The role of low molecular weight hyaluronic acid contained in Wharton's jelly in necrotizing funisitis

The purpose of this research was to study the changes in the molecular weig ht of hyaluronic acid in Wharton's jelly altered by necrotizing funisitis. Umbilical cords were collected at delivery from 20 newborns without funisit is, 6 newborns with acute funisitis, and 4 newborns with necrotizing funisi tis. Agarose gel electrophoresis of Wharton's jelly was performed to analyz e the molecular weight of hyaluronic acid (HA). We also investigated the ef fects of low or high molecular weight HA on the production of interleukin-8 in human umbilical fibroblasts. In Wharton's jelly without funisitis, HA w as 1150 +/- 280 kD in preterm newborns, regardless of gestational week at b irth, and that in full-term newborns was 1100 +/- 200 kD. When acute funisi tis was present, HA was 700 +/- 250 kD, and when necrotizing funisitis was present, HA was 520 +/- kD. The molecular weight of HA was significantly be low normal in newborns with necrotizing funisitis. Low molecular weight HA was associated with increased levels of IL-8 in the supernatant of cultured human umbilical fibroblasts in a time- and dose-dependent manner. High mol ecular weight HA did not induce the production of IL-8 in the same cells. L ow molecular weight PIA has a potent inflammatory action. The conversion fr om high to low molecular weight HA in Wharton's jelly may be important in t he pathophysiology of necrotizing funisitis.