Study investigates kidney illness using sophisticated imaging techniques

HOUSTON: Professors of biomedical engineering report that the potent imaging mass cytometry (IMC) has been used for the first time to examine the kidney">kidneys of patients with lupus (systemic lupus erythematosus), an autoimmune disease that can affect multiple organs and be fatal, and to detect lupus nephritis (LN) in those patients.

Severe renal inflammation caused by LN is one of the leading reasons for death in lupus patients.

IMC may show the simultaneous presence of up to 37 different proteins in human tissue, which is a significant improvement over the limitations of the old approach, which only allowed the analysis of 1-3 different proteins inside a particular tissue.

IMC has been used, typically in conjunction with machine learning methods, to characterise the cellular composition of the human kidney">kidney, distinguish between cell types, and discover new disease markers.

“Due to unique advantages that allow high-dimensional tissue profiling, we postulated imaging mass cytometry may shed novel insights on the molecular makeup of proliferative lupus nephritis,” reported Mohan in the journal Clinical Immunology “This study interrogates the expression profiles of 50 target proteins in lupus nephritis and control kidney">kidneys.” Currently, the standard for LN diagnosis is a painful renal biopsy and study of the tissues that are taken out to determine disease outcome and treatment response.

“However, there is low inter-pathologist concordance when determining classes and pathology indices which can lead to misclassification of LN, improper disease treatment, and sub-optimal patient outcomes,” said Mohan.

“Renal biopsies also provide a limited amount of tissue, restricting the type and extent of analysis that can be performed on a sample."

There are several major advantages to IMC including its ability to pinpoint locations of tissues for further study. During the IMC research and examination of 21 patients, Mohan found both decreased and increased disease markers that point to renal disease and that a subset of glomeruli, (the tiny network of blood vessels that work as cleaners of the kidney">kidney) may be enlarged in some LN patients.

“Decreased expression of epithelial markers along with an increased expression of mesenchymal markers, also termed epithelial to mesenchymal plasticity (EMP) has been reported in kidney">kidney biopsies from patients with renal diseases, including LN,” said Mohan.

“It is very likely that the parietal epithelial cells encircling the glomeruli may be an additional site of EMP in proliferative LN, though this needs to be verified using additional markers. EMP could certainly affect additional cells in LN kidney">kidneys, but this needs to be systematically investigated.”