( ( Antibodies ( to ( carboxypeptidase H ) ) ) ( ( are ( too ( infrequent ( to ( contribute ( to ( ( a ( standard panel ) ) ( of ( autoantibodies ( -LRB- ( 18 -RRB- ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Antibodies) (S (VP (TO to) (VP (VB carboxypeptidase) (NP (NNP H)))))) (VP (VBP are) (ADJP (RB too) (JJ infrequent) (S (VP (TO to) (VP (VB contribute) (PP (TO to) (NP (NP (DT a) (JJ standard) (NN panel)) (PP (IN of) (NP (NP (NNS autoantibodies)) (PRN (-LRB- -LRB-) (NP (CD 18)) (-RRB- -RRB-))))))))))) (. .)))
Antibodies to carboxypeptidase H are too infrequent to contribute to  a standard panel of autoantibodies (18).
(ROOT (S (NP (NNP Autoantibody)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT an) (NN antibody)) (SBAR (WHNP (WDT that)) (S (ADVP (RB inappropriately)) (VP (VBZ marks) (S (NP (NNS self-components)) (ADJP (RB as) (JJ foreign)))))))))) (. .)))