Clinical and radiological correlations of serum procalcitonin levels in patients who are hospitalized with community acquired pneumonia in childhood

ABSTRACTCLINICAL AND RADIOLOGICAL CORRELATIONS OF SERUMPROCALCITONIN LEVELS IN PATIENTS WHO ARE HOSPITALIZEDWITH COMMUNITY ACQUIRED PNEUMONIA IN CHILDHOODWe investigated eighty two 0-16 years of age patients those applied to pediatrypolyclinics and pediatric emergency services of Çukurova University Faculty ofMedicine, Balcalı Hospital, and having no antibiotic use 48 hours before hospitaladmission and having the clinical diagnosis of community acquired pneumonia.Demographic and clinic characteritics of the patients were recorded.Blood samples for complete blood count, erytrocyte sedimentation rate, C-reactive protein (CRP), procalcitonin (PCT), blood culture and Chlamydia Pneumoniaand Mycoplasma pneumonia (Ig M and Ig G) serologies and nasal and nasopharangealswab samples for the detection of the viral etiologies were taken at the time of hospitaladmission. Initial posteroanterior chest X-rays of all patients were checked.The agent of pneumonia were detected in 40 % (33/82) but not in 60 % (49/82)of our patients. In our patients the ratio of antibody positivity against one of the sixinvestigated viral agents, Ig M positivity against M. Pneumonia and Ig M positivityagainst C. Pneumonia were detected to be 26.6% , 2.4% and 7.3% respectively. Alsomixed viral-atypical bacterial agent presence were detected in 4.9% of our patients. Outof 21 viral antibody positive patients, 8 (9.8% ), 8 (9.8% ), 4 (4.9%), 2 (2.4%), 2 (2.4%)and 1 (1.2%) patients were detected to have Respiratory syncytial virus (RSV), InfluenzaA virus, Adenovirüs, Parainfluenza 2, Parainfluenza 3 and Parainfluenza 1respectively. RSV ve Influenza A were most commonly detected (9.8% ) viruses.Out of 82 pneumonia patients those having their diagnosis clinically, 35 (42.7%)had no radiological sign of pneumonia but 47 (57.3%) had. Out of 47 pneumoniapatients those having radiological signs, 19 (40%) and 28 (60%) have detected to havealveolar pneumonia and interstitial pneumonia respectively.While the mean PCT level of 82 pneumonia patients were 0.51 ng/ml, meanPCT level of 82 viral pneumonia patients were 0.24 ng/ml.Serum PCT levels were significantly higher in radiologically pnemonia detectedpatient group (median: 0.12 ng/ml) (0.01-17.80 ng/ml) than in no radiological sign ofpneumonia patient group (median: 0.06 ng/ml) (0.01-1.15 ng/ml) (p=0.035). Out of 19patients with a serum PCT>0.5ng/ml patients 9 have detected to have radiologicalalveolar consolidation. Out of 63 patients with a serum PCT<0.5ng/ml, 10 (15.9%) havedetected to have radiological alveolar consolidation. Presence of alveolar consolidationin serum PCT >0.5 ng/ml group patients were statistically and significantly highercompared to serum PCT<0.5 ng/ml patient group(p=0.010). In this study, alveolarconsolidation, as a highly spesific radiologic sign of bacterial infections, were detectedto be higher in patients group those having higher PCT (as strong indicator of bacterialinfections) levels.In serum PCT>0.5 ng/ml patient group, signs of severe or very severepneumonia findings such as dyspnea, cyanosis, denutrition and nasal flaring werestatistically and significantly higher than serum PCT<0.5 ng/ml patient group.In serum PCT>0.5 ng/ml patient group, median serum CRP levels were 37 (3.0-157.0) mg/dl. In serum PCT<0.5 ng/ml patient group, median serum CRP levels were3.9 (2.9-114). In serum PCT>0.5 ng/ml patient group serum CRP levels werestatistically and significantly higher than serum PCT<0.5 ng/ml patient group(p<0.001). There was a significant positive correlation between serum PCT and CRPlevels(r:0.534).Out of 47 pneumonia patients those having their diagnosis clinically, 6 (12.7%)have detected to have C. pneumoniae IgM positivity. Non of the 35 patients thosehaving no radiological pneumonia sign have C. pneumoniae IgM positivity (p=0.028).In terms of other pneumonia agents, there were no stastically significant differencedetected between radiologically and nonradiologically detected pnemonia groups.Finally, according to our results, measuring of serum PCT level which is aneasily performed simple test that a little amount of serum is needed (20µl) and resultscan be obtained in a very short time (<2 hour) in hospitalized children with communityacquired pneumonia and ıt may be useful for defining clinical and radiologicalcorrelation, degree of illness and deciding for antibiotic therapy. We think thatcontrolled trials are needed with larger patient groups.Key Words: Procalcitonin; radiological pneumonia signs; community acquiredpneumonia