Omental milky spots and peritoneal dialysis - Review and personal experience

Background: Little research has been dedicated to milky spots (MS), except for their rote in oncology. In the field of peritoneat dialysis (PD), studying MS could help in understanding peritoneat defenses. Methods: We reviewed the methods for detecting and counting omentat MS and studied modifications induced by chemical and inflammatory stimuli. The reactions of MS to peritoneat catheters, PD solutions, and infection were studied in 32 rabbits. We also evaluated changes in MS in 39 serial omentat biopsies from 16 patients with different histories of PD, and examined peritoneal biopsies from 38 patients with sclerosing peritonitis. Results: The catheter provoked an immediate increase in the number and size of MS in rabbits. Intraperitoneal infusion of commercial PD solution containing 1.38% or 3.86% glucose for 30 days Led to a slight but significant increase in the number and size of MS, without differences between the two glucose concentrations. Peritonitis caused a sharp increase in the number of MS in rabbits and humans, and a particular transformation. In patients with simple scterosis, we observed normal MS having the same number and size as in patients without simple sclerosis. A few MS were found in only 2 patients with sclerosing peritonitis. Conclusions: Peritoneal dialysis activates omental MS. Peritoneal infection Leads to a marked increase in the activity of MS, some of which undergo a singular transformation, casting doubt on previous theories about differentiation of MS from other Lymphatic organs. Comparison with oncological studies indicates certain contact points. The presence of MS in PO patients with simple sclerosis is in contradiction to other morphological studies sustaining that MS act only when in contact with a fenestrated mesothelial basement membrane. Finally, the shortage of MS in patients with sclerosing peritonitis raises certain questions about etiopathogenesis.