title: Omental milky spots and peritoneal dialysis--review and personal experience.
abstract: BACKGROUND
  Little research has been dedicated to milky spots (MS), except for their role in oncology. In the field of peritoneal dialysis (PD), studying MS could help in understanding peritoneal defenses.
  
  
  METHODS
  We reviewed the methods for detecting and counting omental MS and studied modifications induced by chemical and inflammatory stimuli. The reactions of MS to peritoneal catheters, PD solutions, and infection were studied in 32 rabbits. We also evaluated changes in MS in 39 serial omental 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 sclerosis, 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 PD 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.
authors.affiliation: Nephrology and Dialysis Department, Siena University Hospital, Italy. N.DiPaolo@ao-siena.toscana.it
authors.forename: Nicola
authors.initials: N
authors.lastname: Di Paolo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sacchi
authors.forename: Guido
authors.initials: G
authors.lastname: Garosi
authors.forename: Enrico
authors.initials: E
authors.lastname: Sansoni
authors.forename: Lucia
authors.initials: L
authors.lastname: Bargagli
authors.forename: Paola
authors.initials: P
authors.lastname: Ponzo
authors.forename: Piero
authors.initials: P
authors.lastname: Tanganelli
authors.forename: Enzo
authors.initials: E
authors.lastname: Gaggiotti
mesh_terms: D000818:Animals; D002404:Catheterization / Q000009:adverse effects; D015314:Dialysis Solutions / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008221:Lymphoid Tissue / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D009852:Omentum / Q000187:drug effects / Q000473:pathology* / Q000503:physiopathology; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010532:Peritoneal Diseases / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D011817:Rabbits; D014511:Uremia / Q000473:pathology / Q000503:physiopathology / Q000628:therapy
chemical_list: D015314:Dialysis Solutions