This is a multicenter prospective observational study that included a large cohort (
n
= 397) of allogeneic (allo‐HSCT; (
n
= 311) and autologous (ASCT) hematopoietic stem cell transplant (
n
= 86) recipients who were monitored for antibody detection within 3–6 weeks after complete severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination from February 1, 2021, to July 20, 2021. Most patients (
n
= 387, 97.4%) received mRNA‐based vaccines. Most of the recipients (93%) were vaccinated more than 1 year after transplant. Detectable SARS‐CoV‐2‐reactive antibodies were observed in 242 (78%) of allo‐HSCT and in 73 (85%) of ASCT recipients. Multivariate analysis in allo‐HSCT recipients identified lymphopenia < 1 × 10
9
/ml (odds ratio [OR] 0.33, 95% confidence interval [95% CI] 0.16–0.69,
p
= .003), active graft versus host disease (GvHD; OR 0.51, 95% CI 0.27–0.98,
p
= .04) and vaccination within the first year of transplant (OR 0.3, 95% CI 0.15–0.9,
p
= .04) associated with lower antibody detection whereas. In ASCT, non‐Hodgkin's lymphoma (NHL; OR 0.09, 95% CI 0.02–0.44,
p
= .003) and active corticosteroid therapy (OR 0.2, 95% CI 0.02–0.87,
p
= .03) were associated with lower detection rate. We report an encouraging rate of SARS‐CoV‐2‐reactive antibodies detection in these severe immunocompromised patients. Lymphopenia, GvHD, the timing of vaccine, and NHL and corticosteroids therapy should be considered in allo‐HSCT and ASCT, respectively, to identify candidates for SARS‐CoV‐2 antibodies monitoring.
The objective of this article is to assess the safety of intraspinal infusion of autologous bone marrow mononuclear cells (BMNCs) and, ultimately, to look for histopathological signs of cellular neurotrophism in amyotrophic lateral sclerosis (ALS) patients. We conducted an open single arm phase I trial. After 6 months observation, autologous BMNCs were infused into the posterior spinal cord funiculus. Safety was the primary endpoint and was defined as the absence of serious transplant-related adverse events. In addition, forced vital capacity (FVC), ALS-functional rating scale (ALS-FRS), Medical Research Council scale for assessment of muscle power (MRC), and Norris scales were assessed 6 and 3 months prior to the transplant and quarterly afterward for 1 year. Pathological studies were performed in case of death. Eleven patients were included. We did not observe any severe transplant-related adverse event, but there were 43 nonsevere events. Twenty-two (51%) resolved in ≤2 weeks and only four were still present at the end of follow-up. All were common terminology criteria for adverse events grade ≤2. No acceleration in the rate of decline of FVC, ALS-FRS, Norris, or MRC scales was observed. Four patients died on days 359, 378, 808, and 1,058 post-transplant for reasons unrelated to the procedure. Spinal cord pathological analysis showed a greater number of motoneurons in the treated segments compared with the untreated segments (4.2 ± 0.8 motoneurons per section [mns per sect] and 0.9 ± 0.3 mns per sect, respectively). In the treated segments, motoneurons were surrounded by CD90+ cells and did not show degenerative ubiquitin deposits. This clinical trial confirms not only the safety of intraspinal infusion of autologous BMNC in ALS patients but also provides evidence strongly suggesting their neurotrophic activity.
The automatic method described is effective in terms of CD34+ cell recovery and viability in ASCT. Moreover, Sepax decreased significantly the untoward reactions during the infusion.
Background
The clinical efficacy of SARS-CoV-2 vaccines according to antibody response in immunosuppressed patients such as hematological patients has not yet been established.
Patients and methods
A prospective multicenter registry-based cohort study conducted from December 2020 to December 2021 by the Spanish transplant and cell therapy group was used to analyze the relationship of antibody response at 3–6 weeks after full vaccination (2 doses) with breakthrough SARS-CoV-2 infection in 1394 patients with hematological disorders.
Results
At a median follow-up of 165 days after complete immunization, 37 out of 1394 (2.6%) developed breakthrough SARS-CoV-2 infection at median of 77 days (range 7–195) after full vaccination. The incidence rate was 6.39 per 100 persons-year. Most patients were asymptomatic (19/37, 51.4%), whereas only 19% developed pneumonia. The mortality rate was 8%. Lack of detectable antibodies at 3–6 weeks after full vaccination was the only variable associated with breakthrough infection in multivariate logistic regression analysis (Odds Ratio 2.35, 95% confidence interval 1.2–4.6, p = 0.012). Median antibody titers were lower in cases than in non-cases [1.83 binding antibody units (BAU)/mL (range 0–4854.93) vs 730.81 BAU/mL (range 0–56,800), respectively (p = 0.007)]. We identified 250 BAU/mL as a cutoff above which incidence and severity of the infection were significantly lower.
Conclusions
Our study highlights the benefit of developing an antibody response in these highly immunosuppressed patients. Level of antibody titers at 3 to 6 weeks after 2-dose vaccination links with protection against both breakthrough infection and severe disease for non-Omicron SARS-CoV-2 variants.
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