Kinetics of functionally distinct T-lymphocyte subsets in heart transplant recipients after induction therapy with anti-CD25 monoclonal antibodies

Time-dependent lymphocyte count after transplantation is associated with higher risk of graft failure and death

The transplantation field requires the identification of specific risk factors associated with the level of immunosuppression. Here, our aim was to analyze the association between the number of circulating lymphocytes, monitored routinely by complete blood cell counts during outpatient visits, and patient and graft survival. In total, 2,999 kidney or combined kidney-pancreas recipients transplanted between 2000 and 2016, from two University hospitals, were enrolled. We investigated the etiological relationship between time-dependent lymphocyte count beyond one year after transplantation and patient and graft survival, viral infection and cancer risk using time-dependent multivariate Cox models. Model 1 considered kidney function at one year and model 2 as time-dependent variable. At the time of inclusion (one year after transplantation), 584 patients (19.4%) had deep lymphopenia (under 750 /mm³) and 1,072 (35.7%) had a normal count (over 1,500 /mm³). A patient with deep lymphopenia at a given follow-up time had significantly higher risks of graft failure, death and viral infection than comparable patients with a normal lymphocyte count at the same time point. Thus, after the first year of transplantation, the occurrence of deep lymphopenia within a patient's follow-up is a risk factor for long-term graft failure, death and viral infection.

Peripheral neutrophil CD64 index combined with complement, CRP, WBC count and B cells improves the ability of diagnosing bacterial infection in SLE

OBJECTIVE

To investigate the diagnostic role of complement C3, complement C4, C-reactive protein (CRP), procalcitonin (PCT), white blood cell count (WBC), neutrophil CD64 (nCD64) index, lymphocyte subsets and their combination in differentiating bacterial infection from disease relapse in systemic lupus erythematosus (SLE).

METHODS

The above biomarkers in 36 hospitalized SLE patients with bacterial infection and 45 with lupus flare without infection were retrospectively studied. Bacterial infection was proven by positive cultures or typical clinical symptoms and signs combined with positive response to antibiotics. Lupus flare was defined as three points greater than their previous SLE disease activity index score. The diagnostic value for bacterial infection was evaluated by the areas under the receiver operating characteristic curves (AUC) and a novel bioscore system combining multiple biomarkers.

RESULTS

Increased CRP ( p = 0.049), WBC ( p = 0.028) and nCD64 index ( p = 0.034) were observed in the infected group and C3 ( p = 0.001), C4 ( p = 0.016) and B cells levels ( p = 0.010) were significantly reduced. The AUC for the above six biomarkers had no significant difference. Interestingly, the combination of nCD64 index, CRP, WBC, C3 and C4 improved significantly the diagnostic potential of SLE infection (AUC 0.783 (interquartile range 0.672, 0.871), p < 0.001; sensitivity 85.29% specificity 62.50%). In the bioscore system including the above six biomarkers, the bacterial infection rate in patients with bioscore ≤2, 3, 4, 5 and 6 were 0.00, 39.29, 59.10, 61.54 and 100.00%, respectively.

CONCLUSION

The combination of nCD64 index, C3, C4, CRP, WBC and B cells in a bioscore is useful to diagnose bacterial infection in SLE.

T cell subsets and immunoglobulin G levels are associated with the infection status of systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disorder that affects nearly all organs and tissues. As knowledge about the mechanism of SLE has increased, some immunosuppressive agents have become routinely used in clinical care, and infections have become one of the direct causes of mortality in SLE patients. To identify the risk factors indicative of infection in SLE patients, a case control study of our hospital's medical records between 2011 and 2013 was performed. We reviewed the records of 117 SLE patients with infection and 61 SLE patients without infection. Changes in the levels of T cell subsets, immunoglobulin G (IgG), complement C3, complement C4, globulin, and anti-double-stranded DNA (anti-ds-DNA) were detected. CD4+ and CD4+/CD8+ T cell levels were significantly lower and CD8+ T cell levels were significantly greater in SLE patients with infection than in SLE patients without infection. Additionally, the concentrations of IgG in SLE patients with infection were significantly lower than those in SLE patients without infection. However, complement C3, complement C4, globulin, and anti-ds-DNA levels were not significantly different in SLE patients with and without infection. Therefore, clinical testing for T cell subsets and IgG is potentially useful for identifying the presence of infection in SLE patients and for distinguishing a lupus flare from an acute infection.

Individualized Immunosuppressive Protocol of Liver Transplant Recipient Should be Made Based on Splenic Function Status

BACKGROUND

Lymphocyte subsets play important roles in rejection in liver transplant recipients, and the effect of splenic function on these roles remains unknown. The aim of this study was to explore the feasibility to adjust immunosuppressive agents based on splenic function status through detecting the lymphocyte subsets in liver transplantBeijing recipients.

METHODS

The lymphocyte subsets of 49 liver transplant recipients were assessed in the 309th Hospital of Chinese People's Liberation Army between June 2014 and August 2015. The patients were divided into splenectomy group (n = 9), normal splenic function group (n = 24), and hypersplenism group (n = 16). The percentages and counts of CD4+ T, CD8+ T, natural killer (NK) cell, B-cell, regulatory B-cell (Breg), and regulatory T-cell (Treg) were detected by flow cytometer. In addition, the immunosuppressive agents, histories of rejection and infection, and postoperative time of the patients were compared among the three groups.

RESULTS

There was no significant difference of clinical characteristics among the three groups. The percentage of CD19+CD24+CD38+ Breg was significantly higher in hypersplenism group than normal splenic function group and splenectomy group (3.29 ± 0.97% vs. 2.12 ± 1.08% and 1.90 ± 0.99%, P = 0.001). The same result was found in CD4+CD25+FoxP3+ Treg percentage (0.97 ± 0.39% vs. 0.54 ± 0.31% and 0.56 ± 0.28%, P = 0.001). The counts of CD8+ T-cell, CD4+ T-cell, and NK cell were significantly lower in hypersplenism group than normal splenic function group (254.25 ± 149.08 vs. 476.96 ± 225.52, P= 0.002; 301.69 ± 154.39 vs. 532.50 ± 194.42, P= 0.000; and 88.56 ± 63.15 vs. 188.33 ± 134.51, P = 0.048). Moreover, the counts of CD4+ T-cell and NK cell were significantly lower in hypersplenism group than splenectomy group (301.69 ± 154.39 vs. 491.89 ± 132.31, P= 0.033; and 88.56 ± 63.15 vs. 226.00 ± 168.85, P = 0.032).

CONCLUSION

Splenic function status might affect the immunity of liver transplant recipients, that should be considered when we make immunosuppressive protocols.

Approaches for monitoring of non virus-specific and virus-specific T-cell response in solid organ transplantation and their clinical applications

Opportunistic viral infections are still a major complication following solid organ transplantation. Immune monitoring may allow the identification of patients at risk of infection and, eventually, the modulation of immunosuppressive strategies. Immune monitoring can be performed using virus-specific and non virus-specific assays. This article describes and summarizes the pros and cons of the different technical approaches. Among the assays based on non virus-specific antigens, the enumeration of T-cell subsets, the quantification of cytokines and chemokines and the quantification of intracellular adenosine triphosphate following mitogen stimulation are described and their clinical applications to determine the risk for viral infection are discussed. In addition, current specific methods available for monitoring viral-specific T-cell responses are summarized, such as peptide-MHC multimer staining, intracellular cytokine staining, enzyme-linked immunospot and virus-specific IFN-γ ELISA assays, and their clinical applications to determine the individual risk for opportunistic viral infections with human cytomegalovirus, Epstein-Barr virus and polyoma BK virus are discussed. The standardization of the procedure, the choice of the antigen(s) and the criteria to define cut-off values for positive responses are needed for some of these approaches before their implementation in the clinic. Nevertheless, immune monitoring combined with virological monitoring in transplant recipients is increasingly regarded as a helpful tool to identify patients at risk of infection as well as to assess treatment efficacy.