title: Turbidity of hyperimmune equine antivenom: the role of phenol and serum lipoproteins.
abstract: Twenty batches of polyvalent antivenom produced at the Instituto Clodomiro Picado were analyzed for turbidity, both before and after freezing-thawing and lyophilization. Eight batches became turbid upon freezing-thawing, and this change correlated with high levels of cholesterol, triglycerides and lipoproteins, especially beta-lipoprotein. Since normal horse serum does not become turbid after freezing-thawing, despite the fact that it has high lipoprotein levels, the possibility was raised that phenol, used as a preservative during serum fractionation, might affect lipoproteins, inducing the appearance of turbidity after freezing-thawing. This hypothesis was tested by fractionating a sample of hyperimmune serum either without phenol or using two different phenol concentrations (0.1 g/dl and 0.25 g/dl). Results showed that, although the three samples had the same cholesterol and triglyceride levels before fractionation, only the one having 0.25 g/dl phenol became turbid upon freezing-thawing, containing a diffuse lipoprotein band on electrophoresis. This finding suggests that turbidity in equine antivenoms depends on the interaction of at least three factors: (a) freezing, (b) high initial cholesterol and lipoprotein concentration in the serum, and (c) addition of phenol during fractionation of serum.
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José.
authors.forename: G
authors.initials: G
authors.lastname: Rojas
authors.forename: M
authors.initials: M
authors.lastname: Vargas
authors.forename: A
authors.initials: A
authors.lastname: Robles
authors.forename: J M
authors.initials: JM
authors.lastname: Gutiérrez
mesh_terms: D000818:Animals; D000997:Antivenins / Q000737:chemistry*; D002784:Cholesterol / Q000097:blood; D005615:Freezing; D006736:Horses; D008074:Lipoproteins / Q000097:blood*; D009391:Nephelometry and Turbidimetry; D019800:Phenol; D010636:Phenols / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood
chemical_list: D000997:Antivenins; D008074:Lipoproteins; D010636:Phenols; D014280:Triglycerides; D019800:Phenol; D002784:Cholesterol