Serum Procalcitonin, Adenosine Deaminase and its Isoenzymes in the Aetiological Diagnosis of Pneumonia in Children

Abstract

A prospective study was undertaken to assess the usefulness of leukocyte count, serum C-reactive protein (CRP), procalcitonin (PCT), and the activities of total adenosine deaminase (tADA) and its isoenzymes ADA1 and ADA2, in the aetiological diagnosis of pneumonia in children. The study included three groups. Group A consisted of 23 children with bacterial pneumonia, group B of 50 children with viral and mycoplasmal pneumonia and group C of 46 healthy children. On the first day of admission in the clinic, blood samples were collected before the start of antimicrobial treatment, for culture, serological tests, leukocyte count and for the determination of CRP and PCT levels as well as tADA activity and its isoenzymes ADA1 and ADA2. According to our results, the mean leukocyte count and the mean concentrations of PCT and CRP were significantly higher in the children of group A than those in groups B and C. The admission serum PCT concentration has a higher sensitivity, specificity and positive predictive value for bacterial pneumonia than either CRP or the leukocyte count. The mean serum tADA, ADA1 and ADA2 activity in children of group A was not significantly different from those in group C, while the difference between groups B and C was statistically significant. In conclusion, we found that CRP is a good marker for screening various infectious diseases, but it cannot be used to distinguish between bacterial and viral infections. Serum PCT measurement might be a useful tool for the physician for the aetiological diagnosis of pneumonia in children. Measurements of serum tADA and ADA2 activity may provide useful additional diagnostic information on the aetiology of pneumonia so that appropriate antibiotic therapy can be given promptly. Further studies with larger patients groups are required to confirm our results.

Procalcitonin as an early marker of bacterial infection in neutropenic febrile children with acute lymphoblastic leukemia

“…Serum levels are very low in healthy individuals (\0.5 ng/ml) and in severe infections can reach up to 1,000 ng/ml without changes in serum calcitonin levels [18]. The concentration changes of PCT during infection are rapid and the PCT molecule is stable and easy to determine, making it a potentially useful marker [19,20].…”

Evaluation of Acute-phase Reactants, Immunologic Markers and other Clinical and Laboratory Parameters in Patients with Pneumonia and Non-pneumonic Lower Respiratory Tract Infections

“…In such reports patients with atypical pneumonia seemed to have higher ADA levels than patients with bacterial pneumonia and than healthy controls [17][18][19][20] . Regarding ADA levels in typical bacterial pneumonia, some studies did not find differences with healthy controls [17][18][19] , whereas other authors found higher levels in pneumonic patients [20,21] . In this regard, we did not find significant differences between patients with pneumococcal pneumonia and patients with other or unknown etiologies (data not shown).…”

“…Adenosine deaminase (ADA), an enzyme responsible for the conversion of adenosine and deoxyadenosine to inosine and deoxyinosine, is involved in the proliferation and differentiation of lymphocytes and monocytes [12,13] . Although serum ADA has been evaluated mainly in patients with tuberculosis [12][13][14][15][16] , it has also been analyzed in a few reports of non-tuberculous lower respiratory tract infections [17][18][19][20][21] . β 2 -microglobulin (β2-M), a membrane protein of low molecular weight, is a component of the class 1 major histocompatibility complex.…”

Procalcitonin in sepsis and bacterial infections

“…27 Another study which involved children with bacterial and viral pneumonia revealed that on admission 100% of the children with bacterial pneumonia had high levels of PCT (0.94-6210 ng/mL), while only 34% of the children with viral pneumonia had PCT levels between 0.5-2.13 ng/mL. 28 In this study, it was concluded that PCT concentration of greater than 2.0 ng/mL had 100% sensitivity, 98% specificity, and a positive predictive value of 93% for bacterial pneumonia. CRP levels were elevated in 100% and 88% cases of bacterial and viral pneumonia respectively, giving a specificity of 38% and positive predictive value of 42% for bacterial pneumonia.…”