Clinicians are increasingly recognizing how nontuberculous mycobacteria (NTM) contribute to chronic lung infection and increase the prevalence of NTM lung disease or infection. “However, there is concern about the impact of these mycobacteria on patients, especially those with other underlying pulmonary diseases,” says Vira Pravosud, MS, MPH. Research shows that the prevalence of NTM is notable among patients with preexisting respiratory illnesses. Unfortunately, symptoms of NTM lung disease vary, tend to be nonspecific, and are similar to those typically attributed to coexisting underlying pulmonary disorders.
Symptomatic improvement is a key primary endpoint for monitoring patients on NTM medication, but studies show that the duration of successful treatment outcomes in NTM lung disease varies substantially. Although the severity of symptoms is generally expected to improve with medication, some patients may still experience complications, especially those with other pulmonary comorbidities.
More Symptoms With Medication
Pravosud and colleagues had a study published in Chronic Obstructive Pulmonary Diseases that sought to better understand how and to what extent patients may be affected by NTM lung infection or disease. “We were particularly interested in comparing disease symptoms in patients with or without concurrent use of medication to treat NTM lung infection or disease,” Pravosud says. The study compared symptoms experienced during the past 2 weeks at a single point in time using responses to the “Burden of NTM Survey,” developed by the COPD Foundation, in 266 individuals with NTM lung disease.
According to the results, many respondents had symptoms that bothered them “very often” or “daily,” and many reported at least one comorbid pulmonary illness in addition to their NTM lung disease. “Importantly, when compared with patients not on any medication to treat NTM lung infection or disease, patients on medication reported more symptoms,” says Pravosud. “These findings persisted even after taking into account patient age, gender, time of living with an NTM lung infection, and the presence of other lung diseases.” Patients on medication were significantly more likely to report difficulty in walking 500 meters without stopping, struggling to interact with others, and fatigue or lack of energy. They were also more likely to report feelings of sadness or depression related to illness and shortness of breath, wheezing, or other difficulties (Table). “Overall, more than one-half of surveyed participants reported living with an NTM lung infection or disease for more than 5 years, highlighting the chronic nature of these diseases,” Pravosud says. “Our study also aligns with recent research showing that NTM lung disease predominately affects women, those aged 50 or older, and patients with other underlying respiratory disorders.”
Focal Points for NTM Lung Infection Management
The study demonstrates which disease symptoms matter most to patients, according to Pravosud. “Our results can help with the development of a practical tool—such as a composite symptom score—that clinicians can use to evaluate symptom burden and severity in patients with these lung infections and diseases,” she says. “Our data identify what to focus on when managing symptoms and how to measure quality of life in patients with NTM lung infections or disease.”
In addition, Pravosud notes that the results provide information that may be helpful when aiming to improve current treatment options and evaluate emerging therapies. “Medications for NTM lung infections and diseases can have various side effects,” she says. “In fact, many patients may need to stop treatment due to severe adverse effects.” She adds that the findings are relevant nationwide, as the study included patients across the United States and did not reveal any differences with respect to symptom burden by geographic location.
“It should be noted that roughly 60% of patients not currently on any NTM medication considered themselves as having an ongoing NTM lung infection,” Pravosud says. “This is a very likely indication of non-negligible symptom burden. We don’t know why these patients were not on treatment. Future research should address this question and determine reasons for not initiating or stopping NTM therapy and the impact of these treatment approaches on symptom burden. Furthermore, future studies should follow patients to more accurately assess the effect of treatment on symptoms over time.”