What do we need to do to make protocol biopsies standard of care or should we discontinue doing?

Yield and utility of surveillance kidney biopsies in pediatric kidney transplant recipients at various time points post-transplant

BACKGROUND

Due to a lack of consensus on SB for pediatric kidney transplant recipients, we evaluated the yield and clinical utility of SB findings at various time points post-transplant.

METHODS

Patients transplanted at a single institution between 2014 and 2020 with at least one SB at 1.5, 3, 6, 12, and 24 months post-transplant were included. Additional biopsies were done for indication (IB). TCMR was classified by Banff criteria (score ≥i1t1).

RESULTS

Forty-seven patients had 142 biopsies (SB = 113, IB = 29); 19 (40.4%) of whom experienced at least one TCMR episode in the first-year post-transplant. The greatest SB yield of any pathologic abnormality was at 6 months (57.1%; P < .001). Six months also had the highest yield for TCMR (42.9%), compared with 3.3%, 20.8%, 15.0%, and 9.1% at 1.5, 3, 12 months, and 24 months, respectively (P = .003). SB instigated intensification of immunosuppression (28.3% cases), reduction of immunosuppression (2.7% cases), and other non-immunosuppressant changes (1.8% cases). The 6-month SB led to the greatest number of changes in management (53.6%), compared with 1.5, 3, 12, and 24 months (13.3, 20.8, 25.0, and 36.4%, respectively; P = .012). There were no major biopsy-related complications.

CONCLUSIONS

SBs identify an important burden of subclinical rejection and other pathology leading to changes in clinical management. The greatest yield was at 6 months, whereas the least utility was at the 1.5 months. Selection of SB timing may be tailored such that the optimal yield is balanced against the procedural risk.

Pediatric Kidney Transplantation in Perú: A Single-Center Initial Experience

BACKGROUND

Pediatric kidney transplantation (PKTx) is the preferred therapy for children with end-stage renal disease (ESRD) worldwide. Regrettably, in Perú, access to PKTx is extremely difficult due to recipient/donor socio-economic status, health care structure and especially, scarcity of organs. Our center (the only pediatric institute in the country) has recently started a PKTx program with good midterm results. The aim of this study was to present our outcomes.

METHODS

Retrospective analysis of prospectively collected data between December 2017 and August 2019. Fourteen PKTx (< 18 years old) were achieved. As per our protocol: pre-implantation/protocol biopsies, antibody assessment (T/B cell flow cytometric plus HLA testing applying polymerase chain reaction-based technology), triple immunosuppression (tacrolimus, mycophenolate mofetil, steroids) and induction therapy was performed in every case.

RESULTS

The recipient's mean age at the time of PKTx was 14.14 ± 2.62, 8/14 (57.14%) were male, 50% developed ESRD due to undetermined etiology, 11/14 (78.57%) received a deceased donor allograft, and 9/14 (64.28%) required induction with thymoglobulin. Postoperative complications included: delayed graft function (1/14, 7.14%), 1 (7.14%) developed gross hematuria associated with allograft disfunction post-protocol allograft biopsy that was managed conservatively and 1 recipient (7.14%) developed grade II oligoastrocytoma, at 10 months post PKTx.

CONCLUSIONS

PKTx is the best therapeutic option for children with ESRD. Our group demonstrated that even in countries with limited resources like Perú, good midterm results can be achieved. Emphasis should be given to improve access to transplantation especially in the setting of pediatric recipients.

Safety of dry needling to the upper lumbar spine: a pilot cadaver study

Objective: When inserting a dry needle laterally into the upper lumbar spine (L1-L3) there is an increased risk of piercing the kidney; therefore, the objective of this study was to determine a zone of safety for practitioners to needle in the upper lumbar spine.Methods: Ten cadavers were screened for inclusion. L1 spinous process was identified and confirmed with ultrasound imaging. A digital caliper was used to measure laterally at 1.5 cm, 2.0 cm, and 2.5 cm. Dry needles were inserted maximally at each point and a binary decision, yes or no, was made to determine if bony contact was made. Needle depth and abdominal width measurements were also recorded. Safety of the dry needling procedure was interpreted as such if bony contact was made by the needle. If bony contact was made, then it was assumed that the needle cannot advance further into pleura or kidney.Results: Forty-four percent of needles did not make bony contact at 2.5 cm lateral of the L1 spinous process, whereas 22% did not make bony contact at 1.5 cm and 2.0 cm. There was a weak to moderate negative correlation between abdominal width measurements and needle depth at 1.5 cm (-0.48) and 2.0 cm (-0.45), and at 2.5 cm (-0.39).Conclusion: A safety zone of needling less than 2.5 cm is likely safe, but needs to be confirmed with future study. Dry needling 2.5 cm lateral appears more risky due to the higher frequency of not contacting a bony backdrop.

Protocol biopsies in pediatric renal transplantation: a precious tool for clinical management

BACKGROUND

Kidney transplantation is the best treatment for children with end-stage kidney disease. Early results have improved, but late graft loss is still a major problem. Non-invasive, fully reliable early biomarkers of acute rejection are currently missing.

METHODS

Our aim was to evaluate the efficacy of protocol biopsies (PBXs) in a pediatric population. During 11 years, 209 renal transplantations were performed in 204 pediatric patients. Biopsies were performed 3-6 months, 1 year, and 5 years after transplantation. Procedure-related complications were systematically looked for by means of ultrasound scans.

RESULTS

Unexpected findings (mainly subclinical rejections) requiring therapeutic intervention were found in 19.3% biopsies performed at 3-6 months, in 18.4% in 12-month biopsies and in none of those performed after 5 years. The 13.6% patients at 12-month biopsies and 23.6% at 5-year biopsies showed calcineurin inhibitor (CNI) toxicity. Interstitial fibrosis and tubular atrophy (IF/TA) was found in 17.6 and 83.6% of patients at 12-month and 5-year biopsies, respectively. Complications of the PBX were infrequent. Five-year estimated glomerular filtration rate (GFR) was not significantly different in patients who received treatment for any cause and patients with normal histology.

CONCLUSIONS

Although we do not have a control group, we may speculate that patients who received treatment returned to a "standard" condition possibly improving final outcome. Protocol biopsies are a powerful diagnostic tool for the management of pediatric renal transplant recipients. In view of the lack of evidence that biopsies taken 5 years after transplantation lead to any therapeutic change, their use should be reconsidered.

Safety and utility of surveillance biopsies in pediatric kidney transplant patients

There is currently no way to diagnose a rejection before a change in serum creatinine. This had led some to start doing SB, but little data exist on the utility and safety of SB in pediatric patients. There is also little known on practice patterns of pediatric nephrologists. A retrospective review of pediatric kidney transplant SB between January 2013 and January 2017 at a single center was performed. A survey went to the PedNeph email list. There were 47 SB; 15 at 6 months, 12 at 1 year, 13 at 2 years, and 7 at 3 years. There were 3 minor (1 gross hematuria and 2 hematomas) and no major complications. On 6-month SB, 1 had SC 1A ACR (6.7%) with no BR ACR. On the 12-month SB, there were 5 with SCBR ACR (41.7%) and 1 with SC AMR (8.3%). On the 2-year SB, there were 4 that had SCBR ACR (30.8%), and 1 with SC AMR (7.7%). On the 3-year SB, 1 had chronic transplant glomerulitis (14.3%). The survey showed that 34.3% of pediatric nephrologists perform SB. SB can be performed safely. By early identification of histological lesions, SB gives us an opportunity for individualized immunosuppressive regimens that may prevent chronic allograft dysfunction and improve long-term graft outcome.

Surveillance biopsies in children post-kidney transplant

Surveillance biopsies are increasingly used in the post-transplant monitoring of pediatric renal allograft recipients. The main justification for this procedure is to diagnose early and presumably modifiable acute and chronic renal allograft injury. Pediatric recipients are theoretically at increased risk for subclinical renal allograft injury due to their relatively large adult-sized kidneys and their higher degree of immunological responsiveness. The safety profile of this procedure has been well investigated. Patient morbidity is low, with macroscopic hematuria being the most common adverse event. No patient deaths have been attributed to this procedure. Longitudinal surveillance biopsy studies have revealed a substantial burden of subclinical immunological and non-immunological injury, including acute cellular rejection, interstitial fibrosis and tubular atrophy, microvascular lesions and transplant glomerulopathy. The main impediment to the implementation of surveillance biopsies as the standard of care is the lack of demonstrable benefit of early histological detection on long-term outcome. The considerable debate surrounding this issue highlights the need for multicenter, prospective, and randomized studies.