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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]

• PSA detection and quantification is used as a tumor marker. • UMELISA PSA is an assay for measurement of total and free PSA in human serum samples. • Two-in-one test kit capable of quantifying and differentiating total and free PSA. • Fluorescent assay that uses only 10 µL of sample and reagents. • Cost-effective diagnostic kit implemented in the Cuban Public Health System. [Display omitted] Prostate specific antigen (PSA) is a serine protease used for the screening of prostate cancer. The total portion of PSA (tPSA) can be found in its free form (fPSA), or bound to other proteins forming a stable complex. A heterogeneous sandwich-type UltraMicro Enzyme-Linked ImmunoSorbent Assay (UMELISA) has been developed for the measurement of tPSA and fPSA in human serum samples. Strips coated with a high affinity monoclonal antibody (MAb) directed against PSA are used as solid phase, to ensure the specificity of the assay. Biotinylated MAbs specific for tPSA and fPSA ensured sensitivity, given the high affinity binding to streptavidin. The assay was completed in 1.5 h, with a measuring range 0.019–20 µg/L (tPSA), and 0.009–20 µg/L (fPSA). The intra- and inter-assay CV were lower than 9%. Recovery percentages were 96–105%. High correlations were found between the values of the UMELISA PSA standards and the International Reference Standards 96/670 (R2 = 0.9996) and 96/688 (R2 = 0.9989). The assay did not recognize any of the interfering molecules tested. Regression analysis of serum samples showed a good correlation with Roche Elecsys total PSA (n = 631, R2 = 0.986, ρc = 0.992), BioMérieux VIDAS TPSA (n = 631, R2 = 0.989, ρc = 0.993) and Roche Elecsys free PSA (n = 164, R2 = 0.973, ρc = 0.979), all with a relative difference below 15%, and a p < 0.001. A retrospective study of the use of UMELISA PSA in Cuba was carried out. The analytical performance characteristics of UMELISA PSA support its use for the quantification of tPSA and fPSA in human serum samples in a single kit, making it an affordable diagnostic assay available to Cuban Public Health System and developing countries. Between the years 2014–2020, more than 3 million Cuban patients have benefited from the test for free. [ABSTRACT FROM AUTHOR]