2020) Survival rate in acute kidney injury superimposed COVID-19 patients: a systematic review and meta-analysis, Renal Failure, 42:1, 393-397,

The presence of pre-formed donor-specific antibodies (DSAs) in kidney transplantation is associated with worse overall outcomes compared with DSA-negative transplantation. A positive complement-dependant cytotoxic crossmatch presents a high immunological risk, while a negative flow cytometry crossmatch is at the lower end of the risk spectrum. Yet, the presence of low-level DSA detected by Luminex alone, that is, positive Luminex and negative flow (PLNF) cytometry crossmatch lacks robust scientific exploration. In this systematic review and pooled analysis, we investigate the glomerular filtration rate, acute rejection (AR), graft survival and patient survival of PLNF transplants compared with DSA-negative transplants. Our analysis identified seven retrospective studies consisting of 429 PLNF transplants and 10 677 DSA-negative transplants. Pooled analysis identified no significant difference in the incidence of AR at 1 year [relative risk (RR) = 1.35, 95% confidence interval (CI) 0.90–2.02, Z = 1.46, P = 0.14, I2 = 0%], graft failure at 1 year (RR = 1.66, 95% CI 0.94–2.94, Z = 1.75, P = 0.08, I2 = 23%), graft failure at 5 years (RR = 1.29, 95% CI 0.90–1.87, Z = 1.38, P = 0.17, I2 = 0%), patient mortality at 1 year (RR = 0.89, 95% CI 0.31–2.56, Z = 0.22, P = 0.82, I2 = 0%) and patient mortality at 5 years (RR = 1.76, 95% CI 0.48–6.48, Z = 0.85, P = 0.39, I2 = 61%). Pooled analysis of graft function was not possible due to insufficient data. Current evidence suggests that low-level DSA detected by Luminex alone does not pose significant risk at least in the short–medium term. Considering the shortage of kidney transplants and the ever-increasing waiting time, the avoidance of PLNF transplants may be unwarranted especially in patients who have been enlisted for a long time.

BackgroundReal time ultrasound guided percutaneous kidney biopsy has become the standard procedure to assess the pathology of native kidneys and renal transplants. No specific technique has shown to be totally free of post biopsy bleeding complications. Few Studies have looked at the rates of post biopsy bleeding complications comparing different needle size, post biopsy haematoma size, or clinical predictors of the complication rates. In this study we aim to assess safety and adequacy of the real time ultrasound guided biopsy using free hands (ultrasound-assisted) and ultrasound-guided technique.MethodThe results of 527 elective native and kidney transplant biopsy performed as a day case procedure at Lancashire Teaching Hospitals were retrospectively reviewed (499 native and 28 allograft biopsies). Biopsies were grouped into 4 groups according to the technique and the needle size; group 1 (n = 119; performed by free hands-ultrasound assisted- technique using 14G needle) Group 2 (n = 59; performed by free hands-ultrasound-assisted technique using 16G needle), group 3 (n = 195; performed by ultrasound-guided technique using 14G), and group 4 (n = 154; performed by ultrasound-guided technique using 16G). The 4 groups were matched in age, sex, weight, haemoglobin, serum creatinine, INR, PT, and PTT time.ResultsThe overall tissue specimen was adequate in 80.45 % of the cases, with no difference between group 1 and 3 (81.5 and 80.52 % respectively, p = 0.82) or between group 2 and 4 (86.44 and 77.3 % respectively, p = 0.13). The overall major complications rate was 2.84 %, with no difference between group 1 and 3 (2.5 and 1 % respectively, p = 0.30) or group 2 and 4 (5 and 4.5 % respectively, p = 0.86). The overall minor complications was 3.7 % with no difference between group 2 and 4 (3.3 and 5.84 % respectively, p = 0.46), however, minor complications were higher in group 1 compared to group 3 (5.8 and 1 % respectively, p = 0.01).There was no difference between using 14G and 16G needle size in terms of tissue adequacy(p = 0.7), major complications (p = 0.2 for drop in Hb >10 g/l, p = 0.08 for blood transfusion, p = 0.35 for embolization) or minor complication items(p = 0.4 for drop in Hb, 10 g/l,p = 0.1 for haematuria, p = 0.7 for hematoma).ConclusionWhen using a 14G needle, there is higher risk of minor complications in the free hands-(ultrasound-assisted) technique compared to the ultrasound-guided technique. There is no difference in the rates of major or minor complications between free hand and needle-guided technique using 16G needles. Both techniques showed adequate tissue sampling.