Prospective Evaluation of Fetal Hemoglobin Expression in Maternal Erythrocytes: An Analysis of a Cohort of 345 Parturients.

It is believed that fetal hemoglobin (HbF) expression in adults is largely genetically regulated. The increased expression of HbF in pregnancy has been reported in a small number of articles. Different mechanisms have been proposed, but the description of HbF expression during pregnancy remains unclear. The objectives of this study were to document HbF expression during peri and postpartum periods, confirm its maternal origin, and assess clinical and biochemical parameters potentially associated with HbF modulation. In this observational prospective study, 345 pregnant women were followed. At baseline, 169 had HbF expression (≥1% of total hemoglobin) and 176 did not have HbF expression. Women were followed at the obstetric clinic during their pregnancy. Clinical and biochemical parameters were measured at each visit. Analyses were made to determine which parameters had a significant correlation to HbF expression. Results show that HbF expression of ≥1% during peri and postpartum periods in pregnant women without influencing comorbidities is at its highest peak during the first trimester. In all women, it was proven that HbF was of maternal origin. A significant positive correlation between HbF expression, ßeta-human chorionic gonadotropin (ß-HCG), and glycosylated hemoglobin (HbA1c) was present. A significant negative association between HbF expression and total hemoglobin was found. HbF expression induction during pregnancy is probably associated with an increase in ß-HCG and HbA1C, and a decrease in total hemoglobin, which could temporarily reactivate the fetal erythropoietic system.

Upfront DPYD Genotyping and Toxicity Associated with Fluoropyrimidine-Based Concurrent Chemoradiotherapy for Oropharyngeal Carcinomas: A Work in Progress.

Background: 5-FU-based chemoradiotherapy (CRT) could be associated with severe treatment-related toxicities in patients harboring at-risk DPYD polymorphisms. Methods: The studied population included consecutive patients with locoregionally advanced oropharyngeal carcinoma treated with carboplatin and 5-FU-based CRT one year before and after the implementation of upfront DPYD*2A genotyping. We aimed to determine the effect of DPYD genotyping on grade ≥3 toxicities. Results: 181 patients were analyzed (87 patients before and 94 patients following DPYD*2A screening). Of the patients, 91% (n = 86) were prospectively genotyped for the DPYD*2A allele. Of those screened, 2% (n = 2/87) demonstrated a heterozygous DPYD*2A mutation. Extended genotyping of DPYD*2A-negative patients later allowed for the retrospective identification of six additional patients with alternative DPYD variants (two c.2846A>T and four c.1236G>A mutations). Grade ≥3 toxicities occurred in 71% of the patients before DPYD*2A screening versus 62% following upfront genotyping (p = 0.18). When retrospectively analyzing additional non-DPYD*2A variants, the relative risks for mucositis (RR 2.36 [1.39-2.13], p = 0.0063), dysphagia (RR 2.89 [1.20-5.11], p = 0.019), and aspiration pneumonia (RR 13 [2.42-61.5)], p = 0.00065) were all significantly increased. Conclusion: The DPYD*2A, c.2846A>T, and c.1236G>A polymorphisms are associated with an increased risk of grade ≥3 toxicity to 5-FU. Upfront DPYD genotyping can identify patients in whom 5-FU-related toxicity should be avoided.

A Pan-Canadian Validation Study for the Detection of EGFR T790M Mutation Using Circulating Tumor DNA From Peripheral Blood.

INTRODUCTION: Genotyping circulating tumor DNA (ctDNA) is a promising noninvasive clinical tool to identify the EGFR T790M resistance mutation in patients with advanced NSCLC with resistance to EGFR inhibitors. To facilitate standardization and clinical adoption of ctDNA testing across Canada, we developed a 2-phase multicenter study to standardize T790M mutation detection using plasma ctDNA testing. METHODS: In phase 1, commercial reference standards were distributed to participating clinical laboratories, to use their existing platforms for mutation detection. Baseline performance characteristics were established using known and blinded engineered plasma samples spiked with predetermined concentrations of T790M, L858R, and exon 19 deletion variants. In phase II, peripheral blood collected from local patients with known EGFR activating mutations and progressing on treatment were assayed for the presence of EGFR variants and concordance with a clinically validated test at the reference laboratory. RESULTS: All laboratories in phase 1 detected the variants at 0.5 % and 5.0 % allele frequencies, with no false positives. In phase 2, the concordance with the reference laboratory for detection of both the primary and resistance mutation was high, with next-generation sequencing and droplet digital polymerase chain reaction exhibiting the best overall concordance. Data also suggested that the ability to detect mutations at clinically relevant limits of detection is generally not platform-specific, but rather impacted by laboratory-specific practices. CONCLUSIONS: Discrepancies among sending laboratories using the same assay suggest that laboratory-specific practices may impact performance. In addition, a negative or inconclusive ctDNA test should be followed by tumor testing when possible.

Implementing DPYD*2A Genotyping in Clinical Practice: The Quebec, Canada, Experience.

BACKGROUND: Fluoropyrimidines are used in chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life-threatening toxicities. DPYD*2A polymorphism is one of the most studied variants. The study objective was to document the impact of implementing this test in routine clinical practice. METHODS: We retrospectively performed chart reviews of all patients who tested positive for a heterozygous or homozygous DPYD*2A mutation in samples obtained from patients throughout the province of Quebec, Canada. RESULTS: During a period of 17 months, 2,617 patients were tested: 25 patients tested positive. All were White. Twenty-four of the 25 patients were heterozygous (0.92%), and one was homozygous (0.038%). Data were available for 20 patients: 15 were tested upfront, whereas five were identified after severe toxicities. Of the five patients confirmed after toxicities, all had grade 4 cytopenias, 80% grade ≥3 mucositis, 20% grade 3 rash, and 20% grade 3 diarrhea. Eight patients identified with DPYD*2A mutation prior to treatment received fluoropyrimidine-based chemotherapy at reduced initial doses. The average fluoropyrimidine dose intensity during chemotherapy was 50%. No grade ≥3 toxicities were observed. DPYD*2A test results were available in an average of 6 days, causing no significant delays in treatment initiation. CONCLUSION: Upfront genotyping before fluoropyrimidine-based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. The administration of chemotherapy at reduced doses appears to be safe in patients heterozygous for DPYD*2A. IMPLICATIONS FOR PRACTICE: Fluoropyrimidines are part of chemotherapy combinations for multiple cancers. Deficient dihydropyrimidine dehydrogenase activity can lead to severe life-threatening toxicities. This retrospective analysis demonstrates that upfront genotyping of DPYD before fluoropyrimidine-based treatment is feasible in clinical practice and can prevent severe toxicities and hospitalizations without delaying treatment initiation. This approach was reported previously, but insufficient data concerning its application in real practice are available. This is likely the first reported experience of systematic DPYD genotyping all over Canada and North America as well.

Eosinophilic otitis media diagnosis using flow cytometric immunophenotyping.

OBJECTIVES: (1) To assess the ability of flow cytometric immunophenotyping to detect and quantitate eosinophils in patients with eosinophilic otitis media (EOM). (2) to evaluate the association of EOM to bronchial asthma. METHODS: Twenty-one patients with chronic otorrhea or middle ear effusion (MEE) were included in this prospective cohort study. Group I composed of 10 patients (14 ears) and associated to bronchial asthma. Group II included 11 patients (11 ears) without bronchial asthma. Samples of MEE were sent for flow cytometric analysis at initial presentation. Patients with positive eosinophils on flow cytometric immunophenotyping were analyzed after one-month course of dexamethasone eardrops. RESULTS: EOM was diagnosed in all patients of group I and in three patients of group II. The mean eosinophils percentage was 43.5% and 14.2% for group I and group II, respectively (p = .006). Those patients showed a significant response to dexamethasone eardrops, both on clinical examination and on flow cytometric analysis with a decrease in eosinophil levels post-treatment. However, this improvement was temporary and symptoms recurred after treatment cessation. Bronchial asthma was not associated to all patients with EOM. CONCLUSION: Diagnosis of EOM remained mostly clinical; flow cytometry immunophenotyping of MEE may be helpful as an additional tool in diagnosis and monitoring the response to treatment, particularly in non-asthmatic patients.

Severe agranulocytosis in a patient with metastatic non-small-cell lung cancer treated with nivolumab.

Immune checkpoint inhibitors are novel agents in the process of revolutionising cancer care. These agents have become a very appealing therapeutic alternative since they are much better tolerated than cytotoxic therapy, due to their relatively favorable toxicity profile. However, adverse events associated with these agents usually involve the immune system and can have serious implications jeopardising survival. Herein we report the first case of immune-mediated agranulocytosis due to Nivolumab therapy. The patient suffered from Staphylococcus infection during her agranulocytosis which only responded to high dose corticosteroid therapy.

Mutations in NSCLC and their link with lung cancer-associated thrombosis: a case-control study.

INTRODUCTION: The association of venous thromboembolic events (VTE) and lung cancer is highly prevalent. Additionally, the occurrence of a VTE with cancer has been associated with a worse prognosis and a poor quality of life. Underlying cancer biological features such as tumour mutations may contribute to VTE risk and cancer prognosis. Since preclinical data suggest a link between thrombosis and KRAS mutations in tumours, we aimed to validate this association in a patient registry cohort. METHODS: A retrospective case control study was performed using the CHUM NSCLC registry. Cases had VTE occurring 6months previous to or after a diagnosis of NSCLC. Diagnosis of VTE (venous thrombosis, pulmonary embolism, and migratory superficial thrombophlebitis) was confirmed by a review of the imaging reports. Controls were patients with NSCLC without thrombosis matched for age and stage (I-IIIA/IIIB-IV). Exclusion criteria included insufficient tissue for KRAS/EGFR mutation analysis or insufficient clinical information. RESULTS: Between Jan 2000 and Dec 2009 a total of 57 cases with VTE and 102 controls without VTE were included. The OR for thrombosis in KRAS and EGFR mutated NSCLC patients are respectively 2.67 (1.12-6.42; p=0.014) and 0.99 (0.27-3.48; p=0.99). CONCLUSIONS: KRAS mutation is associated with an increased risk of VTE in this NSCLC cohort. These findings are consistent with preclinical studies. Prospective data on VTE rates from clinical trials with molecularly defined NSCLC are needed to confirm these findings.

Prevalence of K-RAS Codons 12 and 13 Mutations in Locally Advanced Head and Neck Squamous Cell Carcinoma and Impact on Clinical Outcomes.

Background. RAS gene mutations have an impact on treatment response and overall prognosis for certain types of cancer. Objectives. To determine the prevalence and impact of K-RAS codons 12 and 13 mutations in patients with locally advanced HNSCC treated with primary or adjuvant chemo-radiation. Methods. 428 consecutive patients were treated with chemo-radiation therapy and followed for a median of 37 months. From these, 199 paraffin embedded biopsy or surgical specimens were retrieved. DNA was isolated and analyzed for K-RAS mutational status. Results. DNA extraction was successful in 197 samples. Of the 197 specimens, 3.5% presented K-RAS codon 12 mutations. For mutated cases and non-mutated cases, complete initial response to chemoradiation therapy was 71 and 73% (P = 0.32). LRC was respectively 32 and 83% (P = 0.03), DFS was 27 and 68% (P = 0.12), distant metastasis-free survival was 100 and 81% (P = 0.30) and OS was 57 and 65% (P = 0.14) at three years. K-Ras codon 13 analysis revealed no mutation. Conclusion. K-RAS codon 12 mutational status, although not associated with a difference in response rate, may influence the failure pattern and the type of therapy offered to patients with HNSCC. Our study did not reveal any mutation of K-RAS codon 13.

A new insertion mutation in the beta-globin gene [codons 45/46 (+A)] resulting in a beta-thalassemia minor phenotype.

The beta-globin gene of 306 newly diagnosed beta-thalassemia (thal) minor patients were sequenced. Analysis revealed that only one amongst all the identified mutations had not been previously reported. This new mutation, causing a beta(+)-thal minor phenotype, was found in a patient of Arabic origin. The insertion frameshift mutation (+A) between codons 45 and 46 [codons 45/46 (+A)] results in a premature termination signal at codon 52. No truncated beta-globin or abnormal hemoglobin (Hb) was identified.

Prevalence of alpha-globin gene deletions among patients with unexplained microcytosis in a North-American population.

Increasing multi-ethnicity is likely to make alpha-thalassemia (alpha-thal) more prevalent in Western metropolitan areas. Multiplex polymerase chain reaction (m-PCR) allows rapid and precise identification of most of alpha-thal carriers. With this method, we sought to determine the prevalence of alpha-thal and the corresponding genotype, among all non repetitive consecutive blood samples that had an unexplained microcytosis. These specimens had been sent to the hematology laboratory for a blood count analysis, found to be microcytic, and secondarily tested for ferritin level and hemoglobin (Hb) high performance liquid chromatography (HPLC) profile. Five hundred and sixteen microcytic blood samples were evaluated and 197 samples with normal ferritin and Hb HPLC were studied by m-PCR. Among 196 interpretable PCRs, 48 alpha-thal cases (24.5%) were identified: 28 with a single alpha-globin gene deletion and 20 with two alpha-globin gene deletions. Of these 20 cases, six showed two deletions in cis. None of the erythrocytic parameters studied predicted the presence of alpha-thal deletions. We conclude that a significant proportion (24.5%) of blood counts with microcytosis not explained by an iron deficiency, an inflammatory state or an abnormal Hb on HPLC, are caused by an alpha-globin gene deletion. The pertinence of genetic counseling for alpha-thal based on molecular diagnosis should be evaluated more formally in urban centers where this genetic condition is likely to have an increasing prevalence and clinical relevance.

CD4+ T cells from CD4C/HIVNef transgenic mice show enhanced activation in vivo with impaired proliferation in vitro but are dispensable for the development of a severe AIDS-like organ disease.

The cellular and molecular mechanisms of dysfunction and depletion of CD4+ T lymphocytes over the course of human immunodeficiency virus type 1 (HIV-1) infection are still incompletely understood, but chronic immune activation is thought to play an important role in disease progression. We studied CD4+ T-cell biology in CD4C/HIV transgenic (Tg) mice, in which Nef expression is sufficient to induce a severe AIDS-like disease including a preferential decrease of CD4+ T cells. We show here that Nef-expressing Tg CD4+ T cells exhibit an activated/memory-like phenotype which appears to be independent of antigenic stimulation, as documented in experiments involving breeding with AD10 TcR Tg mice. In addition, in vivo bromodeoxyuridine incorporation showed that a larger proportion of Tg than non-Tg CD4+ T cells entered the S phase. However, in vitro, Tg CD4+ T cells were found to have a very limited capacity to divide in response to stimulation with anti-CD3 and anti-CD28 or in allogeneic mixed leukocyte reactions. Interestingly, despite these observations, the deletion of Tg CD4+ T cells had little impact on the development of other AIDS-like organ phenotypes. Thus, the Nef-induced chronic activation of CD4+ T cells may exhaust the T-cell pool and may contribute to the thymic atrophy and the low number of CD4+ T cells observed in these Tg mice.

The AIDS-like disease of CD4C/human immunodeficiency virus transgenic mice is associated with accumulation of immature CD11bHi dendritic cells.

CD4C/human immunodeficiency virus (HIV) transgenic mice develop an AIDS-like disease. We used this model to study the effects of HIV-1 on dendritic cells (DC). We found a progressive decrease in total DC numbers in the lymph nodes, with a significant accumulation of CD11b(Hi) DC. In the thymus, the recovery of transgenic CD8alpha(+) DC had a tendency to be lower. Spleen DC were augmented in the marginal zone. Transgenic DC showed a decreased capacity to present antigen in vitro, consistent with their reduced major histocompatibility complex class II expression and impaired maturation profile. The accumulation of immature DC may contribute to disease and may reflect an adaptive advantage for the virus by favoring its replication and preventing the generation of fully functional antiviral responses.