There is increasing incidence of chronic sickle cell lung disease as survival into adulthood becomes more frequent in patients with sickle cell disease(SCD).Early detection is therefore imperative to permit prompt intervention.99m Tc-DTPA aerosol scintigraphy is a sensitive non-invasive test of membrane permeability,which has been applied to assess degree of lung affection in diabetic patients and to predict disease progression in fibrosing alveolitis.We ecided to evaluate pulmonary involvement in SCD, which is common in Kuwait,using DTPA clearance.
Adults asymptomatic and nonsmoking SCD patients,with normal chest radiograph,attending the Hematlogy clinic,Mubarak hospital were enrolled for the study.Relevant clinical and hematological parameters,and pulmonary function tests were obtained.Tc-DTPA studies were performed using 35 mci,delivered through a nebuliser.Activity generated(t 1/2value)was determined.Values higher than 60 + or - 4 minutes were taken as abnormal,using the normal values established for Kuwait.
27 patients(15 SS,12 SBthal) aged between 16 and 45 years,consisting of 10 males and 17 females,completed the study.DTPA clearance was delayed in 18(66.7%) of the 27 patients,while the trasfer factor for carbon monoxide(TLCO)was decreased in only 7(26%)of the cases.Forced vital capacity(FVC) value was similarly decreased in 9(29%).12 of the patients who had normal TLCO value had delayed DTPA clearance.DTPA was also delayed in 10(37%) of the cases with normal FVC value.There was a significant difference in the DTPA clearance betwwen SS and SBthal patients,(p=0.05)There was a positive correlation between DTPA and FVC(r=0.435,p<0.05) but not with TLCO.CONCLUSIONS: This study revealed that DTPA clearance was delayed in the majority of patients,suggesting an early lung involvement.DTPA clearance appears to be more sensitive than pulmonary function tests in detecting pulmonary involvement in SCD.
It is apparent that SCD patients with normal pulmonary function tests may not be entirely free of lung involvement.
B.O. Onadeko, None.