Estimating motor unit numbers from a CMAP scan: Repeatability study on three muscles at 15 centres.

OBJECTIVE: To assess the repeatability and suitability for multicentre studies of MScanFit motor unit number estimation (MUNE), which involves modelling compound muscle action potential (CMAP) scans. METHODS: Fifteen groups in 9 countries recorded CMAP scans twice, 1-2 weeks apart in healthy subjects from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. The original MScanFit program (MScanFit-1) was compared with a revised version (MScanFit-2), designed to accommodate different muscles and recording conditions by setting the minimal motor unit size as a function of maximum CMAP. RESULTS: Complete sets of 6 recordings were obtained from 148 subjects. CMAP amplitudes differed significantly between centres for all muscles, and the same was true for MScanFit-1 MUNE. With MScanFit-2, MUNE differed less between centres but remained significantly different for APB. Coefficients of variation between repeats were 18.0% for ADM, 16.8% for APB, and 12.1% for TA. CONCLUSIONS: It is recommended for multicentre studies to use MScanFit-2 for analysis. TA provided the least variable MUNE values between subjects and the most repeatable within subjects. SIGNIFICANCE: MScanFit was primarily devised to model the discontinuities in CMAP scans in patients and is less suitable for healthy subjects with smooth scans.

Renal Doppler Resistance Indices in Kidney Transplant Recipients With Proteinuria.

BACKGROUND: The onset of proteinuria in renal transplant recipients may be associated with an increased risk of allograft failure. Little is known about the relationships between factors influencing proteinuria and the Doppler ultrasound (DU) intrarenal resistive index (RI) and pulsatility index (PI) among donor recipients with proteinuria <1000 mg/24 h. METHODS: We assessed correlations between the DU RI and PI and protein content in 93 selected renal transplant recipients: 62 patients with proteinuria 100 to 299 mg/24 h, 16 patients with proteinuria 300 to 499 mg/24 h, and 15 patients with proteinuria 500 to 999 mg/24 h. All patients underwent transplantation in a single center and were monitored by DU for at least 28 months post-transplantation. RESULTS: The DU RI values of the proteinuria 100 to 299 mg/24 h, 300 to 499 mg/24 h, and 500 to 999 mg/24 h groups were 0.67 ± 0.05; 0.65 ± 0.04, and 0.64 ± 0.07, respectively, and the PI values were 1.21 ± 0.20, 1.10 ± 0.14, and 1.15 ± 0.22, respectively. Multivariate logistic regression analysis revealed a correlation between group 100 to 299 mg/24 h and RI values, serum creatinine, living donor (R2 = 19.6%, P = .05); group 300 to 499 mg/24 h and the RI, PI values, cadaver donor (R2 = 17.5%, P = .001); and group 500 to 999 mg/24 h and the RI, PI values, serum creatinine, graft survival (R2 = 15.4%, P = .005). CONCLUSIONS: Among donor recipients with proteinuria <1000 mg/24 h, DU RI values were <0.72 and PI values were <1.41 and correlations were revealed between the incidence of proteinuria and factors such as the RI, PI, and serum creatinine level.

Late-Onset BK Viruria in Renal Transplant Recipients.

BACKGROUND: Most cases of BK virus (BKV) infections emerge within the 1st years of kidney transplantation. We aimed to determine the prevalence of late-onset BKV infection and whether there are any differences between risk factors in early and late BKV infections. METHODS: In this single-center retrospective study, we reviewed 300 kidney transplant recipients that were under regular follow-up and selected recipients with BKV infection and recorded associated risk factors, connection with immunosuppression, and responses to modification of treatment. RESULTS: BKV was detected within the 1st 5 years after transplantation in 20 patients (6.6%, group 1) and after 5 years in 15 patients (5.0%, group 2). There were no significant differences between the 2 groups regarding age, sex, sex mismatches, donor type, BKV elimination time, serum creatinine, and estimated glomerular filtration rate at the times of BKV detection and last follow-up visit. In group 1, 2 recipients had biopsy-proven BKV-associated nephropathy (BKVAN), 3 recipients had BK viruria and viremia without BKVAN (biopsy proven), and 15 recipients (75%) had only BK viruria. In group 2, all of the patients had only BK viruria. In this group, on detection of BK viruria and immediate modification of immunosuppressive regimens prevented BK viremia. CONCLUSIONS: Routine screening of renal transplant recipients for BKV was indicated not only during the 1st 5 years, but also for the full follow-up period after transplantation.

Determining renal resistive and pulsatility indexes long-term after kidney transplantation in kidney transplant recipients on cyclosporine a-, tacrolimus-, or sirolimus-based regimens.

BACKGROUND: Renal Doppler ultrasound intrarenal resistive index (RI) and pulsatility index (PI) are 2 noninvasive Doppler ultrasonographic markers to determine kidney allograft function, and have been used mainly for diagnosing allograft dysfunction during early posttransplantation periods. Little is known about the stability of RI and PI in allograft recipients receiving cyclosporine A (CyA)-, tacrolimus (TAC)-, or sirolimus (SRL)-based immunosuppressive regimens long-term after kidney transplantation. METHODS: This study assessed RI and PI by Doppler ultrasonography in 155 kidney allograft recipients between July 2012 and March 2013. The period from kidney transplantation to performance of allograft Doppler ultrasound was between 23 and 231 months in the TAC group (n = 75), 21 and 261 months in the CyA group (n = 25), and 21 and 210 months in the SRL group (n = 55). RESULTS: Univariate logistic regression analysis revealed no correlation between resistance indexes and estimated glomerular filtration rate, proteinuria, cholesterol, triglyceride, graft and patient survival, human leukocyte antigen mismatches, and creatinine. There was no significant difference among the TAC, CyA, and SRL treatment groups in terms of resistance indexes (RI and PI) (P = .193 and P = .216, respectively). Univariate logistic regression analysis revealed that RI and PI values correlated significantly with the recipients' ages (R = 0.375, P < .001), but not with donor age. The results of multivariate logistic regression analysis also revealed statistically the strongest correlation between recipients' ages and RI (95% confidence interval = 0.002, R(2) = 20.5%, P < .001) and PI (95% confidence interval = 0.008, R(2) = 16.2%, P < .001) values. CONCLUSIONS: Intrarenal RI and PI remained stable over time in allograft recipients after transplantation, and there was no significant difference between calcineurin inhibitor-based and calcineurin inhibitor-free immunosuppressive treatment groups. Only recipients' ages showed a positive correlation with RI and PI values. Long-term allograft and patient survival were both excellent (100%) and associated with RI < 0.75.