Objective: To analyse the differences in ascitic and serum levels of immunoglobulins and albumin between two groups of cirrhotic patients (with ascitic total protein levels higher and lower than 10 g/l).
Design: A prospective study.
Patients and methods: We studied 39 cirrhotic patients with sterile ascites. The patients were classified into two groups: group A (18 patients) comprised those with an ascitic total protein level less than 10 g/l and group B (21 patients) those with an ascitic total protein level higher than 10 g/l. Ascitic and serum levels of albumin and immunoglobins G, A and M were analysed.
Results: Ascitic immunoglobulin G and A levels in group B were higher than ascitic immunoglobulin G and A levels in group A. Ascitic levels of these immunoglobulins correlated linearly with ascitic total protein levels. The serum levels of immunoglobulins G and A in groups A and B were not significantly different. Ascitic and serum immunoglobulin M concentrations in the two groups were similar. Transfer of immunoglobulins G and A and albumin from plasma to ascites seemed to be similar in group B. Transfer of immunoglobulins G and A seemed to be impaired in group A. Differences in ascitic immunoglobulin levels between groups A and B were also observed in the presence of diuretic treatment. Differences in ascitic immunoglobulin levels were related to the Child-Pugh score.
Conclusion: Patients with a low ascitic total protein level show low ascitic immunoglobulin G and A concentrations. The low ascitic immunoglobulin G and A levels could be related to an impairment in the transfer of these immunoglobulins from plasma in those patients who have poor liver function. Ascitic immunoglobulin M is not related to ascitic total protein, and its origin is not clear. The putative transfer of immunoglobulin M to the peritoneal cavity is not related to the mechanism of transfer of albumin or of immunoglobulins G and A from serum. The physiological significance of ascitic immunoglobulin M is unclear.