Prenatal typing of Rh and Kell blood group system antigens: the edge of a watershed

Knowledge of the molecular basis of the blood group systems has enabled the development of assays for blood group genotyping. At this time, polymerase chain reaction (PCR)-based assays validated on fetal material obtained by invasive means (chorionic villus sampling or amniocentesis) are available for all clinically relevant fetal blood groups, However, only Rh typing (D, C, c, E, and e) and K1 genotyping assays are discussed in this review. Importantly, one must remember that results of genotyping assays will not always be concordant with serological typing. Thus, the RhD genotyping assays have to be modified in response to increased understanding of the molecular biology of this blood group system. RhD typing assays should produce negative results when tested on the black RhD-negative RHD alleles, RHDpsi and r's. PCR-based assays can be used to determine paternal zygosity. For RhD zygosity testing, the real-time quantitative PCR approach and the direct detection of the hybrid Rhesus box, which is the result of the deletion of the RHD gene are available. Recently, methods for noninvasive prenatal genotyping have been investigated. The use of fetal cells circulating in the maternal circulation has been explored; however, the scarcity of circulating fetal cells has limited the use of this approach. More promising are the results obtained with RhD typing assays with cell-free fetal DNA, which is present in the maternal circulation in a concentration of 25 genomic equivalents per milliliter of maternal blood in early pregnancy increasing to 100 copies per milliliter in the third trimester, which is cleared from the circulation within a few hours of delivery. The positive predictive value of this approach is virtually 100%, but false-negative results are (infrequently) encountered. Therefore, this assay can at present only be used for screening of RhD-negative women to make the use of antenatal prophylaxis more targeted and hence more cost-effective. For the clinical management of the pregnancies of alloimmunized women, the development of a control for the presence and the amplification of fetal DNA is needed, which is at present only available in male pregnancies. Assays for the genotyping of the other Rh antigens or Kell antigens with cell-free fetal DNA have not yet been described.     

First‐line therapy for chronic lymphocytic leukemia in patients older than 79 years is feasible and achieves good results: A FILO retrospective study

The mean age at diagnosis of chronic lymphocytic leukemia (CLL) is 72 years, with 22.8% of patients being older than 80 years. However, the elderly are underrepresented in clinical studies of CLL. We performed a retrospective study of CLL patients aged 80 years or older at the initiation of first‐line therapy in hospitals affiliated with the French intergroup on CLL (French Innovative Leukemia Organization) between 2003 and 2013. Here, we describe the clinical and biological characteristics, treatment, and outcomes for 201 patients. The median age of the cohort was 83.2 years (80–92 years). The median Cumulative Index Rating Scale comorbidity score was 5 and the median creatinine clearance was 48 mL/min (Cockcroft‐Gault formula). At treatment initiation, Binet stage was A (26.4%), B (27.9%), or C (40.3%). Therapy consisted mainly of chlorambucil (65.7%), bendamustine (10.5%), and rituximab (44.3%) as follows: chlorambucil alone (45.3%) or immunochemotherapy (48.3%) with rituximab + chlorambucil (22.7%), rituximab + bendamustine (10.4%), or rituximab + cyclophosphamide + dexamethasone (5.5%). The overall response rate was 66.2% with 31.8% clinical complete remission. The median overall and progression‐free survival from treatment initiation was 53.7 and 18.3 months, respectively. These results suggest that treatment is feasible in this age group, even with immunochemotherapy. Thus, prospective trials should target this population and oncogeriatric evaluation and new targeted therapies should be part of such future trials.     

RIPOR2: A new gene of non-syndromic cochleovestibular dysfunction,discrepancy between human pathology and animal models

Cochleovestibular dysfunctions are rare conditions misrecognized. A homozygous pathogenic variation c.1561C > T (p.Arg521*) in RIPOR2 (RHO family interacting cell polarization regulator 2) has been identified by WES in Tunisian siblings suffering from congenital bilateral profound hearing and vestibular dysfunctions. In contrast to the vestibular areflexia observed in our patients, deaf Ripor2 KO mouse model and our zebrafish model have normal vestibular function.     

Tumor biology,biomarkers, and liquid biopsy in pediatric renal tumors

The expansion of knowledge regarding driver mutations for Wilms tumor (WT) and malignant rhabdoid tumor of the kidney (MRT) and various translocations for other pediatric renal tumors opens up new possibilities for diagnosis and treatment. In addition, there are growing data surrounding prognostic factors that can be used to stratify WT treatment to improve outcomes. Here, we review the molecular landscape of WT and other pediatric renal tumors as well as WT prognostic factors. We also review incorporation of circulating tumor DNA/liquid biopsies to leverage this molecular landscape, with potential use in the future for distinguishing renal tumors at the time of diagnosis and elucidating intratumor heterogeneity, which is not well evaluated with standard biopsies. Incorporation of liquid biopsies will require longitudinal collection of multiple biospecimens. Further preclinical research, identification and validation of biomarkers, molecular studies, and data sharing among investigators are crucial to inform therapeutic strategies that improve patient outcomes.     

Optimising urinary catecholamine metabolite diagnostics for neuroblastoma

Introduction

The analysis of urinary catecholamine metabolites is a cornerstone of neuroblastoma diagnostics. Currently, there is no consensus regarding the sampling method, and variable combinations of catecholamine metabolites are being used. We investigated if spot urine samples can be reliably used for analysis of a panel of catecholamine metabolites for the diagnosis of neuroblastoma.

Methods

Twenty-four-hour urine or spot urine samples were collected from patients with and without neuroblastoma at diagnosis. Homovanillic acid (HVA), vanillylmandelic acid (VMA), dopamine, 3-methoxytyramine, norepinephrine, normetanephrine, epinephrine and metanephrine were measured by high-performance liquid chromatography coupled with fluorescence detection (HPLC-FD) and/or ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (UPLC-MS/MS).

Results

Catecholamine metabolite levels were measured in urine samples of 400 neuroblastoma patients (24-hour urine, n = 234; spot urine, n = 166) and 571 controls (all spot urine). Excretion levels of catecholamine metabolites and the diagnostic sensitivity for each metabolite were similar in 24-hour urine and spot urine samples (p > .08 and >.27 for all metabolites). The area under the receiver-operating-characteristic curve (AUC) of the panel containing all eight catecholamine metabolites was significantly higher compared to that of only HVA and VMA (AUC = 0.952 vs. 0.920, p = .02). No differences were observed in metabolite levels between the two analysis methods.

Conclusion

Catecholamine metabolites in spot urine and 24-hour urine resulted in similar diagnostic sensitivities. The Catecholamine Working Group recommends the implementation of spot urine as standard of care. The panel of eight catecholamine metabolites has superior diagnostic accuracy over VMA and HVA.     

Two-year trajectories of COVID-19 symptoms and their association with illness perception: A prospective cohort study in Amsterdam,the Netherlands

Background

We used data from a prospective cohort to explore 2-year trajectories of ‘long COVID’ (persistent symptoms after SARS-CoV-2 infection) and their association with illness perception.

Methods

RECoVERED participants (adults; prospectively enrolled following laboratory-confirmed SARS-CoV-2 infection, May 2020–June 2021) completed symptom questionnaires at months 2–12, 18 and 24, and the Brief Illness Perception Questionnaire (B-IPQ) at months 1, 6 and 12. Using group-based trajectory models (GBTM), we modelled symptoms (mean total numbers and proportion with four specific complaints), including age, sex, BMI and timing of infection as covariates. In a multivariable linear mixed-effects model, we assessed the association between symptom trajectories and repeated B-IPQ scores.

Results

Among 292 participants (42% female; median age 51 [IQR = 36–62]), four trajectories were identified, ranging from Trajectory 4 (8.9%; 6 + symptoms) to Trajectory 1 (24.8%; no symptoms). The occurrence of fatigue and myalgia increased among 23% and 12% of participants, respectively. Individuals in Trajectory 4 experienced more negative adjusted B-IPQ scores over time than those in Trajectories 1–3.

Conclusions

We observed little fluctuation in the total number of symptoms, but individual symptoms may develop as others resolve. Reporting a greater number of symptoms was congruent with more negative illness perception over time.