Metformin downregulates Th17 cells differentiation and attenuates murine autoimmune arthritis

INTRODUCTION

This study was undertaken to determine whether metformin has anti-inflammatory effects in the collagen antibody-induced arthritis (CAIA) murine model. The effect of metformin on Th17 cell differentiation was also investigated.

METHODS

CAIA mice were treated with 100 and 150 mg/kg i.p. metformin (low- and high-dose groups, respectively). Arthritis activity and histological joint destruction were studied. Flow cytometry was used to (i) determine RORγt-expressing CD4+ percentages in draining axillary lymph nodes (ALNs) from metformin-treated and untreated mice with CAIA, (ii) determine Th17 percentages in splenic CD4+ T cells cultured ex vivo for 3 days in Th17-differentiation-inducing conditions, and (iii) determine the percentages of RORγt+CD4+ T cells when normal splenic T cells from DBA/1 mice were cultured in Th17-differentiation-inducing conditions together with various metformin doses. Western blot analysis was used to assess the intracellular signaling of the metformin-treated splenocytes.

RESULTS

Metformin attenuated both arthritis scores and bone destruction in CAIA mice, decreased the serum levels of the pro-inflammatory cytokines, TNF-α and IL-1, and reduced the number of RORγt+CD4+ T cells in the ALNs. Splenocytes from metformin-treated CAIA mice differentiated less readily into Th17 cells upon ex vivo stimulation. Metformin treatment of normal cells cultured in Th17-differentiation-inducing conditions decreased the number of RORγt-expressing CD4+ cells in a dose-dependent manner and downregulated STAT3 phosphorylation via the AMPK pathway.

CONCLUSIONS

Metformin had an anti-inflammatory effect on murine autoimmune arthritis due to the inhibition of Th17 cell differentiation. Metformin may have a possible therapeutic value for treatment of rheumatoid arthritis.

Interleukin-27 suppresses osteoclastogenesis via induction of interferon-γ

Interleukin (IL)-27 is a heterodimeric cytokine that is known to have both stimulatory and inhibitory functions during immune responses. We investigated the effects of IL-27 on arthritis and bone erosion in the murine collagen-induced arthritis (CIA) model. We demonstrate that the inhibitory effect of IL-27 on osteoclastogenesis is associated with interferon-γ (IFN-γ) production by using an IFN-γ knockout mouse model. The IL-27-Fc was injected into both CIA and IFN-γ-deficient mice. The effects of IL-27-Fc on osteoclast differentiation were evaluated both in vitro and in vivo. The IL-27-Fc-injected mice showed significantly lower arthritis indices and fewer tartrate-resistant acid-phosphatase-positive osteoclasts in their joint tissues than untreated mice. Interleukin-27 inhibited osteoclastogenesis from bone marrow-derived mononuclear cells in vitro, which was counteracted by the addition of anti-IFN-γ antibody. The IL-27-Fc did not affect arthritis in IFN-γ knockout mice. Interleukin-27 also suppressed osteoclast differentiation in human and intriguingly, it could promote the expression of IFN-γ on priming osteoclasts. These results imply that IL-27 suppressed the generation of CIA and osteoclastogenesis, which were mediated by the induction of IFN-γ.

IL-17-mediated Bcl-2 expression regulates survival of fibroblast-like synoviocytes in rheumatoid arthritis through STAT3 activation

Introduction

Fibroblast-like synoviocytes (FLSs) are a major cell population of the pannus that invades adjacent cartilage and bone in rheumatoid arthritis (RA). The study was undertaken to determine the effect of interleukin-17 (IL-17) on the survival and/or proliferation of FLSs from RA patients and to investigate whether signal tranducer and activator of transcription 3 (STAT3) is implicated in this process.

Methods

Bcl-2 and Bax expression in FLSs was determined using the real-time PCR and western blot analysis. The expression of Bcl-2 and phosphoSTAT3 in synovial tissues was investigated by confocal microscope. Apoptosis of FLSs was detected by Annexin V/propidium iodide staining and/or phase contrast microscopy. The proliferation of FLSs was determined by CCK-8 ELISA assay.

Results

The pro-apoptotic Bax is decreased and anti-apoptotic Bcl-2 is increased in FLSs from RA patients compared with those from patients with osteoarthritis (OA). IL-17 upregulated the expression of Bcl-2 in FLSs from RA patients, but not in FLSs from OA patients. STAT3 was found to mediate IL-17-induced Bcl-2 upregulation in FLSs from RA patients. Additionally, IL-17 promoted the survival and proliferation of FLSs from RA patients. Most importantly, treatment with STAT3 inhibitor reversed the protective effect of IL-17 on FLSs apoptosis induced by sodium nitroprusside (SNP).

Conclusions

Our data demonstrate that STAT3 is critical in IL-17-induced survival of FLS from RA patients. Therefore, therapeutic strategies that target the IL-17/STAT3 pathway might be strong candidates for RA treatment modalities.

Predictors of renal relapse in Korean patients with lupus nephritis who achieved remission six months following induction therapy

Renal relapse in patients with lupus nephritis (LN) is a risk factor for poor renal function. Therefore, there is a need to identify clinical and serological risk factors for renal relapse. A total of 108 patients with LN were enrolled in this study. All the subjects had achieved complete remission or partial remission following six months of induction therapy. We retrospectively analyzed their clinical and laboratory indices, final renal function, and kidney biopsy findings. The median follow-up period after LN diagnosis was 81 months. Renal relapse had occurred in 36 patients; it occurred in 38% and 46% of patients within five and 10 years after achievement of renal remission, respectively. There was no difference between the relapsed rate in patients with complete remission and that in those with partial remission. Clinical variables at LN onset and renal biopsy findings in the patients with sustained remission and relapsed patients were also not different. The probability of renal relapse was significantly higher in patients with an earlier age of onset of systemic lupus erythematosus (SLE) (≤ 28 years versus >28 years; HR 7.308, P = 0.001), seronegativity for anti-Ro antibody (seronegativity versus seropositivity; HR 3.514, P = 0.007), and seropositivity for anti-dsDNA antibody at six months after initiation of induction therapy (HR 8.269, P = 0.001). Our study demonstrated that early onset of SLE, seronegativity for anti-Ro antibody and increased anti-dsDNA antibody following six months of induction therapy independently predict renal relapse among the LN patients.

Temporal differential effects of proinflammatory cytokines on osteoclastogenesis

Bone destruction and inflammation are closely linked. Cytokines play an important role in inflammatory bone destruction by upregulating the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL). The direct role of cytokines that act in a non-RANKL-dependent manner has yet to be elucidated. The aim of this study was to investigate the direct osteoclastogenic properties of inflammatory cytokines at different time-points of osteoclastogenesis. Mouse bone marrow macrophages were stimulated with the macrophage colony-stimulating factor (M-CSF) and various concentrations of RANKL. Inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-17 and IL-23, were added to the culture system of osteoclastogenesis. Two time-points of cytokine treatment were set. The ‘early’ effect of each cytokine was investigated at the time of first RANKL treatment, whereas the ‘late’ effect was investigated 48 h after the first RANKL challenge. Osteoclast differentiation and function were assessed using an osteoclast marker [tartrate-resistant acid phosphatase (TRAP)] and by visualization of pit formation. A permissive level of RANKL was required for cytokine-associated osteoclastogenesis in all experiments. In the M-CSF/RANKL monocellular culture system, IL-1β enhanced and IL-6 decreased osteoclast formation in a dose-dependent manner, regardless of temporal differences. Other cytokines showed various responses according to the phase of osteoclast maturation and the concentration of each cytokine and RANKL. Furthermore, luciferase assays showed that both IL-1β and RANKL activated the NF-κB signaling pathway. Collectively, our data revealed that targeting IL-1β may be a promising strategy to inhibit inflammation-associated bone destruction and osteoporosis.

Periarticular osteoporosis is a prominent feature in early rheumatoid arthritis: estimation using shaft to periarticular bone mineral density ratio

We aimed to quantify periarticular osteoporosis and investigate its significance in 45 patients with rheumatoid arthritis (RA) and 106 controls. Dual-energy X-ray absorptiometry (DXA) was used to determine the ratio of shaft to periarticular bone mineral density (BMD) as an index of periarticular demineralization. Periarticular osteoporosis was measured by conventional radiography. The BMDs of shaft and periarticular regions in eight designated areas on proximal phalanges were quantified. Clinical variables were examined to identify risk factors for periarticular osteoporosis. The assessment of periarticular osteoporosis on X-ray images reached a moderate degree of interobserver agreement among four physicians (ĸ = 0.47). For BMD quantification, we designed three types of mathematical formulae: the ratio of shaft to periarticular BMD, the mean of the ratios, and the ratio of the sums. These ratios were significantly higher in the patients with early RA (disease duration ≤ 3 yr) than in controls (P < 0.01). The findings were not as distinctive in patients with established RA. Body mass index, cumulative dose of corticosteroid, and C-terminal telopeptide were correlated with BMD ratios. Conclusively, DXA-assisted localized quantification and BMD ratio calculations are feasible for assessing periarticular demineralization. Periarticular osteoporosis is a relatively distinctive feature of early RA.

Predictors of end-stage renal disease and recurrence of lupus activity after initiation of dialysis in patients with lupus nephritis

OBJECTIVES

The present paper aims at identifying the predictors of end-stage renal disease (ESRD) and at determining the long-term outcome of ESRD patients according to renal replacement modality in Korean patients with lupus nephritis (LN).

METHODS

Between 1985 and 2010, 321 Korean patients with LN were enrolled in this study. We analysed the clinical and laboratory indices, the treatment responses and the biopsy findings. The events of interest were estimated by the Kaplan-Meier method and the risk factors were assessed by univariate and multivariate Cox proportional hazards regression analyses.

RESULTS

The median follow-up time after the diagnosis of LN was 84 months. During follow-up, twenty-nine patients evolved to ESRD. Renal survival rate at 5 and 10 years after LN onset was 95.9% and 91.1%, respectively. Deteriorated renal function (estimated glomerular filtration rate <60 ml/min/1.73m2) at LN onset (hazard ratio: 9.223) was found to be an independent risk factor for the development of ESRD. Recurrence of lupus nephritis in renal allograft and flare-ups of lupus activity were not observed among the patients undergoing kidney transplantation (KT) (n=11). In contrast, those with maintenance dialysis (n=18) developed 13 episodes of lupus flare in 10 patients and 5 died of either infection (n=2) or lupus flare (n=3).

CONCLUSIONS

The impaired renal function at baseline is an independent predictor of ESRD in Korean patients with LN. The benefits of KT on the control of lupus activity and survival should be emphasised.

The paradoxical effects of TNF inhibitors on bone mineral density and radiographic progression in patients with ankylosing spondylitis

OBJECTIVES

To determine the longitudinal effects of TNF inhibitors on BMD and radiographic progression in patients with AS and to assess independent factors associated with increased BMD in the lumbar spine.

METHODS

Sixty-three patients with AS were included. Twenty-six patients were treated with TNF inhibitors and 37 were not. BMD in the lumbar spine and right femur was measured by DXA at baseline and 1 and 2 years later. Lumbar spine radiography was performed at baseline and after 2 years. Radiographic progression was scored using the Stoke AS Spinal Score (SASSS) and the modified SASSS. Univariate and multivariate linear regression analyses were performed to identify factors independently associated with spinal BMD increase.

RESULTS

BMD in the lumbar spine and total proximal femur of patients receiving TNF inhibitors increased consistently over 2 years compared with that in patients not receiving TNF inhibitors (P < 0.01 and P = 0.02), and treated patients showed increased SASSS scores (P = 0.05); however, syndesmophyte development was no different between the two groups. There was a significant difference in the change of SASSS in patients treated with both TNF inhibitors and bisphosphonates compared with those treated with TNF inhibitors alone (P < 0.01). TNF inhibitor therapy and the increase in SASSS were independently associated with increased lumbar spine BMD (P = 0.009 and P < 0.001).

CONCLUSION

TNF inhibitors appear to be associated with increased SASSS scores and improvements in BMD. Further prospective studies with larger subject numbers are needed to validate this paradoxical role of TNF inhibitors.

Upregulation of stromal cell-derived factor by IL-17 and IL-18 via a phosphatidylinositol 3-kinase-dependent pathway

Th17 cells that produce interleukin (IL)-17 play a key role in the pathogenesis of autoimmune inflammation. Among the various cytokines that are involved in the IL-17 pathway, members of the IL-1β family, including IL-18, have recently gained attention. In this study, we stimulated synovial fibroblasts with a combination of IL-17 and IL-18 and quantified their stromal cell-derived factor-1 (SDF-1) production by enzyme-linked immunosorbent assay and their transcript levels by reverse transcription-polymerase chain reaction. Both IL-17 and IL-18 significantly increased the level of SDF-1, not only individually but also synergistically (P< 0.05). The synergism was effectively suppressed by anti-IL-17 and -IL-18 antibodies, and a PI3K inhibitor. To the best of our knowledge, this is the first report of PI3K-dependent synergism between IL-18 and IL-17, and this work adds a novel perspective of the role of IL-18 in immune regulation. The individual effects of these two cytokines, and their interactions, suggest an interrelationship between the IL-1 family and IL-17.

Regression of syndesmophyte after bone marrow transplantation for acute myeloid leukemia in a patient with ankylosing spondylitis: a case report

Introduction

Disease progression of ankylosing spondylitis has been considered irreversible. However, we report a case of spontaneous regression of syndesmophyte development following allogeneic peripheral blood stem cell transplantation in a patient with acute myeloid leukemia, who was also diagnosed as having ankylosing spondylitis. To the best of our knowledge, this is the first case report presenting the partial radiologic regression of syndesmophytes.

Case presentation

A 39-year-old man with active ankylosing spondylitis achieved clinical remission and partial radiological regression of cervical spine syndesmophytes following a peripheral blood stem cell transplantation for acute myeloid leukemia. Our patient received an allogeneic peripheral blood stem cell transplantation following a pre-transplantation conditioning regimen of total body irradiation and cyclophosphamide. The donor was a human leukocyte antigen-matched 29-year-old man. Our patient has remained asymptomatic and has received no medication for ankylosing spondylitis for nearly three years.

Conclusions

Several explanations are proposed for the regression of syndesmophytes and clinical improvement in active ankylosing spondylitis observed in our patient, including changes in bone remodeling and immune reconstitution following stem cell transplantation, the effect of immunosuppressive agents, or fluctuation in the natural course of ankylosing spondylitis although further studies are required. The regression of syndesmophytes in ankylosing spondylitis in this case raises the possibility that stem cell transplantation might contribute to the development of a novel therapeutic strategy for treatment of the disease.

Fulminant amoebic colitis mimicking intestinal vasculitis in a patient with systemic lupus erythematosus

Colitis in patients with systemic lupus erythematosus (SLE) is quite rare. It can be caused by intestinal vasculitis, mesenteric vascular thrombosis, concomitant inflammatory bowel disease or infectious colitis. It is important to make an accurate and early diagnosis as the treatments for each condition differ and a delayed diagnosis can result in life-threatening complications. However, non-specific gastrointestinal symptoms make a timely diagnosis challenging. Amoebic colitis is a rare condition in patients with SLE. Here we present a case of fulminant amoebic colitis in a patient with SLE which was initially misdiagnosed as ischemic colitis due to intestinal vasculitis. Her colitis was complicated with multiple intestinal perforations, disseminated intravascular coagulation and acute respiratory distress syndrome; but in the end, the patient was successfully treated with metronidazole and paromomycin.

Tacrolimus treatment increases bone formation in patients with rheumatoid arthritis

Tacrolimus is a calcineurin inhibitor, and it is used for the treatment of rheumatoid arthritis (RA). It works by inhibiting nuclear factor of activated T cells and inducting immunosuppression. This study aims to evaluate the influence of tacrolimus on the bone metabolism of patients with RA. Twenty-eight RA patients in three centers received tacrolimus 3 mg once daily for 24 weeks. Blood samples for evaluating bone metabolism and cytokines were collected at Weeks 0 and 24. We measured the serum C-telopeptide of type I collagen (sCTx-I), osteocalcin and inflammatory cytokines. We analyzed the data using the Kruskal-Wallis test and Spearman's correlation. IL-2 and IL-6 were significantly decreased after the administration of tacrolimus (p = 0.027 and p = 0.024). There was no significant difference in the serum level of sCTx-I before and after treatment. The level of serum osteocalcin at Week 24 was significantly increased compared to the level at Week 0 (p = 0.002). The increase of osteocalcin was correlated with the reductions of IL-2 and IFN-γ (r = 0.405, p = 0.033 and r = 0.380, p = 0.046, respectively). Tacrolimus treatment increased bone formation markers in RA patients. This suggests that tacrolimus may play a role to inhibit bone erosion by increasing bone formation as well as improving the clinical symptoms of RA.

Grape seed proanthocyanidin extract ameliorates monosodium iodoacetate-induced osteoarthritis

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution (P < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-1β and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.

TLR2 ligation induces the production of IL-23/IL-17 via IL-6, STAT3 and NF-kB pathway in patients with primary Sjogren's syndrome

INTRODUCTION

The study was undertaken to investigate the interrelation of toll-like receptor (TLR) and interleukin (IL)-17 in the salivary glands of patients with primary Sjogren's syndrome (pSS) and to determine the role of TLR and IL-17 in the pathophysiology of pSS.

METHODS

The expressions of various TLRs, IL-17 and the cytokines involved in Th17 cell differentiation including IL-6, IL-23, tumor necrosis factor-alpha (TNF-α) and IL-1β were examined by immunohistochemistry in salivary glands of pSS patients. The IL-17 producing CD4+ T cells (Th17 cells) were examined by flow cytometry and confocal staining in peripheral mononuclear blood cells (PMBCs) and salivary glands of pSS patients. After PBMCs were treated with TLR specific ligands, the induction of IL-17 and IL-23 was determined using real-time PCR and ELISA. The signaling pathway that mediates the TLR2 stimulated production of IL-17 and IL-23 was investigated by using treatment with specific signaling inhibitors.

RESULTS

We showed that TLR2, TLR4, TLR6, IL-17 and the cytokines associated with Th17 cells were highly expressed in salivary glands of pSS patients but not in controls. The expressions of TLR2, TLR4 and TLR6 were observed in the infiltrating mononuclear cells and ductal epithelial cells, whereas IL-17 was mainly observed in infiltrating CD4+ T cells. The number of IL-17 producing CD4+ T cells was significantly higher in pSS patients both in PBMCs and minor salivary glands. The stimulation of TLR2, TLR4 and TLR6 additively induced the production of IL-17 and IL-23 from the PBMCs of pSS patients especially in the presence of TLR2 stimulation. IL-6, signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappaB (NF-kB) pathways were implicated in the TLR2 stimulated IL-17 and IL-23.

CONCLUSIONS

Our data demonstrate that TLR2 ligation induces the production of IL-23/IL-17 via IL-6, STAT3 and NF-kB pathway in pSS. Therefore, therapeutic strategies that target TLR/IL-17 pathway might be strong candidates for treatment modalities of pSS.

Idiopathic intracranial hypertension as a significant cause of intractable headache in patients with systemic lupus erythematosus: a 15-year experience

Objective: To evaluate the occurrence of idiopathic intracranial hypertension (IIH) in patients with systemic lupus erythematosus (SLE) and to describe the manifestations, treatments and outcomes in these patients. Methods: We reviewed the medical records of 1084 patients with SLE followed up from January 1997 to June 2011 in our unit. We identified patients with IIH and analyzed the demographic, clinical and laboratory characteristics of these patients. Results: Among the 1084 SLE patients, 47 underwent cerebrospinal fluid studies because of their intractable headache and eight (17%) of these were diagnosed as IIH. All were females aged 14 to 32 years. Nobody belonged to the obesity group. Headache, nausea, vomiting and blurred vision were the most common presenting symptoms. All patients had active SLE at the time of admission (SLE disease activity index ≥6). Five patients had lupus nephritis. In eight patients, there were two with antiphospholipid antibodies, two with anti-ribosomal P antibodies and six with anti-Ro antibodies. All subjects recovered without any complication after high dose steroid therapy. Conclusions: IIH accounts for a considerable part of the causes of intractable headache in SLE patients and steroids should be considered as a first-line treatment.

Reactive hemophagocytic syndrome in adult Korean patients with systemic lupus erythematosus: a case-control study and literature review

OBJECTIVE

To determine the characteristics of hemophagocytic syndrome (HPS) in adult Korean patients with systemic lupus erythematosus (SLE).

METHODS

We reviewed the medical records of 1033 adult patients with SLE for a recent 14-year period and identified 15 patients who had developed HPS. Forty-two age- and sex-matched patients with SLE admitted for other manifestations were included as disease controls. Features of HPS in these patients were analyzed.

RESULTS

Reactive HPS occurred from some distinct causes during the course of SLE. HPS was associated with SLE in 11 patients (4 at onset of SLE and 7 at SLE flare), infection in 3 patients (2 bacterial infection; 1 viral infection), and drug use (azathioprine) in 1 patient. Common clinical features included fever (93.3%), hepatomegaly (60.0%), and splenomegaly (60.0%). Steroid pulse therapy (46.7%), immunosuppressants (46.7%), and intravenous immunoglobulin (46.7%) were frequently used for treatment of HPS. One patient (6.7%) died. Compared with SLE patients without HPS, those with HPS showed a higher SLEDAI score (p = 0.003) and lower levels of plasma leukocytes (p < 0.001), hemoglobin (p = 0.013), and platelets (p < 0.001) as well as a higher serum C-reactive protein level (p = 0.039) and a lower serum albumin level (p = 0.004).

CONCLUSION

HPS was observed in 1.5% of adult Korean patients with SLE. The occurrence of HPS was most frequently associated with the SLE disease activity. Profound pancytopenia, a high SLEDAI score, and notable changes in the level of acute-phase reactants can be the characteristics of SLE patients with HPS.

Impact of interleukin-21 in the pathogenesis of primary Sjögren's syndrome: increased serum levels of interleukin-21 and its expression in the labial salivary glands

INTRODUCTION

Interleukin (IL)-21 is a cytokine that controls the functional activity of effector T helper cells and the differentiation of Th17 cells, and promotes B-cell differentiation. To test whether IL-21 participates in the pathogenesis of primary Sjögren's syndrome (SS), serum IL-21 level was measured and IL-21 expression in the labial salivary glands (LSG) was examined.

METHODS

Serum IL-21 levels in 40 primary SS, 40 rheumatoid arthritis (RA), and 38 systemic lupus erythematosus (SLE) patients and 20 healthy controls were measured. Serum IL-21 levels of SS patients were assessed for correlations with laboratory data, including anti-nuclear antibody, anti-Ro/La antibodies, globulin, immunoglobulin (Ig) class, and IgG subclass. LSGs from 16 primary SS and 4 controls with sicca symptoms were evaluated for IL-21 and IL-21 receptor (IL-21R) expression by immunohistochemistry. Confocal microscopy was performed to further characterize the IL-21 positive cells.

RESULTS

Primary SS patients had significantly higher serum IL-21 levels than controls, and these increments correlated positively with levels of IgG, IgG1. Serum IgG1 levels correlated with anti-Ro antibody titers. Immunohistochemical analyses showed that lymphocytic foci and the periductal area of the LSGs from SS patients expressed high levels of IL-21 and lower levels of IL-21R, whereas the control LSGs showed minimal expression of both antigens. The more the lymphocyte infiltrated, IL-21 expression in LSGs showed a tendency to increase. Confocal microscopic analyses revealed that IL-21 expressing infiltrating lymphocytes in the LSGs of SS patients also expressed CXCR5.

CONCLUSIONS

Primary SS is associated with high serum IL-21 levels that correlate positively with serum IgG, especially IgG1, levels. The expression of IL-21 is increased as more lymphocytes infiltrated in LSGs. These observations suggest that IL-21 may play an important role in primary SS pathogenesis.

Predictors of chronic kidney disease in Korean patients with lupus nephritis

OBJECTIVE

Since chronic kidney disease (CKD) is closely associated with cardiovascular disease and mortality as well as endstage renal disease, prediction of progressive CKD is a clinically important issue. We investigated the independent risk factors for the development of CKD in patients with lupus nephritis (LN).

METHODS

The cohort included 322 Korean patients diagnosed with LN between 1985 and 2010. We retrospectively analyzed the clinical and laboratory indices, treatment response, the final renal function, and the biopsy findings. The timing and cumulative risk of developing CKD were identified by Kaplan-Meier methods. The independent risk factors for developing CKD were examined by univariate and multivariate Cox proportional hazards regression analyses.

RESULTS

The median followup time after the diagnosis of LN was 84 months. CKD occurs in 22% of the patients within 10 years after the diagnosis of LN. The probability of developing CKD was significantly associated with the onset time of LN (delayed-onset LN vs initial-onset LN; HR 2.904, p = 0.003), deteriorated renal function [an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2) body surface area] at the onset of LN (HR 7.458, p < 0.001), relapse of LN after achieving remission (HR 2.806, p = 0.029), and resistance to induction therapy (HR 8.120, p < 0.001).

CONCLUSION

Our results demonstrate that delayed-onset LN, a decreased eGFR at the time of LN onset, and the failure to achieve a sustained remission are predictors for the development of CKD in Korean patients with LN.