Mesenchymal stromal cell therapy for COVID-19 acute respiratory distress syndrome: a double-blind randomised controlled trial.

Mesenchymal stromal cells (MSC) have immunomodulatory and tissue-regenerative properties and have shown promising results in acute respiratory distress syndrome (ARDS) of multiple causes, including COVID-19. We conducted a randomised (1:1), placebo-controlled, double-blind clinical trial to assess the efficacy and safety of one bone marrow-derived MSC infusion in twenty patients with moderate to severe ARDS caused by COVID-19. The primary endpoint (increase in PaO2/FiO2 ratio from baseline to day 7, MSC 83.3 versus placebo 57.6) was not statistically significant, although a clinical improvement at day 7 in the WHO scale was observed in MSC patients (5, 50% vs 0, 0%, p = 0.033). Median time to discontinuation of supplemental oxygen was also shorter in the experimental arm (14 versus 23 days, p = 0.007), resulting in a shorter hospital stay (17.5 versus 28 days, p = 0.042). No significant differences were observed for other efficacy or safety secondary endpoints. No infusion or treatment-related serious adverse events occurred during the one-year follow-up. This study did not meet the primary endpoint of PaO2/FiO2 increase by day 7, although it suggests that MSC are safe in COVID-19 ARDS and may accelerate patients' clinical recovery and hospital discharge. Larger studies are warranted to elucidate their role in ARDS and other inflammatory lung disorders.Trial Registration: EudraCT Number: 2020-002193-27, registered on July 14th, 2020, https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-002193-27/ES . NCT number: NCT04615429, registered on November 4th, 2020, https://clinicaltrials.gov/ct2/show/NCT04615429 .

Results of a pilot study on the use of third-party donor mesenchymal stromal cells in cord blood transplantation in adults.

BACKGROUND AIMS: Cord blood (CB) transplants with co-infusion of third-party donor (TPD) mobilized hematopoietic stem cells (MHSC) have been shown to result in 'bridge' engraftment with prompt neutrophil recovery and high final rates of CB engraftment and full chimerism. This strategy overcomes the limitation posed by low cellularity of CB units for unrelated transplants in adults. Enhancement of adaptive immunity reconstitution without increasing risks of graft-versus-host disease (GvHD) is required to optimize results further. Our objectives were to evaluate co-infusion of mesenchymal stromal cells (MSC) from the same TPD regarding tolerance, CB engraftment and effects on acute (a)GvHD, both preventive and therapeutic. METHODS: Ex vivo-expanded bone marrow MSC were infused at the time of the transplant or the in case of refractory aGvHD. RESULTS: Nine patients received 1.04 - 2.15 x 10(6)/kg (median 1.20) MSC immediately after CB and TPD MHSC. Neither immediate adverse side-effects nor significant differences regarding CB engraftment or aGvHD development were observed. Four patients developed grade II aGvHD, refractory to steroids in two. These reached complete remission after therapeutic infusions of MSC. CONCLUSIONS: In recipients of 'dual CB/TPD MHSC transplants', MSC infusions were therapeutically effective for severe aGvHD but no significant differences in CB engraftment and incidence of severe aGvHD were observed following their prophylactic use. Although results of this study alone cannot conclusively determine the application of MSC in CB transplantation, we believe that, in this setting, the best use of MSC could be as pre-emptive treatment for aGvHD.

Expression of human leukocyte antigen-G in systemic lupus erythematosus.

The purpose of this study was to examine the expression of human leukocyte antigen-G (HLA-G) in patients with systemic lupus erythematosus (SLE) and its relation with interleukin-10 (IL-10) production. The study included 50 female SLE patients and 59 healthy female donors. HLA-G expression in peripheral blood and cutaneous biopsies was determined by flow cytometry and immunohistochemistry, respectively. Soluble HLA-G (sHLA-G) and IL-10 were quantified in serum samples by enzyme-linked immunosorbent assay. SLE patients presented with serum sHLA-G and IL-10 levels significantly higher than that observed in controls (median [interquartile range (IQR)] = 43.6 U/ml [23.2-150.2] vs 26.84 U/ml [6.0-45.2], p = 0.004; and 1.4 pg/ml [0-2.3] vs 0 pg/ml [0-1.5], p = 0.01, respectively). But no correlation was observed between sHLA-G and both IL-10 levels and the disease activity index for SLE patients. The expression of membrane HLA-G in peripheral lymphocytes from SLE patients was low, but higher than in controls (median [IQR] = 1.5% [0.6-1.8] and 0.3% [0.2-0.8], respectively; p = 0.02). Finally, these findings were in accordance with the weak expression of HLA-G in skin biopsies. Despite the fact that patients present higher levels of HLA-G than healthy controls, which suggests a possible relevance of this molecule in SLE, it seems not to be related to IL-10 production or disease activity.

CD5 provides viability signals to B cells from a subset of B-CLL patients by a mechanism that involves PKC.

B-chronic lymphocytic leukaemia (B-CLL) is a heterogeneous disease characterized by an accumulation of B lymphocytes expressing CD5. To date, the biological significance of this molecule in B-CLL B cells remains to be elucidated. In this study, we have analysed the functional consequences of the binding of an anti-CD5 antibody on B-CLL B cells. To this purpose, we have measured the percentage of viability of B-CLL B cells in the presence or in the absence of anti-CD5 antibodies and also examined some of the biochemical events downstream the CD5-signalling. We demonstrate that anti-CD5 induces phosphorylation of protein tyrosine kinases and protein kinase C (PKC), while no activation of Akt/PKB and MAPKs is detected. This signalling cascade results in viability in a group of patients in which we observe an increase of Mcl-1 levels, whereas the levels of bcl-2, bcl-x(L) and XIAP do not change. We also report that this pathway leads to IL-10 production, an immunoregulatory cytokine that might act as an autocrine growth factor for leukaemic B cells. Inhibition of PKC prevents the induction of Mcl-1 and IL-10, suggesting that the activation of PKC plays an important role in the CD5-mediated survival signals in B cells from a subset of B-CLL patients.

CD5 does not regulate the signaling triggered through BCR in B cells from a subset of B-CLL patients.

CD5 is a transmembrane protein expressed on all T lineage cells and a subset of B cells. It is known that CD5 is physically associated with the T-cell receptor and B-cell receptor (BCR), inhibiting the signaling triggered by both of them. CD5 is also characteristic of B-chronic lymphocytic leukemia (B-CLL) B cells, although its implication in the development of this lymphoproliferative disorder has not been studied. In the present study, we examined the effect of CD5 in apoptosis, cell viability and global protein tyrosine phosphorylation mediated by BCR in B cells from B-CLL patients. As opposed to tonsil B cells, we did not observe an increase in the apoptotic or viability signals induced by anti-immunoglobulin M or SAC/interleukin-2 when CD5 was dissociated from BCR in leukemic cells of the majority of patients. We also observed that CD5 did not regulate the BCR-induced phosphotyrosine pattern in B-CLL B cells. These findings suggest that CD5 does not inhibit properly the BCR-mediated signaling in leukemic cells. This defect in inhibiting the BCR might contribute to the enhanced survival of B-CLL B cells.

Polymorphism in the CD5 gene promoter in B-cell chronic lymphocytic leukemia and mantle cell lymphoma.

Despite the low incidence of microsatellite instability (MSI) in lymphoid malignant neoplasms, it has been reported that the CD5 promoter MSI was relatively frequent among B-cell chronic lymphoproliferative disorders. We studied the presence of MSI in the CD5 promoter in 134 cases of B-cell chronic lymphocytic leukemia (B-CLL) and 47 of mantle cell lymphoma (MCL) by comparing the pattern of microsatellite repeats on autologous germline and tumor DNA samples. Microsatellite alterations were not observed in any case. However, the allele distribution of this polymorphism showed a higher frequency of the 18 CA allele (0.585) in MCL cases (P = .026; odds ratio [OR], 1.75; 95% confidence interval [CI], 1.07-2.87) and of the 19 CA allele (0.179) in B-CLL cases (P = .005; OR, 2.26; 95% CI, 1.27-4.01) compared with control cases (0.442 and 0.087, respectively). This suggests that although MSI seems not to be involved in the pathogenesis of these 2 lymphoid malignant neoplasms, the polymorphic CD5 promoter is associated with increased susceptibility to these disorders.

Haematopoietic transplants combining a single unrelated cord blood unit and mobilized haematopoietic stem cells from an adult HLA-mismatched third party donor. Comparable results to transplants from HLA-identical related donors in adults with acute leukaemia and myelodysplastic syndromes.

We describe results of the strategy, developed by our group, of co-infusion of mobilized haematopoietic stem cells as a support for single-unit unrelated cord blood transplant (dual CB/TPD-MHSC transplants) for treatment of haematological malignancies in adults, and a comparative analysis of results obtained using this strategy and transplants performed with mobilized haematopoietic stem cells from related HLA-identical donors (RTD) for treatment of adults with acute leukaemia and myelodysplastic syndromes. Our data show that the dual CB/TPD-MHSC transplant strategy results in periods of post-transplant neutropenia, final rates of full donor chimerism and transplant-related mortality rates comparable to those of the RTD. Final survival outcomes are comparable in adults transplanted because of acute leukaemia, with different incidences of the complications that most influence these: a higher incidence of infections related to late recovery of protective immunity dependent on T cell functions, and a lower incidence of serious acute graft-versus-host disease and relapses. Recent advances in cord blood transplant techniques allow allogeneic haematopoietic stem cell transplantation (HSCT) to be a viable option for almost every patient who may benefit from this therapeutic approach. Development of innovative strategies to improve the post-transplant recovery of T cells function is currently the main challenge to further improving the possibilities of unrelated cord blood transplantation.

Association of the microsatellite in the 3' untranslated region of the CD154 gene with rheumatoid arthritis in females from a Spanish cohort: a case-control study.

CD40-CD154 interaction is an important mediator of inflammation and has been implicated in T helper type 1-mediated autoimmune diseases including rheumatoid arthritis (RA). Linkage studies have shown association of markers in the proximity of the CD154 gene. In the present work we investigated whether specific allele variants of the microsatellite in the 3' UTR of the CD154 gene might modulate the risk of RA. The study, in a case-control setting, included 189 patients and 150 healthy controls from the Canary Islands, Spain. The 24CAs allele was less represented in female patients than in controls (0.444 in controls versus 0.307 in patients, P = 0.006, odds ratio (OR) 0.556, 95% confidence interval (CI) 0.372 to 0.831) but not in males (0.414 versus 0.408), and only when homozygous (P = 0.012; OR 0.35, 95% CI 0.16 to 0.77). We also verified that CD154 association with RA was independent of human leukocyte antigen (HLA) phenotype. A further functional study showed that after stimulation anti-CD3, CD154 mRNA was more stable in CD4+ T lymphocytes from patients with RA bearing the 24CAs allele (mRNA half-life 208 minutes) than in patients without the 24CAs allele (109 minutes, P = 0.009). However, a lower percentage of CD154+CD4+ T lymphocytes was seen in freshly isolated peripheral blood mononuclear cells from patients carrying 24CAs alleles (mean 4.28 versus 8.12; P = 0.033), and also in CD4+ T lymphocytes stimulated with anti-CD3 (median 29.40 versus 47.60; P = 0.025). These results were concordant with the smaller amounts of CD154 mRNA isolated from stimulated T lymphocytes with 24CAs alleles. The CD154 microsatellite therefore seems to affect the expression of the gene in a complex manner that implies not only mRNA stability. These data suggest that the CD154 microsatellite contributes to the regulation of mRNA and protein expression, although further studies will be necessary to elucidate its role in disease predisposition.