Comprehensive analysis of multiple cytokines and blood parameters for the diagnosis of bacterial infections in rheumatoid arthritis.

Patients with rheumatoid arthritis (RA) are more susceptible to infections, which elevate the levels of relative cytokines. However, the ability of the cytokines levels to predicate bacterial infections in RA patients remains unclear. Here, we assessed the ability of the combination of serum cytokine levels and blood parameters to diagnose bacterial infections in RA patients. We measured the levels of a panel of serum cytokine and blood parameters in 168 RA patients and 81 healthy individuals. RA patients were divided into the bacterial infection (INFE) group (n = 76) and RA flare without INFE group (n = 92). Bacterial infection was confirmed by microbial culture, imaging, antibiotic response, and typical clinical symptoms. The discriminative ability of the combination of the cytokine levels and inflammatory parameters was assessed using the receiver-operating characteristic (ROC) curves analysis and a novel bioscore system. The levels of interleukin (IL)-6 (p = 0.006), IL-10 (p = 0.019), interferon (IFN)-γ (p = 0.033), CRP (p < 0.001), and ESR (p < 0.001) were higher in patients of the INFE group than in patients with RA flare, and the absolute numbers of CD19+ B cells (p < 0.001) and CD4+ T cells (p = 0.009) were lower. For discriminating bacterial infection, the combination of IL-6, IL-10, IFN-γ, ESR, CRP, CD19+ B cells, and CD4+ T cells, provided an area under the curve (AUC) of 0.827 [(95% confidence interval (CI): 0.760-0.881)], which was profoundly larger than that of IL-6, IL-10, IFN-γ, ESR, CRP, CD19+ B cells, or CD4+ T cells alone. In addition, we also developed a bioscore system based on the combination of these seven biomarkers. Seventeen (100%) patients with a bioscore of 0 were non-infected, while seven (100%) patients with a score of 7 had bacterial infections. The bioscore based on the combination of ESR, CRP, IL-6, IL-10, IFN-γ, CD19+ B cells and CD4+ T cells may be a promising and robust tool to diagnose bacterial infections in RA patients.

Sirolimus therapy restores the PD-1+ICOS+Tfh:CD45RA-Foxp3high activated Tfr cell balance in primary Sjögren's syndrome.

BACKGROUND: Primary Sjögren's syndrome (pSS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands. The current study was performed to investigate the roles of follicular helper T (Tfh) and follicular regulatory T (Tfr) subsets in patients with pSS, and to evaluate the effects of sirolimus on these cells. METHODS: Levels of circulating Tfh and Tfr subsets in 58 pSS patients and 26 healthy controls (HC) were determined by flow cytometry. These T cell subsets were also analyzed in 12 patients before and after treatment with sirolimus. Clinical features and correlations with follicular T cells were analyzed systematically. The discriminative ability of the cells and ratios was evaluated based on the area under the receiver operating characteristic curves. RESULTS: Patients with pSS had higher percentage and absolute number of PD-1+ICOS+Tfh cells, while lower percentage and absolute number of Tfr, activated regulatory T (aTreg) cells, and CD45RA-Foxp3high activated Tfr cells. Furthermore, increased number of PD-1+ICOS+Tfh cells was associated with B cells, while decreased numbers of Tfr and their subsets was strongly associated with aTreg cells in pSS patients. Also, the higher proportion of PD-1+ICOS+Tfh cells was positively correlated with higher level of autoantibodies, ESR, IgG, cytokines (IL-2, IL-4, IL-10, IL-17, IFN-γ, TNF-α, IL-21 and sIL-2αR), and disease activity. Unexpectedly, the elevated PD-1+ICOS+Tfh:CD45RA-Foxp3high activated Tfr ratio had the greatest ability to discriminate between pSS and HC, and sirolimus therapy restored the PD-1+ICOS+Tfh cells:CD45RA-Foxp3high activated Tfr ratio, and controlled disease activity. CONCLUSION: The novel ratio of PD-1+ICOS+Tfh to CD45RA-Foxp3high activated Tfr cells can effectively discriminate the pSS patients from controls, and Tfr cell subsets may resemble Treg cell lineages. Furthermore, the PD-1+ICOS+Tfh cells can be used as a biomarker of disease activity and to verify the therapeutic effects of sirolimus in pSS.

Altered levels of circulating CD8+CXCR5+PD-1+T follicular cytotoxic cells in primary Sjögren's syndrome.

BACKGROUND: Circulating CD8+ T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) (CD8+CXCR5+T), a recently identified follicular cytotoxic T cell subset, are involved in antiviral immunity and autoimmunity, but their abundance and role in the pathogenesis of primary Sjögren syndrome (pSS) are unknown. METHODS: Circulating CD8+CXCR5+T cell and CD8+ regulatory T cells (CD8+Treg) were evaluated in 49 pSS patients (19 patients with pulmonary involvement) and 24 age- and sex-matched healthy controls (HCs) by flow cytometry. Orthogonal partial least squares discriminant analysis (OPLS-DA) was performed, and receiver operating characteristic curves (ROC) were generated to identify characteristic cell subsets. Spearman's correlation analysis was conducted to examine the relationships between CD8+ T cell subsets and clinical features. RESULTS: The proportions and numbers of CD8+CXCR5+, CD8 + CXCR5+ programmed death 1-positive (PD-1+), and CD8+CXCR5-PD-1+T cells were significantly higher, whereas those of CD8+Treg were markedly lower, in pSS patients than HCs. The CD8+CXCR5+PD-1+T cell to CD8+Treg ratio had the greatest discriminatory power for pSS and HCs according to OPLS-DA and ROC analyses. The increased numbers of CD8+CXCR5+T cells and CD8+CXCR5+PD-1+T cells were strongly associated with those of CD4+CXCR5+T and B cells. The proportions and numbers of CD8+CXCR5+PD-1+T cells were increased in pSS patients with lung involvement. CONCLUSIONS: We identified a new CD8+CXCR5+PD-1+T subset, which was increased in abundance in pSS patients, particularly those with lung involvement, compared with HCs. Also, the CD8+CXCR5+PD-1+T to CD8+Treg ratio may be useful for identifying pSS. Our findings suggest that targeting follicular CD8+T cell subsets has therapeutic potential for pSS. Key Points • CD8+CXCR5+ T cells were expanded in the circulation of patients with pSS. • Reduced numbers CD8+Treg cells in pSS patients. • Increased CD8+CXCR5+PD-1+T cells in pSS patients with pulmonary involvement.

Double-negative T cells are absolutely elevated in patients with antineutrophil cytoplasmic autoantibody-associated vasculitis.

CD3+CD4-CD8- [double-negative (DN)] T cells play vital roles in the pathogenesis of autoimmune disorders. In this study, we investigated the exact level of DN T cells in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). Forty patients with active AAV and 19 healthy controls (HCs) were enrolled in this study. Peripheral mononuclear cells were characterised phenotypically via flow cytometry. The potential clinical value of DN T cells was then assessed by the receiver operating characteristic (ROC) curves. The percentage (p < 0.001) and absolute number (p = 0.028) of DN T cells were found to be significantly higher in patients with AAV than in HCs. Relative to HCs, a lower percentage of DN T cells from patients with AAV was of the CD62L+CD45RO+ phenotype (p = 0.024), a higher percentage of these cells was of the CD62L-CD45RO- phenotype (p = 0.043). Patients with AAV had increased percentages of DN T cells expressing interferon (IFN)-γ (p = 0.032), interleukin (IL)-4 (p = 0.039) and IL-17 (p = 0.042). Furthermore, the percentages of IL-17-producing CD4+ T cells and IFN-γ-producing CD8+ T cells were significantly higher in patients with AAV than in HCs (p = 0.014, p = 0.008). Compared with the CD4+ and CD8+ T-cell subsets, DN T cells had the highest fractions of intracellular IL-17 in HCs and patients with AAV (both p < 0.001). In patients with AAV and renal damage, the percentage of DN T cells was expanded relative to that in patients without renal damage (p = 0.016). In addition, conventional methylprednisolone effectively reduced the percentage and overall number of DN T cells in patients with AAV (p = 0.028, p = 0.007). DN T cells represent a T-lymphocyte subset that produces inflammatory cytokines (IFN-γ, IL-4 and IL-17) and is absolutely elevated in patients with AAV. Additional investigations are required to determine their precise role in patients with AAV.

Development of Prediction Models for New Integrated Models and a Bioscore System to Identify Bacterial Infections in Systemic Lupus Erythematosus.

Objectives: Distinguishing flares from bacterial infections in systemic lupus erythematosus (SLE) patients remains a challenge. This study aimed to build a model, using multiple blood cells and plasma indicators, to improve the identification of bacterial infections in SLE. Design: Building PLS-DA/OPLS-DA models and a bioscore system to distinguish bacterial infections from lupus flares in SLE. Setting: Department of Rheumatology of the Second Hospital of Shanxi Medical University. Participants: SLE patients with flares (n = 142) or bacterial infections (n = 106) were recruited in this retrospective study. Outcome: The peripheral blood of these patients was collected by the experimenter to measure the levels of routine examination indicators, immune cells, and cytokines. PLS-DA/OPLS-DA models and a bioscore system were established. Results: Both PLS-DA (R2Y = 0.953, Q2 = 0.931) and OPLS-DA (R2Y = 0.953, Q2 = 0.942) models could clearly identify bacterial infections in SLE. The white blood cell (WBC), neutrophile granulocyte (NEUT), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), IL-10, interferon-γ (IFN-γ), and tumor necrosis factor α (TNF-α) levels were significantly higher in bacteria-infected patients, while regulatory T (Treg) cells obviously decreased. A multivariate analysis using the above 10 dichotomized indicators, based on the cut-off value of their respective ROC curve, was established to screen out the independent predictors and calculate their weights to build a bioscore system, which exhibited a strong diagnosis ability (AUC = 0.842, 95% CI 0.794-0.891). The bioscore system showed that 0 and 100% of SLE patients with scores of 0 and 8-10, respectively, were infected with bacteria. The higher the score, the greater the likelihood of bacterial infections in SLE. Conclusions: The PLS-DA/OPLS-DA models, including the above biomarkers, showed a strong predictive ability for bacterial infections in SLE. Combining WBC, NEUT, CRP, PCT, IL-6, and IFN-γ in a bioscore system may result in faster prediction of bacterial infections in SLE and may guide toward a more appropriate, timely treatment for SLE.

Characteristics of and reference ranges for peripheral blood lymphocytes and CD4+ T cell subsets in healthy adults in Shanxi Province, North China.

OBJECTIVE: To guide clinical decision making, race-, age- and gender-specific reference ranges for lymphocytes and CD4+ T-cell subsets are required. METHODS: Single platform flow cytometry to determine reference intervals for lymphocyte subpopulations and CD4+ T-cell subsets in 196 healthy Han Chinese adults. RESULTS: The frequencies and absolute numbers of B cells were slightly lower in Han Chinese individuals of the Shanxi region than in individuals from Hong Kong, Germany and Singapore, while percentages and absolute numbers of NK cells were slightly higher compared with individuals from Hong Kong. CD4+/CD8+ T-cell ratios, CD4+ T cell percentages and Th2 cell counts were higher, while frequencies and numbers of CD8+ T cells, numbers of NK cells and percentages of Th1 cells were lower, in females compared with males. CD4+ T cell percentages, CD4+/CD8+ T-cell ratios, numbers of CD8+ T cells and Treg cells, and Th17/Treg cell ratios differed by age. CONCLUSION: We established lymphocyte and CD4+ T-cell subset reference intervals for healthy Han Chinese adults of the Shanxi region. Ethnicity, gender and age affected lymphocyte subset composition.

Increased levels of BPI-ANCA in patients with primary Sjögren's syndrome are associated with lung involvement.

BACKGROUND: The goal of this study was to investigate the association between bactericidal permeability increasing (BPI)-antineutrophil cytoplasmic antibody (ANCA) protein levels and primary Sjogren's syndrome (pSS) with lung involvement, as well as the potential diagnostic performance of BPI-ANCA. METHODS: The levels of BPI-ANCA in pSS patients with (n = 36) and without (n = 85) lung involvement were measured using a commercial ELISA kit. Serological biomarkers and cytokines were measured in these patients as well. Lung involvement was determined by high-resolution computed tomography (HRCT) and/or clinical symptoms. The diagnostic performance of lung involvement was determined by receiver operating characteristic (ROC) curves. RESULTS: The percentage of neutrophils (NEUT%), neutrophil-lymphocyte ratio (NLR), erythrocyte sedimentation rate (ESR), and the levels of BPI-ANCA, C-reactive protein (CRP), interleukin-2 (IL-2) and IL-6 exhibited an upward trend, while the percentage of lymphocytes (LYMP%) and albumin (ALB) level exhibited a downward trend in the lung involvement group. The combination of BPI-ANCA, NEUT% and ALB significantly increased the area under the ROC curve (AUC) to 0.837 (95% confidence interval: 0.742-0.907, sensitivity: 82.14%, specificity: 81.36%, P < 0.001). CONCLUSIONS: Increased BPI-ANCA was found in pSS patients with lung involvement and was associated with inflammation. A combination of BPI-ANCA, NEUT% and ALB had the best AUC, and may serve as anadjunct to distinguish between pSS patients with and without lung involvement.

Reduced activated regulatory T cells and imbalance of Th17/activated Treg cells marks renal involvement in ANCA-associated vasculitis.

The role of naturally occurring regulatory T cells (Treg) in the control of the immune tolerance of ANCA-associated vasculitis (AAV) has not been well defined. Therefore, we separate the phenotypically heterogeneous Treg cells into different subsets based on the expression of FOXP3 and CD45RA during AAV pathogenesis. Fifty-four AAV patients (38 patients with renal involvement) and 19 healthy controls (HCs) were enrolled in this study. Levels of CD4+T cell subsets and cytokines were detected by flow cytometry. Treg immunesuppression capacity was measured in co-culture experiments. The diagnostic value for Treg subsets was evaluated by the areas under the receiver operating characteristic curves (AUC). Patients with AAV had lower percentages and numbers of activated Treg cells (aTreg, P = 0.044, P = 0.002), while higher levels of total Treg cells (P = 0.001, P = 0.026) with diminished immunosuppression capacity. The proportions of effector memory T-cell subpopulation (P < 0.001) were increased in AAV patients. Interestingly, the AUC of the aTreg improved significantly the diagnostic potential of AAV. Furthermore, the ratio of Th17/aTreg was significantly increased in active and renal vasculitis patient and positive correlation between Th17/Treg subset ratio and creatinine or BUN. In addition, we found that cytokine IL-2 and IL-4 exhibited a downward while IL-6, IL-10, TNF-α, IFN-γ and IL-17A trend upward in AAV patients. Increase in total Treg levels, along with functional deficiency, and decrease in aTreg cells constitute potential novel biomarkers for AAV. And the ratio of Th17/aTreg might serve as an important tool to recognize and monitor AAV patients with renal involvement and disease remission.

Absolute reduction of regulatory T cells and regulatory effect of short-term and low-dose IL-2 in polymyositis or dermatomyositis.

AIM: The study aimed to investigate the changes in peripherallymphocyte and CD4+T subsets and to observe the regulatory effect of low-dose interleukin-2 (ld-IL2) on these cells in polymyositis or dermatomyositis (PM/DM). METHODS: Lymphocyte subsets (CD3+T, CD4+T, CD8+T, B and natural killer (NK) cells), CD4+T subsets (Th1, Th2, Th17 and regulatory T (Treg) cells) and multiple cytokines of 71 patients after admission and treatment were measured by flow cytometry, as well as these indicators in 30 healthy controls (HCs). In DM, 35 cases were administrated with ld-IL2 combined with conventional therapy, the remaining 26 patients received conventional therapy only. RESULTS: The numbers of CD3+T and CD4+T cells in PM/DM were markedly decreased. Meanwhile, the absolute number and percentage of peripheral Treg cells in PM/DM, as well as Th1 cells in DM, were significantly lower than those in HCs (P < 0.05), but Th2 and Th17 cells had no significant difference. The ratio of Th17/Treg in PM (P = 0.031) and in DM (P = 0.003) were obviously higher than that in HCs. The deficiency of Treg cells was associated with the occurrence of interstitial lung disease (ILD) in myositis patients. Meanwhile, reduced production of IL-2 was also observed in PM/DM (P < 0.001). ld-IL2 combination therapy could significantly increase the numbers of CD4+T subsets in DM, especially Treg cells (expanded 2.5 times). CONCLUSIONS: The decline of peripheral Treg cells and serum IL-2 were found in PM/DM. ld-IL2 combination therapy could significantly increase the number of Treg cells.