Functional tests for lymphocytes - quantitation other than by microscopy of: (a) proliferation induced by 1 or more mitogens; or (b) proliferation induced by 1 or more antigens; or (c) estimation of 1 or more mixed lymphocyte reactions; including a test described in item 65066 or 65070 (if performed), 1 of this item to a maximum of 2 in a 12 month period