Search

From early 2020, a high demand for SARS-CoV-2 tests was driven by several testing indications, including asymptomatic cases, resulting in the massive roll-out of PCR assays to combat the pandemic. Considering the dynamic of viral shedding during the course of infection, the demand to report cycle threshold (Ct) values rapidly emerged. As Ct values can be affected by a number of factors, we considered that harmonization of semi-quantitative PCR results across laboratories would avoid potential divergent interpretations, particularly in the absence of clinical or serological information. A proposal to harmonize reporting of test results was drafted by the National Reference Centre (NRC) UZ/KU Leuven, distinguishing four categories of positivity based on RNA copies/mL. Pre-quantified control material was shipped to 124 laboratories with instructions to setup a standard curve to define thresholds per assay. For each assay, the mean Ct value and corresponding standard deviation was calculated per target gene, for the three concentrations (10 7 , 10 5 and 10 3 copies/mL) that determine the classification. The results of 17 assays are summarized. This harmonization effort allowed to ensure that all Belgian laboratories would report positive PCR results in the same semi-quantitative manner to clinicians and to the national database which feeds contact tracing interventions.

Background: Hemolytic disease of the fetus and newborn (HDFN) due to rhesus D (RhD) immunization is a potentially life-threatening situation for which use of Rh Immunoglobulin (RhIg) has decreased risk drastically. Determination of fetal RHD on maternal plasma can be used to restrict prenatal RhIg administration to women carrying an RhD-positive child, avoiding unnecessary administration of blood-derived products., Study Design and Methods: The aim of this study is to determine the performance of fetal RHD typing in our center. We prospectively collected 205 fetal RHD and 127 serological cord blood RhD data from RhD-negative women starting at 11 weeks of pregnancy (from October 2019 to October 2021). Real-time polymerase chain reaction targeting RHD exon 5 and 7 was used, similar to the screening program in The Netherlands, supplemented with an amplification control (beta-actin; ACTB) and a sex determination marker located on the Y-chromosome (SRY gene)., Results: Fetal RHD testing reached a sensitivity and specificity of 100%. No false-negative nor false-positive results were reported. Inconclusive results (6%, 13/205) were due to weak amplification in 10 cases, a maternal RHD variant in 2 cases (RHD*01N.71 and partial DVI), and a fetal RHD variant (partial DVI) in 1 case. Unnecessary administration of RhIg prophylaxis was avoided in 33% of cases and on the other hand was administered in one case (fetal partial DVI) which would have been missed with cord blood serology., Discussion: This study demonstrates the high accuracy of routine prenatal fetal RHD gene screening after 11 weeks of pregnancy, encouraging routine clinical practice., (© 2022 AABB.)

Molecular diagnostic testing has become an important tool in clinical laboratories. Accreditation according to the international quality standard ISO15189:2007 for medical laboratories is required for reimbursement of several molecular diagnostic tests in Belgium. Since the ISO15189:2007 standard applies to medical laboratories in general, the particular requirements for quality and competence are mentioned in general terms, not taking into account the specificities of molecular biology testing. Therefore, the working group "MolecularDiagnostics.be" described a consensus interpretation of chapter 5, Technical requirements, of the ISO standard for application in molecular diagnostic laboratories. The manuscript can be used as an instrument to prepare internal and external audits that meet the 15015189:2007 (chapter 5) criteria.

This paper summarizes the minimal workout of chronic lymphoproliferative disorders in a routine laboratory of haematology as recommended by a team of experienced laboratory supervisors in Belgium, taking into account the specific organisation of healthcare in Belgium, the innovations in the field of molecular analyses and related reimbursement. The starting point was essentially based upon clinical and/or haematological indications and it is emphasized that conclusions should be drawn in close dialogue with the clinician and experts in cytogenetics and histopathology. Reports made in the laboratory should be based upon an integration of cytomorphological, immunophenotypical and molecular data. These guidelines are not intended to be used as universal 'diagnostic pathways', but should be useful in developing local diagnostic pathways. It is well understood that this consensus, being valid anno 2009, may rapidly change with new technologies being introduced and new targets discovered.