Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease (1), characterized by the production of autoantibodies, and formation of immune complexes due to the polyclonal activation of T and B lymphocytes that result in tissue and organ damage (2). During inflammation, neutrophils and macrophages release serine proteases to cleave progranulin (PGRN) into granulin (GRN), which exert their pro-inflammatory effects that counteract the anti-inflammatory effects of intact PGRN (3). Insulin-like growth factor-2 (ILGF-2) binds to insulin-like growth factors (IGFs) with high affinity (4). Although reports suggest that IGFBP-2 is a reliable biomarker of renal deterioration, it is still needed to confirm that it has high sensitivity and specificity in discriminating kidney disease caused by SLE from other origins.

Objectives

The aim of this study was to explore whether PGRN and ILGF-2 can be used as useful markers not only for accurate diagnosis of patients with active lupus nephritis (LN) but also for prediction of the disease activity in these patients.

Methods

Twenty-five patients with systemic lupus erythematosus, twenty-five patients with chronic renal failure and twenty-five age- and sex-matched healthy volunteers were enrolled in the study. Routine laboratory investigations and measurement of serum PRGN and IGFBP-2 levels were done.

Results

Our results showed that the mean age of SLE, CRF and control groups 31.12±12.34, 38.7±9.4 and 32.96±13.66 respectively with no significant difference between the three groups. There was female predominance in the three groups. Disease duration was 4.78±4.26 in SLE patients.The mean of SLEDAI score was 15.04±7.54. All renal biopsy results were class 2, 3, and 5 with a percentage of 32%, 24%, and 44% respectively.

Conclusions

PGRN and ILGF-2 are significantly elevated in SLE than CRF and control and were associated with SLEDAI. Hence they are considered specific to LN.

References

Rahman A, Isenberg DA. (2008) Systemic lupus erythematosus. N Engl J Med 358:929–939. Kotzin BL. (1996) Systemic lupus erythematosus. Cell 85: 303–306. Park B, Buti L, Lee S et al. (2011) Granulin is a soluble cofactor for toll-like receptor 9 signaling. Immunity 34(4):505–513. Firth SM, Baxter RC. (2002) Cellular actions of the insulin-like growth factor binding proteins. Endocr Rev 23(6):824–54.

Disclosure of Interest

None declared

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