MEASUREMENT OF SERUM GRANULOCYTE COLONY-STIMULATING FACTOR LEVELS IN PATIENTS WITH DIFFERENT PHASE OF INFECTION

Objective To detect the serum granulocyte colony-stimulating factor (G-CSF) levels betweenthe patients with frequently repeated infection ( repeaters) and others (non-repeaters) in different phase of infection.Methods An enzyme-linked immunosorbent assay (ELISA) method was used to detect serum G-CSF levels in 50cases (32 non-repeaters and 18 repeaters) with acute phase of infection. Serum G-CSF levels were detected inrecovery phase in 10 cases. Results Serum G-CSF levels were significantly higher (1429. 97 ±506. 43ng/L) in32 non-repeaters with acute infection. There was a positive correlation between white blood cell count ( WBC) andserum G-CSF level (r =0. 396, P <0. 05). There was also a positive correlation between absolute neutrophil count(ANC) and serum G-CSF level (r =0. 346,P <0. 05). Serum G-CSF levels were higher (98. 62 ±56. 40ng/L) in18 repeaters with acute infection. It was showed that serum G-CSF levels were significantly higher in non-repeatersthan in repeaters with acute phase of infection (P <0. 001). In the meanwhile, the body temperature was signifi-cantly higher in non-repeaters than in repeaters with acute infection (37. 95 ±0. 14 vs 36. 91 ±0. 13 ,P<0. 001). There were no significant differences in age, WBC, ANC, type of bacterial, liver function and renal func-tion (P >0. 05). Serum G-CSF levels in recovery phase of the two groups were below the sensitivity of the assay( <60 ng/L). Conclusion It is suggested that application of recombinant G-CSF may be useful for the patientswith repeated infection.

Role of immunodeficiency in Acinetobacter baumannii associated pneumonia in mice

Background:Acinetobacter baumannii(A.baumannii)has become one of the most important opportunistic pathogens inducing nosocomial pneumonia and increasing mortality in critically ill patients recently.The interaction between A.baumannii infection and immune response can influence the prognosis of A.baumannii related pneumonia.The target of the present study was to investigate the role of immunodeficiency in A.baumannii induced pneumonia.Methods:Male BALB/c mice were randomly divided into the normal immunity control(NIC)group,normal immunity infection(NIA)group,immune compromised control(CIC)group,and immune compromised infection(CIA)group(n=15 for each group).Intraperitoneal injection of cyclophosphamide and intranasal instillation of A.baumannii solution were used to induce compromised immunity and murine pneumonia,respectively.The mice were sacrificed at 6 and 24 h later and the specimens were collected for further tests.Seven-day mortality of mice was also assessed.Results:After A.baumannii stimulation,the recruitment of neutrophils in mice with normal immunity increased sharply(P=0.030 at 6 h),while there was no significant raise of neutrophil counts in mice with compromised immune condition(P=0.092 at 6 h,P=0.772 at 24 h).The Th cell polarization presented with pulmonary interleukin(IL)-4 and interferon(IFN)-γlevel in response to the A.baumannii in CIA group were significantly depressed in comparison with in NIA group(IFN-γ:P=0.003 at 6 h;P=0.001 at 24 h;IL-4:P<0.001 at 6 h;P<0.001 at 24 h).The pulmonary conventional dendritic cell accumulation was even found to be inhibited after A.baumannii infection in immunocompromised mice(P=0.033).Correspondingly,A.baumannii associated pneumonia in mice with compromised immunity caused more early stage death,more severe histopathological impairment in lung.Conclusion:A.baumannii could frustrate the immune response in immunocompromised conditions,and this reduced immune response is related to more severe lung injury and worse outcome in A.baumannii induced pneumonia.