In rare cases, patients with Sjögren’s syndrome may develop an unusual degradation of the kidney’s filtering system — a condition called fibrillary glomerulonephritis — a case report shows.
While this is only the third case describing this association, the study adds Sjögren’s to the list of disorders linked to fibrillary glomerulonephritis. It is critical that patients undergo clinical vigilance to identify the primary disorder, so that appropriate therapies are put in place to slow down the progression into kidney failure.
The case report, “Fibrillary Glomerulonephritis in a Patient with Sjogren’s Syndrome,” was published in the journal Cureus.
Fibrillary glomerulonephritis, a disease that affects the filtering units of the kidneys is found in approximately 1 percent of native kidney biopsies. The condition is associated with a poor prognosis, with almost half of patients progressing to end-stage renal disease within three years after diagnosis. This is mostly because of its rarity and the lack of standardized treatment.
While the cause of fibrillary glomerulonephritis is largely unknown, the condition has been linked to certain autoimmune diseases, including Graves’ disease, systemic lupus nephritis, Crohn’s disease, and idiopathic thrombocytopenic purpura.
Researchers at Raleigh General Hospital in West Virginia described the case of a 75-year-old woman with asymptomatic primary Sjögren’s syndrome who developed fibrillary glomerulonephritis.
The patient arrived at the emergency department with severe hypertension. She was not taking any medication at home. Considering her past medical history of Sjögren’s syndrome, clinicians suspected the women might have acute renal inflammation.
Microscopic analysis of the patient’s kidney showed signs of damage, i.e., scarring. Another microscopy technique, called electron microscopy, showed fibril deposits in the glomeruli, confirming fibrillary glomerulonephritis.
The condition is usually treated with immunosuppressive therapy, consisting of glucocorticoids alone or in combination with other therapies. But results to date have been inconsistent.
In this case, the patient “was not able to withstand the immunosuppressant treatment due to her fragile state,” the investigators wrote. Therefore, she continued therapy with glucocorticoids and angiotensin-converting-enzyme inhibitors, which led to improvements in her renal function for about a year.
After this, however, her condition worsened, and she experienced abnormally high levels of potassium in the blood and bicarbonate-resistant metabolic acidosis, a clinical disturbance characterized by an increase in plasma acidity. The patient has been on hemodialysis ever since.
In one of the two previous cases of fibrillary glomerulonephritis secondary to Sjögren’s syndrome, a 77-year-old man also received immunosuppressive therapy, but ended up requiring hemodialysis as well.
Overall, these findings suggest that “due to the rarity of this disease and lack of literature, physicians should carefully look for any underlying condition in a patient with FGN, as treating the underlying conditions may help us in slowing the progression of this disease,” the study concluded.