Havenar-Daughton C, etal., Proc Natl Acad Sci U S A. 2016 Mar 8;113(10):2702-7. doi: 10.1073/pnas.1520112113. Epub 2016 Feb 23.
Significantly higher levels of plasma CXCL13 [chemokine (C-X-C motif) ligand 13] were associated with the generation of broadly neutralizing antibodies (bnAbs) against HIV in a large longitudinal cohort of HIV-infected individuals. Germinal centers (GCs) perfo
rm the remarkable task of optimizing B-cell Ab responses. GCs are required for almost all B-cell receptor affinity maturation and will be a critical parameter to monitor if HIV bnAbs are to be induced by vaccination. However, lymphoid tissue is rarely available from immunized humans, making the monitoring of GC activity by direct assessment of GC B cells and germinal center CD4(+) T follicular helper (GC Tfh) cells problematic. The CXCL13-CXCR5 [chemokine (C-X-C motif) receptor 5] chemokine axis plays a central role in organizing both B-cell follicles and GCs. Because GC Tfh cells can produce CXCL13, we explored the potential use of CXCL13 as a blood biomarker to indicate GC activity. In a series of studies, we found that plasma CXCL13 levels correlated with GC activity in draining lymph nodes of immunized mice, immunized macaques, and HIV-infected humans. Furthermore, plasma CXCL13 levels in immunized humans correlated with the magnitude of Ab responses and the frequency of ICOS(+) (inducible T-cell costimulator) Tfh-like cells in blood. Together, these findings support the potential use of CXCL13 as a plasma biomarker of GC activity in human vaccine trials and other clinical settings.
The chemokine CXC ligand 13 protein (CXCL13) is reported to closely related to the disease activity and severity of systemic lupus erythematosus (SLE), moreover, the level of CXCL13 was markedly raised in kidney tissues of l
upus nephritis (LN) patients. The aim of the present study was to explore whether the blockade of CXCL13 has therapeutic effects on murine LN. MRL/lpr mice received 50mug anti-CXCL13 neutralizing antibody or isotype IgG by intraperitoneal injection everyday for six weeks, and renal damage of each group was determined. Our results showed that the blockade of CXCL13 significantly reduced urine protein, serum creatinine, and dramatically attenuated renal pathology injury. Treatment with anti-CXCL13Ab also reduced serum anti-dsDNA level, renal immune complex deposition as well as inflammatory cytokines secretion. Meanwhile, Th17/Treg ratio in spleens of MRL/lpr mice was significantly decreased by the blocking of CXCL13. These findings suggested that CXCL13 may be a promising target for the therapy of LN.
Recent studies have implicated chemokines in microglial activation and pathogenesis of neuropathic pain. C-X-C motif chemokine 13 (CXCL13) is a B lymphocyte chemoattractant that activates CXCR5. Using the spinal nerve ligation (SNL) model of neuropathic pain, w
e found that CXCL13 was persistently upregulated in spinal cord neurons after SNL, resulting in spinal astrocyte activation via CXCR5 in mice. shRNA-mediated inhibition of CXCL13 in the spinal cord persistently attenuated SNL-induced neuropathic pain. Interestingly, CXCL13 expression was suppressed by miR-186-5p, a microRNA that colocalized with CXCL13 and was downregulated after SNL. Spinal overexpression of miR-186-5p decreased CXCL13 expression, alleviating neuropathic pain. Furthermore, SNL induced CXCR5 expression in spinal astrocytes, and neuropathic pain was abrogated in Cxcr5-/- mice. CXCR5 expression induced by SNL was required for the SNL-induced activation of spinal astrocytes and microglia. Intrathecal injection of CXCL13 was sufficient to induce pain hypersensitivity and astrocyte activation via CXCR5 and ERK. Finally, intrathecal injection of CXCL13-activated astrocytes induced mechanical allodynia in naive mice. Collectively, our findings reveal a neuronal/astrocytic interaction in the spinal cord by which neuronally produced CXCL13 activates astrocytes via CXCR5 to facilitate neuropathic pain. Thus, miR-186-5p and CXCL13/CXCR5-mediated astrocyte signaling may be suitable therapeutic targets for neuropathic pain.
In the ectopic lymphoid-like structures present in chronic inflammatory conditions such as rheumatoid arthritis, a subset of human effector memory CD4(+) T cells that lacks features of follicular helper T (Tfh) cells produces CXCL13. Here, we report that TGF-bet
a induces the differentiation of human CXCL13-producing CD4(+) T cells from naive CD4(+) T cells. The TGF-beta-induced CXCL13-producing CD4(+) T cells do not express CXCR5, B-cell lymphoma 6 (BCL6), and other Tfh-cell markers. Furthermore, expression levels of CD25 (IL-2Ralpha) in CXCL13-producing CD4(+) T cells are significantly lower than those in FoxP3(+) in vitro induced Treg cells. Consistent with this, neutralization of IL-2 and knockdown of STAT5 clearly upregulate CXCL13 production by CD4(+) T cells, while downregulating the expression of FoxP3. Furthermore, overexpression of FoxP3 in naive CD4(+) T cells downregulates CXCL13 production, and knockdown of FoxP3 fails to inhibit the differentiation of CXCL13-producing CD4(+) T cells. As reported in rheumatoid arthritis, proinflammatory cytokines enhance secondary CXCL13 production from reactivated CXCL13-producing CD4(+) T cells. Our findings demonstrate that CXCL13-producing CD4(+) T cells lacking Tfh-cell features differentiate via TGF-beta signaling but not via FoxP3, and exert their function in IL-2-limited but TGF-beta-rich and proinflammatory cytokine-rich inflammatory conditions.
Hu R, etal., Int J STD AIDS. 2016 Feb;27(2):141-6. doi: 10.1177/0956462415577229. Epub 2015 Mar 12.
Diagnosing asymptomatic neurosyphilis (ANS) in HIV-infected patients is difficult. A recent report suggested that CXCL13 is a promising diagnostic marker for neurosyphilis in HIV-positive patients. However, whether CXCL13 ca
n be a diagnostic marker for ANS in HIV-infected patients remains unknown. The purpose of our study was to determine the role of CXCL13 in diagnosing ANS in HIV-infected patients. This study comprised two study and three control groups. Two study groups included 12 HIV-infected patients with ANS and 25 patients with syphilis and HIV co-infection (without ANS). Three control groups included 9 patients with ANS without HIV infection, 25 HIV-infected patients without syphilis and 10 healthy volunteers. Concentrations of CSF CXCL13 were measured before and after neurosyphilis therapy. Our results showed that CSF CXCL13 concentrations were significantly increased in all of the HIV-infected patients with ANS, the 25 HIV patients with syphilis and the 9 ANS patients without HIV, but not in the patients of the other two control groups. CSF CXCL13 concentrations declined in the two study groups of patients following neurosyphilis therapy. Therefore, CSF CXCL13 concentrations could improve the diagnosis of ANS in HIV-infected patients.
Wang C, etal., Sci Rep. 2016 Sep 21;6:33569. doi: 10.1038/srep33569.
At present, diagnosis for neurosyphilis remains a major clinical challenge. Venereal Disease Research Laboratory (VDRL) titer of the cerebrospinal fluid (CSF) is suboptimally sensitive to diagnose neurosyphilis, which can be negative in neurosyphilis patients, especially in asymptomatic neurosyphili
s patients. In the search for biomarkers of neurosyphilis, we investigated the chemokine profile in CSF of neurosyphilis patients and found that the concentrations of CXCL13, CXCL10 and CXCL8 were selectively elevated in neurosyphilis patients and correlated with CSF protein concentration and CSF-VDRL titer. After antibiotic treatment, the concentration of these chemokines was dramatically reduced. The area under the ROC curve (AUC) of CSF CXCL13, CXCL8,CXCL10 and the CSF/serum ratio of CXCL13, CXCL8,CXCL10 in the diagnosis of neurosyphilis were 0.940, 0.899, 0.915, 0.963, 0.846 and 0.926, respectively. The corresponding sensitivities/specificities of CSF CXCL13, CXCL8,CXCL10 and the CSF/serum ratio of CXCL13, CXCL8,CXCL10 in diagnosis of neurosyphilis were 85.4%/89.1%, 79%/90.1% and 79.6%/91.1%, 86.6%/99%, 79%/73.3% and 86%/92.1%, respectively. Our results suggest that the elevated concentrations of CXCL13, CXCL8, and CXCL10 or their increasing CSF/serum ratios may be potential biomarkers of neurosyphilis, particularly for asymptomatic neurosyphilis. Reduced concentration of these chemokines may indicate the prognosis of antibiotic therapy.
OBJECTIVE: Non-Hodgkin's lymphoma (NHL) is a severe complication of primary Sjogren's syndrome (SS). Ectopic germinal centers (GCs) in the salivary glands are predictors of the occurrence of NHL. Given the association between CCL11 and CXCL13 and ectopic GCs, w
e assessed the link between these chemokines and NHL, as well as the association between these chemokines and disease activity, in patients with primary SS. METHODS: Serum levels of CCL11 and CXCL13 were evaluated by multiplex assay in 385 patients included in the Assessment of Systemic Signs and Evolution of Sjogren's Syndrome (ASSESS) cohort. The association between chemokine levels, B cell biomarkers, and patient subsets was assessed using Spearman's test for continuous data and the nonparametric Mann-Whitney U test for categorical data. Multivariate analyses were performed to identify parameters associated with lymphoma and disease activity. RESULTS: Seventeen patients had a history of lymphoma, and 5 of them had developed NHL during followup. The median serum levels of CCL11 and CXCL13 in the total cohort were 106.48 pg/ml (interquartile range 69.33-149.85) and 108.31 pg/ml (interquartile range 58.88-200.13), respectively. Patients with lymphoma had higher levels of CXCL13 than did patients without lymphoma (P = 0.006) and a trend toward a higher level of CCL11 (P = 0.056). Low C4 and high BAFF levels were associated with NHL on multivariate analysis (P = 0.01 and P = 0.0002, respectively). CCL11 and CXCL13 levels correlated positively with the rheumatoid factor titer, the kappa-to-lambda free light chain ratio, and the beta2 -microglubulin level. CXCL13 was the only parameter associated with disease activity on multivariate analysis. CONCLUSION: These findings demonstrate a link between CXCL13 and CCL11 and disease activity and lymphoma. This highlights the continuum between chronic B cell activation, disease activity, and lymphomagenesis in patients with primary SS.
Han JH, etal., Arthritis Res Ther. 2015 Sep 19;17:260. doi: 10.1186/s13075-015-0773-4.
INTRODUCTION: C-X-C motif chemokine 10 (CXCL10) is produced in response to interferon-gamma, and tumor necrosis factor-alpha (TNF-alpha) triggers the accumulation of activated lymphocytes. CXCL13 is constitutively expressed in secondary lymphoid tissues, and the
expression is upregulated by TNF-alpha, via T cell stimulation. It appears that CXCL10 and CXCL13 could play a potential role in the pathogenesis of adult-onset Still's disease (AOSD), therefore, we investigated the associations between CXCL10 and CXCL13 levels and clinical manifestations in patients with active AOSD. METHODS: Blood samples were collected from 39 active AOSD patients, 32 rheumatoid arthritis (RA) patients and 40 healthy controls (HC). Of the AOSD patients, follow-up samples were collected from 15 9.6 +/- 9.2 months later. Serum levels of CXCL10 and CXCL13 were determined using enzyme-linked immunosorbent assay. CXCL10, CXCL13, and C-X-C chemokine receptor type 3 (CXCR3) expression levels in biopsy specimens obtained from 26 AOSD patients with skin rashes were investigated via immunohistochemistry. RESULTS: The CXCL10 levels in AOSD patients (1,031.3 +/- 2,019.6 pg/mL) were higher than in RA (146.3 +/- 91.4 pg/mL, p = 0.008) and HC (104.4 +/- 47.9 pg/mL, p = 0.006). Also, the CXCL13 levels of AOSD patients (158.8 +/- 151.2 pg/mL) were higher than those of RA (54.4 +/- 61.1 pg/mL, p < 0.001) and HC (23.5 +/- 18.1 pg/mL, p < 0.001). Serum CXCL10 levels correlated with ferritin and systemic scores. Serum CXCL13 levels correlated with those of hemoglobin, C-reactive protein, ferritin, and albumin, and systemic scores. In follow-up AOSD patients, the levels of CXCL10 and CXCL13 fell significantly (153.7 +/- 130.1 pg/mL, p = 0.002, and 89.1 +/- 117.4 pg/mL, p = 0.001, respectively). On immunohistochemistry, the percentages of inflammatory cells expressing CXCL10 ranged from 1 to 85%, CXCL13 from 1 to 72%, and CXCR3 from 2 to 65%. The percentage of CXCL10-positive inflammatory cells was higher in skin biopsy samples exhibiting mucin deposition than in those that did not (p = 0.01). CXCL13 levels were correlated with those of CD4 and CD68. CONCLUSIONS: Serum CXCL10 and CXCL13 levels may serve as clinical markers for assessment of disease activity in AOSD. CXCL10/CXCR3 and CXCL13 may contribute to the inflammatory response, especially skin manifestations thereof, in AOSD.
The three skin disorders of Lyme borreliosis in Europe include erythema migrans, an acute, self-limited lesion; borrelial lymphocytoma, a subacute lesion; and acrodermatitis chronica atrophicans, a chronic lesion. Using quantitative reverse transcription-PCR, we determined mRNA expression of select
ed chemokines, cytokines, and leukocyte markers in skin samples from 100 patients with erythema migrans, borrelial lymphocytoma, or acrodermatitis chronica atrophicans and from 25 control subjects. Chemokine patterns in lesional skin in each of the three skin disorders included low but significant mRNA levels of the neutrophil chemoattractant CXCL1 and the dendritic cell chemoattractant CCL20 and intermediate levels of the macrophage chemoattractant CCL2. Erythema migrans and particularly acrodermatitis lesions had high mRNA expression of the T-cell-active chemokines CXCL9 and CXCL10 and low levels of the B-cell-active chemokine CXCL13, whereas lymphocytoma lesions had high levels of CXCL13 and lower levels of CXCL9 and CXCL10. This pattern of chemokine expression was consistent with leukocyte marker mRNA in lesional skin. Moreover, using immunohistologic methods, CD3(+) T cells and CXCL9 were visualized in erythema migrans and acrodermatitis lesions, and CD20(+) B cells and CXCL13 were seen in lymphocytoma lesions. Thus, erythema migrans and acrodermatitis chronica atrophicans have high levels of the T-cell-active chemokines CXCL9 and CXCL10, whereas borrelial lymphocytoma has high levels of the B-cell-active chemokine CXCL13.
Olsson KM, etal., Respir Res. 2016 Feb 29;17:21. doi: 10.1186/s12931-016-0336-5.
BACKGROUND: Chemokine CXC ligand 13 (CXCL13) has been implicated in perivascular inflammation and pulmonary vascular remodeling in patients with idiopathic pulmonary artery hypertension (IPAH). We wondered whether CXCL13 ma
y also play a role in chronic thromboembolic pulmonary hypertension (CTEPH) and whether serum levels of CXCL13 might serve as biomarkers in these conditions. METHODS: Lung tissue from patients with IPAH or CTEPH was immunostained for CXCL13. Serum samples were obtained from patients with IPAH (n = 42) or CTEPH (n = 50) and from healthy controls (n = 13). Serum CXCL13 concentrations were measured by enzyme-linked immunosorbent assay technology and were evaluated for associations with markers of disease severity and survival. RESULTS: CXCL13 was expressed in pulmonary vascular lesions and lymphocytes of patients with IPAH and inoperable CTEPH, respectively. Serum CXCL13 was elevated in patients compared to healthy controls [median, interquartile range, 83 (55,114) pg/ml versus 40 (28, 48) pg/ml; p < 0.001]. Serum CXCL13 showed only weak and inconsistent correlations with markers of inflammation or disease severity. In both populations, patients with serum CXCL13 above the median of the respective groups did not have a higher risk of death than patients with lower serum CXCL13. CONCLUSIONS: CXCL13 was overexpressed in pulmonary vascular lesions of patients with IPAH and CTEPH, and increased serum concentrations were found in patients with IPAH and CTEPH, suggesting a potential pathogenic role of CXCL13 in both diseases. However, given the weak associations between serum CXCL13 and markers of disease severity and outcome, CXCL13 is unlikely to become a promising biomarker in these patient populations.
BACKGROUND: A considerable proportion of autoimmune hemolytic anemia (AIHA) are secondary to underlying autoimmune disorders, especially syetemic lupus erythematosus (SLE), and the clinical and laboratory index for early discrimination between primary and SLE-related AIHA has yet to be defined. In t
he present study, we proposed novel cytokine patterns in the pathogenesis of AIHA as well as parameters for the timely identification of SLE-related patients. METHODS: AIHA patients confirmed by immunohematology techniques from September 2010 to December 2012 in our facility were consecutively included and categorized into primary (n = 19) and SLE-related (n = 18) groups. Plasma cytokine profiles were measured in a single procedure by Quantibody Human Inflammatory Array 1 (RayBiotech, Norcross, GA). RESULTS: SLE-related AIHA patients demonstrated younger age (39 +/- 20 vs.57 +/- 16 years, p = 0.004), poorer reticulocyte compensation (6.8 +/- 7.1 vs.12.2 +/- 8.6%, p = 0.045), lower levels of lactate dehydrogenase [361 (265-498) vs. 622 (387-1154) U/L, p = 0.004], and higher occurrence of anticardiolipin antibody [9/18 (50%) vs. 2/19 (10.9%), p = 0.009]. MCP-1/CCL2, MIP-1beta/CCL4, BLC/CXCL13, IL-8/CXCL8, sTNFRI, and sTNFRII were significantly up-regulated in both groups, while sTNFRII was remarkably higher in SLE-related patients. Among both groups, hemoglobin level was negatively correlated with CXCL13 (r = -0.332, p = 0.044), while reticulocyte count was positively correlated with CCL4 (r = 0.456, p = 0.005). CONCLUSION: CXCL13 and CCL4 could act as circulating biomarkers in AIHA, and indicated disease severity and erythroid compensation, respectively. Higher plasma sTNFRII might favor the diagnosis of SLE-related instead of primary AIHA.
Sharma A, etal., Clin Immunol. 2016 Mar;164:85-94. doi: 10.1016/j.clim.2016.01.015. Epub 2016 Jan 28.
Sjogren's syndrome (SS) is a debilitating autoimmune disease. Patients with SS may develop xerostomia. This process is progressive, and there are no therapeutics that target disease etiology. We hypothesized BAFF receptor (BAFFR) blockade would mitigate SS disease development, and neutralization of
CXCL13 and BAFF signaling would be more efficacious than BAFFR blockade alone. We treated NOD/ShiLtJ SS mice with soluble BAFF receptor (BAFFR-Fc) or anti-CXCL13/BAFFR-Fc in combination, prior to the development of clinical disease. Our results show treatment with BAFFR-Fc reduced peripheral B cell numbers and decreased sialadenitis. In addition, this treatment reduced total serum immunoglobulin as well as IgG and IgM specific anti-nuclear autoantibodies. NOD/ShiLtJ mice treated with BAFFR-Fc and anti-CXCL13 antibody were protected from salivary deficits. Results from this study suggest blockade of CXCL13 and BAFFR together may be an effective therapeutic strategy in preventing salivary hypofunction and reducing autoantibody titers and sialadenitis in patients with SS.
C-X-C ligand 13 (CXCL13), a regulator of mucosal immunity, is secreted by human endometrial epithelium and may be involved in embryo implantation. However, cyclic expression of human endometrial CXCL13 in health and disease
is not well studied. This study examines cycle stage-specific endometrial CXCL13 expression in normal humans when compared to those with biopsy-confirmed, stage 1 to 4 endometriosis using real-time reverse transcriptase, real-time polymerase chain reaction and immunohistochemistry. Eutopic endometrial CXCL13 expression was also compared between normal, control Rhesus macaques, and macaques with advanced endometriosis. In healthy women, CXLC13 messenger RNA expression was minimal in the proliferative phase and maximal in the secretory phase. However, in the presence of endometriosis, proliferative-phase endometrial expression markedly increased in both humans and rhesus subjects (P < .05). The cross-species and cross-stage concordance suggests a pathophysiologic role for CXCL13 in endometriosis and its use as a biomarker for disease.
Moniuszko A, etal., Immunol Lett. 2014 Jan-Feb;157(1-2):45-50. doi: 10.1016/j.imlet.2013.11.002. Epub 2013 Nov 12.
PURPOSE: Knowledge of the role of chemokines in the inflammation during neuroborreliosis (NB) is limited. We evaluated the pre- and post-treatment concentration of CXCL8, CXCL10, CXCL11, CXCL12, and CXCL13 in serum (s) and cerebrospinal fluid (csf) in
patients with NB. RESULTS: There was a statistically significant increase in pre-treatment s CXCL8, CXCL10, CXCL11, CXCL12, CXCL13 and csf CXCL8, CXCL11, CXCL12, CXCL13 in patients with early form of NB. CXCL8, CXCL11, CXCL12 and CXCL13 increase was the highest in csf. After treatment, a significant decrease in csf chemokine levels (except CXCL10) and s levels (except CXCL11) was observed. CONCLUSIONS: CXCL8, CXCL10, CXCL11, CXCL12, CXCL13 are involved in the pathomechanism of NB but their role is different in s and csf. CXCL13 seems to be a good biomarker for NB. In early NB, it may facilitate the diagnosis and monitoring of therapy. However tick-borne encephalitis needs to be excluded as it also increases chemokine concentration. Decrease in all examined chemokines in s and csf after treatment suggests that chemokines may be useful in monitoring response to NB therapy.
Duan Z, etal., Oncotarget. 2015 Dec 29;6(42):44239-53. doi: 10.18632/oncotarget.6235.
The present study reveals an immunological characterization of circulating and tumor-infiltrating T follicular helper cells (Tfh), namely CXCR5+CD45RA-CD4+ T cells, and their related cytokines in hepatitis B virus-related hepatocellular carcinoma (HCC) patients. In HCC patients, circulating Tfh cell
s showed a CCR7+ and/or ICOS+ phenotype with increased Th2-like cells and decreased Th1-like and Th17-like subsets. Although the bulk frequency of circulating Tfh cells was not altered in HCC patients, the frequency of infiltrated CXCR5+CD45RA-CD4+ CD3+cells was higher in tumor than in para-tumor tissues, and Th1-like cells were the predominant phenotype. Circulating Tfh cells in HCC patients were defective in the production of IL-21 in vitro, which was in accordance with lower IL-21 levels in tumor tissues than in para-tumor tissues. Serum CXCL13 was increased in HCC patients and associated with recurrence-free survival after hepatectomy. This was confirmed in an additional HCC cohort of 111 patients with up to 5 years follow-up. Immunohistochemical staining indicated that the percentage of CXCR5+ or CXCL13+ cells was higher in poorly differentiated than in well-differentiated tumors. In conclusion, patients with HBV-related HCC showed altered phenotypes and impaired function of Tfh cells or subpopulations. CXCL13 could be a potential biomarker for predicting recurrence in HCC patients after hepatectomy.
Wang GZ, etal., Elife. 2015 Nov 13;4. pii: e09419. doi: 10.7554/eLife.09419.
More than 90% of lung cancers are caused by cigarette smoke and air pollution, with polycyclic aromatic hydrocarbons (PAHs) as key carcinogens. In Xuanwei City of Yunnan Province, the lung cancer incidence is among the highest in China, attributed to smoky coal combustion-generated PAH pollution. H
ere, we screened for abnormal inflammatory factors in non-small cell lung cancers (NSCLCs) from Xuanwei and control regions (CR) where smoky coal was not used, and found that a chemokine CXCL13 was overexpressed in 63/70 (90%) of Xuanwei NSCLCs and 44/71 (62%) of smoker and 27/60 (45%) of non-smoker CR patients. CXCL13 overexpression was associated with the region Xuanwei and cigarette smoke. The key carcinogen benzo(a)pyrene (BaP) induced CXCL13 production in lung epithelial cells and in mice prior to development of detectable lung cancer. Deficiency in Cxcl13 or its receptor, Cxcr5, significantly attenuated BaP-induced lung cancer in mice, demonstrating CXCL13's critical role in PAH-induced lung carcinogenesis.
BACKGROUND: Young breast cancer occupies a higher and higher proportion of breast cancer, especially in Asia, and is associated with a more unfavorable prognosis compared with the disease arising in older women. However, the poor prognosis of young breast cancer cannot be fully explained by the cli
nical and molecular factors. METHODS: This study investigated 1125 Chinese breast cancer patients diagnosed from 2009 to 2013. A data mining of gene expression profiles was performed for the young and older breast cancer patients, identifying significantly differentially expressed genes. Quantitative RT-PCR, Western blotting and immunohistochemistry assay were carried out for the clinical sample validations. RESULTS: The investigation firstly displayed that young patients (=45 years) accounted for 47.6 % (535/1125) of breast cancer, and clinically associated with some unfavorable factors related to poor prognosis, such as invasive pathological type, high tumor grade, lymph node positive, ER negative and triple-negative subtype. Subsequently, 553 significantly differentially expressed genes were identified by the data mining. Of them, a set of genes related to immune function were observed to be up-regulated in young patients with breast cancer. Impressively, the CXCL13 (C-X-C motif chemokine 13) expression level showed the most significant difference (FC = 2.64, P = 8.2 x 10(-4)). Furthermore, the validations with clinical samples and correlation analysis demonstrated that CXCL13 was indeed highly expressed in young breast cancer and closely associated with some prognostic factors including lymph node positive and ER negative. CONCLUSION: This is the first to indicate the clinical relevance of CXCL13 to young breast cancer and represents a potential therapeutic target for young breast cancer.