Objective: To analyze the effect of special staining and immunohistochemical staining in distinguishing the types of renal amyloidosis to improve the diagnosis accuracy.
Methods: Congo red staining with different methods, and immunohistochemical staining of Kappa, Lambda and Amyloid A with different antigen retrieval methods were used for staining frozen and paraffin-embedded renal tissue sections.
Results: Wright's Congo red staining produced a better contrast and a higher resolution and showed a greater stability than the other 2 methods after repeated use for staining the renal tissue sections (P<0.05). Immunofluorescent staining produced better results in frozen renal tissue sections than in paraffin-embedded tissues. Immunofluorescent staining produced had better performance than immunohistochemical staining in paraffin-embedded tissues. The retrieval effect with protein kinase K was the best among the antigen retrieval methods in paraffin-embedded tissues.
Conclusion: Wright's Congo red staining is better than the other 2 methods in diagnosing renal amyloidosis. Immunohistochemical staining of Kappa, Lambda and Amyloid A in frozen renal tissue sections is necessary to discriminate the types of renal amyloidosis. For paraffin-embedded renal tissues, antigen retrieval using protein kinase K is better than the other 2 methods.