Striking differences in the radiological patterns in patients with cystic fibrosis (CF)are seen. CT scans have been correlated with spirometry and mortality. Chest Xrays(CXR) are usually the first and commonest method of following these patients. CXR patterns have not been correlated with genotype, sex, age or outcome. CXRs on 110 adult CF patients at a single center were reviewed and the pattern of CF changes were correlated with these demographics. We present the preliminary data on the first 36 patients.
Three independent reviewers graded CXRs as having one of the following patterns: diffuse bilateral(DB), unilateral, upper lobe(UL)vs.lower lobe predominant disease or normal. When the reviewers disagreed the CXR was assigned to the DB category. Genotyping was done at a central CF reference laboratory. These data was then compared to genotype, sex, age. Age and genotype, and sex (male[M], female [F]) vs. genotype were compared.
The most common radiological appearances were of DB(58%)and UL(31%)of cases. The commonest genotype was homozygous for δF508 (64%)[2F508]; 8 patients (22%)were heterozygous for F508 with an unidentified second allele(F508/No ID). The other radiological patterns and genotypes were infrequently seen. No association was seen between genotype and CXR pattern. 74% M vs. 53% F expressed the 2F508 gene. Pts. less than 30 yrs old more commonly expressed the 2F508 gene than those 30 and over [75% vs. 50%]. DB pattern was more commonly seen in F(70%) vs. M (47%). UL was seen predominantly in M(42%) vs. only 18% of F.
In this small preliminary evaluation of CF patients, genotype does not appear to predict radiological disease pattern. However UL and DB disease are associated with M and F sex respectively. Interestingly the 2F508 genotype is less predominant in the older pts. suggesting a possible negative survival impact.
Chest Xrays pattern though inexpensive and simple to obtain and assess may prove a useful adjunct in risk assessment particularly when combined with age and sex in evaluation and management of CF patients.
Vaidehi Kaza, None.