KIR (Killer Cell Immunoglobulin-like Receptors) are small, flexible ‘locks’ (receptors) that are located on the cell wall of immune cells (killer cells) of the mother. These killer cells generally have the task of recognizing and destroying foreign cells coming in from outside. The ‘foreign cells’ have small arms (HLA molecules) in their cell wall, which look like ‘keys’ in HLA diagnostics.
Killer cells scan the foreign cells and look for these keys, when they find a key that fits the lock, they destroy the foreign cell. But they also destroy the foreign cells if they cannot find any keys (HLA molecules).
So far, 16 different KIR genes (these are sections on chromosome 19 that produce ‘locks for the outer shell of the killer cells) have been discovered.
If the father of the child passes the HLA C2 molecules (C2 key) to the baby and the mother lacks the KIR AA receptors (killer cells without AA locks), then a connection with pregnancy poisoning and recurrent miscarriage has been reported.
There may also be a connection between the lack of activating KIR (AA) and the response to therapy with Intralipid as part of fertility treatments.
In Linz you can have KIR or HLA typing carried out.