Aviv,
The answer is - it's possible, but really hard.
You would need to create what is called a side-band TCP connection in the irule to send correctly-formatted data to the AD server. If the AD server uses TLS, you would need to handle the encryption (or pass your side-band through a virtual with a server-ssl profile). At the very least, your irule will be responsible for handling every step of the LDAP protocol to bind, authenticate, and then update the attribute.
It would be easier to do this using irulesLX, as there is bound to be a NodeJS library to handle the LDAP operation. But irulesLX is a separate license.
It would be way easier just to log usage data from the irule to a remote syslog server, and use those logs to make your decision about permissions.