BackgroundContrast-induced nephropathy (CIN) is a common cause of hospital-acquired acute kidney injury (AKI). Neutrophil gelatinase-associated lipocalin (NGAL) represents a promising biomarker for AKI. Its role in the early diagnosis of CIN has already been examined in adults and children undergoing coronary angiography. This study was designed to prospectively evaluate plasma NGAL compared with serum creatinine (SCr) for early CIN detection among hospitalized patients undergoing contrast-enhanced computed tomography (CT).MethodsWe prospectively enrolled consecutive hospitalized patients undergoing elective CT with intravenous (IV), low-osmolar contrast administration. Patients with pre-procedure SCr >150 μmol/L (1.7 mg/dL), congestive heart failure, haemodynamic instability, sepsis, or urinary tract infection were excluded. Plasma NGAL was measured using the standardized Triage® NGAL test (Biosite Incorporated, San Diego, CA, USA) at baseline and 6 h post-procedure. SCr, blood urea nitrogen (BUN), albumin and sodium (Na) were measured and eGFR MDRD4 was calculated at the same intervals, as well as at 24 and 48 h post-procedure. CIN was defined as an increase in SCr of >25% or >44 μmol/L (0.5 mg/dL) from baseline within 48 h post-procedure, in the absence of other obvious causes.ResultsForty-seven patients, male/female 27/20, median age 68 (31–88) years, 16/47 diabetics, with baseline SCr 91.94 ± 20.33 μmol/L (1.04 ± 0.23 mg/dL) and eGFR MDRD4 68.40 ± 18.22 mL/min/1.73 m2 were enrolled. A contrast volume of 120 mL (range 100–150 mL) was administered. CIN was found in four subjects (8.51%), but detection by SCr was only possible 24 h in 1 and 48 h post-procedure in three. In contrast, significant elevation of plasma NGAL was found at 6 h post-procedure in those with versus those without CIN (779.25 ± 361.49 versus 82.30 ± 40.64 ng/mL, P < 0.001). Using a cutoff value of 200 ng/mL, sensitivity, specificity and area under the receiver-operating characteristic (ROC) curve of 6-h plasma NGAL for CIN prediction were excellent (100, 100 and 1.00%, respectively). Subjects with CIN did not differ in baseline demographics, renal function and diabetes status compared with those without CIN. No differences in any variable were noted between diabetics and non-diabetics. Plasma NGAL at 6 h (R2 = 0.24, P < 0.001) was found to be an independent predictor of CIN.ConclusionsPlasma NGAL 6 h after contrast administration measured by the rapid, point-of-care Triage® NGAL test appears to be a useful biomarker in the early prediction of CIN among hospitalized patients undergoing elective contrast-enhanced CT. However, the small sample size and the very small number of CIN events are important limitations. In any case, according to our evaluation, CIN incidence in this well-controlled population underlines the importance of early detection by an adequate and simple procedure such as the 6-h plasma NGAL test.

Contrast-induced nephropathy (CIN) is a common cause of hospital-acquired acute kidney injury (AKI) and a source of significantly increased short-and long-term mortality. Studies of large cohorts have revealed that more than half of these cases are in subjects undergoing cardiac catheterization and intra-arterial coronary angiography, and nearly a third follow computed tomography (CT) scans. Neutrophil gelatinase-associated lipocalin (NGAL) represents an early predictive troponin-like biomarker for AKI. Its role in the timely diagnosis of CIN has already been examined in adults and children undergoing coronary angiography and a metaanalysis revealed a very good performance of plasma or urine NGAL in the prediction of CIN. Much of these data have been extrapolated to patients receiving intravenous (IV) contrast agent for CT scans, although major differences in patient populations, contrast volume administered and intra-procedural complications between the two settings exist. In this context, a recent prospective study by our group evaluated plasma NGAL, measured using standardized Sriage Õ NGAL test (Biosite Incorporated, San Diego, CA) at baseline and 6-h postprocedure, for early detection of CIN among hospitalized patients undergoing elective contrastenhanced CT. CIN, defined as an increase in serum creatinine (SCr) of 425% or 40.5 mg/dL from baseline within 48-h post-procedure, was found in 8.51% of subjects. In contrast, significant elevation of plasma NGAL was found at 6-h post-procedure with excellent performance characteristics. This review presents the current status of NGAL in the prediction of CIN after IV contrast administration among hospitalized patients undergoing elective contrast-enhanced CT.

Peritoneal dialysis (PD) is limited mainly by a higher technique failure rate as compared to hemodialysis (HD), catheter malfunction being an important reason. Intra- and extra-peritoneal catheter configuration may be associated with mechanical and infectious complications affecting method survival. We report our experience with two extra-peritoneal catheter configurations: the straight and the swan-neck (SN) catheters. A total of 85 consecutive patients, 58 males and 27 females were included in the study. Among them, 26 were diabetics; 52 were treated with automated PD (APD) and 33 with continuous ambulatory PD (CAPD). Straight catheters were used in 38 patients (straight group) and SN catheters in 47 patients (SN group). Straight catheters were mostly used in the first 6-year period while SN catheters in the last 6-year period. The baseline demographics were similar between the two groups. A significantly higher frequency of APD use was observed in SN group. Technique survival was better with SN versus straight (log-rank test, P = 0.01) while patient and catheter survival were similar. A better technique survival is noted in our group of patients with SN catheters. An additional factor could be the significantly higher frequency of APD use in this group. Changes in PD solutions’ composition could also contribute to improvement in technique survival. The outcome for patients and catheter types used was similar.

To the Editor: We read with interest the case of an exfoliative rash related to icodextrin in the August 2014 issue nephrology image section and the reported incidence of about 10%. 1 Our single-center experience with this complication in 86 consecutive patients on peritoneal dialysis over a period of 20 years with 43 (17 diabetics) exposed to icodextrin (median exposure time 29 months) is of only one case of icodextrinrelated skin allergy (exfoliative rash) in a diabetic female, nine days after icodextrin initiation, resolving after solution withdrawal (incidence rate 2.3%).Skin rash incidence related to icodextrin use is variously reported up to 18.9%. 2 Wolfson et al. 3 metanalysis reported a higher rash incidence (10.1%) compared with controls (4.6%, Po0.003). On the opposite, in Cho et al. 4 metanalysis, rash risk is not increased under icodextrin, discontinued only in up to 4.3% of patients.Icodextrin solution is an important tool in peritoneal dialysis improving ultrafiltration and reducing exposure to glucose. In our experience rash incidence was low. The wide variation in the complication's reported incidence may represent an overestimation taking into account skin manifestations of various origins, common in uremia.

BACKGROUND AND AIMS Haemodialysis (HD) patients have a great risk of severe infection from coronovirus 2(SARS-CoV-2). However, chronic kidney disease is often associated with immunodeficiency and other existing vaccines have reduced efficacy in HD patients [1]. Humoral immune response to SARS-CoV-2 vaccination in chronic HD patients was investigated during a period of 7 months. METHOD A total of 39 patients, M/F = 34/5, aged 71 (47–90) years, dialyzed for 55(18–286) months, vaccinated with mRNA Comirnaty vaccine (BNT 162b2; BioNTech & Pfizer) were studied. Patients received two initial vaccine doses in March and April 2021, respectively, and 24 out of 39 patients received a third dose in October 2021. We analyzed the antibody response to the spike (S) antigen of SARS-CoV-2 at 0, 1, 4 and 7 months (November) after second vaccine dose in all patients. We also compared serum antibody titers at time-point 7 between the 24/39 patients and 20 healthy age-matched individuals, also vaccinated with three doses at the same months. RESULTS At time-point 0, titers of S protein-targeting antibodies(S-Abs) were 5 ± 1 AU/mL. At 1 month S-Abs were &lt; 50 AU/mL in 2 patients (5.15%), between 51 and 100 AU/mL in 2/39 patients (5.15%), between 101 and 1000(528 ± 292) AU/mL in 19/39 patients (48.7%) and between 1001 and 10 000 (4486 ± 2547) AU/mL in 13/39 patients(33.3%). S-Abs were higher than 10 000(14 516 ± 3062) AU/mL in 3/39 patients (7.7%) after previous infection. In the 36/39 patients not infected, at 4 months there was a significant titer decrease compared with values at 1 month: from 3108 ± 4361 to 1442 ± 4357 AU/mL; P &lt; 0.001. At 7 months, the 24/39 patients vaccinated with the third dose showed increased titers in comparison with values at 1 and 4 months, respectively (9285 ± 11 202 versus 1957 ± 2763 AU/mL; P &lt; 0.001 and versus 584 ± 669 AU/mL; P &lt; 0.001, respectively). Among 15/39 patients who did not receive the third dose, 4/15 with an average titer of 739 AU/mL died from other causes, 3/15 with an average titer of 25 468 AU/mL were hospitalized for COVID-19 and discharged and 8/15 showed further titer decrease (2117 ± 4887 to 950 ± 1855 AU/mL; P = 0.031). After the third dose higher S-Abs were observed in healthy controls compared with HD patients (18 050 ± 15 374 versus 9285 ± 11 202 AU/mL; P = 0.032). CONCLUSION Healthy controls showed a better humoral immune response compared with patients. Two doses of mRNA BNT162b2 vaccine induced an initial satisfactory humoral response in HD patients but S-Abs significantly declined subsequently [2]. Humoral response was significantly better after the third dose and booster immunization seems necessary [3].