The results of the present study differ somewhat from those that have been reported previously. Spring-meyer et al prospectively evaluated pulmonary function in a large group of marrow transplant patients returning at yearly intervals and noted the development of mild restrictive ventilatory changes. Pulmonary function changes within the population as a whole were examined but a well-defined cohort was not available for longitudinal study. In the current study, our patient population had excellent baseline pulmonary function with a tendency toward preservation of lung function with a mean of two years of followup. For the population as a whole, there was a progressive decline in Dsb most marked in patients with a diagnosis of CML. In the study cited previously, air flow obstruction appeared with increasing frequency in patients followed up at one, two and three years post-bone marrow transplantation. In contrast to the present study, that study did not find an association of progressive airway obstruction with CGVHD.
In more recent work from the same authors, CGVHD was identified as an important risk factor for the development of airflow obstruction at one year post-marrow transplantation. The combined use of methotrexate and the occurrence of CGVHD was strongly associated with decreases in FEV/FVC ratio at one year of followup. Methotrexate was not utilized as a GVHD prophylactic regimen in our patients. Sorensen et al observed a progressive decline in Dsb and VC in a group of patients with leukemia followed up for one year post-marrow transplantation. They attributed these changes to the use of TBI as a primary preparative regimen for transplantation. Similar changes were noted by Depledge et al11 in AML patients treated with TBI and marrow grafting. In the present study, we found the greatest decline in percent predicted Dsb in patients receiving TBI in combination with cyclophosphamide although the decline was not of statistical significance compared with that of patients receiving cyclophosphamide and busulfan. The use of cyclophosphamide alone actually showed a net preservation of lung function with a mean of two years of follow up. www.canadianhealthcaremallinc.com
In conclusion, follow-up pulmonary function studies in a well characterized cohort of patients post-bone marrow transplantation revealed well preserved spirometry and lung volumes at a mean of two years of follow up. Progressive decline in Dsb was noted especially in patients with a diagnosis of CML. No significant difference was noted in the preparative regimen of busulfan and cyclophosphamide vs TBI and cyclophosphamide, although there was a tendency for the latter to show a greater loss of Dsb with time. The development of CGVHD was associated with a progressive loss of FEVj and stable FVC suggesting progressive airway obstruction. We speculate that an asymptomatic group of patients with CGVHD may represent a subclinical spectrum of patients who may progress to the development of interstitial pneumonitis and obstructive airway disease post-bone marrow transplantation.
Category: Bone Marrow Transplantation
Tags: bone marrow transplantation, obstructive airway, Pulmonary function