Non-Invasive Assessment of Disease Activity in Lupus Nephritis by MRI-Based Molecular Imaging

Siranush Anna Sargsyan¹, Kendra M. Hasebroock, Brandon Renner, Brian Larsen², Conrad Stoldt², V. Michael Holers, Joshua M. Thurman, Natalie Serkova

Lupus nephritis is characterized by immune-complex deposition as well as complement C3 activation within the glomeruli of the kidney. Percutaneous renal biopsy is the gold standard for monitoring disease activity, yet less invasive methods of obtaining biopsy information are needed. We have developed a non-invasive method for detecting tissue-bound iC3b/C3d using MRI and superparamagnetic iron oxide (SPIO) nanoparticles linked to the iC3b/C3d binding region of complement receptor type 2 (CR2). We found that CR2-targeted SPIO nanoparticles caused a reduction in the T2-relaxation time in nephritic kidneys corresponding to the peak glomerular iC3b deposition and disease severity.