Improve in-depth immunological risk assessment to optimize genetic-compatibility and clinical outcomes in child and adolescent recipients of parental donor kidney transplants: protocol for the INCEPTION study.

BACKGROUND: Parental donor kidney transplantation is the most common treatment option for children and adolescents with kidney failure. Emerging data from observational studies have reported improved short- and medium-term allograft outcomes in recipients of paternal compared to maternal donors. The INCEPTION study aims to identify potential differences in immunological compatibility between maternal and paternal donor kidneys and ascertain how this affects kidney allograft outcomes in children and adolescents with kidney failure. METHODS: This longitudinal observational study will recruit kidney transplant recipients aged ≤18 years who have received a parental donor kidney transplant across 4 countries (Australia, New Zealand, United Kingdom and the Netherlands) between 1990 and 2020. High resolution human leukocyte antigen (HLA) typing of both recipients and corresponding parental donors will be undertaken, to provide an in-depth assessment of immunological compatibility. The primary outcome is a composite of de novo donor-specific anti-HLA antibody (DSA), biopsy-proven acute rejection or allograft loss up to 60-months post-transplantation. Secondary outcomes are de novo DSA, biopsy-proven acute rejection, acute or chronic antibody mediated rejection or Chronic Allograft Damage Index (CADI) score of > 1 on allograft biopsy post-transplant, allograft function, proteinuria and allograft loss. Using principal component analysis and Cox proportional hazards regression modelling, we will determine the associations between defined sets of immunological and clinical parameters that may identify risk stratification for the primary and secondary outcome measures among young people accepting a parental donor kidney for transplantation. This study design will allow us to specifically investigate the relative importance of accepting a maternal compared to paternal donor, for families deciding on the best option for donation. DISCUSSION: The INCEPTION study findings will explore potentially differential immunological risks of maternal and paternal donor kidneys for transplantation among children and adolescents. Our study will provide the evidence base underpinning the selection of parental donor in order to achieve the best projected long-term kidney transplant and overall health outcomes for children and adolescents, a recognized vulnerable population. TRIAL REGISTRATION: The INCEPTION study has been registered with the Australian New Zealand Clinical Trials Registry, with the trial registration number of ACTRN12620000911998 (14th September 2020).

LUEGO: a cost and time saving gel shift procedure.

We developed a new approach to prepare DNA probes for electrophoretic mobility gel shift assays that presents a number of advantages compared with the classical approach. The method relies on two complementary oligonucleotides containing the desired transcription factor binding sequence, one of them being extended at its 3' end with a universal tail that complements a third, short oligonucleotide labeled with a fluorophore or any other label. The use of this third "universal" oligonucleotide allows labeling many different probes with minimal time, effort and cost. We show that probes prepared this way are as effective and reliable as probes prepared by conventional methods. We refer to this short oligonucleotide as LUEGO for labeled universal electrophoretic gel shift oligonucleotide.

Radiographic assessment of segmental motion at the atlantoaxial junction in the Klippel-Feil patient.

STUDY DESIGN: A retrospective review of 33 consecutive Klippel-Feil syndrome (KFS) patients at a single institution. OBJECTIVES: To assess in KFS patients the presence and degree of radiographic segmental motion at the atlantoaxial junction, factors contributing to such motion, and associated clinical manifestations. SUMMARY OF BACKGROUND DATA: Studies suggest that abnormal segmentation in KFS patients may result in cervical hypermobility, increasing the risk of developing neurologic compromise and the need for surgical intervention. The use of the anterior and posterior atlantodens interval (AADI/PADI) has gained interest as a method for assessing atlantoaxial instability and for space available for the cord. Although helpful for identifying instability after trauma, these measurements are not understood in KFS patients. In addition, the effects of the fusion process associated with KFS on atlantoaxial motion and associated clinical findings have not been properly addressed. METHODS: Radiographs were analyzed for the presence of occipitalization, number/location of congenitally fused segments, and the AADI and PADI. RESULTS: There were 15 males and 18 females (mean age, 13.9 years). Occipitalization occurred in 48.5% of patients. A fused C2-C3 segment was noted in 72.7% of cases. More motion with respect to AADI was evident on O-C1 and C2-C3 fusion only patients, which were all asymptomatic. Overall, 24.2% of patients were symptomatic. Mean AADI and PADI difference was 2.0 mm (symptomatic: mean, 1.5 mm; asymptomatic: mean, 2.1 mm) and -1.7 mm (symptomatic: mean, -1.0 mm; asymptomatic: mean, -2.0 mm), respectively (P > 0.05). CONCLUSIONS: Hypermobility of the atlantoaxial junction, as indicated by increased AADI on flexion-extension radiographs, is not necessarily associated with an increased risk for the development of symptoms or neurologic signs in the KFS patient. Occipitalization plays an integral role in the degree of motion at the atlantoaxial region. Greatest AADI values were in patients with occipitalization and a fused C2-C3 segment. The presence of symptoms was not related to the degree of AADI change. Evaluation of the PADI provides additional information for identifying patients at risk for developing symptoms. Nonetheless, KFS patients remain largely asymptomatic.