Immunohistochemical assessment of peroxidase-like immunoreactivity in the thyroid gland and its correlation with biochemical assay.
BACKGROUND
Peroxidase content has been recently evaluated in normal thyroid and in different thyroid disorders by biochemical, histochemical, ultrastructural and immunocytochemical methods. Nevertheless immunocytochemical detection of thyroid peroxidase in thyroid samples conventionally processed for histology has never been done using a commercially available antibody, neither its correlation with the biochemical activity on adjacent samples.


METHODS
In this study we have analyzed normal thyroid tissue (3 patients), follicular adenoma (2 patients) and multinodular goiter (2 patients) conventionally processed for histology and stained by immunocytochemistry (Avidin Biotin System) using a polyclonal (rabbit) antibody for horseradish peroxidase (Serotec). Biochemical assay was performed on adjacent samples according to Hosoya method.


RESULTS
Normal thyroid showed peroxidase immunoreactivity in the majority of follicular cells; neoplastic cells of adenomas were variably stained. Biochemical assay showed positive correlation with ICC ranging from 20.4 micrograms/mg/prot a in multinodular goiter to 42.12 in normal thyroid, up to 122 of follicular adenoma.


CONCLUSIONS
Peroxidase content in the thyroid gland may be of clinical interest in several thyroid diseases, and in this study we have demonstrated that thyroid peroxidase can be detected by ICC in routinely processed thyroid samples using a commercially available antibody.
Carlei
F
F
Dipartimento di Medicina Sperimentale, Università degli Studi, L'Aquila.
Schietroma
M
M
Ventura
T
T
Risetti
A
A
Casciani
G
G
Mattucci
S
S
Baschieri
I
I
Lezoche
E
E
Simi
M
M
D000236:Adenoma / Q000737:chemistry / Q000201:enzymology; D015415:Biomarkers / Q000032:analysis; D006044:Goiter, Nodular / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D010544:Peroxidases / Q000032:analysis / Q000378:metabolism*; D012016:Reference Values; D013961:Thyroid Gland / Q000737:chemistry / Q000201:enzymology* / Q000276:immunology; D013964:Thyroid Neoplasms / Q000737:chemistry / Q000201:enzymology
D015415:Biomarkers; D010544:Peroxidases