Prognosis of hyperviscosity syndrome in newly diagnosed multiple myeloma in modern-era therapy: A real-life study.

Hyperviscosity syndrome (HVS) is a rare complication of newly diagnosed multiple myeloma (NDMM) related to high tumour burden. Studies about the prognosis of HVS in modern-era therapy for NDMM are missing. We investigated a retrospective cohort study of NDMM with HVS between 2011-2021. Thirty-nine NDMM patients with HVS were included. HVS presentation was heterogeneous, with asymptomatic, mild, and neurological forms in 23%, 59%, and 18% of cases, respectively. No thrombosis or major bleeding was observed. Therapeutic plasma exchanges were used in 92% of patients, which were effective and well tolerated. No rebound effect was observed. All patients except one had at least one CRAB criterion. Most of the patients received bortezomib and high-dose steroids (95%) associated with an immunomodulatory drug (43%) or alkylating agents (42%). HVS in NDMM patients had dismal overall survival matched to multiple myeloma patient controls (without HVS) in our center (median: 3.6 vs. 7.7 years, p=0.01), as confirmed by multivariate analysis. Early deaths (in the first two months) occurred in 21% of older patients (>65 years). HVS in NDMM patients is a rare but life-threatening complication associated with high lethality in older patients and be a potential dismal prognosis factor in the modern treatment era.

Inflammatory Waldenström's macroglobulinaemia: A French monocentric retrospective study of 67 patients.

Waldenström's macroglobulinaemia (WM) is a B-cell neoplasm resulting from bone marrow lymphoplasmacytic infiltration and monoclonal IgM secretion. Some patients present concomitant inflammatory syndrome attributed to the disease activity; we named this syndrome inflammatory WM (IWM). We retrospectively analysed all WM patients seen in a single tertiary referral centre from January 2007 to May 2021, and after excluding aetiologies for the inflammatory syndrome using a pertinent blood workup, including C-reactive protein (CRP), and imaging, we identified 67 (28%) IWM, 166 (68%) non-IWM, and nine (4%) WM with inflammatory syndrome of unknown origin. At treatment initiation, IWM patients had more severe anaemia (median Hb 90 vs 99 g/l; p < 0.01), higher platelet count (median 245 vs 196 × 109/l; p < 0.01) and comparable serum IgM level (median 24.9 vs 23.0 g/l; p = 0.28). A positive correlation was found between inflammatory and haematological responses (minimal response or better) (odds ratio 32.08; 95% confidence interval 8.80-98.03; p < 0.001). Overall survivals (OS) were similar (median OS: 17 vs 20 years; p = 0.11) but time to next treatment (TNT) was significantly shorter for IWM (TNT1: 1.6 vs 4.8 years, p < 0.0001). IWM mostly shared the same presentation and outcome as WM without inflammatory syndrome.

Developmental bifurcation of human T follicular regulatory cells.

Germinal centers (GCs) are anatomic structures where B cells undergo affinity maturation, leading to production of high-affinity antibodies. The balance between T follicular helper (TFH) and regulatory (TFR) cells is critical for adequate control of GC responses. The study of human TFH and TFR cell development has been hampered because of the lack of in vitro assays reproducing in vivo biology, along with difficult access to healthy human lymphoid tissues. We used a single-cell transcriptomics approach to study the maturation of TFH and TFR cells isolated from human blood, iliac lymph nodes (LNs), and tonsils. As independent tissues have distinct proportions of follicular T cells in different maturation states, we leveraged the heterogeneity to reconstruct the maturation trajectory for human TFH and TFR cells. We found that the dominant maturation of TFR cells follows a bifurcated trajectory from precursor Treg cells, with one arm of the bifurcation leading to blood TFR cells and the other leading to the most mature GC TFR cells. Overall, our data provide a comprehensive resource for the transcriptomics of different follicular T cell populations and their dynamic relationship across different tissues.