γ-Glutamyl Transferase Testing, Change of Its Designation on the Laboratory Request Form, and Resulting Ratio of Inappropriate to Appropriate Use.

OBJECTIVES: To determine the effect of a modified request form on the total use of γ-glutamyl transferase (GGT) usage and the ratio of inappropriate testing. METHODS: We modified a test request form by moving GGT from the "Liver profile" to the "Other" section. The criteria for appropriate GGT ordering were developed based on literature review and then validated by expert consensus. To determine the appropriateness of GGT requests, we reviewed the medical records of patients for whom GGT testing was requested, before and after the change in the request form. RESULTS: The total number of GGT tests performed was reduced from 81,020 tests before the change to 35,816 tests after the change (a 44.2% reduction). Of the 349 patients whose records we examined, GGT testing was ordered for 169 patients before the change in the form and for 180 patients after the change. The percentage of inappropriate GGT ordering was nonsignificantly reduced (from 85.8% to 81.7%; P =.30). CONCLUSIONS: The change in the classification of GGT testing on the laboratory request form was associated with a reduction in total test usage and nonsignificantly associated with a reduction in the proportion of inappropriate testing. Hence, we strongly recommend that physicians be given feedback and education concerning clinical indication.

Evaluation of five commercial assays for the detection of anti-dsDNA antibodies: three Crithidia luciliae indirect immunofluorescence test kits and two enzyme immunoassay kits.

OBJECTIVE: There are various methods for anti-dsDNA detection. Crithidia luciliae indirect immunofluorescence test (CLIFT) and enzyme immunoassay (EIA) are the most commonly used at present. A number of CLIFT and EIA kits are commercially available. The objective of the present study was to evaluate the diagnostic performance of three commercial CLIFT kits, two commercial EIA kits, and their combinations for anti-dsDNA detection. MATERIAL AND METHOD: One hundred thirty nine sera sent for anti-dsDNA testing were investigated. Three commercial CLIFT kits (kit C1, C2, and C3) and two commercial EIA kits (kit E1 and E2) were evaluated. Sensitivities and specificities were calculated. The gold standard methods were the consensus results of all five kits, together with the clinical diagnosis when the results of five kits were discrepant. RESULTS: Of 139 sera investigated, 94 (67.6%) sera showed concordant results for all five kits and 45 (32.4%) sera showed discordant results. Thirty-five of those 45 patients (77.7%) were diagnosed as SLE. Sensitivities and specificities of the kits were as follows, Cl 82.1% and 94%, C2 46.4% and 100%, C3 78.6% and 98.8%, E1 71.4% and 94%, and E2 75% and 93.8%, respectively. Kit C3 yielded the maximum sum of sensitivity and specificity (177.4%). Sensitivities and specificities of the combinations of CLIFT and EIA kits were as follows, C1 + E1 89.3% and 90.4%, C1 + E2 98.2% and 87.9%, C2 + E1 73.2% and 94%, C2 + E2 82.1% and 92.8%, C3 + E1 85.7% and 94%, and C3 + E2 94.6% and 91.6%, respectively. The combination of kit C3 and E2 yielded the maximum sum of sensitivity and specificity (186.2%). CONCLUSION: Kit C3 was the assay of choice for anti-dsDNA detection. EIA kits yielded lower sensitivities and specificities than two of three CLIFT kits. Therefore, they should not be used as the first assay for anti-dsDNA screening. When CLIFT and EIA assays were combined, sensitivities were increased Kit E2 helped CLIFT kits to detect more SLE cases than E1.

Multiple KIR gene polymorphisms are associated with plasma viral loads in SIV-infected rhesus macaques.

Innate immune mechanisms play a deterministic role in the rate of disease progression during acute infection in HIV infected humans and SIV infection of non-human primates. The role NK cells play in mediating such an effect has thus gained importance. One of the major sets of molecules that regulate NK cell function are the killer cell immunoglobulin-like molecules (KIR's). Our laboratory has previously shown an association of KIR3DL alleles 13 and 14 with high plasma viral loads in a cohort of SIV-infected rhesus macaques. To gain a more detailed understanding of the role of KIR polymorphisms, our laboratory herein conducted studies of three additional KIR loci and show that select KIR3DH alleles appear to be more strongly associated with high plasma viral loads than KIR3DL alleles 13 and 14. In addition, we herein document the existence of additional new alleles for the KIR1D, KIR2DL4, and the KIR3DH loci.

Decreased NK cell frequency and function is associated with increased risk of KIR3DL allele polymorphism in simian immunodeficiency virus-infected rhesus macaques with high viral loads.

NK cells have been established as an important effector of innate immunity in a variety of viral infections. In HIV-1 infection in humans, alterations of NK cell function, frequency, and expression of various NK receptors have been reported to be associated with differential dynamics of disease progression. Expression of certain alleles of KIR3DL and KIR3DS receptors on NK cells was shown to correlate with levels of virus replication. In the SIV-infected rhesus macaque (RM) model of AIDS, several families of killer inhibitory Ig-related receptors (KIR receptors) corresponding to their human counterparts have been characterized, but only at the level of individual sequence variants. Here we define 14 different alleles of KIR3DL expressed among 38 SIV-infected RM, characterized by either high or low levels of SIV replication, by analyzing multiple sequences from individual animals and show an unequal distribution of certain alleles in these cohorts. High levels of SIV replication were associated with significant increases in KIR3DL mRNA levels in addition to decreases in both the frequency and function of NK cells in these animals. The higher frequency of inheritance of two KIR3DL alleles characterized by a single nucleotide polymorphism 159 H/Q was associated with RM that exhibited high plasma viral load. This data for the first time defines multiple alleles of KIR3DL in RM and shows an association between virus control, NK cell function and genetic polymorphisms of KIR receptors.