Silent lupus nephritis: a pediatric center experience of baseline kidney biopsies and review of the published evidence.

BACKGROUND

Silent lupus nephritis (sLN) describes the histopathological presence of nephritis in systemic lupus erythematosus (SLE) without evident clinical or biochemical kidney manifestations. Kidney biopsy practises in suspected sLN vary widely among centers. We report three cases of sLN from our center and review existing literature on sLN prevalence and the role of baseline kidney biopsies.

METHODS

Characteristics of three patients with childhood-onset (cSLE) sLN from our center, including clinical and laboratory features as well as kidney biopsy findings, are reported. A systematic literature review was performed to evaluate the prevalence of proliferative LN among patients with sLN. Relevant studies were identified using a predefined search strategy on Ovid, MEDLINE, EMBASE, CINAHL Plus, Scopus, and Web of Science. Publications meeting inclusion criteria and reporting baseline kidney biopsy results with histopathological classification were included.

RESULTS

Three cSLE patients with sLN from our center who underwent baseline kidney biopsies revealing class III LN in two and class II LN in one. The systematic review identified 4153 potential articles, of which 37 studies met inclusion criteria describing 639 patients with sLN; patients were aged 2-70 years. Among them, 30% had proliferative LN (class III, class IV) or class V, while 70% had class I or II LN.

CONCLUSIONS

Significant histologic LN findings are observed in 30% of SLE patients without overt kidney disease; frequently associated with high-titer dsDNA, anti-Smith antibodies, and/or hypocomplementemia. Thus, baseline kidney biopsy in newly diagnosed SLE patients, irrespective of clinical and laboratory manifestations, may aid in guiding therapy.