Lung Function and Inflammation in Adult Sickle Cell Disease in a West Indian Sickle Cell Cohort

Abstract

Background: The commonest cause of mortality in sickle cell disease (SCD) is an acute condition called the acute chest syndrome. Little is known of the long term effects of this condition or of its effect on lung function.   Objective: To determine lung function in sickle cell disease (SCD) adults and its relation to acute chest syndrome, baseline haemoglobin and systemic inflammation as estimated by serum C-reactive protein.   Methods: The lung function in sickle cell disease (SCD) outpatients was compared to that in asymptomatic age and sex matched controls. Stable haemoglobin and serum C-reactive protein (CRP) were measured.   Results: 74 controls of mean age 31 years and 154 sickle cell disease (SCD) outpatients with mean age 31 with 44% males were recruited. Controls and sickle cell disease (SCD) patients did not differ in age or sex. 18% sickle cell disease (SCD) patients had at least one episode of acute chest syndrome and 7% had two or more episodes. Forced vital capacity was lower in sickle cell disease (SCD) patients than controls and 47% of sickle cell disease (SCD) patients had a restrictive ventilatory defect. A further 19% had obstruction but the presence of this abnormality was not related to smoking habit. Patients with a history of two or more acute chest syndrome episodes were more likely to have poor lung function. Haemoglobin was positively correlated with forced vital capacity and inversely correlated C-reactive protein. Multivariate analysis showed that haemoglobin in sickle cell disease (SCD) patients was lower if patients also had a low forced vital capacity, high serum C-reactive protein, low body mass index, older age or male gender.   Conclusions: Abnormal lung function is common in sickle cell disease (SCD) adults. In sickle cell disease (SCD), adult’s low haemoglobin is related to a restrictive ventilatory defect and systemic inflammation. Severity of stable disease in sickle cell patients is related to poor lung function and systemic inflammation.