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Updated: Apr 16, 2026
Isolation, Characterization, and Purification of Macrophages from Tissues Affected by Obesity-related Inflammation
Published on: April 3, 2017
Macrophages from patients with cirrhotic ascites showed function alteration of host defense receptor
Abdel Motaal M Ahmed1, Abdel Gadir Y Kadaru2, Ibtihal Omer3
1Department of Medicine, The National University for Medical and Allied Sciences, Khartoum 11123, Sudan.
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.
Conclusion:
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.
Insights
Patients with cirrhotic ascites have impaired macrophage phagocytosis, but this function improves after IL-4 treatment, suggesting potential therapeutic avenues for spontaneous bacterial peritonitis.
Area of Science:
- Immunology
- Gastroenterology
- Cell Biology
Background:
- Patients with cirrhotic ascites (PCA) are at high risk for spontaneous bacterial peritonitis (SBP), a serious complication.
- Altered functions of peritoneal macrophages (PMɸ) in PCA may contribute to increased infection susceptibility.
Purpose of the Study:
- To investigate factors related to receptor-mediated phagocytosis in peritoneal macrophages from patients with cirrhotic ascites.
- To assess the role of the mannose receptor (MR) and IL-4 in macrophage phagocytic activity.
Main Methods:
- Peritoneal macrophages (PMɸ) were isolated from ascitic fluid of 12 PCA patients.
- Phagocytosis of mannose receptor ligand and yeast particles was measured pre- and post-IL-4 treatment.
- MRC1 gene expression was analyzed using PCR.
Main Results:
- PCA patients' PMɸ showed significantly lower uptake of MR-specific ligand compared to controls.
- IL-4 treatment enhanced phagocytosis in PCA patients' PMɸ.
- MRC1 gene was not detected in PCA patients, unlike controls.
Conclusions:
- Decreased phagocytosis and MR uptake in PCA patients may be due to MR downregulation, which is reversible with IL-4.
- The absence of MRC1 gene expression warrants further investigation.
- These findings highlight altered host defense mechanisms relevant to SBP pathophysiology in PCA.
