BACES score linked to clinical treatment outcomes in M. avium complex lung disease

Key takeaways:

• BACES stands for BMI, age, cavity presence, erythrocyte sedimentation rate and sex.
• Significance was found between BACES score and two types of treatment responses.

BOSTON — BACES score in Mycobacterium avium complex lung disease is linked to clinical treatment outcomes and may be able to predict clinical improvement, according to data presented at the CHEST Annual Meeting.

Factors involved in the BACES score, which is used to predict all-cause mortality in non-tuberculosis mycobacteria lung disease, include a BMI less than 18.5 kg/m², age 65 years or older, cavity presence, elevated erythrocyte sedimentation rate and male sex, according to researchers.

“Our study findings are important, but they would need larger and ideally prospective cohort studies to validate,” Patricio Escalante, MD, MSc, professor of medicine at Mayo Clinic Rochester, told Healio. “If these study results hold true with additional studies, then the BACES score can help clinicians to make important treatment decisions with their patients to start antibiotics or more intensive treatments earlier rather that carefully wait with active clinical and radiological surveillance to determine individual disease progression for these patients.”

In this retrospective cohort study, Escalante and colleagues assessed 86 U.S. patients (median age, 69.1 years; BMI, 22 kg/m²) with non-cavitary M. avium complex lung disease (MAC-LD) to find out the impact of BACES scores on three types of treatment outcomes: clinical, radiological and microbiological.

“The BACES score was validated to predict mortality in an Asian cohort of patients with non-tuberculous mycobacterial lung disease but not to determine risk of disease progression and treatment response, which are different and are also an important disease characteristic that can be challenging to predict for clinicians and patients,” Escalante told Healio.

Within the study population, more patients had received treatment with antimicrobials vs. with a non-antimicrobial approach over 2 years (53 patients vs. 33 patients). None of the patients had significant cavitary disease, according to researchers.

Patients with a BACES score of 1 had the highest rate of clinical improvement/stability at 100%, followed by patients with a BACES score of 0 (90%), a BACES score of 2 (82.6%) and a BACES score of 3 (40%). The link between BACES score and this rate was significant (P < .001), according to the presentation.

In terms of overall clinical-radiological improvement-stability response rates, researchers again observed the highest rate in the group with a score of 1 (100%). Those with a score of 0 had the second highest response rate at 90%, followed by a score of 2 (81.8%) and a score of 3 (40%). Significance was also found between BACES score and this rate (P < .001).

“We found that this BACES score [in addition to predicting mortality] can also be associated with clinical treatment response but in a cohort of patients with mostly non-cavitary lung disease in our region in the United States,” Escalante told Healio.

Unlike above, the link between BACES score and worsening radiological response rates was not significant.

Additionally, significance was not reported between BACES score and the sputum culture persistence rate. Patients with BACES scores of 0, 1 or 2 had similar rates (21.1% vs. 26.7% vs. 29.4%), according to researchers.

“We envision that a future study will be prospective to reduce selection bias and include not only the BACES score but also other promising prognostic parameters and/or novel biomarkers to accurately determine individual disease trajectories and help to make appropriate shared treatment decisions for these difficult-to-treat chronic lung infections,” Escalante told Healio.

“We are hopeful that ongoing studies in the U.S. and abroad, including the one we are conducting at our institution sites in collaboration with our research partners from Purdue University and other institutions, will help us to better understand the main factors that drive disease progression in these patients,” Escalante added.