BVAS and FFS Both Useful Tools for Predicting AAV Prognosis and Choosing Therapy, Study Says

Joana Carvalho, PhD avatar

by Joana Carvalho, PhD |

Share this article:

Share article via email
AAV, CNS involvement

The Birmingham Vasculitis Activity Score (BVAS) and the Five Factors Score (FFS) are both useful tools for predicting the prognosis of ANCA-associated vasculitis, and for selecting the best first-line therapy, a study says.

Researchers recommended using both for best patient care.

The study, “Comparison of the birmingham vasculitis activity score and the five factors score to assess survival in anca‐associated vasculitis,” was published in Arthritis Care & Research.

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, or AAV, is an autoimmune disease caused by the production of autoantibodies — antibodies that wrongly target and attack healthy cells — leading to blood vessel inflammation and swelling in affected tissues and organs.

“In the absence of reliable serological markers of the disease activity, accurate clinical tools have been designed to assess vasculitis activity, prognosis and damage, in order to help choose the first-line therapy and improve the patient’s outcome,” the investigators said.

The first version of BVAS was published in 1994, based on a list of 66 clinical parameters to assess AAV activity. Now in its third version — v.3; approved in 2003 — BVAS examines 56 clinical features divided into nine categories, and has become the standard tool to score disease activity in people with AAV.

The French Vasculitis Study Group (FVSG) created the first version of FFS in 1996. Its goal was to develop a tool that would be able to predict the survival of patients with polyarteritis nodosa (PAN), eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis (MPA).

The classic FFS created in 1996 (v.1996) scored five parameters associated with a higher risk of death: proteinuria (the presence of proteins in the urine); kidney insufficiency (measured by the levels of creatinine); heart muscle diseases; severe gastrointestinal (GI) symptoms; and nervous system involvement.

In 2009, a new version of FFS (v.2009) was created, based on four parameters reflecting poor outcomes — age, kidney insufficiency, heart involvement, and severe GI symptoms — and on one associated with better clinical outcomes, specifically ear-nose-throat involvement.

“Both, BVAS and FFS have been shown useful tools at baseline to assess activity and/or prognosis in AAV, but studies comparing both scores are scarce, and no study including the 2009FFS has been published,” the researchers said.

To learn more, a team of Spanish researchers set out to compare the accuracy of BVAS (v.3) with both versions (v.1996 and v.2009) of the FFS at predicting the survival and disease activity of AAV patients.

The study involved a total 550 AAV patients, including 226 (41.1%) with granulomatosis with polyangiitis (GPA), 205 (37.7%) with MPA, and 119 (21.6%) with EGPA. All participants had been diagnosed between 1990 and 2016 in 20 different clinical centers in Spain.

The overall mortality was 33.1%. At diagnosis, the mean BVAS was significantly higher among patients who passed away, compared with patients who survived (20.0 versus 16.95). Likewise, the mean FFS scores were higher in non-survivors than in survivors (1.17 versus 0.63 for v.1996; 2.13 versus 1.15 for v.2009).

Correlation analyses found that BVAS and both versions of the FFS were strongly correlated with patients’ mortality. However, further analyses demonstrated the 2009 version of the FFS was more accurate at predicting patients’ survival, while BVAS was better at assessing disease activity.

The analyses also identified a moderate correlation between BVAS and FFS v.1996, and a weaker correlation between BVAS and FFS v.2009.

“In summary, our results confirm that BVAS, 1996FFS and 2009FFS are useful in patients with AAV to measure the initial disease severity, provide prognostic information, compare different groups of patients, and make therapeutic decisions,” the researchers said.

“The 2009FFS is better adapted than the 1996FFS and BVAS to predict survival, both at short- and long-term follow-up. However, the BVAS is a more precise measure of disease activity and can be used to assess follow-up. We recommend using both scores to increase the ability to evaluate prognosis and choose first-line therapy,” they added.