Enzyme immunoassays and related procedures in diagnostic medical virology

This review article describes several applications of the widely used enzyme immunoassay (EIA) procedure. EIA methods have been adapted to solve problems in diagnostic virology where sensitivity, specificity, or practicability is required. Concurrent developments in hybridoma and conjugation methods have increased significantly the use of these assays. A general overview of EIA methods is given together with typical examples of their use in diagnostic medical virology; attention is drawn to possible pitfalls. Recent advances in recombinant DNA technology have made it possible to produce highly specific nucleic acid probes that have a sensitivity approximately 100 times greater than that of EIA. Some applications of these probes are described. Although the non-labelled nucleic acid probes for use in the field are not as refined as non-labelled immunoassays, their range of applications is expected to expand rapidly in the near future.     

Detection and maturation of VEP albino asymmetry: an overview and a longitudinal study from birth to 54 weeks.

The genetic anomaly in albinism prevents adequate melanin metabolism within the fetal eye cup and stalk. This results in severe disruption of pre- and postnatal retinal development and the condition of abnormal temporal retinal projections. The obligate misrouting of retinal-geniculate-cortical projections in albinism can be detected in the topographical representation across the occiput of the visual evoked potential (VEP). Age-dependent misrouting detection methods are described which yield 100% detection rates with zero false positives across the life span. By combining appropriate state-defined neonatal recording procedures with the albino infant VEP test paradigm, the presence of aberrant optic pathway projections was observed in a 5-day-old full-term infant. Maximum asymmetry was observed within a long-latency window of the response which shifted during the postpartum period to shorter latencies. Longitudinal studies show two specific latency regions of significant VEP asymmetry. The first occurs within 40-70 ms after stimulus onset and remains constant across the age range. The second, more robust, cluster of asymmetry occurs within a longer latency window and shows an age-related shift towards shorter latencies. The decreasing latency of this asymmetry is concomitant with normal maturational changes of the evoked response. These results show that VEP misrouting can be extended to reliable albino diagnosis within the neonatal period and to the assessment of visual maturation.     

Propriospinal myoclonus after treatment with ciprofloxacin.

The clinical and electrophysiological features of a truncal myoclonus in a 55-year-old man are described. The electromyographic characteristics point toward propriospinal myoclonus. It is suggested that a myoclonic generator was released after use of ciprofloxacin, by antagonising the gamma-aminobutyric acid metabolism.     

KIR gene and KIR ligand analysis to predict graft rejection after renal transplantation

BACKGROUND: The identification of transplant patients at high risk for rejection after reduction of immunosuppression would allow minimization of immunosuppression and avoidance of side effects in low-risk patients. Next to T cells, innate natural killer (NK) cells may contribute to graft rejection. NK cell activation depends on the balance between activating and inhibitory signals, delivered by self-human leukocyte antigens (HLA) through binding of killer-cell immunoglobulin receptors (KIR). In transplantation, KIR and/or HLA mismatching may lead to NK cell activation. METHODS: In this study, we have evaluated whether acute rejection after reduction of immunosuppression after renal transplantation was associated with peripheral blood NK cell frequencies or with predicted NK cell alloreactivity based on KIR gene and ligand analysis. HLA and KIR genotyping was used to analyze the presence of single KIR genes and haplotypes, and to predict NK cell alloreactivity based on the "missing self" and "missing ligand" hypothesis. NK cell frequencies were analyzed using flow cytometry. RESULTS: No association was found between NK cell alloreactivity based on KIR gene analysis or peripheral blood NK cell subset frequencies and the occurrence of acute rejection after reduction of immunosuppression. CONCLUSIONS: Our data suggest that in a setting where immunosuppression is reduced, prior analysis of NK cell reactivity cannot identify patients at risk for subsequent graft rejection.