According to a recent article, a new study looked into the histopathologic spectrum of patients with monoclonal gammopathy of renal significance (MGRS).

Monoclonal Gammopathy of Undetermined Significance (MGUS)

Monoclonal gammopathy of undetermined significance (MGUS) is a typically innocuous condition determined by the presence of an unusual protein in the blood. The protein, referred to as monoclonal or M protein, is produced by plasma cells in bone marrow. MGUS rarely causes complications but has been observed in some cases to progress to some forms of blood cancer. 

Symptoms:

Most people with MGUS do not experience symptoms. In some cases, rash or irritation may be present. In others, there has been observed issue relating to the nerves such as tingling or numbness.

Diagnosis:

MGUS is most typically diagnosed during blood tests for other disorders or conditions. The blood tests may show abnormal proteins or unusual amounts of normal proteins. Under these circumstances, your doctor may order further tests. Further blood tests, urine tests, MRI or PET scan, and/or bone marrow tests may be ordered to rule out other causes.

The Study

The study aimed to look at the renal effects of monoclonal gammopathy. Researchers looked at a group of patients from one nephrology hospital, all of whom were diagnosed with monoclonal gammopathy and kidney disorders.

Specifically, the patients that were looked at were ones who had monoclonal gammopathy and also had a kidney biopsy done at the hospital in the past twenty-one years. In total, 700 patients were looked at.

Researchers used multivariable logistic regression in order to find the clinical features that are connect with MGRS.

Results of the Study

The study found that out of the patients that had one kidney biopsy, and not counting the thirteen patients who had multiple kidney biopsies, 261 of the patients had MGRS lesions and 426 had non-MGRS kidney disorders. 164 of patients with MGRS had their issues caused by Ig-related amyloidosis, 23 of them were caused by monoclonal Ig deposition disease, and 22 of them were caused by thrombotic microangiopathy. As for the non-MGRS group, the most common diagnosis was membranous nephropathy with 40% of patients in said group being diagnosed with it.

Researchers concluded that monoclonal Ig amyloidosis was the most prevalent cause for patients diagnosed with MGRS. Furthermore, MGRS has now been associated with irregular free light chain ratio, being of an older age, and having an abundance of proteinuria.