Measurement of BCR-ABL1 by RT-qPCR in chronic myeloid leukaemia: findings from an International EQA Programme.

Sequential measurement of BCR-ABL1 mRNA levels by reverse transcription quantitative polymerase chain reaction (RT-qPCR) is embedded in the management of patients with chronic myeloid leukaemia (CML), and has played an important role in the remarkable improvement in patient outcomes seen in this disease. As a provider of external quality assessment (EQA) in this area, UK NEQAS for Leucocyte Immunophenotyping (UKNEQAS LI) has a unique perspective on the changing face of BCR-ABL1 testing in CML. To assess the impact of technical standardisation and the development of the International Scale (IS) upon the accuracy of BCR-ABL1 testing, we reviewed EQA trial data from 2007 to 2015. Comparison of participant results identified considerable variability at both high and low levels of disease, including therapeutically important decision points; however, results converted to the IS showed less variability compared to unconverted data sets. We also found that different methods of converting to the IS produce consistently different median results within UKNEQAS LI IS data sets. This data suggests that whilst the development of the IS has improved the comparability of results between centres, there is still the need for further improvement in the processes of converting raw results to the IS in order to fully realise the benefits of molecular monitoring of CML.

Assessment of acute myeloid leukemia molecular measurable residual disease testing in an interlaboratory study.

The European LeukaemiaNet (ELN) measurable residual disease (MRD) working group has published consensus guidelines to standardize molecular genetic MRD testing of the t(8;21)(q22;q22.1) RUNX1::RUNX1T1, inv(16)(p13.1q22) CBFB::MYH11, t(15;17)(q24.1;q21.2) PML::RARA, and NPM1 type A markers. A study featuring 29 international laboratories was performed to assess interlaboratory variation in testing and the subsequent interpretation of results, both crucial to patient safety. Most participants in this study were able to detect, accurately quantify, and correctly interpret MRD testing results, with a level of proficiency expected from a clinical trial or standard-of-care setting. However, a few testing and interpretive errors were identified that, in a patient setting, would have led to misclassification of patient outcomes and inappropriate treatment pathways being followed. Of note, a high proportion of participants reported false-positive results in the NPM1 marker-negative sample. False-positive results may have clinical consequences, committing patients to unneeded additional chemotherapy and/or transplant with the attendant risk of morbidity and mortality, which therefore highlights the need for ongoing external quality assessment/proficiency testing in this area. Most errors identified in the study were related to the interpretation of results. It was noted that the ELN guidance lacks clarity for certain clinical scenarios and highlights the requirement for urgent revision of the guidelines to elucidate these issues and related educational efforts around the revisions to ensure effective dissemination.

Genetic testing in the assessment of living related kidney donors at risk of autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of renal failure. In most patients who develop end-stage renal disease, transplantation is the renal replacement modality of choice. For living related kidney donation (LRKD), the major challenge is to exclude the diagnosis of ADPKD in potential donors. Renal imaging may not exclude ADPKD particularly in younger donors and molecular genetic testing is advised. We report the largest series to date evaluating the role of genetic testing for ADPKD in LRKD assessment. METHODS: A cohort of patients with ADPKD and potential LRKD were referred for genetic testing for ADPKD between April 2010 and October 2012. DNA sequencing of PKD1 and PKD2 was performed. Imaging investigations and transplant outcomes after genetic testing were collected. RESULTS: Nineteen patients and 25 potential LRKD underwent genetic testing. Of potential LRKD, one tested positive for ADPKD and one with a diagnostic ultrasound tested negative. Despite negative genetic testing, two potential LRKD were considered unsuitable because of the detection of stage I ("simple") renal cysts on computed tomography. Four living related kidney transplants have occurred, and two are planned. Three patients subsequently refused the donation as the potential donor was a child. CONCLUSION: Predictive genetic testing can facilitate donor evaluation and augment living related kidney transplantation in ADPKD. Psychologic challenges associated with accepting an LRKD require careful consideration during recipient assessment. The acceptability of using a kidney with cysts from a mutation-negative donor should be evaluated by a multidisciplinary team.