Joint Disease More Common With P. aeruginosa Infection, Female Sex

Chronic Pseudomonas aeruginosa infection in adults with cystic fibrosis increases their likelihood of developing CF arthropathy, a painful inflammation of the joints, a German study reported.

Additional risk factors for CF arthropathy include older age, female sex, and more severe disease.

These findings were published in the Journal of Cystic Fibrosis, in the study “Risk factors for cystic fibrosis arthropathy: Data from the German cystic fibrosis registry.”

As CF patients are living longer, age-related conditions, such as joint and bone disorders, are becoming more prevalent.

Arthropathy, a collective term for joint diseases, is associated with CF when patients have pain in the joints with signs of inflammation, but without evidence of periostitis (inflammation of the tissue that surrounds the bone) and with no other causes for joint inflammation.

Previous studies estimate that CF arthropathy affects between 2.6 up to 29% of people with CF, making it the most common reason for joint pain in this patient population. Its onset is known to be generally between ages 13 to 20. However, a comprehensive analysis of risk factors underlying this condition is lacking.

A research team conducted a retrospective analysis of data covering patients in the German CF Registry from January 2016 to December 2017.

Overall, 6,069 CF patients (infants to 78-year-olds) were included in the analysis. Those who had undergone organ transplant were excluded.

CF arthropathy was found in a total of 299 of these patients (4.9%). In general, they were more likely to be female and to show signs of more severe disease, worse lung function, more exacerbations, a greater need for medications, as well as to have co-existing conditions (comorbidities), and infections.

An increased prevalence of CF arthropathy was evident with aging — from 5.7% in the age range 18–29, to 11% among those 30–39 years old, and 12.5% in those 40 or older. CF arthropathy was significantly more prevalent in adults compared with children, 8.4% vs 0.7%.

CF arthropathy was also significantly more prevalent among adults with a chronic P. aeruginosa infection than among those who remained infection free, 11.7% vs. 4.8%. Notably, P. aeruginosa is a key bacterial agent of CF lung infections and severe lung disease.

Potential risk factors for CF arthropathy in adult patients was also evaluated, and a significant risk for CF arthropathy was found with increasing age, a higher number of hospitalizations, CF-related diabetes, and the presence of comorbidities. Children, due to their small number, were not in this analysis.

Women were more than twice as likely to have CF arthropathy, as were patients with pancreatic insufficiency. In people with CF, thick mucus forms in multiple organs, including the pancreas. This blocks the release of enzymes needed to properly digest food, resulting in pancreatic insufficiency.

Those with sinusitis — when fluid accumulates in the air-filled pockets of the nose and head — or nasal polyps (soft, noncancerous growths on the lining of the nose or sinuses) were also at higher risk for CF arthropathy. Patients without P. aeruginosa infection were generally younger, had better lung function and nutritional status, as well as fewer co-existing conditions.

Treatment with antimycotics (anti-fungal medications) linked with an almost three times greater risk of CF arthropathy in adults without P. aeruginosa.  

“While patients with chronic P. aeruginosa infection more frequently developed CFA [CF arthropathy] than patients without infection,” the scientists wrote, “factors indicating increased disease severity (age, number of hospitalizations and pancreatic insufficiency) associated significantly with CFA in patients regardless of P. aeruginosa status.”

Additional studies are warranted to assess “CFA in detail, to improve effective and distinct diagnosis and treatment strategies beyond the optimization of CF pulmonary therapy,” they concluded.