Methods for treating a host suffering from a chronic immune disease, e. The arrangement includes a set of electronic components. If the cavitation detection component determines that pump cavitation is likely or suspected, the controller may operate the pump motor according to the cavitation signal, in order to reduce or eliminate the cavitation condition, before resuming normal control according to the setpoint. The front side member 1 is formed with a second inclination portion which abuts on the first inclination portion.