Laser microdissection-based analysis of cytokine balance in the kidneys of patients with lupus nephritis

To determine the cytokine balance in patients with lupus nephritis (LN), we analysed kidney-infiltrating T cells. Renal biopsy samples from 15 systemic lupus erythematosus (SLE) patients were used. In accordance with the classification of International Society of Nephrology/Renal Pathology Society, they were categorized into Class III, Class III+V (Class III-predominant group, n = 4), Class IV, Class IV+V (Class IV-predominant group, n = 7) and Class V (n = 4) groups. The single-cell samples of both the glomelular and interstitial infiltrating cells were captured by laser-microdissection. The glomerular and interstitial infiltrating T cells produced interleukin (IL)-2, IL-4, IL-10, IL-13 and IL-17 cytokines in the Class III-predominant, Class IV-predominant and Class V groups. Interferon-gamma was detected only in the glomeruli of the Class III-predominant and Class V group samples. The expression level of IL-17 was correlated closely with clinical parameters such as haematuria, blood urea nitrogen level, SLE Disease Activity Index scores in both glomeruli and interstitium, urine protein level in glomeruli and serum creatinine and creatinine clearance levels in interstitium. This suggests that the glomerular infiltrating T cells might act as T helper type 1 (Th1), Th2 and Th17 cells while the interstitial infiltrating T cells, act as Th2 and Th17 cells in the Class III-predominant and Class V groups. In contrast, both the glomerular and interstitial infiltrating T cells might act as Th2 and Th17 cells in the Class IV-predominant group. The cytokine balances may be dependent upon the classification of renal pathology, and IL-17 might play a critical role in SLE development.

B cells play a crucial role as antigen-presenting cells and collaborate with inflammatory cytokines in glucose-6-phosphate isomerase-induced arthritis

Anti-glucose-6-phosphate isomerase (GPI) antibodies from K/BxN mice directly induce arthritis; however, the transfer of these antibodies from mice with GPI-induced arthritis does not induce arthritis. CD4(+) T cells play an important role in the induction and effector phase in this model; however, the roles of B cells and immunoglobulins (Igs) have not been elucidated. We investigated the roles of B cells and Igs in GPI-induced arthritis by using adoptive transfer system into SCID mice. Transfer of splenocytes of male DBA/1 mice immunized with GPI into SCID mice induced arthritis on day 6 in the latter, in association with the production of anti-GPI antibodies. Co-localization of C3 and IgG on the articular surface was identified in arthritic SCID mice. Inoculation of IgG (or anti-GPI antibodies) and CD19(+)-depleted splenocytes from arthritic DBA/1 mice induced arthritis in SCID mice, but not CD19(+)-depleted or CD4(+)-depleted splenocytes from DBA/1 mice. In vitro analysis of cytokine production by splenocytes from DBA/1 arthritic mice demonstrated production of large amounts of tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 in an antigen-specific manner (P < 0.01), and production was dominated by CD19(+)-depleted than CD4(+)-depleted splenocytes (P < 0.05). Addition of IgG from DBA/1 arthritic mice to the culture enhanced TNF-alpha but not IL-6 production, and this effect was blocked by anti-Fcgamma receptor antibody. In vivo analysis of neutralization with TNF-alpha protected arthritis completely in SCID mice. Our results highlight the important role of B cells in GPI-induced arthritis as autoantibody producers, and these autoantibodies can trigger joint inflammation in orchestration with inflammatory cytokines, especially TNF-alpha.

Invariant NKT cells produce IL-17 through IL-23-dependent and -independent pathways with potential modulation of Th17 response in collagen-induced arthritis

Invariant natural killer T (iNKT) cells play a protective role in the development of certain autoimmune diseases. However, their precise role in the pathogenesis of autoimmune arthritis remains unclear. In this study, we examined the possible contribution of iNKT cells in collagen-induced arthritis (CIA) by using iNKT cell-deficient mice (Jalpha281-/- mice). CIA in these mice was markedly suppressed and interleukin (IL)-17 production was reduced in a native type II collagen (CII)-specific T cell response. Draining lymph nodes of CII-immunized Jalpha281-/- mice contained a significantly low number of IL-17-producing T helper cells. To determine whether iNKT cells produce IL-17, we measured IL-17 by enzyme-linked immunosorbent assay in iNKT cells stimulated with the ligand, alpha-galactosylceramide (alpha-GalCer). Notably, splenocytes from Jalpha281-/- mice stimulated in this way were negative for IL-17, whereas those from C57BL/6 mice produced IL-17. Immunostaining for IL-17 in iNKT cells confirmed intracellular staining of the protein. RT-PCR analysis showed that iNKT cells expressed retinoid-related orphan receptor gammaT and IL-23 receptor. Moreover, cell sorting demonstrated that NK1.1- iNKT cells were the main producers of IL-17 compared with NK1.1+ iNKT cells. IL-17 production by iNKT cells was induced by IL-23-dependent and -independent pathways, since iNKT produced IL-17 when stimulated with either IL-23 or alpha-GalCer alone. Our findings indicate that iNKT cells are producers and activators of IL-17 via IL-23- dependent and -independent pathways, suggesting that they are key cells in the pathogenesis of CIA through IL-17.

Distinguished effects of antiphospholipid antibodies and anti-oxidized LDL antibodies on oxidized LDL uptake by macrophages

Several interpretations have been made regarding the specificity of antiphospholipid antibodies and antibodies against oxidized low-density lipoprotein (oxLDL), but these are still controversial. In the present study, we delineated specificity of these two types of antibodies and analyzed their regulatory effect on oxLDL and/or beta( 2)-glycoprotein I (beta(2)GPI) binding to macrophages. Scavenger receptor-mediated binding of oxLDL (or its beta(2)GPI complexes) to macrophages was observed and the binding was partly prevented by beta( 2)GPI. The IgG monoclonal anti-beta(2)GPI antibody (WB-CAL-1), which was derived from NZW x BXSB F1 mouse (a model of antiphospholipid syndrome), significantly increased the oxLDL/beta(2)GPI binding to macrophages. In contrast, IgM anti-oxLDL natural antibody, EO6 (derived from apoe( -/-) mouse), prevented the binding. Different antigenic specificity of these antibodies to oxLDL and its beta(2)GPI complexes was also confirmed in TLC-ligand blot and ELISA. Thus, IgG anti-beta(2) GPI autoantibodies contribute to lipid metabolism (housekeeping of oxLDL by macrophages) whereas IgM natural anti-oxLDL antibodies may protect against atherogenesis. In addition, in vitro data suggest that relatively high dose of intravenous immunoglobulin preparations (mainly contain IgG anti-oxLDL antibodies) might also prevent atherogenesis by inhibiting the oxLDL binding to macrophages.

TCR Valpha14 natural killer T cells function as effector T cells in mice with collagen-induced arthritis

Natural killer (NK) T cells are a unique, recently identified cell population and are suggested to act as regulatory cells in autoimmune disorders. In the present study, designed to investigate the role of NKT cells in arthritis development, we attempted to induce arthritis by immunization of type II collagen (CIA) in Jalpha281 knock out (NKT-KO) and CD1d knock out (CD1d-KO) mice, which are depleted of NKT cells. From the results, the incidence of arthritis (40%) and the arthritis score (1.5 +/- 2.2 and 2.0 +/- 2.7) were reduced in NKT-KO and CD1d-KO mice compared to those in respective wild type mice (90%, 5.4 +/- 3.2 and 2.0 +/- 2.7, P < 0.01). Anti-CII antibody levels in the sera of NKT-KO and CD1d-KO mice were significantly decreased compared to the controls (OD values; 0.32 +/- 0.16 and 0.29 +/- 0.06 versus 0.58 +/- 0.08 and 0.38 +/- 0.08, P < 0.01). These results suggest that NKT cells play a role as effector T cells in CIA. Although the cell proliferative response and cytokine production in NKT-KO mice after the primary immunization were comparable to those in wild type mice, the ratios of both activated T or B cells were lower in NKT-KO mice than wild type mice after secondary immunization (T cells: 9.9 +/- 1.8% versus 16.0 +/- 3.4%, P < 0.01, B cells: 4.1 +/- 0.5% versus 5.1 +/- 0.7%, P < 0.05), suggesting that inv-NKT cells contribute to the pathogenicity in the development phase of arthritis. In addition, IL-4 and IL-1beta mRNA expression levels in the spleen during the arthritis development phase were lower in NKT-KO mice, while the IFN-gamma mRNA expression level was temporarily higher. These results suggest that inv-NKT cells influence cytokine production in arthritis development. In conclusion, inv-NKT cells may promote the generation of arthritis, especially during the development rather than the initiation phase.

Association of mannose binding lectin (MBL) gene polymorphism and serum MBL concentration with characteristics and progression of systemic lupus erythematosus

OBJECTIVE

To determine whether occurrence, characteristics, and progression of systemic lupus erythematosus (SLE) are associated with polymorphism of the mannose binding lectin (MBL) gene and with serum MBL concentration.

METHODS

Codon 54 MBL gene polymorphism of 147 patients with SLE and 160 healthy controls was determined by polymerase chain reaction-restriction fragment length polymorphism. Serum concentration of MBL was measured by enzyme immunoassay. Fluctuations of serum MBL were analysed with respect to disease characteristics and activity.

RESULTS

Frequency of homozygosity for codon 54 minority allele was 6% (9/147) in patients with SLE, and significantly higher than in controls (p = 0.0294, Fisher's exact test). MBL polymorphism in patients with SLE was not significantly associated with disease characteristics or immunological phenotypes. Patients homozygous for the B allele tended to have a higher risk of infection during treatment. Levels of C3 and CH(50) were slightly, but significantly, associated with serum MBL concentration in patients with SLE homozygous for the majority allele. During the course of SLE, serum MBL concentration increased in 6/14 patients, and decreased in 7 after initiation of immunosuppressive treatment.

CONCLUSIONS

MBL gene polymorphism influences susceptibility to SLE, but has no direct effect on disease characteristics. Serum MBL levels fluctuate during the course of SLE in individual patients. MBL genotyping may be useful in assessing the risk of infection during treatment of SLE.

Anti-mannose binding lectin antibodies in sera of Japanese patients with systemic lupus erythematosus

Mannose-binding lectin (MBL) is a key element in innate immunity with functions and structure similar to that of complement C1q. It has been reported that MBL deficiency is associated with occurrence of systemic lupus erythematosus (SLE). We hypothesized that anti-MBL antibodies, if present, would affect the occurrence or disease course of SLE, by reduction of serum MBL levels, interference of MBL functions, or binding to MBL deposited on various tissues. To address this hypothesis, we measured the concentration of anti-MBL antibodies in sera of 111 Japanese SLE patients and 113 healthy volunteers by enzyme immunoassay. The titres of anti-MBL antibodies in SLE patients were significantly higher than those in healthy controls. When the mean + 2 standard deviations of controls was set as the cut off point, individuals with titres of anti-MBL antibodies above this level were significantly more frequent in SLE patients (9 patients) than in controls (2 persons). One SLE patient had an extremely high titre of this antibody. No associations of titres of anti-MBL antibodies and (i) genotypes of MBL gene, (ii) concentrations of serum MBL, or (iii) disease characteristics of SLE, were apparent. Thus, we have confirmed that anti-MBL antibodies are indeed present in sera of some patients with SLE, but the significance of these autoantibodies in the pathogenesis of SLE remains unclear.

Fhit expression in human gastric adenomas and intramucosal carcinomas: correlation with Mlh1 expression and gastric phenotype

The fragile histidine triad (FHIT) gene, encompassing the FRA3B fragile site at chromosome 3p14.2, is a candidate tumour suppressor gene involved in a variety of tumours, including gastric carcinomas. Recently, it has been reported that the FHIT gene may be a target of damage in some of mismatch-deficient tumours. To clarify further the role of the Fhit protein in gastric carcinogenesis, we investigated whether Fhit expression in early gastric neoplasia is associated with mismatch repair protein expression and cellular phenotype. Fhit, Mlh1 and phenotypic expression were evaluated immunohistochemically in 87 early gastric neoplasias, comprising 32 adenomas and 55 intramucosal carcinomas, resected by endoscopic mucosal resection therapy. Significant loss or reduction of Fhit expression was noted in four (12.5%) of the 32 adenomas and 21 (38.2%) of the 55 intramucosal carcinomas. The rate of abnormal Fhit expression was significantly higher in intramucosal carcinomas than in adenomas (P=0.021). Moreover, reduced Fhit expression was found to be significantly associated with loss of Mlh1 expression in early gastric neoplasia (P=0.0011). Furthermore, we also detected a significant association between reduced Fhit expression and gastric phenotype (P=0.0018). These results suggested that reduced Fhit expression occurs in the early stage of gastric carcinogenesis and could be correlated with a lack of Mlh1 expression and gastric phenotype.

An HLA-B27-positive patient diagnosed with ulcerative colitis 15 years after the onset of arthropathy

Abstract A 28-year-old woman had persistent pain of both hip joints since the age of 13 years. X-ray analysis showed destructive changes in both hip joints and ossification of sacroiliitic joints. The patient had mild diarrhea and slight abdominal pain for 8 years. Blood-stained stool was not noticed. Barium enema showed changes consistent with the diagnosis of ulcerative colitis (UC). Inflammatory bowel syndrome should be considered in patients with persistent coxitis, even in the absence of severe abdominal symptoms.

Significance of magnetic resonance imaging in the diagnosis of nodular regenerative hyperplasia of the liver complicated with systemic lupus erythematosus: a case report and review of the literature

Nodular regenerative hyperplasia of the liver (NRH), characterized by multiple hepatic nodules in the absence of fibrosis, is a rare but important complication of systemic lupus erythematosus (SLE) associated with non-cirrhotic portal hypertension. The diagnosis of NRH is based on the pathological examination, and radiological findings of NRH are poorly documented. We report a case of a 40-year-old woman with SLE complicated with NRH. Sixteen years after diagnosis of SLE, esophageal varices were incidentally found and diagnosis of portal hypertension due to NRH was made by magnetic resonance imaging (MRI) and confirmed by needle liver biopsy. Although MRI showed the lesions as significant nodules, neither computed tomography nor ultrasonography could demonstrate the nodules. However, serial MRI showed significant enlargement of the nodules for 2 years Because NRH may lead to portal hypertension with life-threatening variceral haemorrhage in patients with SLE, MRI is a useful, non-invasive examination to screen the patients for its presence and follow-up. We reviewed the literature regarding NRH in SLE and discuss the management of the affected patients.