Psychiatric manifestations are relatively common in systemic lupus erythematosus (SLE) patients. Since there are factors causing psychiatric manifestations other than SLE, the diagnosis of lupus psychosis (LP) is often difficult. Previous studies disclosed that cerebrospinal fluid (CSF) IL-6 was elevated in SLE patients with neuropsychiatric manifestation. The current studies were therefore designed to examine the efficacy of CSF IL-6 in diagnosis of LP. Multicenter retrospective study was performed with 45 SLE patients who showed psychiatric manifestations between 1993 and 2000. The diagnosis of LP and psychosis due to causes other than SLE (non-LP) was confirmed by retrospective review of the clinical records. Thirty-two of the 45 patients were reconfirmed as LP in the retrospective study. Receiver operating characteristic curve analysis revealed that the sensitivity and specificity of CSF IL-6 for diagnosis of LP were 87.5% and 92.3%, respectively, at the cut-off value of 4.3 pg/ml. These results indicate that CSF IL-6 might be an effective measure in diagnosing LP, although exclusion of infectious meningoencephalitis and cerebrovascular accident is necessary.

BAFF may play a pathogenic role in SLE by stimulating T cell-dependent B cell autoantibodies production. Blockade of BAFF is a promising therapeutic approach for SLE especially in patients with kidney involvement.

Both the frequency and the absolute number of CD161(+)CD8(+) T cells were decreased in the peripheral blood of patients suffering from SLE, MCTD, SSc and PM/DM. This result suggests that there is also an abnormality of NKT cells in the CD8(+) population.

The significance of both the acceleratory and inhibitory functions of the CD72 molecule was investigated among patients with systemic lupus erythematosus (SLE) during modification of B cell differentiation. Expression of the CD72 molecule and mRNA on B cells was decreased in SLE with lupus nephritis, while CD100 expression on both CD4+ T cells and CD8+ T cells was not significant in comparison with the controls. When the relationship between CD72 expression and other B cell markers was examined, decreased expression of CD72 was associated with differences in the stage of differentiation. In patients with decreased expression of CD72, switching to IgG was evident, and the disease stage was started to severe. In patients with lupus nephritis, the decreased expression of CD72 was related to class switching on B cells, suggesting that CD72 is a useful marker for determining class switching of B cells in lupus nephritis.

Proliferative lupus nephritis (PLN) is the common, severe, and important form of lupus nephritis. Recent report showed that T cells producing Interferon (IFN)gamma (Th1 cells) increased in patients with World Health Organization class IV. However, the relation between the increase of Th1 cells and the pathogenesis has been made unclear. The aim of this study was to examine the chemoattractant mechanism of Th1-producing cells and whether in vitro IFNgamma secretion from Th1-producing cells in PLN. The Th1:Th2 ratio in peripheral blood was measured by flow cytometry. The serum levels of IL-2, IFNgamma, IL-13, monocyte chemoattractant protein-1 (MCP-1) and IP-10 were determined by using enzyme-linked immunosorbent assay. In in vitro IFNgamma production assay, CD4(+)T cells co-cultured with IL-12 and/or IL-18. Th1:Th2 ratio in PLN was high and not correlated with the serum Th1 cytokine level. This Th1-producing cell tended to go toward the inflammatory lesion by low CD62L expression and chemokines. The level of MCP-1 and IP-10 in patients with PLN significantly increased. Lastly, in vitro IFNgamma production assay, patients with PLN CD4(+)T cells produced IFNgamma by the addition of IL-12 and IL-18, while CD4(+)T cells in normal controls did not produce. These findings suggest that combination of Th1 inducers and chemokine inhibition might be powerful threrapeutic approach in PLN.