Aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL)
Aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL) is a histological entity denoting a chronic inflammatory response to metal particles (cobalt and chromium ions) from a metal-on-metal prosthesis. The finding falls on the spectrum of adverse reactions to metal debris.
Pathology
It is thought to be a T-lymphocyte-mediated type IV hypersensitivity reaction. The particles activate cytotoxic T-lymphocytes and macrophages, which in turn leads to tissue damage.
Although it is thought to be proportional to the amount of debris, ALVAL is also observed in cases of small debris amount.
See also
