Cardiopulmonary Exercise Testing in CVID and X-LA patients

Introduction: An heterogeneous group of chronic lung diseases occurs in CVID e X-LA and can affect the prognosis. The lung disease is usually assessed by spirometry, lung CT-scan, and 6-minute walking test (6MWT). Cardiopulmonary exercise testing (CPET) is considered the gold standard to study a patient's exercise intolerance and its causes. CPET is a safe, reproducible and clinically useful method to assess functional capacity to follow disease progression and response to treatment in several clinical conditions. Aims: To characterize the pulmonary function and exercise capacity of adult patients with CVID and X-LA. Methods: CPET was performed by six CVID and two X-LA patients. Spirometry, CT-lung scan and 6MWT data were acquired. Results: Two patients didn't reach the predicted peak work rate (46-47%), four patients reached the submassimal peak (68-74%) and two reached up to the 85%. The aerobic exercise capacity (VO2) was abnormal in six patients. The anaerobic threshold had a mean value of 44.8% (n.v. 49-63%) of the peak. The adequacy of ventilatory response to exercise expressed by VE/VCO2 at the anaerobic thresholds was abnormal in five patients. The increase in the VE/VCO2 ratio is due to the underlying pulmonary disease. Deconditioning was an adjunctive cause of bad CPET performance in seven patients. 6MWT was almost normal in seven patients. CT-lung scan and spirometry showed lung disease in five patients. Conclusions: CPET can improve early detection of ventilatory disfunctions and help to set a highly individualized training intensity for exercise prescription to improve prognosis and quality of life