Clinical Investigation
Membranous (Class V) Renal Disease in Systemic Lupus Erythematosus May Be More Common Than Previously Reported: Results of a 6-Year Retrospective Analysis

https://doi.org/10.1097/MAJ.0b013e3181c9529cGet rights and content

Abstract

Background

The actual incidence and prevalence of the various histological classes (based on World Health Organization classification) of lupus nephritis (LN) are not known but seem to vary with sex, age, and ethnicity. We have analyzed renal biopsies in patients with systemic lupus erythematosus (SLE) at our center, and hereby report our experience.

Methods

All renal biopsies performed at the University of Mississippi between January 1999 and December 2004 in patients with SLE were retrospectively analyzed. Results were validated by a detailed review of renal biopsy reports and additional records were reviewed for data specific to LN disease activity.

Results

There were 92 renal biopsies performed in patients with SLE during a 6-year period. These included 84 African Americans (72 women and 12 men), 5 whites (4 women and 1 man), and 3 unknown race (1 F, 2 M) subjects. The prevalence of LN classes in our cohort was as follows: class I (0%), class II (9.8%), class III (8.7%), class IV (36.9%), class V (40.2%), and class VI (4.3%). Prevalence of class V LN among males was high at 40%.

Conclusions

In contrast to previous literature, isolated membranous lupus nephritis (MLN) was much more prevalent in this series—40% versus 14%. Also, no sex difference in the prevalence of MLN was seen. This biopsy cohort suggests that MLN/ class V disease may be more common than previously reported especially in African American population.

Section snippets

METHODS

All renal biopsies were performed in patients with SLE at the University of Mississippi between January 1999 and December 2004 and retrospectively analyzed. Patients were included if they met ≥ 4 American College of Rheumatology criteria for SLE with evidence of kidney involvement. All renal biopsies tallied in this study had been earlier interpreted by the same renal pathologist. Results were validated by a detailed review of the original renal biopsy pathological reports (including electron

RESULTS

Ninety-two renal biopsies in patients with SLE were performed between January 1999 and December 2004. The majority of patients were African American (91.3%), with 5 whites and 3 of unknown race. Of 92 patients, 83.6% were women. The median age for patients with class V LN was 26 years, compared with class IV LN at 23 years. Class V pathology was the most common in our cohort (40.2%), followed by class IV at 36.9% (Table 2, Table 3).

The median serum creatinine level in the class IV LN group was

DISCUSSION

SLE is a multisystem disease that carries significant mortality and morbidity especially with regard to renal involvement. However, cumulative 5-year survival in LN has improved from < 50% in 1960s to > 80% in 1990s,11 possibly reflecting early implementation of more potent immunosuppressive therapies. It is also well established that there are considerable racial differences in the prevalence, severity, and prognosis of LN. Relatively, overall incidence of SLE is ~ 2 to 5 cases/100,000 persons

CONCLUSION

We analyzed 6 years of data from SLE kidney biopsies at a large, tertiary care center predominantly derived from African American population, and membranous lupus nephropathy was more common than previously reported. Interestingly, there were no sex differences in the prevalence of membranous lupus nephropathy in our biopsy cohort. It will be important that we continue to follow up this cohort over a long term to better understand the pathogenesis, clinical outcome, and management of MLN.

REFERENCES (19)

There are more references available in the full text version of this article.

Cited by (0)

View full text