IMMUNOHISTOCHEMICAL STUDIES ON SPECIFICITY AND AFFINITY OF THE BB5-ANTIBODY AGAINST HUMAN PARATHYROID TISSUE

Localisation of parathyroid tissue in hyperparathyroidism may be diffi cult with standard methods. Immunoscintigraphy, using radiolabeled ant ibodies against epitopes of human parathyroid cells, could be a promis ing alternative. Therefore, we studied the necessary preconditions, wh ether the so-called BB5-antibody, directed against parathyroid cell me mbranes possesses sufficient specificity and affinity to be employed i n immunoscintigraphy. Specificity was tested immunohistochemically wit h APAAP-staining of 39 different human tissues. Additionally, an immun oscore-based quantitative comparison was performed to test the affinit y of BB5-antibody for normal and pathologic parathyroid tissue. Specif icity was proven by the fact that of all 39 tested tissue-types only t he parathyroid tissue was BB5-positive. Normal parathyroid tissue show ed a significantly higher affinity to the BB5-antibody than pathologic parathyroid tissue (p < 0.03). However, all tissue samples from prima ry or secondary hyperparathyroidism exhibited sufficient staining. We conclude that the BB5-antibody fulfills the necessary conditions to be tried for immunoscintigraphical localisation of the parathyroid gland s.