Indications and Outcomes of Patients Receiving Therapeutic Plasma Exchange under Critical Care Conditions: A Retrospective Eleven-Year Single-Center Study at a Tertiary Care Center.

Background: Therapeutic plasma exchange (TPE) is frequently performed in critical care settings for heterogenous indications. However, specific intensive care unit (ICU) data regarding TPE indications, patient characteristics and technical details are sparse. Methods: We performed a retrospective, single-center study using data from January 2010 until August 2021 for patients treated with TPE in an ICU setting at the University Hospital Zurich. Data collected included patient characteristics and outcomes, ICU-specific parameters, as well as apheresis-specific technical parameters and complications. Results: We identified n = 105 patients receiving n = 408 TPEs for n = 24 indications during the study period. The most common was thrombotic microangiopathies (TMA) (38%), transplant-associated complications (16.3%) and vasculitis (14%). One-third of indications (35.2%) could not be classified according to ASFA. Anaphylaxis was the most common TPE-related complication (6.7%), while bleeding complications were rare (1%). The median duration of ICU stay was 8 ± 14 days. Ventilator support, renal replacement therapy or vasopressors were required in 59 (56.2%), 26 (24.8%), and 35 (33.3%) patients, respectively, and 6 (5.7%) patients required extracorporeal membrane oxygenation. The overall hospital survival rate was 88.6%. Conclusion: Our study provides valuable real-world data on heterogenous TPE indications for patients in the ICU setting, potentially supporting decision-making.

B-Cell Reconstitution After Autologous Hematopoietic Stem Cell Transplantation in Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Autologous hematopoietic stem cell transplantation (aHSCT) is increasingly used to treat aggressive forms of multiple sclerosis (MS). This procedure is believed to result in an immune reset and restoration of a self-tolerant immune system. Immune reconstitution has been extensively studied for T cells, but only to a limited extent for B cells. As increasing evidence suggests an important role of B cells in MS pathogenesis, we sought here to better understand reconstitution and the extent of renewal of the B-cell system after aHSCT in MS. METHODS: Using longitudinal multidimensional flow cytometry and immunoglobulin heavy chain (IgH) repertoire sequencing following aHSCT with BCNU + Etoposide + Ara-C + Melphalan anti-thymocyte globulin, we analyzed the B-cell compartment in a cohort of 20 patients with MS in defined intervals before and up to 1 year after aHSCT and compared these findings with data from healthy controls. RESULTS: Total B-cell numbers recovered within 3 months and increased above normal levels 1 year after transplantation, successively shifting from a predominantly transitional to a naive immune phenotype. Memory subpopulations recovered slowly and remained below normal levels with reduced repertoire diversity 1 year after transplantation. Isotype subclass analysis revealed a proportional shift toward IgG1-expressing cells and a reduction in IgG2 cells. Mutation analysis of IgH sequences showed that highly mutated memory B cells and plasma cells may transiently survive conditioning while the analysis of sequence cluster overlap, variable (IGHV) and joining (IGHJ) gene usage and repertoire diversity suggested a renewal of the late posttransplant repertoire. In patients with early cytomegalovirus reactivation, reconstitution of naive and memory B cells was delayed. DISCUSSION: Our detailed characterization of B-cell reconstitution after aHSCT in MS indicates a reduced reactivation potential of memory B cells up to 1 year after transplantation, which may leave patients susceptible to infection, but may also be an important aspect of its mechanism of action.

Dynamics of Inflammatory and Neurodegenerative Biomarkers after Autologous Hematopoietic Stem Cell Transplantation in Multiple Sclerosis.

Autologous hematopoietic stem cell transplantation (aHSCT) is a highly efficient treatment of multiple sclerosis (MS), and hence it likely normalizes pathological and/or enhances beneficial processes in MS. The disease pathomechanisms include neuroinflammation, glial cell activation and neuronal damage. We studied biomarkers that in part reflect these, like markers for neuroinflammation (C-X-C motif chemokine ligand (CXCL) 9, CXCL10, CXCL13, and chitinase 3-like 1 (CHI3L1)), glial perturbations (glial fibrillary acidic protein (GFAP) and in part CHI3L1), and neurodegeneration (neurofilament light chain (NfL)) by enzyme-linked immunosorbent assays (ELISA) and single-molecule array assay (SIMOA) in the serum and cerebrospinal fluid (CSF) of 32 MS patients that underwent aHSCT. We sampled before and at 1, 3, 6, 12, 24 and 36 months after aHSCT for serum, as well as before and 24 months after aHSCT for CSF. We found a strong increase of serum CXCL10, NfL and GFAP one month after the transplantation, which normalized one and two years post-aHSCT. CXCL10 was particularly increased in patients that experienced reactivation of cytomegalovirus (CMV) infection, but not those with Epstein-Barr virus (EBV) reactivation. Furthermore, patients with CMV reactivation showed increased Th1 phenotype in effector memory CD4+ T cells. Changes of the other serum markers were more subtle with a trend for an increase in serum CXCL9 early post-aHSCT. In CSF, GFAP levels were increased 24 months after aHSCT, which may indicate sustained astroglia activation 24 months post-aHSCT. Other CSF markers remained largely stable. We conclude that MS-related biomarkers indicate neurotoxicity early after aHSCT that normalizes after one year while astrocyte activation appears increased beyond that, and increased serum CXCL10 likely does not reflect inflammation within the central nervous system (CNS) but rather occurs in the context of CMV reactivation or other infections post-aHSCT.

Mobilization of Hematopoietic Progenitor Cells with Standard- or Reduced-Dose Filgrastim after Vinorelbine in Multiple Myeloma Patients: A Randomized Prospective Single-Center Phase II Study.

Vinorelbine combined with filgrastim at a dose of 10 µg/kg of body weight (BW) per day is a reliable and well-tolerated regimen for mobilization of hematopoietic progenitor cells (HPCs) in patients with multiple myeloma. This prospective, randomized, phase II study was initiated to assess the feasibility of a reduced filgrastim dosage. Vinorelbine was combined with either standard-dose filgrastim (10 µg/kg BW per day) or reduced-dose filgrastim (5 µg/kg BW per day). Leukapheresis sessions were planned to start at day 8 and were continued until the predefined target amount of 4 × 106 HPCs/kg BW was collected. The study demonstrated the feasibility of vinorelbine combined with reduced daily filgrastim with a mean of 1.29 leukapheresis sessions necessary per patient (95% confidence interval, .95 to 1.7). All patients could start leukapheresis as planned at day 8, and the collection success rate was 100% for the whole patient collective after a maximum of 2 leukapheresis sessions. No statistically significant differences with regard to the amount of HPCs collected between the 2 groups were observed (P = .99). Accordingly, no differences were seen with regard to length of hospitalization for autotransplant (P = .34) and duration of neutrophil (P = .93) and platelet engraftment (P = .42). Patients receiving reduced-dose filgrastim reported significantly lower peak pain values in a numeric analogue scale (P = .01), and the costs were significantly lower than in patients undergoing standard-dose chemomobilization (P = .001). Vinorelbine 35 mg/m2 plus filgrastim 5 µg/kg BW once per day until completion of HPC collection is feasible and appears to be advantageous with respect to the severity of pain intensity and treatment costs.