BACKGROUND: The expansion of the use of immunohistochemistry (IHC) in numerous laboratories extends the power of diagnostic resolution, but may impart heterogeneity in procedures and results. Following recent international proposals, participants of the Club of IHC of the Brazilian Society of Pathology developed actions of quality control applying routine protocols for detection of some of the most relevant antigens as quality probes. OBJECTIVES: Ten laboratories participated on the present study on keratins and estrogen receptors. MATERIAL AND METHOD: On control-slides sent from each laboratory, each participant performed IHC reaction according to his daily practice, returning the slides with the filled procedure form. The evaluation of the intensity of the specific reaction and back-ground was performed individually during data show projection in a meeting of the Club of IHC, yielding a final score of performance. DISCUSSION AND CONCLUSION: The methodology adopted was found useful to ascribe the performance to the heterogeneous systems of antigenic retrieval and amplification, leading to the identification of moderate variation in intensity of immunoreaction and in back-ground, but not compromising the antigen detection in any of these laboratories. Other studies must approach interpretative questions, including semi-quantitation and cut-offs.
Immunohistochemistry; Quality control; Cytokeratins; Estrogen receptor
