Early nephrologist involvement in hospital-acquired acute kidney injury: a pilot study.

BACKGROUND: The optimal timing of nephrology consultation in patients with hospital-acquired acute kidney injury (AKI) is unknown. STUDY DESIGN: Prospective controlled nonrandomized intervention study. SETTING & PARTICIPANTS: We screened daily serum creatinine (SCr) levels of 4,296 patients admitted to the St. Louis Veterans Affairs Medical Center between September and November 2008 (control group) and January to May 2009 (intervention group). 354 patients (8.2%) met the definition of in-hospital AKI (SCr level increase of 0.3 mg/dL over 48 hours); 176 of whom met all inclusion criteria; 85 and 91 patients were enrolled in the control (standard care) and intervention groups, respectively. INTERVENTION: Early renal service involvement (EARLI), defined as a 1-time nephrology consultation within 18 hours of the onset of AKI. OUTCOME: Primary outcome defined as 2.5-fold increase in SCr level from admission. MEASUREMENT: Daily SCr until discharge. RESULTS: The 2 groups had similar characteristics at baseline and at the time of AKI. The intervention was completed at a mean of 13.1 ± 0.8 hours from the onset of AKI. Nephrology recommendations in the EARLI group included specific diagnostic, therapeutic, and preventative components. The primary outcome occurred in 12.9% of patients in the control group compared with 3.3% of patients in the EARLI group (P = 0.02). Patients in the EARLI group had a lower peak SCr level of 1.8 ± 0.1 versus 2.1 ± 0.2 mg/dL in controls (P = 0.01). LIMITATIONS: Single-center nonrandomized study of mostly US male veterans. CONCLUSIONS: Early nephrologist involvement in patients with AKI may reduce the risk of a further decrease in kidney function. A larger randomized trial is needed to confirm the findings.

Renal allograft biopsies in the era of C4d staining: the need for change in the Banff classification system.

C4d immunostaining in the peritubular capillaries (PTC) is a marker of antibody-mediated rejection (AMR). We evaluated the histopathologic diagnoses of 388 renal transplant biopsies since the implementation of routine C4d immunostaining at our center. Of these, 155 (40%) biopsies had evidence of acute cellular rejection (ACR), out of which 119 (77%) had pure ACR, 31 (20%) had ACR with concomitant features of AMR, and five (3%) had ACR with focal C4d staining. Sixty-four (16%) biopsies exhibited features of AMR [33 (52%) pure AMR, and 31(48%) concomitant AMR and ACR]. One hundred and fifty-five (40%) biopsies had features of interstitial fibrosis and tubular atrophy (IFTA). Of these, 20 (13%) had concomitant AMR [13 (8.5%) had pure AMR and seven (4.5%) had concomitant ACR and AMR]. Creatinine at the time of biopsy was higher in patients with mixed ACR and AMR and the clinical behavior of mixed lesions is more aggressive over time. Despite having a lower serum creatinine at the time of biopsy, patients with IFTA experienced gradual decline in graft function over time. The pathologic findings in renal allograft biopsies are often mixed and mixed lesions appear to have more aggressive clinical behavior. These findings suggest the need for change in the Banff classification system to better capture the complexity of renal allograft pathologies.