Hematopoiesis and immune reconstitution after CD19 directed chimeric antigen receptor T-cells (CAR-T): A comprehensive review on incidence, risk factors and current management.

Impaired function of hematopoiesis after treatment with chimeric antigen T-cells (CAR-T) is a frequent finding and can interest a wide range of patients, regardless of age and underlying disease. Trilinear cytopenias, as well as hypogammaglobulinemia, B-cell aplasia, and T-cell impairment, can severely affect the infectious risk of CAR-T recipients, as well as their quality of life. In this review, we provide an overview of defects in hematopoiesis after CAR-T, starting with a summary of different definitions and thresholds. We then move to summarize the main pathogenetic mechanisms of cytopenias, and we offer insight into cytomorphological aspects, the role of clonal hematopoiesis, and the risk of secondary myeloid malignancies. Subsequently, we expose the major findings and reports on T-cell and B-cell quantitative and functional impairment after CAR-T. Finally, we provide an overview of current recommendations and leading experiences regarding the management of cytopenias and defective B- and T-cell function.

Quality control initiative on the evaluation of the dysmegakaryopoiesis in myeloid neoplasms: Difficulties in the assessment of dysplasia.

Evaluation of megakaryocyte morphology is difficult but can be essential for the diagnosis of myelodysplastic syndromes (MDS) and other myeloid neoplasms. We agreed upon descriptions and provided images of megakaryoblasts and of normal and dysplastic megakaryocytes, which were used as a basis for assessing the concordance of expert morphologists in their recognition. We showed a high rate of concordance for the recognition of micromegakaryocytes and confirmed their strong association with hematologic neoplasia, including MDS. Concordance was also found to be good for the recognition of multinucleated megakaryocytes, which showed a significant association with MDS. However cytoplasmic abnormalities were found not to be useful in MDS recognition. The occurrence of appreciable numbers of nonlobulated and hypolobulated megakaryocytes in individuals without a myeloid neoplasm was confirmed. We demonstrated that subjects without a myeloid neoplasm can have some megakaryocytes that are assessed as 'dysplastic' or 'possibly dysplastic' and that to avoid over diagnosis of dysplasia, 'possibly dysplastic' forms should be excluded from the count of dysplastic cells. Our results demonstrate that the nature as well as the presence of megakaryocyte dysplasia is important in the diagnosis of MDS; although evaluation of 30 megakaryocytes is strongly recommended, it may be possible to recognize diagnostically important dysplasia when fewer megakaryocytes are present but highly diagnostic forms are seen.

Exhaled and non-exhaled non-invasive markers for assessment of respiratory inflammation in patients with stable COPD and healthy smokers.

We aimed at comparing exhaled and non-exhaled non-invasive markers of respiratory inflammation in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects and define their relationships with smoking habit. Forty-eight patients with stable COPD who were ex-smokers, 17 patients with stable COPD who were current smokers, 12 healthy current smokers and 12 healthy ex-smokers were included in a cross-sectional, observational study. Inflammatory outcomes, including prostaglandin (PG) E2 and 15-F2t-isoprostane (15-F2t-IsoP) concentrations in exhaled breath condensate (EBC) and sputum supernatants, fraction of exhaled nitric oxide (FENO) and sputum cell counts, and functional (spirometry) outcomes were measured. Sputum PGE2 was elevated in both groups of smokers compared with ex-smoker counterpart (COPD: P < 0.02; healthy subjects: P < 0.03), whereas EBC PGE2 was elevated in current (P = 0.0065) and ex-smokers with COPD (P = 0.0029) versus healthy ex-smokers. EBC 15-F2t-IsoP, a marker of oxidative stress, was increased in current and ex-smokers with COPD (P < 0.0001 for both) compared with healthy ex-smokers, whereas urinary 15-F2t-IsoP was elevated in both smoker groups (COPD: P < 0.01; healthy subjects: P < 0.02) versus healthy ex-smokers. FENO was elevated in ex-smokers with COPD versus smoker groups (P = 0.0001 for both). These data suggest that the biological meaning of these inflammatory markers depends on type of marker and biological matrix in which is measured. An approach combining different types of outcomes can be used for assessing respiratory inflammation in patients with COPD. Large studies are required to establish the clinical utility of this strategy.