Renal involvement in systemic lupus erythematosus. A study of 180 patients from a single center

Antiphospholipid syndrome nephropathy in systemic lupus erythematosus

In the course of the antiphospholipid syndrome (APS), the existence of vaso-occlusive lesions capable of affecting numerous organs is now well established. The renal involvement attributable to primary APS, APS nephropathy (APSN), corresponds to vaso-occlusive lesions of the intrarenal vessels, associating side-by-side, acute thromboses with chronic arterial and arteriolar lesions, leading to zones of cortical ischemic atrophy. A retrospective study of 114 lupus patients undergoing renal biopsy was undertaken to determine the following: (1) if APSN can be found in the course of systemic lupus erythematosus (SLE); (2) if certain clinical and biologic factors can permit the prediction of the presence of APSN; and (3) if APSN is a superadded renal morbidity factor in lupus patients. This study shows the following: (1) APSN occurs in SLE (32% of patients with renal biopsies) in addition to, and independently of, lupus nephritis; (2) APSN is statistically associated with lupus anticoagulant but not with anticardiolipin antibodies; (3) APSN is associated with extrarenal APS, mainly arterial thromboses and obstetrical fetal loss, but not with the venous thromboses of APS; (4) APSN is an independent risk factor, over and above lupus nephritis, that contributes to an elevated prevalence of hypertension, elevated serum creatinine, and increased interstitial fibrosis. Thus, it seems likely that, because of its associations with hypertension, elevated serum creatinine, and increased interstitial fibrosis, APSN may worsen the prognosis in these patients. APSN may also have therapeutic significance in that its recognition should permit a better balance between immunosuppressor and antithrombotic and/or vasoprotective therapy. Finally, this study suggests that APSN should be considered as an element to be included in the classification criteria of APS.

Interferon-gamma is required for lupus nephritis in mice treated with the hydrocarbon oil pristane

BACKGROUND

Although the precise mechanisms leading to lupus nephritis remain obscure, both TH1 and TH2 cytokines have been implicated. The present study examined the roles of interleukin (IL)-4 and interferon-gamma (IFN-gamma) in a novel inducible form of lupus that develops in non-autoimmune mice treated with the hydrocarbon oil pristane.

METHODS

BALB/c IL-4 or IFN-gamma deficient mice (IL-4 -/-, IFNgamma -/-) and wild type controls (+/+) received either pristane or phosphate-buffered saline (PBS) IP. Serial sera were analyzed for anti-DNA/chromatin, anti-RNP/Sm, and total immunoglobulin levels. Proteinuria was measured and kidneys were examined by direct immunofluorescence and light microscopy.

RESULTS

Renal disease did not develop in pristane-treated IFN-gamma -/- mice, as assessed by the absence of capillary immune deposits, glomerular pathology and proteinuria whereas IL-4 -/- mice developed renal disease similar to +/+ mice. Production of IgG anti-single stranded DNA and anti-chromatin antibodies was abrogated in IFN-gamma -/- mice. In contrast, these autoantibodies were produced at similar or higher frequencies and levels by IL-4 -/- versus wild-type mice. The frequency of anti-nRNP/Sm was markedly reduced in IFN-gamma -/- mice. IL-4 deficiency had little effect on the production of anti-DNA/chromatin and anti-nRNP/Sm.

CONCLUSIONS

IFN-gamma is essential for the induction of nephritis and anti-DNA/chromatin following pristane exposure in BALB/c mice, suggesting that genetic or environmental factors influencing TH1-TH2 balance could be an important determinant of renal disease in lupus.

Tubular lesions and tubular cell adhesion molecules for the prognosis of lupus nephritis

BACKGROUND

To assess the prognostic value of tubular lesions and cell adhesion molecules' expression, a retrospective study with immunohistochemistry was performed on 152 patients presenting lupus nephritis from January 1985 to December 1999.

METHODS

The following clinical parameters were recorded: age, sex, race, time of systemic lupus erythematosus (SLE) diagnosis, time of the biopsy, proteinuria, creatininemia, and renal function at the end of follow-up. All biopsies were re-evaluated according to a tubular grading, an inflammatory grading, the percentage of sclerosed glomeruli, the percentage of crescents, and the current WHO classification. Immunohistochemistry was performed with anti-CD40, anti-CD44, and anti-intercellular adhesion molecule-1 (anti-ICAM-1) antibodies.

RESULTS

Patients were 136 women (89.5%) and 16 men with a mean age of 31.2 years +/- 12.8 at the time of biopsy. The mean follow-up period was 94.3 months +/- 64.1. Eighty-eight biopsies (58%) showed various degrees of tubular atrophy. Males (P = 0.001) and tubular grading (P = 0.0001) were linked with renal survival in univariate and multivariate analysis. CD40 (P = 0.01) and ICAM-1 (P = 0.001) tubular expressions were linked with renal survival. ICAM-1 tubular expression provided additional information for the prognosis of the patients with biopsies showing tubular atrophy (P = 0.005) or not (P = 0.05).

CONCLUSIONS

Our study shows that tubular lesions are good indicator of lupus nephritis outcome. Furthermore, tubular expression of cell adhesion molecules like ICAM-1 and CD40 also serves to predict the outcome.

Lupus nephritis in Lebanon

This is a retrospective study of the clinicopathological characteristics of 50 systemic lupus erythematosus patients with nephritis who underwent a kidney biopsy and were admitted to the American University of Beirut Medical Center, in Lebanon, between 1979 and 1999. There were 43 females and seven males, with a median age of 24 y. Renal histology slides from these patients were assessed according to the World Health Organization classification, and were distributed as follows: class I (n = 3, 6%); class II (n = 14, 28%); class III (n = 11, 22%); class IV (n = 19, 38%); class V (n = 1, 2%); class VI (n = 2, 4%). All the patients received oral prednisone, in addition the following treatments were used: pulse intravenous (i.v.) cyclophosphamide (n = 23, 46%); azathioprine (n = 22, 44%); pulse i.v. steroids (n = 19, 38%); chloroquine sulfate (n = 17, 34%); methotrexate (n = 5, 10%); and plasmapheresis (n = 2, 4%). The median duration of follow-up was 5 y (range 1-33 y). On their last evaluation, out of 37 patients who were followed, 20 patients (54%) had controlled disease, eight patients (22%) were still on active medical treatment, four patients (11%) were on chronic hemodialysis, and five patients (13%) had died. Unlike three other Arab populations studies from Kuwait, United Arab Emirates and Saudi Arabia, where the most frequent histopathologic abnormality was class III, diffuse proliferative LN (class IV) was the most common type of lupus nephritis in Lebanon, similarly to reports from USA, France, Netherlands, South Africa, Thailand and Taiwan.

Pregnancy in past or present lupus nephritis: a study of 32 pregnancies from a single centre

OBJECTIVE

To study maternal and fetal outcome in women with past or present histologically proven systemic lupus erythematosus (SLE) nephritis.

METHOD

Retrospective study of 32 pregnancies in 22 women with past or present histologically proven SLE nephritis in a single French centre.

RESULTS

Pregnancy (25 planned and 7 not planned) occurred in a mean (SD) of 8 (5) years after SLE diagnosis and 6 (4) years after renal disease onset. Seven occurred in women with antiphospholipid syndrome. At pregnancy onset, all but one woman had creatininaemia below 100 micromol/l, five had proteinuria >0.5 g/day, none had hypertension. Twelve pregnancies occurred in women previously treated with immunosuppressant drugs. Treatment comprised prednisone (n=31), hydroxychloroquine (n=11), aspirin (n=22), heparin (n=12), and azathioprine in one patient with steroid resistant nephrotic syndrome disclosing SLE. No therapeutic abortion was done. During pregnancy or the postpartum period, or both, proteinuria >0.5 g/day occurred in 10 women (five related to pre-eclampsia, four to renal flare, one to stable nephrotic syndrome). One flare consisted of mild arthralgias. Pregnancy outcome comprised one feto-maternal death in SLE disclosed by pregnancy, five embryonic losses, two fetal deaths, and 18 premature (one neonatal death) and six full term births. No criterion appeared to influence fetal survival significantly. At long term, one patient died during an SLE flare, three women had renal relapses. At the last visit, all had creatininaemia below 100 micromol/l except one woman with creatinine level 115 micromol/l, nine had proteinuria >0.5 g/day, and one was treated for hypertension.

CONCLUSION

Pregnancy need not be discouraged in women with a history of SLE nephritis with normal or mildly impaired renal function. Deterioration of renal function rarely occurs. However, these pregnancies are at high risk of pre-eclampsia and prematurity.

Fcgamma receptor polymorphisms in systemic lupus erythematosus: association with disease and in vivo clearance of immune complexes

OBJECTIVE

Fc receptors for IgG (FcgammaR) play a prominent role in the clearance of immune complexes in systemic lupus erythematosus (SLE). Polymorphisms of FcgammaR have been proposed as genetic factors that influence susceptibility to SLE. We analyzed 3 functional FcgammaR polymorphisms in a strictly Caucasian population of SLE patients, and determined the influence of these polymorphisms on the clearance of immune complexes in vivo.

METHODS

Genomic DNA was isolated from 230 Caucasian patients with SLE and 154 controls. Amplification of FcgammaR-genomic regions in allotype-specific polymerase chain reactions was used to distinguish the genotypes. In addition, we analyzed the FcgammaR genotypes of 13 patients with SLE who participated in a study determining the half-life of IgG-coated erythrocytes in the blood.

RESULTS

We found a strong trend toward skewing of FcgammaRIIa, with an enrichment of the homozygous FcgammaRIIa-R/R131 genotype in patients compared with controls. We did not find a correlation between this genotype and the development of lupus nephritis. However, we established that the half-life of IgG-coated erythrocytes in the blood was prolonged in patients expressing the FcgammaRIIa-R/R131 genotype. The homozygous FcgammaRIIIa-F/F158 genotype was found more frequently in patients with arthritis and/or serositis.

CONCLUSION

In Caucasian populations, the R/H polymorphism of FcgammaRIIa is a minor determinant in susceptibility to SLE, whereas the V/F polymorphism of FcgammaRIIIa is associated with a set of disease manifestations. Notably, the R/H polymorphism of FcgammaRIIa affects the clearance of immune complexes in vivo, which may influence the course of a disease such as SLE.

Progress in the treatment of proliferative lupus nephritis

Lupus nephritis is often well developed at the time of diagnosis. High-dose corticosteroids are universally accepted as the initial approach to the control of severe inflammation in the kidney. Long-term disease control and the minimization of iatrogenic risk usually require adjunctive therapies that target the more fundamental immunoregulatory disturbances of lymphoid cells. Of the available cytotoxic drugs, cyclophosphamide is currently among the most effective, although it cannot be considered ideal in terms of efficacy or toxicity. New prospects for the treatment of proliferative lupus nephritis include novel immunosuppressive agents (e.g. mycophenolate, cyclosporine, fludarabine), combination chemotherapy (e.g. cyclophosphamide plus fludarabine), and sequential chemotherapy (e.g. cyclophosphamide-azathioprine), immunological reconstitution using intensive cytoreductive chemotherapy (with or without stem cell rescue), co-stimulatory molecule inhibition (e.g. humanized anti-CD154 monoclonal antibody, CTLA4-Ig). Gene therapy remains an attractive prospect, but its feasibility clearly depends on the further definition of lupus-promoting genes and the availability of methods to establish stable expression of disease-corrective genes in the appropriate lymphoid cells.