A plasmonic nanoparticle-embedded polydopamine substrate for fluorescence detection of extracellular vesicle biomarkers in serum and urine from patients with systemic lupus erythematosus.

There is an unmet clinical need to develop noninvasive liquid biopsy tools for systemic lupus erythematosus (SLE) diagnosis and therapeutic effect evaluation. Extracellular vesicles (EVs), which are abundant in body fluids, have emerged as a valuable resource for liquid biopsy. Herein, we describe a simple and robust EV detection platform that is based on a plasmonic nanoparticle-embedded polydopamine substrate that is modified with EV-capture molecules and detection probes. We investigated three EV biomarkers, namely, programmed cell death protein-1 (PD-1), microRNA-146a (miRNA-146a) and sialic acid (SA), in serum and urine from SLE patients and healthy controls. This platform prevents complex pretreatment while enabling highly efficient EV capture to the substrate surface, and the multiple functionalization of the detection interface with specific biomarker probes enables simultaneous detection of PD-1, miRNA-146a and SA that are carried by EVs via fluorescence (FL) imaging at the single-vesicle level. Via comparison of EV biomarker profiles, SLE patients can be distinguished from normal controls and classified into treated and untreated groups. Due to its ease of preparation, simplicity and stability, our approach shows good potential in the design of EV-based biosensors for clinical use.

Epidemiology of Takayasu arteritis in Shanghai: A hospital-based study and systematic review.

BACKGROUND: Takayasu arteritis (TAK) is a rare large vessel vasculitis, and epidemiological data on TAK are lacking in China. Thus, we designed this study to estimate the TAK prevalence and incidence in residential Shanghai, China. METHODS: Data on diagnosed TAK cases aged over 16 years were retrieved from 22 tertiary hospitals in Shanghai through hospital electronic medical record systems between January 1, 2015 and December 31, 2017 to estimate the prevalence and incidence. A systematic literature review based on searches in PubMed, Ovid-Medline, Excerpta Medica Database (EMBASE), Web of Science, and China National Knowledge Infrastructure (CNKI) was performed to summarize TAK distribution across the world. RESULTS: In total 102 TAK patients, with 64% female, were identified. The point prevalence (2015-2017) was 7.01 (95% CI 5.65-8.37) cases per million, and the mean annual incidence was 2.33 (1.97-3.21) cases per million. The average age of TAK patients was 44 ± 16 years, with the highest prevalence (11.59 [9.23-19.50] cases per million) and incidence (3.55 [0.72 3.74] cases per million) in the 16 to 34 years population. Seventeen reports were included in the system review, showing that the epidemiology of TAK varied greatly across the world. The incidence and prevalence were both relatively higher in Asian countries, with the prevalence ranging 3.3-40 cases per million and annual incidence ranging 0.34-2.4 cases per million. CONCLUSIONS: The prevalence and incidence of TAK in Shanghai was at moderate to high levels among the previous reports. The disease burden varied globally among racial populations.

Anti-Interferon Autoantibodies in Adult-Onset Immunodeficiency Syndrome and Severe COVID-19 Infection.

Adult-onset immunodeficiency syndrome due to anti-interferon (IFN)-γ autoantibodies has attracted much attention in recent years. It usually occurs in previously healthy people and usually presents as chronic, recurrent, and hard-to-control infections that can be effectively treated with aggressive antibiotic therapy. Adult-onset immunodeficiency syndrome is also referred to as AIDS-like syndrome. Anti-type I IFN (IFN-I) autoantibodies have been reported to play a significant role in the pathogenesis of coronavirus disease 2019 (COVID-19) and preexisting anti-IFN-I autoantibodies are associated with an increased risk of severe COVID-19. This review summarizes the effects of anti-IFN autoantibodies on the susceptibility and severity of various infectious diseases, including SARS-CoV-2 infection. In addition, we discuss the role of anti-IFN autoantibodies in the pathogenesis of autoimmune diseases that are characterized by recurrent infections.

The amino acid variants in HLA II molecules explain the major association with adult-onset Still's disease in the Han Chinese population.

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease with systemic involvement, and its pathophysiology remains unclear. Genome-wide association studies (GWAS) in the Chinese population have revealed an association between AOSD and the major histocompatibility complex (MHC) locus; however, causal variants in the MHC remain undetermined. In the present study, we identified independent amino-acid polymorphisms in human leukocyte antigen (HLA) molecules that are associated with Han Chinese patients with AOSD by fine-mapping the MHC locus. Through conditional analyses, we identified position 34 in HLA-DQα1 (p = 1.44 × 10-14) and Asn in HLA-DRß1 position 37 (p = 5.12 × 10-11) as the major determinants for AOSD. Moreover, we identified the associations for three main HLA class II alleles: HLA-DQB1*06:02 (OR = 2.70, p = 3.02 × 10-14), HLA-DRB1*15:01 (OR = 2.44, p = 3.66 × 10-13), and HLA-DQA1*01:02 (OR = 1.97, p = 1.09 × 10-9). This study reveals the relationship between functional variations in the class II HLA region and AOSD, implicating the MHC locus in the pathogenesis of AOSD.

Clinical performance of automated chemiluminescent methods for anticardiolipin and anti-ß2-glycoprotein I antibodies detection in a large cohort of Chinese patients with antiphospholipid syndrome.

INTRODUCTION: To assess the clinical performance and correlations of automated chemiluminescence assay (CIA) and enzyme-linked immunosorbent assay (ELISA) for detecting antiphospholipid (aPL) antibodies in the diagnosis of antiphospholipid syndrome (APS). METHODS: The study recruited 505 subjects, including 192 with APS, 193 with connective tissue diseases other than APS, and 120 healthy donors. We measured anticardiolipin (aCL) and anti-ß2-glycoprotein I (anti-ß2GPI) antibodies IgG, IgM, and IgA in all the samples using both CIA and ELISA. RESULTS: Total agreement between the two methods ranged from 83.50% for anti-ß2GPI IgG antibodies to 92.76% for anti-ß2GPI IgM antibodies in all the groups. Anti-ß2GPI and aCL IgG assays showed the highest Spearman's rho coefficients (anti-ß2GPI IgG = 0.742, aCL IgG = 0.715). Anti-ß2GPI IgG CIA showed the highest sensitivity for diagnosis of APS at 80.21%, which was significantly higher than the sensitivity of anti-ß2GPI IgG ELISA (52.08%). For diagnosis of APS, anti-ß2GPI IgG CIA had the best discrimination power with the area under the curves (AUC) of 0.922, followed by aCL IgG CIA (AUC of 0.905). While the CIA AUC was slightly higher in all cases, the difference was not statistically significant. CONCLUSION: CIA measurements had a good agreement and correlation with comparative ELISA assays. The CIA anti-ß2GPI IgG however was significantly more sensitive for APS diagnosis. The two assay methodologies showed comparable predictive powers and support the value of the CIA method for improved diagnosis and management of patients with APS.

Pathogenesis, disease course, and prognosis of adult-onset Still's disease: an update and review.

OBJECTIVE: Adult-onset Still's disease (AOSD) is a rare but clinically well-known polygenic systemic autoinflammatory disease. In this review, we aim to present frontiers in the pathogenesis, clinical features, diagnosis, biomarkers, disease course, prognosis, and treatment in AOSD. DATA SOURCES: We retrieved information from the PubMed database up to July 2019, using various search terms and relevant words, including AOSD and Still's disease. STUDY SELECTION: We included data from peer-reviewed journals. Both basic and clinical studies were selected. RESULTS: Pathogenesis of AOSD involves genetic background, infectious triggers, and immunopathogenesis, mainly the activation of macrophages and neutrophils followed by a cytokine storm. Diagnosis and prognosis evaluation of AOSD is still challenging; therefore, there is an urgent need to identify better biomarkers. Biologic agents, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α antagonists in the treatment of AOSD, have good prospect. CONCLUSION: This review highlights the advances in pathogenesis, potential biomarkers, disease course, and treatment in AOSD.

Clinical features and current treatments of adult-onset Still's disease: a multicentre survey of 517 patients in China.

OBJECTIVES: As a rare systemic autoinflammatory disease, adult-onset Still's disease (AOSD) has heterogeneous clinical manifestations, response to treatment and outcome. This study tried to assess the clinical characteristics, laboratory tests, and treatments of Chinese AOSD patients, and make a retrospective analysis. METHODS: We collected from 7 hospitals in China a total of 517 Chinese patients with AOSD who satisfied the Yamaguchi criteria. We retrospectively evaluated their clinical features, laboratory tests, treatments and compared them with published data from different studies. All the data in this study were from medical records and further statistic analyses. RESULTS: We evaluated a total of 517 AOSD patients, 72% female, average age of onset was 37.7; spiking fever, rash and arthralgia occurred in 472 (91.3%), 413 (79.9%), 378 (73.1%) cases, respectively. There were 439/513 (85.6%) cases with leukocytosis and 456/476 (95.8%) cases with raised serum ferritin. The highest frequently used medications and regimens for remission were glucocorticoids (498/517, 96.3%), methotrexate (273/517, 52.8%) and hydroxychloroquine (174/517, 33.7%). 84.4%. 357/423 of AOSD cases were able to achieve initial remission with different regimens, mostly including glucocorticoids, methotrexate or hydroxychloroquine. 47.2% of them (244/517) received 30

Hydroxychloroquine Improves Obesity-Associated Insulin Resistance and Hepatic Steatosis by Regulating Lipid Metabolism.

The burden of obesity and associated cardiometabolic diseases has been considered as an important risk factor for lupus patients. Therefore, whether obesity is involved in the over-activation of autoimmune response has attracted more and more attention. Hydroxychloroquine is a synthetic antimalarial drug and has been the clinical treatment of rheumatic diseases irreplaceable first-line drugs. Hydroxychloroquine has been suggested to have beneficial effects on lipids and insulin sensitivity, which may contribute in lowering high cardiovascular risk in SLE patients. However, its mechanism on insulin sensitivity and lipid disorders is far from being completely understood. In the present study, the therapeutic effects of hydroxychloroquine were evaluated under pathological conditions in vivo. Obesity was induced in C57BL/6 mice fed with high-fed diet, or in mice fed with high-fat diet and hydroxychloroquine. In addition, healthy mice that received normal chow diet were also monitored. The present results revealed that hydroxychloroquine reduced weight, hepatic steatosis, glucose, and insulin resistance. Furthermore, hydroxychloroquine downregulated the expression of peroxisome proliferator-activated receptor gamma in the liver. According to these present results, genes about lipid metabolism went down in high-fat mice liver. Hydroxychloroquine shows potential in ameliorating obesity-induced pathology, which acts though PPARγ to facilitate the healthy function of hepatic tissues. This evidence shows that hydroxychloroquine plays a role in improving obesity-induced lipotoxicity and insulin resistance though the peroxisome proliferator-activated receptor gamma pathway.

Causes of death in hospitalized patients with systemic lupus erythematosus: a 10-year multicenter nationwide Chinese cohort.

To estimate the mortality and describe the causes of death in a large multicenter cohort of hospitalized patients with SLE in China. This was a retrospective study of a nationwide SLE cohort (10 centers, 29,510 hospitalized patients) from 2005 to 2014 in China. Standardized mortality ratios (SMRs) were calculated for all death and were stratified by sex and age. Chi-square test was used to determine whether the major causes of death vary in age, sex, duration of SLE, disease activity, or medications. Comparison between dead patients and survival controls was used to identify the risk factors for mortality. Logistic regression analysis was used to evaluate the risk factors for mortality. A total of 360 patients died during the study period, accounting for 1.22%. The overall SMR was 2.13 (95% CI 1.96, 2.30), with a particularly high SMR seen in subgroups characterized by younger age. Infection (65.8%) was the most common cause of death, followed by lupus nephritis (48.6%), hematological abnormality (18.1%), neuropsychiatric lupus/NPSLE (15.8%), and interstitial pneumonia (13.1%). Cardiovascular disease and malignancy contributed little to the causes of death. Infection, in particular severe pulmonary infection, emerged as the foremost risk factor for mortality, followed by lupus encephalopathy. However, lupus nephritis and hematological abnormalities occurred more frequently in survival patients. SLE patients at a younger age of diagnosis have a poorer prognosis. Infection dominated the causes of death in recent China. Ethnicity and medications might account for the differences in causes of death compared with western populations.

Antiphosphatidylserine/prothrombin antibodies (aPS/PT) as potential diagnostic markers and risk predictors of venous thrombosis and obstetric complications in antiphospholipid syndrome.

BACKGROUND: The aim of the study was to determine the prevalence and clinical associations of antiphosphatidylserine/prothrombin antibodies (aPS/PT) with thrombosis and pregnancy loss in Chinese patients with antiphospholipid syndrome (APS) and seronegative APS (SNAPS). METHODS: One hundred and eighty six Chinese patients with APS (67 primary, 119 secondary), 48 with SNAPS, 176 disease controls (79 systemic lupus erythematosus [SLE], 29 Sjogren's syndrome [SS], 30 ankylosing spondylitis [AS], 38 rheumatoid arthritis [RA]) and 90 healthy donors were examined. IgG and IgM aPS/PT, IgG/IgM/IgA anticardiolipin (aCL) and IgG/IgM/IgA anti-ß2-glycoprotein I (anti-ß2GPI) antibodies were tested by ELISA. RESULTS: One hundred and sixty (86.0%) of APS patients were positive for at least one aPS/PT isotype. One hundred and thirty five (72.6%) were positive for IgG aPS/PT, 124/186 (66.7%) positive for IgM aPS/PT and 99 (53.2%) positive for both. Approximately half of the SNAPS patients were positive for IgG and/or IgM aPS/PT. Highly significant associations between IgG aPS/PT and venous thrombotic events (odds ratio [OR]=6.72) and IgG/IgM aPS/PT and pregnancy loss (OR=9.44) were found. Levels of IgM aPS/PT were significantly different in APS patients with thrombotic manifestations and those with fetal loss (p=0.014). The association between IgG/IgM aPS/PT and lupus anticoagulant (LAC) was highly significant (p<0.001). When both were positive, the OR for APS was 101.6. Notably, 91.95% (80/87) of LAC-positive specimens were positive for IgG and/or IgM aPS/PT, suggesting aPS/PT is an effective option when LAC testing is not available. CONCLUSIONS: Anti-PS/PT antibody assays demonstrated high diagnostic performance for Chinese patients with APS, detected some APS patients negative for criteria markers and may serve as potential risk predictors for venous thrombosis and obstetric complications.

IgMk paraprotein from gammopathy patient can bind to cardiolipin and interfere with coagulation assay: a case report.

BACKGROUND: The monoclonal gammopathies are a group of plasma-cell proliferative disorders characterized by the secretion of monoclonal immunoglobulin (M protein or paraprotein). Some rare cases have revealed the specific affinity of paraprotein as autoantibody. Here we report a patient with monoclonal gammopathy of undetermined significance (MGUS) accompanied by a remarkable increase of anticardiolipin antibody (aCL) and an extensively decreased coagulation factor activity, however, without any clinical signs of antiphospholipid syndrome (APS) and bleeding. RESULTS: Our further investigation indicated that IgMκ paraprotein of this patient possessed an antibody activity against phospholipids so as to bind to cardiolipin and interfere with coagulation assay in vitro. CONCLUSIONS: This case might be indicative that an abnormality of coagulation tests, disturbed by IgMκ paraprotein, does not predict a risk of bleeding in this patient.

5-Aminosalicylic Acid Attenuates Monocrotaline-Induced Pulmonary Arterial Hypertension in Rats by Increasing the Expression of Nur77.

The aim of this study is to investigate the effect of 5-aminosalicylic acid (5-ASA) on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats and its molecular mechanism. Sixty male Sprague-Dawley rats (250-300 g) were evenly randomized into six groups: control group; PAH group induced by MCT intraperitoneal injection (50 mg/kg) on day 1; and four PAH groups treated for 30 days from day 2 with 5-ASA at 50 (5-ASA-50 group), 100 (5-ASA-100 group), 150 (5-ASA-150 group), and 200 mg/kg/day (5-ASA-200 group), respectively. Body mass, weight increment, survival rates, pulmonary artery pressure (PAP), right ventricular hypertrophy index (RVHI), and the signal pathway regulated by 5-ASA were assessed. (1) Compared with the control group, the PAH group had lower body mass and weight increment, and relative to the latter, 5-ASA-treated groups had larger body mass and weight increment except for groups 5-ASA-150 and 5-ASA-200 and greater overall survival rates; (2) SPAP, DPAP, MPAP, and RVHI in 5-ASA-treated groups, except for MPAP and RVHI in 5-ASA-200 group, were lower than those in the PAH group; (3) compared with the PAH group, Nur77 expression in the pulmonary arteries of 5-ASA-treated groups was increased; and (4) expression of inflammatory mediators (NF-κB p65) was lower, while that of IκBα was higher in the pulmonary arteries of 5-ASA-treated groups and control group than that in the PAH group (all P < 0.05). 5-ASA attenuates PAH in MCT-injected rats, reducing pulmonary arterial pressures and right ventricular hypertrophy and improving survival rates, via the Nur77-NF-κB/IκBα pathway involved in modulating the pulmonary vascular remodeling.

Clinical characteristics and laboratory findings of 252 Chinese patients with anti-phospholipid syndrome: comparison with Euro-Phospholipid cohort.

This study aims to characterize the Chinese Han patients with anti-phospholipid syndrome (APS) and compare the data with those of the Euro-Phospholipid cohort. We conducted a single center study consisting of 252 patients with definite APS from 2000 to 2015. We analyzed the clinical and laboratory characteristics of our cohort and compared the data with those of the Euro-Phospholipid cohort. Our cohort consisted of 216 females and 36 males, with a mean age at entry into this study of 41 years (range 11-74 years). Of these patients, 69 (27.4%) patients had primary APS, and 183 (72.6%) had secondary APS (SAPS), including 163 (64.7%) patients had systemic lupus erythematosus (SLE). Thrombotic events occurred in 190 (75.4%) patients, and the most common ones were deep vein thrombosis (40.1%) and stroke (23.8%), which were similar to the reports of the Euro-Phospholipid cohort. In contrast, our cohort had less pulmonary embolism (6.7%). Among 93 females with 299 pregnancy episodes, the rates of early (<10 weeks) and late fetal loss (≥10 weeks) were, respectively, 37.8% and 24.4%. The latter was significantly higher than that of the Euro-Phospholipid cohort. Moreover, 7 APS nephropathy patients (characterized histopathologically by thrombotic microangiopathy) and 8 catastrophic APS patients were found in our cohort. Anti-cardiolipin antibodies (aCL) were detected in 169 (67.1%) patients, lupus anti-coagulant (LA) was detected in 83 (32.9%), and anti-ß2 glycoprotein I antibodies (anti-ß2GPI) in 148 (58.7%) patients. These results show that some clinical manifestations of APS may vary among different racial groups.

Erratum to "The Characteristics and Significance of Locally Infiltrating B Cells in Lupus Nephritis and Their Association with Local BAFF Expression".

[This corrects the article DOI: 10.1155/2013/954292.].

The Application of Intravascular Ultrasound to Evaluate Pulmonary Vascular Properties and Mortality in Patients with Pulmonary Arterial Hypertension.

BACKGROUND: The aim of this study was to explore the application of intravascular ultrasound (IVUS) to evaluate pulmonary vascular properties and mortality in patients with pulmonary arterial hypertension (PAH). METHODS: Patients (n = 51) with systolic pulmonary artery pressures ≥ 40 mm Hg on echocardiography were prospectively enrolled. All patients underwent right-heart catheterization and IVUS and were divided into three groups: PAH associated with connective tissue diseases (group 1, n = 25), PAH due to other causes (group 2, n = 15), and patients with connective tissue diseases without pulmonary hypertension (group 3, n = 11). PAH groups (groups 1 and 2) were divided into distal (n = 22) and proximal (n = 18) remodeling subtypes on the basis of IVUS results. All patients were followed (19 ± 10 months) to compare the differences among clinical variables, pulmonary vascular properties, and survival rates. RESULTS: A total of 408 segments of pulmonary arteries were studied. The PAH groups demonstrated a greater mean wall thickness than group 3 (P < .01 for all). Pulmonary vascular mechanical properties, including compliance, distensibility, elastic modulus, and stiffness index ß, were found to be worse in the PAH groups than in group 3 (P < .01 for all), but they tended to be better in group 1 than in group 2. An inverse exponential association was found between pulmonary vascular mechanical properties and hemodynamics, with R(2) values ranging from 0.54 to 0.78 (P < .001). In the PAH groups, the mortality in group 1 was similar to that in group 2 (12% vs 13%, P > .05), while the distal remodeling subtype had higher mortality than the proximal remodeling subtype (23% vs 0%, P < .05). CONCLUSIONS: IVUS is useful in PAH assessment by evaluating pulmonary vascular properties and predicting mortality. The classification of the proximal and distal remodeling type of PAH may be proposed to predict mortality and evaluate the prognosis of patients with PAH in clinical practice.

Two-dimensional echocardiography in the assessment of long-term prognosis in patients with pulmonary arterial hypertension.

OBJECTIVE: To investigate the relationship between cardiac diastolic dysfunction and outcomes in patients with pulmonary arterial hypertension (PAH) and to clarify the potential effect of two-dimensional echocardiography (2D-echo) on prognostic value in patients with PAH. METHODS: Patients diagnosed with PAH (as WSPH (World Symposia on Pulmonary Hypertension) classification I) confirmed by right heart catheterization (RHC), received targeted monotherapy or combination therapy. 2D-echo parameters, World Health Organization (WHO) functional classification and 6-minute walking distance (6MWD) were recorded. The clinical prognosis of patients was assessed by the correlation between echo parameters and clinical 6MWD using receiver operating characteristic (ROC) curve analysis. RESULTS: Fifty-eight patients were included. Left and right ventricular diastolic dysfunction (LVDD and RVDD) scores measured by 2D-echo had good correlation with 6MWD at baseline (rLVDD  = -0.699; rRVDD  = -0.818, both P < 0.001) and at last follow-up (rLVDD  = -0.701; rRVDD  = -0.666, both P<0.001). Furthermore, bi-ventricular (LVDD + RVDD) scores measured by 2D-echo had a better correlation with 6MWD at baseline and last follow-up (r =  0.831; r = -0.771, both P < 0.001). ROC curve analysis showed that the area under curves (AUCs) for LVDD score, RVDD score and (LVDD + RVDD) scores were 0.823 (P < 0.0001), 0.737 (P = 0.0002), and 0.825 (P < 0.0001), respectively. Compared with ROC analysis of other single parameters, cardiac diastolic function score was more accurate in predicting survival in patients with PAH. CONCLUSION: LVDD score, RVDD score and (LVDD + RVDD) scores yielded a comprehensive quantitative assessment of LV and RV diastolic function that correlated moderately with clinical functional parameters and might be useful in the assessment of PAH.

Infective endocarditis with antineutrophil cytoplasmic antibody: report of 13 cases and literature review.

OBJECTIVE: Chronic infections tend to induce the production of antineutrophil cytoplasmic antibody (ANCA). Infective endocarditis (IE) has been reported to exhibit positive ANCA tests and to mimic ANCA-associated vasculitis, which may lead to a misdiagnosis and inappropriate treatment. The aim of this study was to clarify whether there is any difference in the clinical features between ANCA-positive IE and ANCA-negative IE. METHODS: A retrospective study was carried out on 39 IE patients whose proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA levels were measured. After dividing the patients into ANCA-positive and ANCA-negative IE, we compared their clinical features. RESULTS: we compared 13 ANCA-positive IE patients with 26 ANCA-negative IE patients. All 13 ANCA-positive IE patients were proteinase-3-ANCA positive. Compared with the ANCA-negative IE group, the prevalence of edema of the lower extremities, the serum lactate dehydrogenase (LDH) level and positive blood cultures rate were higher in ANCA-positive IE group, but there was no significant difference in other clinical features. CONCLUSION: Therefore, if a patient presents with fever, arthralgia, skin rash and is ANCA-positive, appropriate steps should be taken to exclude infection (especially IE) before confirming the diagnosis of ANCA-associated vasculitis and embarking on long-term immunosuppressive therapy.

The Characteristics and Significance of Locally Infiltrating B Cells in Lupus Nephritis and Their Association with Local BAFF Expression.

Introduction. Dysfunction of the B lymphocyte is considered to be involved in the pathogenesis of lupus nephritis (LN). Intrarenal B cells have been found in several forms of inflammatory kidney disease. B-cell activating factor (BAFF) regulates B lymphocyte proliferation and survival, and contributes to human autoimmune disease. Their role in renal inflammation is not well defined. Methods. Clinical parameters and renal biopsies from 62 LN patients were prospectively analyzed. We performed standard immunohistochemistry on serial paraffin tissue sections using monoclonal antibodies to CD20 and BAFF to investigate the characteristics and significance of locally infiltrating B cells and local BAFF expression in patients with LN. Results. Intrarenal B cells and/or BAFF were mainly distributed in the renal interstitium. Compared to the LN-non-B-cell/BAFF expression group, proteinuria (g/24 hour), blood urea nitrogen, serum creatinine levels, LN renal activity, and chronicity indices, were all significantly greater in the LN-B-cell/BAFF expression groups. The expression of BAFF was strongly associated with the quantity of B-cell infiltrate in the interstitium. Conclusion. As BAFF expression was strongly associated with B-cell infiltration, we hypothesize that altered B-cell differentiation and tolerance induced by excess BAFF may be central to the pathogenesis of LN.