title: Macrophages from patients with cirrhotic ascites showed function alteration of host defense receptor.
abstract: BACKGROUND
  Patients with cirrhotic ascites (PCA) are susceptible to spontaneous bacterial peritonitis (SBP) which has increased morbidity and mortality. Since some host defense aspects of peritoneal macrophages (PMф) from PCA are altered this study examined factors related to receptor-mediated phagocytosis.
  
  
  METHODS
  Twelve PCA were studied. PMɸ were isolated from ascitic fluid (AF) samples removed from these patients. Uptake of mannose receptor (MR)-specific ligand, fluorescein isothiocyanate-mannosylated-bovine serum albumin (FITC-man-BSA), by patients' PMɸ and controls, a human monocytic cell line, was measured pre- and post-IL-4 treatment. Phagocytosis of FITC-labeled yeast particles by patients' PMɸ was measured pre- and post-IL-4 treatment. Fluorescence values were obtained using a spectrofuorometer. MRC1 gene was analyzed in blood samples from PCA and controls, healthy donors, using standard polymerase chain reaction (PCR) technique.
  
  
  RESULTS
  Past SBP episode(s) were reported in 58.3% of patients. Mean AF volume analyzed per patient was 1.3L. PMɸ ratio in cell yield was 53.73% (SD 18.1). Mean uptake absorbance of patients' PMф was 0.0841 (SD 0.077) compared to 0.338 (SD 0.34) of controls, P = 0.023. Following IL-4 treatment absorbance increased to 0.297 (SD 0.28) in patients' PMф (P = 0.018 on paired sample t-test), and to 0.532 (SD 0.398 in controls (P = 0.053 on independent sample t-test). Mean phagocytosis absorbance of patients' PMф was 0.1250 (SD 0.032) before IL-4 treatment compared to 0.2300 (SD 0.104) after (P = 0.026). PCR analysis for MRC1 gene was negative in all PCA samples compared to positive results in all controls.
  
  
  CONCLUSIONS
  Since decreased phagocytosis and MR uptake were enhanced post-IL-4 treatment MR downregulation pre-treatment is plausible. Negative PCR results for MRC1 might suggest an anomaly, but this awaits further ellucidation. These altered host defense findings are relevant to infection pathophysiology, and their relevance to SBP susceptibility in PCA is worth verifying.
authors.affiliation: Department of Medicine, The National University for Medical and Allied Sciences, Khartoum 11123, Sudan.
authors.forename: Abdel Motaal M
authors.initials: AM
authors.lastname: Ahmed
authors.affiliation: Department of Medicine, Faculty of Medicine, University of Khartoum, Khartoum 11123, Sudan.
authors.forename: Abdel Gadir Y
authors.initials: AG
authors.lastname: Kadaru
authors.affiliation: Microbiology Department, Ribat University, Khartoum 11123, Sudan.
authors.forename: Ibtihal
authors.initials: I
authors.lastname: Omer
authors.affiliation: Institute of Endemic Diseases, University of Khartoum, Khartoum 11123, Sudan.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Musa
authors.affiliation: Molecular Biology Unit, The National Research Laboratory Centre, Khartoum 11123, Sudan.
authors.forename: Khalid
authors.initials: K
authors.lastname: Enan
authors.affiliation: Virology Department, Faculty of Medicine, University of Khartoum, Khartoum 11123, Sudan.
authors.forename: Isam M
authors.initials: IM
authors.lastname: El Khidir
authors.affiliation: Institute of Hepatology, The Foundation for Liver Research, London, UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Williams
keywords: AF, ascitic fluid; FBS, foetal bovine serum; FITC, fluorescein isothiocyanate; IL-4, interleukin-4; MR, mannose receptor; MRC1 gene; MRC1, gene encoding human MR; PCA, patients with cirrhotic ascites; PCR, polymerase chain reaction; PMф, peritoneal macrophages; RPMI and DMEM, cell culture media; cirrhosis; macrophage host defense; man-BSA, mannosylated bovine serum albumin; mannose receptor; spontaneous bacterial peritonitis