Immuno-biochemical evaluations of phenol and thimerosal as antigen preservatives in Montenegro skin test.

• Autor(a) principal: Mayrink, Wilson
• Data de Publicação: 2006
• Outros Autores: Coelho, George Luiz Lins Machado, Guimarães, Tânia Mara Pinto Dabés, Andrade, Hélida Monteiro de, Peres, Elúzia de Castro, Costa, Carlos Alberto da, Toledo, Vicente de Paulo Coelho Peixoto de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFOP
• Texto Completo: http://www.repositorio.ufop.br/handle/123456789/3773; http://www.sciencedirect.com/science/article/pii/S0001706X06000349
• topic: Cutaneous leishmaniasis; Montenegro skin test; Thimerosal; Phenol; Stability

Montenegro skin test (MST) represents the main complementary diagnostic test for tegumentary leishmaniases (TL) in endemic regions. Most antigen formulations used for the MST contain thimerosal as preservative. The Food and Drug Administration (FDA), however, recommended reducing or eliminating thimerosal from vaccines and other biological reagents and the Agˆencia Nacional de Vigilˆancia Sanit´aria (ANVISA) in Brazil, prohibited the use of mercurial compounds in immunobiologicals. In the search for an alternative stabilizer, phenol and thimerosal were tested as antigen preservatives in MST. Formulations were tested when fresh and after a 12-month storage at 4 ◦C in TL confirmed mice and human patients, and were evaluated for protein constitution by SDS-PAGE, Western blot and anti-gp63 ELISA. In mice, a decrease in the diagnostic effectiveness in merthiolate formulation was observed after a 12-month storage. SDS-PAGE, Western blot and anti-gp63 ELISA analyses showed a degradation of antigen proteins in both formulations after 12-month storage and that phenol-preserved antigen was quantitatively and qualitatively better than the merthiolate-preserved one. In patients, the average of induration diameter was larger in fresh antigens (p < 0.05). However, storage time did not jeopardize their diagnostic capacity.No non-specific reactions produced by phenol or merthiolate were observed neither in humans nor in mice. Phenol could be a good alternative to replace the merthiolate in MST, and despite the proteolytic activity, antigens remain viable for at least 12 months.