To determine the spectrum of clinical manifestations of hypokalemia associated with tenofovir, we reviewed all reports of grades 3/4 hypokalemia received by Gilead Sciences Department of Safety and Public Health. Of 32 cases identified in 2001-2006, 23 were attributed to proximal renal tubular dysfunction, and medically significant conditions attributable to hypokalemia occurred in four, which all improved with medical management. In none of the six fatal cases did hypokalemia appear to contribute to death.

Primary isolates of human immunodeficiency virus type 1 (HIV-1) predominantly use chemokine receptor CCR5 to enter target cells. The natural ligands of CCR5, the beta-chemokines macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and RANTES, interfere with HIV-1 binding to CCR5 receptors and decrease the amount of virions entering cells. Although the inhibition of HIV-1 entry by beta-chemokines is well documented, their effects on postentry steps of the viral life cycle and on host cell components that control the outcome of infection after viral entry are not well defined. Here, we show that all three beta-chemokines, and MIP-1alpha in particular, inhibit postentry steps of the HIV-1 life cycle in primary lymphocytes, presumably via suppression of intracellular levels of cyclic AMP (cAMP). Productive HIV-1 infection of primary lymphocytes requires cellular activation. Cell activation increases intracellular cAMP, which is required for efficient synthesis of proviral DNA during early steps of viral infection. Binding of MIP-1alpha to cognate receptors decreases activation-induced intracellular cAMP levels through the activation of inhibitory G proteins. Furthermore, inhibition of one of the downstream targets of cAMP, cAMP-dependent PKA, significantly inhibits synthesis of HIV-1-specific DNA without affecting virus entry. These data reveal that beta-chemokine-mediated inhibition of virus replication in primary lymphocytes combines inhibitory effects at the entry and postentry levels and imply the involvement of beta-chemokine-induced signaling in postentry inhibition of HIV-1 infection.

PURPOSE: To assess efficacy, safety, and adherence with compact quadruple therapy comprising one lamivudine 150-mg/zidovudine 300-mg tablet (COM) twice daily + one abacavir (ABC) 300-mg tablet twice daily + three efavirenz (EFV) 200-mg capsules at bedtime for 24 weeks, followed by one lamivudine 150-mg/zidovudine 300-mg/ABC 300-mg triple nucleoside tablet (TZV) twice daily + three EFV 200-mg capsules at bedtime for 24 weeks. METHOD: A pilot 48-week, prospective, open-label trial in which 38 antiretroviral-naïve HIV-infected adults (baseline median HIV-1 RNA 5.1 log(10) copies/mL, CD4+ cell count 285/microL) received the above treatment and were monitored regularly with respect to plasma HIV-1 RNA levels, CD4+ cell counts, T-cell receptor excision circles (TRECs), adherence, and adverse events. RESULTS: At Week 48, intent-to-treat, switch-included analysis showed plasma HIV-1 RNA levels <400 copies/mL in 100%(29/29) of patients and <50 copies/mL in 93%(27/29); 59% of patients who achieved <50 copies/mL had <3 copies/mL (16/27). Similar virologic suppression was observed in patients with baseline HIV-1 RNA above or below 100000 copies/mL. HIV-1 RNA and CD4+ cell counts changed from baseline by a median of -3.4 log(10) copies/mL and +172 cells/microL, respectively. One virologic failure occurred at Week 16. Median TRECs/100000 peripheral blood lymphocytes increased 6-fold between baseline and Week 48. Median adherence rates were consistently 100% by self-report and 94% by pill count. Grade 2-4 treatment-related adverse events included dreams (16%), nausea (13%), decreased white cells (8%), dizziness (8%), sleep disorders (8%), and malaise and fatigue (8%). A suspected ABC hypersensitivity reaction occurred in 8%(3/38) of patients. CONCLUSION: COM/ABC/EFV or TZV/EFV produced potent, durable virologic suppression and immunologic benefits, was associated with high adherence rates, and was generally well tolerated.

Cytomegalovirus (CMV) may be transmitted by transfusion of whole blood and cellular components processed according to standard processing procedures. A need exists to develop new procedures to remove CMV and other leukocyte-borne viruses from donor blood. Ten patients (AIDS/bone marrow transplants) who were CMV antigenemic (virus subsequently confirmed by isolation), donated 50 mL of venous blood within 24 to 72 hours of the initial antigen detection. Twenty-five-milliliter aliquots of each specimen were passed through Purecell Neo Neonatal Leukocyte Reduction Filters (Pall, East Hills, NY). The remaining 25-mL nonfiltered aliquots, as well as the blood filtrates, were subjected to infectivity endpoint determinations. The Purecell Neo filter effected a 3 to 4 log10 leukocyte reduction. CMV input titers ranged from less than 10 to 7.3 x 10(1) median tissue culture infectious dose (TCID50) per milliliter. CMV was not isolated from any postfiltration effluent (i.e., leukocytes, erythrocytes, or plasma). CMV DNA was not detected by nested polymerase chain reaction in 8 of 10 postfiltrate blood specimens. The Purecell Neo filter was efficacious in eliminating or significantly reducing viral (CMV) load in venous blood.

The current report summarizes the available published and unpublished data from several investigators on resistance in clinical isolates following prolonged stavudine therapy. Results suggest that stavudine resistance is both modest in degree and infrequent in appearance. Phenotypic evaluation of 61 patients on stavudine therapy showed only modest changes in drug sensitivity following up to 29 months of treatment. The post-treatment isolates from 15 patients exhibited an increase in EC50 value > fourfold (level above variability of assay) when compared with the corresponding pretreatment isolates. However, the vast majority (11) of these pretreatment isolates either had unexpectedly low EC50 levels and/or had post-treatment isolates that lacked any amino acid changes within their reverse transcriptase (RT) gene to account for the observed change in sensitivity. Of the four remaining isolates, two appeared to have a multi-resistant phenotype to several nucleoside analogues and two had no detectable RT amino acid changes to account for the observed change in stavudine sensitivity. To date, clinical HIV-1 isolates displaying stavudine-specific resistance have yet to be reported. Furthermore, full or partial RT sequence analysis of 194 post-treatment isolates failed to identify any consistent amino acid changes. The strain-specific V75T mutation reported to confer stavudine resistance to the HXB2 HIV-1 strain in vitro, was found in only six isolates and did not correlate with stavudine resistance. This low incidence of stavudine resistance is in striking contrast to that observed with other nucleoside analogues and further supports the use of stavudine in first-line combination therapy for HIV patients.

With the availability of anticytomegalovirus (CMV) therapeutic agents, rapid detection of CMV is important in the care and management of the immunosuppressed patient. The PrimeCapture CMV DNA Detection Plate System (PC-PCR) was evaluated for the detection of CMV in blood and cerebrospinal fluid (CSF). The resolution of discordant results was performed by consensus testing utilizing a combination of conventional cell culture (TC-CPE), the CMV-antigenemia (CMV-Ag) assay, one or more in-house CMV nested PCR assays, and/or patient evaluation and follow-up. Of 51 blood specimens from 34 patients, 23 (45%) were identified as true positives. PC-PCR was significantly more sensitive than the CMV-Ag assay, TC-CPE, or a combination of both tests. The sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) for PC-PCR, the CMV-Ag assay, TC-CPE, and a combination of CMV-Ag and TC-CPE were 78, 75, 72, 81%; 46, 100, 100, 70%; 39, 100, 100, 67%; and 58, 100, 100, 73%, respectively. CMV was not detected or isolated in CSF, resulting in a combined PC-PCR sensitivity, specificity, PPV, and NPV of 77, 90, 68, and 93%, respectively. Among those laboratorians considering the incorporation of molecular CMV diagnostics into their clinical microbiology or virology laboratories, the CMV PC-PCR offers a relatively simple-to-perform and sensitive assay system.

One-hundred twenty AIDS patients, tested by an optimized cytomegalovirus antigenemia (CMV-Ag) assay, were followed over a 6-month period in an attempt to correlate viral (CMV) load with severe CMV organ-specific disease. Among patients available for follow-up, CMV organ-specific disease was present in seven of eight (88%) with pp65 antigen levels > or = 50 cells per 4 x 10(5) polymorphonuclear leukocytes. One-hundred six patients of 107 patients with levels < 50 pp65 reactive cells did not develop CMV organ-specific disease within our 6-month follow-up period. The CMV-Ag assay, as standardized in our clinical setting, served as a marker and predictor of CMV organ-specific disease in our AIDS patient population.