Early, Severe Infections Strongly Predict Mortality in Older Patients with Kidney Inflammation, Study Shows

The occurrence of a severe infection during the first month of care is a strong predictor of one-year mortality among patients 65 and older with ANCA-associated renal vasculitis — a form of kidney inflammation caused by ANCA antibodies — a retrospective study reports.

The study, “Early predictors of one-year mortality in patients over 65 presenting with ANCA-associated renal vasculitis: a retrospective, multicentre study,” was published in the journal BMC Nephrology.

AAV, an autoimmune disease that causes inflammation in small and medium blood vessels, is a condition of the elderly whose prognosis worsens with a patient’s age.

The condition may affect vessels in several organs, but in 70% of cases patients develop inflammation in the kidneys, severely impairing their function. Along with being over 65, severe kidney failure is the best predictor of a poor prognosis. These patients are more susceptible to infections and are usually less tolerant of immunosuppressive therapies.

Now, a team of researchers aimed to identify factors that predicted one-year mortality in a high-risk population of AAV patients over 65 with kidney involvement.

“We hypothesized that by combining disease severity markers, a comorbidity index and serious adverse event reports, we would be able to identify early predictors of one-year mortality in this population,” researchers stated.

Researchers performed a retrospective analysis of 149 AAV patients, median age at diagnosis 72.7 years, presenting renal impairments. Patients were followed at six tertiary hospitals in northern France from January 2002 to June 2015.

More than half of patients (54%) had microscopic polyangiitis (MPA), followed by 40% with granulomatosis with polyangiitis (GPA), and 9% with vasculitis limited to their kidneys.

Patients were followed for a median of 5.8 years, during which 52 patients died. Infections were the most common cause of death (29 patients), followed by cardiovascular disease (seven patients), and more rarely active vasculitis (four patients), and related diseases (four patients).

In the first year after diagnosis, a total of 29 patients (19.5%) died. Most of these deaths occurred in the first six months (83%) and were related to infections (70%).

Several disease severity markers — abnormally low protein levels, anemia, a poor prognosis score (five-factor score), and impaired renal function — were significantly associated with one-year mortality.

However, a poor prognosis score and the occurrence of a severe infection in the first month of treatment were the best predictors of one-year mortality, with patients with these factors being 2.5 and 2.7 times more likely to die in the first year compared to those without.

But despite the high risk of infections and the clear impact they had on mortality rates, only 57% of patients received preventive treatment against infections.

During follow-up, 43 patients relapsed. The relapses mostly involved the kidneys (67%) and occurred after patients stopped immunosuppression therapy (63%). The median time patients lived without a relapse was 39.7 months.

“When considering various disease severity markers in over-65 patients with ANCA-associated renal vasculitis, we found that an early, severe infection (which occurred in about a quarter of the patients) is a strong predictor of one-year mortality,” researchers said.

“A reduction in immunosuppression, the early detection of infections, and [antibiotic] prophylaxis might help to reduce mortality in this population,” the study concluded.