title: Serum protein electrophoresis: an interesting diagnosis tool to distinguish viral from bacterial community-acquired pneumonia.
abstract: 29-69 % of pneumonias are microbiologically documented because it can be considered as an invasive procedure with variable test sensitivity. However, it drastically impacts therapeutic strategy in particular the use of antibiotics. Serum protein electrophoresis (SPEP) is a routine and non-invasive test commonly used to identify serum protein disorders. As virus and bacteria may induce different globulins production, we hypothesize that SPEP can be used as an etiological diagnosis test. Retrospective study conducted from 1/1/13 until 5/1/15 among patient hospitalized for an acute community-acquired pneumonia based on fever, crackles and radiological abnormalities. α/β, α/γ, β/γ globulins and albumin/globulin (A/G) ratio were calculated from SPEP. Data were analyzed in 3 groups: documented viral (DVP) or bacterial pneumonia (DBP) and supposedly bacterial pneumonia (SBP). We used ANOVA statistic test with multiple comparisons using CI95 and ROC curve to compare them. 109 patients included divided into DBP (n = 16), DVP (n = 26) and SBP (n = 67). Mean age was 62 ± 18 year-old with a sex ratio M/F of 1.3. Underlying conditions (e.g. COPD, diabetes) were comparable between groups in multivariate analysis. Means of A/G ratio were 0.80 [0.76-0.84], 0.96 [0.91-1.01], 1.08 [0.99-1.16] respectively for DBP, SBP and DVP (p = 0.0002). A/G ratio cut-off value of 0.845 has a sensitivity of 87.5 % and a specificity of 73.1 %. A/G ratio seems to be an easy diagnostic tool to differentiate bacterial from viral pneumonia. A/G ratio cut-off value below 0.845 seems to be predictable of a bacterial origin and support the use of antibiotics.
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France. benjamin.davido@gmail.com.|Infectious Diseases Department, Raymond Poincaré Teaching Hospital, Garches, 92380, France. benjamin.davido@gmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Davido
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: C
authors.initials: C
authors.lastname: Badr
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: A
authors.initials: A
authors.lastname: Lagrange
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: S
authors.initials: S
authors.lastname: Makhloufi
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: P
authors.initials: P
authors.lastname: De Truchis
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: C
authors.initials: C
authors.lastname: Perronne
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: J
authors.initials: J
authors.lastname: Salomon
authors.affiliation: Maladies Infectieuses, Hôpital Universitaire Raymond-Poincaré, AP-HP, Garches, France.
authors.forename: A
authors.initials: A
authors.lastname: Dinh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001798:Blood Proteins; D017714:Community-Acquired Infections / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D015897:Comorbidity; D003937:Diagnosis, Differential; D004586:Electrophoresis / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D011024:Pneumonia, Viral / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D012372:ROC Curve; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001798:Blood Proteins