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Every year a number of individuals are interpreted as indeterminate when tested by Western blot, then, a follow up is required to clear up their HIV serological status. To deepen in the study of this group, 571 persons whose Western blot was interpreted as indeterminate in the confirmatory algorithm of the AIDS Research Laboratory in Cuba (LISIDA) during the years 2004 and 2005 were studied for antibody response to the different HIV viral proteins; the serological evolution of 57 persons who only showed reactivity to p53 and/or p55 Kd, with a probable reactivity to p17 Kd protein was also studied. A greater reactivity (p < 0,001) to proteins 53 and 55 Kd was observed, and the percentage of persons who became negative in their Western blot bands pattern during the serological evolution was also significant. The results correlate with those reported by other researchers in similar studies, and justify the strategy of serological and epidemiological follow up in HIV- 1 individuals with Indeterminate Western blot tests, even when its reactivity is only against proteins 53 or 55 Kd, it also confirms the fact that HIV diagnosis is beyond an interpretation criteria or the reactivity value to a particular protein, success lies on the conjugation of clinical and epidemiological laboratory results. [ABSTRACT FROM AUTHOR]

The validation of manufacturing process is one of the principal requirements for the quality assurance, in biopharmaceutical industry. In this paper are shown the evaluation of the components production for diagnostic system that are produced in DAVIH Laboratories. The critical processes: the sterilization, lyophilization, preparation of liquid components and the tightness of the components packing were validated in four protocols using specific simulation methodologies for each one. The simulation proceedings revealed the main vulnerabilities in each operation. The sterilization and lyophilization were valid operations but the preparation of liquid components and the tightness of polylaminate component were critical operations. These results represent the first documental validation evidences in this type of product in DAVIH Laboratories. [ABSTRACT FROM AUTHOR]

Introduction: antigen immobilization in solid supports is used for the development of several immunoassays. One of the first technologies developed was the protein adsorption by direct application to nitrocellulose., Objective: to standardize the immobilization of a synthetic peptide of the HIV-2 transmembrane protein gp36 to nitrocellulose support for diagnostic purposes and to evaluate the performance parameters in a group of serum samples with recognized interesting reactivity., Methods: the peptide was freely immobilized, conjugated to bovine serum albumin (BSA) and to keyhole limpet hemocyanin (KLH) as carrier proteins. Immobilization parameters were analyzed and then, the optimal immobilization alternative was determined. Using the chosen variant, the diagnostic sensitivity and specificity against reference panels of the AIDS Research Laboratory were evaluated. Analytical specificity was evaluated with reactive samples to HIV-1 and HTLV-1., Results: the analysis of the immobilized peptide variants to nitrocellulose membranes showed that the gp36 peptide-BSA was the one that succeeded in setting the greatest differentiation between positive and negative samples. There were observed 100 % sensitivity, 95.2 % diagnostic specificity and 100 % analytical specificity., Conclusions: the gp36-BSA peptide immobilized on nitrocellulose membranes showed efficacy for the serological diagnosis of HIV-2, which will allow considering this peptide for diagnostic uses in systems with nitrocellulose -based solid phase.

The results of the design and evaluation of DAVIH VIH-2 diagnosing system, an indirect Elisa for screening of HIV-2 antibodies, which uses a HIV-2 glycoprotein gp36 synthetic peptide in its solid phase, were exposed. In the system evaluation using WHO reference panels, 100% sensitivity, 99,81% specificity, 99,81% efficacy and very good concordance level (kappa = 0.978) were attained. Serum samples of 959 individuals with undetermined or negative results to the HIV-1 antibodies confirmation (DAVIH blot) were evaluated by the DAVIH VIH-2 system. Twenty four samples were reactive, six of which had confirmed HIV-2 antibodies. These results allowed recommending the introduction of this diagnostic kit in the HIV infection diagnosing algorithm in Cuba.

The objective of this report was to evaluate oral fluid and urine as optional samples for HIV-1 confirmatory test using DAVIH-BLOT system (Laboratorios DAVIH, La Habana, Cuba), for which they were compared with their corresponding serum samples in a group of 125 individuals. In band pattern analysis, predominant antibodies in positives oral fluid and urine samples against p34, p68, gp41, gp120, were no different from their corresponding sera according to the proportion comparison test (p < 0,001). Relative sensitivity and specificity of this system were 100% in oral fluid and 98, 75% and 100% in urine samples respectively. These results support optional use of oral fluid and urine that, with slight modifications in the diagnostic system, can be applied for HIV-1 antibody confirmation testing.