The average age of appearance of the condition is 65 years, however, there are clinical exceptions under study.
Interstitial lung disease related to rheumatoid arthritis is associated with decreased survival compared to the general population and the radiographic pattern of pneumonia The usual interstitial tumor increases the risk of mortality regardless of other factors, according to a Spanish study published in BMC Pulmonary Medicine.
A meta-analysis already suggested that a pattern of pneumonia Usual interstitial seems to be linked to a higher risk of mortality, compared to other patterns, however, it shows notable heterogeneity with variable methodological quality among the studies included.
Given this situation, it is relevant to know what factors can affect survival in order to evaluate the prognosis.
Dr. Francisco Javier Narváez, spokesperson for the Spanish Society of Rheumatology and a rheumatologist at the Bellvitge University Hospital in Barcelona, commented: “Interstitial lung disease related to rheumatoid arthritis It is a complex clinical situation due to its frequency and potential severity, as well as the difficulty involved in its therapeutic management. For this reason, multidisciplinary follow-up between the rheumatologist and the pulmonologist is recommended in all cases, which will undoubtedly result in better care for these patients.”
“The development of pulmonary involvement in rheumatoid arthritis is associated with sustained moderate or high disease activity. For this reason, it has been shown that controlling the activity of rheumatic disease prevents and improves the prognosis of lung disease,” said the rheumatologist.
Mortality and radiographic patterns
The primary objective of the study was to analyze all-cause mortality obtained from the records of both hospitals.
Radiographic patterns of interstitial lung disease associated with rheumatoid arthritis initially, based on high-resolution computed tomography images: pneumonia usual interstitial, nonspecific and others (pneumonia organized crypto and other pneumonia idiopathic interstitial). As well as the sociodemographic, clinical, laboratory and duration of the disease characteristics.
High specific incidence of mortality
Forty-seven patients were included and the mean follow-up was 5.3 ± 2.7 years, with a total follow-up of 242 patient-years and a maximum of 12 years. In the majority of patients (89.4%) the diagnosis of rheumatoid arthritis preceded interstitial lung disease.
The pneumonia Usual interstitial was the most frequent, followed by non-specific. After adjusting for confounding factors, the pattern of pneumonia habitual interstitial was associated with an increased risk of mortality, compared with the pattern of pneumonia non-specific interstitial.
As for the general standardized mortality rate, it was 2.57, which resulted in excess mortality in patients, compared to the general population. Men and women, as well as those aged between 75 and 84 years, presented excess mortality, while this effect disappeared at 85 years. After stratifying by age and sex, women between 60 and 75 years of age were the group with the highest standardized mortality rate.
The estimated incidence of all-cause mortality was 64.3 (39.4 to 104.9) per 1,000 patient-years. Patients were death-free for up to 1.5 years after interstitial lung disease diagnosis, with 10% mortality at 3 years, 30% at 6 years, and 50% at 8.3 years after diagnosis. Regarding deaths directly attributable to interstitial lung disease, the specific incidence was 41.4 (22.3 to 76.9), with a median survival of 10.9 years.
Death occurred in 16 patients (34%) in the study throughout the follow-up. The most frequent cause was progression of interstitial lung disease, acute exacerbation of the same or pneumonia (62.5%), followed by abdominal sepsis (12.5%), one due to neoplasia, one due to heart disease and another due to cognitive impairment.
Predictive factors of progression
The main predictors of functional progression of diffuse interstitial lung disease identified were the radiological pattern of pneumonia interstitial tissue, elevated titers of anti-cyclic citrullinated peptide antibodies, degree of baseline impairment of pulmonary diffusion of carbon monoxide (DLCO), greater than or equal to a 10% decrease in forced vital capacity during follow-up, extensive lung involvement on high-resolution chest computed tomography and elevated serum levels of interleukin-6 and Krebs von den Lungen glycoprotein-6 (KL-6).
All patients were included from the time of diagnosis and were followed up by multidisciplinary autoimmune interstitial rheumatologic lung disease units, attended by a tandem of pulmonologists and rheumatologists.