Tacrolimus is effective for lupus nephritis patients with persistent proteinuria

OBJECTIVES

To evaluate the safety and potential efficacy of tacrolimus for the treatment of patients with lupus nephritis and persistent proteinuria.

METHODS

A total of 23 Japanese patients with lupus nephritis (21 females/2 males) were enrolled in this study. Patients were administered tacrolimus at a dose of 2-3 mg once daily after the evening meal for 6 months. The dose of tacrolimus was unchanged throughout the study period. Concomitant prednisolone therapy was unchanged or gradually tapered, while other immunosuppressants were stopped at the start of tacrolimus treatment.

RESULTS

Tacrolimus was well tolerated, and none of the patients developed adverse drug reactions that required discontinuation of the study. Daily urinary protein loss, the U-prot/U-creat ratio, and serum albumin were significantly improved after 4 months, 3 months, and 1 month of treatment with tacrolimus (p<0.05), respectively, and the improvement persisted until 6 months. The serum complement hemolytic activity (CH50), complement C3 level, and CRP level were also significantly improved after treatment with tacrolimus (p<0.05). Improvement of the U-prot/U-creat ratio was most prominent for patients who were in WHO class IV.

CONCLUSIONS

Tacrolimus is safe and effective as maintenance therapy for patients with lupus nephritis, at least for 6 months. A larger randomised, controlled trial over a longer period is needed to confirm these results.

[Microbiological and clinical studies with Streptococcus pneumoniae isolated in 5 Kitakyushu municipal hospitals]

Epidemiological and microbiological studies were carried out using 200 strains of pneumococci isolated from clinical specimens in 5 Kitakyushu municipal hospitals, between October 1994 and July 1995. Eighty nine percent of pneumococci were detected in the specimens from the respiratory tract. Pneumococci were isolated mainly from infants under 3-years of age and adults over 50-years of age, and the rates of isolation were 40.5% and 39.5%, respectively. MICs of 8 antimicrobial agents, such as PCG, NFLX, CPFX, LFLX, FLRX, TFLX, SPFX, LVFX, were determined using broth microdilution methods. According to NCCLS standard (1997), recovery rates of PSSP, PISP and PRSP were 48.0%, 39.5% and 12.5%, respectively. Among 7 quinolones, TFLX, SPFX and LVFX were effective so far examined, except for a few resistant strains. Four cases in which quinolones resistant pneumococci were isolated were reviewed retrospectively. Among them 3 cases had been given quinolones before the strains were detected.

Urinary C4 excretion in systemic lupus erythematosus

The fourth component of complement (C4) in urine was measured in 19 patients with systemic lupus erythematosus (SLE). Urinary C4 was detectable in all SLE patients using an enzyme linked immunosorbent assay. In 11 of 13 patients whose urinary C4 was serially measured, a decrease of urinary C4 was found in parallel with a decrease of disease activity of SLE. In the remaining 2 patients, the amount of C4 increased preceding a flare-up of the disease. The measurement of urinary C4 may be useful in evaluating the disease activity of SLE in individual patients and sometimes in predicting the flare-up of the disease. The specific hemolytic activity of excreted C4 and Western blotting analysis showed that urinary C4 consisted mainly of degraded fragments of C4. In two cases, camostat, a serine protease inhibitor, rapidly decreased the urinary C4 excretion, suggesting that the complement activation occurred in the glomerulus in lupus nephritis.

Effect of T cells on the complement production by monocytes

We studied the role of T cells in the regulation of C3 or C4 production by monocytes. While cocultured T cells reduced C3 production, they enhanced C4 production by monocytes in a number-dependent manner. Interleukin-2 enhanced these effects of T cells on C3 and C4 production, indicating that activated T cells had greater effects on complement production by monocytes. CD4+ T cells had greater effects than those of CD8+ T cells on the C3 or C4 production by monocytes, indicating that CD4+ T cells were mainly involved in the regulation of C3 and C4 production by monocytes. T-cell-conditioned medium (T-CM) also decreased C3 and enhanced C4 production, but the effect of T-CM on C3 and C4 production was less remarkable than that of T cells. T cells separated by transwell inserts from monocytes had similar effects as those of T-CM on complement production. Anti-IFN-gamma antibody completely blocked the suppressing effect on C3 production and partially blocked the stimulating effect of T cells on C4 production. These results indicate that T cells regulate C3 or C4 production by monocytes via IFN-gamma as a humoral factor. Moreover, the stimulating effect of T cells on C4 production was partially blocked when monocytes and T cells were incubated with anti-CD2, anti-LFA-1, and anti-HLA-DR antibodies, and anti-CD2 partially blocked the suppressing effect of T cells on C3 production by monocytes. These results indicate that T cells modulate the C3 and C4 production by monocytes not only via a humoral factor but also via a direct interaction with monocytes.

Effects of cell differentiation on the synthesis of the third and fourth component of complement (C3, C4) by the human monocytic cell line U937

Association of complement synthesis with cell differentiation in U937 cells was investigated using granulocyte-macrophage colony-stimulating factor (GM-CSF), vitamin D3 and interferon-gamma (IFN-gamma) as differentiation-inducing agents. GM-CSF or vitamin D3 enhanced the synthesis of the third component of complement (C3) by U937 cells, but had no stimulatory effect on the synthesis of the fourth component of complement (C4). IFN-gamma increased both C3 and C4 synthesis by U937 cells. Combination of two of these three agents resulted in synergistic enhancement and all three agents caused maximal enhancement of C3 synthesis. Vitamin D3 enhanced IFN-gamma-induced C4 synthesis by U937 cells. These results were confirmed by ELISA and SDS-PAGE after biosynthetic labelling. GM-CSF, vitamin D3 or IFN-gamma increased the expression of complement receptor type 3 (CR3), one of the markers of monocyte/macrophage differentiation. Two of these agents caused a further increase and all three agents maximal increase in CR3 expression. Since C3 was synthesized in parallel with the degree of CR3 expression, the synthesis of C3, but not C4, by U937 cells is thought to be closely related to cell differentiation. It was reconfirmed that the synthesis of C3 and C4 by U937 cells was independently regulated.

Okadaic acid enhances human T cell activation and phosphorylation of an internal substrate induced by phorbol myristate acetate

Okadaic acid is a potent tumor promoter and an inhibitor of serine/threonine-specific protein phosphatases. We studied the effect of okadaic acid in human T cell activation and phosphorylation of internal substrates. Okadaic acid at up to 4 nM enhanced phorbol myristate acetate (PMA)-induced proliferation and CD25 (IL-2 receptor, p55) expression, although it showed no activation by itself. Okadaic acid induced hyperphosphorylation of a 60 kDa protein in T cells as well as non-T cells, as reported in fibroblasts and keratinocytes. Preincubation with 4 nM okadaic acid enhanced PMA induced phosphorylation of the 80 kDa protein, an internal substrate of protein kinase C in T cells. These results suggest that okadaic acid inhibited dephosphorylation of protein kinase C specific substrates, and as a result, enhanced T cell activation mediated by protein kinase C pathway.

[A case of cardiomyopathy due to allergic bronchopulmonary aspergillosis]

We report a rare occurrence of cardiomyopathy associated with allergic bronchopulmonary aspergillosis (ABPA). A 49-year-old man with a history of bronchial asthma was referred to the Matsuyama Red Cross Hospital for evaluation of the abnormal shadow on his chest X-ray. Laboratory examination showed blood eosinophilia and marked elevation of serum IgE concentration and IgE antibody to A fumigatus. The immediate and late skin reactivities to A fumigatus antigen were both positive. The diagnosis of ABPA was made. Treatment using prednisolone was effective in ameliorating the symptoms. However, he was admitted again due to dyspnea, edema and anorexia 6 months later. Chest X-ray, ECG, UCG and scintigraphy suggested severe cardiac failure. The clinical diagnosis of hypertrophic cardiomyopathy, and the pathohistological diagnosis of endomyocardial fibrosis were made by cardiac catheterization and biopsy of endocardium. Retrospectively, cardiomegaly had gradually increased during the past several months while peripheral blood eosinophilia had continued. All these data strongly suggested that eosinophilia due to ABPA might cause severe cardiac damage.