conversion): Peripheral blood mononuclear cells (PBMCs) were isolated from heparinized samples on Ficoll-Hypaque gradients. Tregs were enumerated utilizing extracellular immunofluorescent staining with CD3-FITC (fluorescein isothiocyanate), CD4-PerCP (peridinin-chlorophyll protein complex), CD8-PerCP, CD25-APC, and CD127-FITC (BD Biosciences, San Diego, CA). After fixation and permeabilization, the cells were washed and incubated with anti-human FOXP3-PE (phycoerythrin) or rat immunoglobulin G2a-PE isotype control (eBioscience, San Diego, CA) (21, 22).