CMV infection, CD19+ B cell depletion, and Lymphopenia as predictors for unexpected admission in the institutionalized elderly

Background

Chronic infections played a detrimental role on health outcomes in the aged population, and had complex associations with lymphocyte subsets distribution. Our study aimed to explore the predictive roles of chronic infections, lymphopenia, and lymphocyte subsets on unexpected admission and mortality in the institutionalized oldest-old during 3 year follow-up period.

Results

There were 163 participants enrolled prospectively with median age of 87.3 years (IQR: 83.1–90.2), male of 88.3%, and being followed for 156.4 weeks (IQR: 136.9–156.4 weeks). The unexpected admission and mortality rates were 55.2 and 24.5% respectively. The Cox proportional hazards models demonstrated the 3rd quartile of cytomegalovirus IgG (OR: 3.26, 95% CI: 1.55–6.84), lymphopenia (OR: 2.85, 95% CI: 1.2–6.74), and 1st quartile of CD19⁺ B cell count (OR: 2.84, 95% CI: 1.29–6.25) predicted elevated risks of unexpected admission after adjusting for potential confounders; while the 3rd quartile of CD3⁺ T cell indicated a reduced risk of mortality (OR: 0.19, 95% CI: 0.05–0.71). Negative association between CMV IgG and CD19⁺ B cell count suggested that CMV infection might lead to B cell depletion via decreasing memory B cells repertoire.

Conclusions

CMV infection, lymphopenia, and CD19⁺ B cell depletion might predict greater risk of unexpected admission, while more CD3⁺ T cell would suggest a reduced risk of mortality among the oldest-old population. A non-linear or U-shaped relationship was supposed between health outcomes and CMV infection, CD3⁺ T cell, or CD19⁺ B cell counts. Further prospective studies with more participants included would be needed to elucidate above findings.

A phase I study of CAR-T bridging HSCT in patients with acute CD19+ relapse/refractory B-cell leukemia

Chimeric antigen receptor (CAR)-T cell therapy is a novel cellular immunotherapy for relapsed/refractory(R/R) B acute lymphoblastic leukemia (B-ALL). However, the survival duration of CAR-T cells in vivo is noteworthy, and in some cases recurrence occurs following CAR-T cell therapy. There is controversy over the benefits of bridging to allo-HSCT after CAR-T cell therapy. The present study explored the efficacy and safety of CD19 chimeric antigen receptor (CAR) T-bridged allogeneic hematopoietic stem cell transplantation (allo-HSCT) treatment in relapsed/refractory B-cell acute lymphocytic leukemia (R/R B-ALL). A total of 9 patients with B-ALL treated at The First Affiliated Hospital of Wenzhou Medical University between December 2016 and November 2017 were included. The results demonstrated that the total response rate on day 28 after receiving CD19-CAR T-cell therapy was 100% (9/9) and all patients exhibited complete remission. The 1-year overall survival (OS) rate for 5 patients who received CAR-T bridged HSCT was 100%, the 1-year DFS rate was 100%; the 1-year OS rate for the 4 patients who received CAR-T therapy was 75%, and the 1-year DFS rate was 75%. Patients who received CAR-T bridged to HSCT had no significant prolongation of myeloid and platelet engraftment median time compared with patients who received CAR-T alone, and the incidence of acute graft-versus-host disease or extensive chronic graft-versus-host disease did not increase. Overall, the present clinical trial demonstrated that CAR-T therapy bridging to HSCT is a feasible, safe and effective method to treat adult patients with R/R B-ALL.

Troponin 1 of human filarial parasite Brugia malayi: cDNA cloning, expression, purification, and its immunoprophylactic potential

In the search for immunoprophylactics for the control of human lymphatic filariasis, we recently identified troponin 1 (Tn1) in Brugia malayi adult worms. The present study reports the cloning and expression of the B. malayi Tn1 (Tn1bm), its immunoprophylactic efficacy against B. malayi infection, and the immunological responses of the host. The Tn1bm gene was cloned (Acc no. JF912447) and expressed, and the purified recombinant Tn1bm (rTn1bm) presented a single ~ 27 kDa band. Parasite load in rTn1bm-immunized BALB/c mice challenged with B. malayi infective larvae (L₃) was assessed. In rTn1bm-immunized animals, IgE, IgG, and IgG subclasses in the serum, cell proliferative response, Th1 and Th2 cytokine secretion (from splenocytes), and NO release (from peritoneal macrophages) were determined. Antibody-dependent cell-mediated cytotoxicity (ADCC) to L₃ was assayed using rTn1bm-immune serum. The innate immune response markers MHC class-I, MHC class-II, TLR2, TLR4, and TLR6 expression in peritoneal macrophages and CD3+, CD4+, CD8+, and CD19+ in the splenocyte population were determined in Tn1bm-exposed cells from naïve mice. rTn1bm-immunized L₃-challenged animals showed a 60% reduction in parasite burden. Immunization upregulated cellular proliferation, cytokine (IFN-γ, TNF-α, IL-1β, IL-4, IL-6, and IL-10) secretion, NO release, and antigen-specific IgG, IgG1, and IgG2b antibody levels. rTn1bm-immune serum killed > 65% of L₃ in the ADCC assay. Increased MHC class-II, TLR2, and TLR6 expression and the relative CD4+ and CD19+ cell populations of naïve animal cells indicated the ability of rTn1bm to mobilize innate immune responses. This is the first report of the immunoprophylactic potential of rTn1bm against B. malayi.

Peripheral blood lymphocyte subset levels differ in patients with hepatocellular carcinoma

We investigated the levels of target lymphocyte subsets in peripheral blood lymphocyte samples from patients with hepatocellular carcinoma (HCC). A total of 715 high-risk patients with primary HCC were recruited in Guangxi, China as the case group. The control group included 100 patients who received health examinations at the same hospital during the same period. Fasting elbow venous blood (10 mL) was collected from each participant, and flow cytometry was used to detect the levels of NK cells and CD3⁺, CD4⁺ and CD19⁺ T cells in peripheral blood samples. All included patients with prmary HCC were treated by surgical resection, and followed up for one year. The levels of CD19⁺ and NK cells were lower in cases than in controls (both P < 0.05). In addition, the level of CD8⁺ cells was greater in the case group than in the control group (P < 0.05). In the high-HCC-risk population, CD8⁺, CD19⁺ and NK cell levels all differed between male and female patients, patients in TNM stages I–II and stages III–IV, patients with and without extrahepatic metastasis, and patients with and without HBV infection (all P < 0.05). After follow-up, detected recurrence and survival rate was 33.71% and 83.64%, respectively. CD8⁺ levels was reduced following surgical resection, whereas the levels of CD19⁺ and NK cells were increased (all P < 0.05). In conclusion, altered levels of CD8⁺, CD19⁺ and NK cell levels may be used as reference values for monitoring immune function in certain populations with high HCC risk, and as potential evidence for the clinical diagnosis and treatment of HCC.

The effects of intrathecal rituximab on biomarkers in multiple sclerosis

OBJECTIVES

Clinical trials of IV-rituximab have proved successful. It is unclear whether intrathecal (IT)-rituximab is more efficacious at lower doses. We examine its effects on B-cell biomarkers.

METHODS

MS patients received IT-rituximab at 3 time-points. CSF and serum samples were obtained at up to 5 time-points (days 0, 7, 14, 56 and 112). Serum and CSF BAFF and CXCL13, and CSF kappa and lambda free light chains (FLC) were measured. Flow cytometry was performed, examining effects on lymphocytes, CD3-19+ and CD3-20+ cells.

RESULTS

CSF BAFF fell following rituximab (p=0.0091 absolute values, p=0.0284 change from baseline) whilst serum BAFF increased across time-points 1-4 (p=0.0005 absolute values, p=0.0017 change from baseline). There were significant reductions in CD20+ and CD19+ cells in blood from baseline (p<0.0001) but not in CSF. CSF kappa FLC levels significantly increased (p=0.0480).

CONCLUSIONS

BAFF levels fall in CSF but increase in serum following IT-rituximab. Rituximab appears to act peripherally with dramatic decreases in peripheral CD20+ and CD19+ cells. It is likely that CSF B-cell counts were too low to enable differences to be seen. The rapid reduction in B-cells suggests rituximab has immediate effects. The profound depletion of B-cells, despite low doses of rituximab, underlines rituximab's efficacy.

Rituximab in neuromyelitis optica: A review of literature

Neuromyelitis optica spectrum disorders, or neuromyelitis optica (NMO), is an autoimmune disease of the central nervous system that must be distinguished from multiple sclerosis. Therapeutic approaches to relapse prevention in NMO include immunosuppressants and monoclonal antibodies. Rituximab, a monoclonal antibody that targets CD20 antigen expressed on the surface of pre-B, mature B-lymphocytes and a small subset of T-lymphocytes, has been widely used for the treatment of NMO. In this review, we aim to summarize global experience with rituximab in NMO. We identified 13 observational studies that involved a total of 209 NMO patients treated with rituximab. Majority of rituximab-treated patients evidenced stabilization or improvements in their disability scores compared to pre-treatment period and 66% of patients remained relapse-free during treatment period. Monitoring rituximab treatment response with CD19+ or CD27+ cell counts appears to improve treatment outcomes. We offer clinical pointers on rituximab use for NMO based on the literature and authors’ experience, and pose questions that would need to be addressed in future studies.