Low rate of CMV end-organ disease in HIV-infected patients despite low CD4+ cell counts and CMV viremia: results of ACTG protocol A5030.

PURPOSE: To describe cytomegalovirus (CMV) end-organ disease (EOD) rate in AIDS patients with low CD4+ cell count despite HAART who were enrolled in a randomized, placebo-controlled trial of preemptive valganciclovir (VGCV) to prevent CMV EOD in those with CMV viremia. METHODS: Subjects (N = 338) were HIV-infected with CD4+ count <100 cells/mm3, plasma HIV RNA >400 copies/mL, and on stable or no HAART. All underwent plasma CMV DNA PCR testing every 8 weeks (Step 1); those with detectable CMV DNA were randomized to VGCV or placebo (Step 2). RESULTS: Plasma CMV DNA was detected in 68 (20%), of whom 4 developed CMV EOD. During Step 1, 53 died. Of the 47 who entered Step 2 (24 VGCV, 23 placebo), CMV EOD was diagnosed in 10 (4 VGCV, 6 placebo) and 15 died (7 VGCV, 8 placebo). Of those randomized to placebo, 14% were diagnosed with CMV EOD at 12 months. CONCLUSIONS: We observed a lower CMV EOD rate among subjects receiving HAART than predicted based on published literature. However, mortality was high in this study. Our findings suggest that preemptive anti-CMV therapy in patients with persistently low CD4+ cell counts in the current treatment era may not be warranted given the low incidence of CMV EOD and high all-cause mortality observed in this study population.

The safety of discontinuation of maintenance therapy for cytomegalovirus (CMV) retinitis and incidence of immune recovery uveitis following potent antiretroviral therapy.

BACKGROUND: Reconstitution of immune function during potent antiretroviral therapy can prompt discontinuation of maintenance cytomegalovirus (CMV) therapy but has also been associated with sight-threatening inflammatory conditions including immune recovery uveitis (IRU). METHOD: Patients with inactive CMV retinitis and a CD4+ cell count above 100/mm3, receiving CMV therapy and stable combination antiretroviral therapy, were assigned to one of two groups based on willingness to discontinue CMV therapy. RESULTS: Thirty-eight participants were enrolled: 28 discontinued anti-CMV therapy (Group 1) and 10 continued CMV treatment (Group 2). Median on-study follow-up was 16 months. One Group 1 participant who experienced an increase in plasma HIV viral load and a decline in CD4+ cell count developed confirmed progression of CMV retinitis. Progression or reactivation CMV retinitis was not observed among Group 2. IRU was present at study entry in 3 participants. Six participants in Group 1 and 3 participants in Group 2 developed IRU on-study. CMV viremia was not detected in any participants, and urinary shedding of CMV was intermittent. CONCLUSION: Recurrence of CMV retinitis following discontinuation of anti-CMV therapy among patients with antiretroviral-induced increases in CD4+ cell count was rare. However, IRU was common in both those who maintained and discontinued anti-CMV therapy.

Decreased inflammatory pain due to reduced carrageenan-induced inflammation in mice lacking adenosine A3 receptors.

Mice with a targeted disruption of adenosine A(3) receptor (A(3)AR) gene were assessed for their nociceptive threshold and for their localized inflammatory response following carrageenan injected into the hindpaw. Under basal conditions no difference was seen between A(3)AR knock-out (A(3)AR(-/-)) and wild-type (A(3)AR(+/+)) mice in nociceptive response to mechanical or heat stimuli. The antinociceptive response to the intrathecal adenosine analogue R-phenylisopropyl adenosine (R-PIA) was also unchanged in the A(3)AR(-/-) mice. In contrast, heat hyperalgesia, plasma extravasation and edema following carrageenan-induced inflammation in the hind paw were significantly reduced in A(3)AR(-/-) mice compared to the A(3)AR(+/+) controls. Thus, mice lacking A(3)AR had deficits in generating the localized inflammatory response to carrageenan, supporting a pro-inflammatory role of A(3)AR in peripheral tissues. However, no evidence for a role of A(3)AR in nociception and the antinociceptive effect of R-PIA was found.

Presence of macrolide resistance in respiratory flora of HIV-Infected patients receiving either clarithromycin or azithromycin for Mycobacterium avium complex prophylaxis.

Clarithromycin 500 mg po bid or azithromycin 1200 mg po weekly is recommended as first line prophylaxis for Mycobacterium avium complex (MAC) in patients with HIV infection whose CD4 counts are <50 cells/microL. HIV-infected patients with CD4+ T-cell counts <200 cells/microL were randomized to receive either clarithromycin 500 mg po bid or azithromycin 1200 mg po weekly for 12 weeks. Nasopharyngeal swabs for Streptococcus pneumoniae and Haemophilus influenzae plus an anterior nare culture for Staphylococcus aureus were obtained at pretreatment, at 6 weeks, and at 12 weeks. A throat culture for oral flora was obtained for susceptibility testing against erythromycin. Minimum inhibitory concentrations (MICs) for clarithromycin and azithromycin were performed on all S. pneumoniae, H. influenzae, and S. aureus isolates. The study was terminated after respiratory flora, from all participants, revealed macrolide resistance. Because results of recent randomized trials indicate minimal efficacy of continuing MAC prophylaxis in patients who respond to potent combination antiretroviral therapy, the observed high incidence of macrolide-resistant bacterial colonization of the respiratory tract in this trial supports the discontinuation of macrolide prophylaxis in all AIDS patients whose CD4 counts have risen above 100 cells/microL.

Targeted deletion of A(3) adenosine receptors improves tolerance to ischemia-reperfusion injury in mouse myocardium.

A(3) adenosine receptors (A(3)ARs) have been implicated in regulating mast cell function and in cardioprotection during ischemia-reperfusion injury. The physiological role of A(3)ARs is unclear due to the lack of widely available selective antagonists. Therefore, we examined mice with targeted gene deletion of the A(3)AR together with pharmacological studies to determine the role of A(3)ARs in myocardial ischemia-reperfusion injury. We evaluated the functional response to 15-min global ischemia and 30-min reperfusion in isovolumic Langendorff hearts from A(3)AR(-/-) and wild-type (A(3)AR(+/+)) mice. Loss of contractile function during ischemia was unchanged, but recovery of developed pressure in hearts after reperfusion was improved in A(3)AR(-/-) compared with wild-type hearts (80 +/- 3 vs. 51 +/- 3% at 30 min). Tissue viability assessed by efflux of lactate dehydrogenase was also improved in A(3)AR(-/-) hearts (4.5 +/- 1 vs. 7.5 +/- 1 U/g). The adenosine receptor antagonist BW-A1433 (50 microM) decreased functional recovery following ischemia in A(3)AR(-/-) but not in wild-type hearts. We also examined myocardial infarct size using an intact model with 30-min left anterior descending coronary artery occlusion and 24-h reperfusion. Infarct size was reduced by over 60% in A(3)AR(-/-) hearts. In summary, targeted deletion of the A(3)AR improved functional recovery and tissue viability during reperfusion following ischemia. These data suggest that activation of A(3)ARs contributes to myocardial injury in this setting in the rodent. Since A(3)ARs are thought to be present on resident mast cells in the rodent myocardium, we speculate that A(3)ARs may have proinflammatory actions that mediate the deleterious effects of A(3)AR activation during ischemia-reperfusion injury.

Cytomegalovirus (CMV)-specific CD4+ T lymphocyte immune function in long-term survivors of AIDS-related CMV end-organ disease who are receiving potent antiretroviral therapy.

To better understand the relation of cytomegalovirus (CMV)-specific CD4+ T lymphocyte immunity and clinical outcome in AIDS-related CMV end-organ disease, 2 patient groups were prospectively studied: patients recently diagnosed with active CMV end-organ disease and survivors of CMV retinitis who had responded to highly active antiretroviral therapy and had quiescent retinitis when anti-CMV therapy was discontinued. Most patients with active CMV disease had negative CMV-specific CD4+ T lymphocyte responses at diagnosis, as measured by lymphoproliferation (7/7) or cytokine flow cytometry (3/5) assays. In contrast, all 10 subjects with quiescent retinitis and >150 absolute CD4+ T lymphocytes/microL whose anti-CMV therapy was discontinued during 6 months of follow-up had positive CMV-specific immune responses at least once by each assay. However, 6 of these 10 subjects also had negative CMV-specific immune responses > or =1 time. Such patients may be at risk for future CMV disease progression and should be closely monitored.

Targeted deletion of the A3 adenosine receptor confers resistance to myocardial ischemic injury and does not prevent early preconditioning.

We used mice with genetic disruption of the A3 adenosine receptor (AR) gene (A3AR(-/-)mice) to assess the in vivo role of the A3AR in modulating myocardial ischemia/reperfusion injury and preconditioning (PC). Surprisingly, infarct size induced by 30 min of coronary artery occlusion and 24 h of reperfusion was 35% smaller in A3AR(-/-)compared to wild-type mice (A3AR(+/+)). The reduction in infarct size was not the result of differences in heart rate, body temperature or increased cardiac expression of A1ARs. However, neutrophil infiltration within infarcted regions was less in A3AR(-/-)mice. Furthermore, ischemic PC induced by either a single episode (one 5 min occlusion) or multiple episodes (six 4 min occlusions) of ischemia produced equivalent reductions in infarct size in A3AR(-/-)and A3AR(+/+)mice. These results indicate that, in the mouse, (i) A3ARs play an injurious role during acute myocardial ischemia/reperfusion injury, possibly by exacerbating the inflammatory response, and (ii) A3ARs are not necessary for the development of the early phase of ischemic PC.

Invasive fungal sinusitis and meningitis due to Arthrographis kalrae in a patient with AIDS.

We report the first described case of Arthrographis kalrae pansinusitis and meningitis in a patient with AIDS. The patient was initially diagnosed with Arthrographis kalrae pansinusitis by endoscopic biopsy and culture. The patient was treated with itraconazole for approximately 5 months and then died secondary to Pneumocytis carinii pneumonia. Postmortem examination revealed invasive fungal sinusitis that involved the sphenoid sinus and that extended through the cribiform plate into the inferior surfaces of the bilateral frontal lobes. There was also an associated fungal meningitis and vasculitis with fungal thrombosis and multiple recent infarcts that involved the frontal lobes, right caudate nucleus, and putamen. Post mortem cultures were positive for A. kalrae.

Phase 1 trial of a single dose of recombinant human interleukin-12 in human immunodeficiency virus-infected patients with 100-500 CD4 cells/microL.

A phase 1 dose-escalation trial of a single subcutaneous dose of recombinant human (rh) interleukin (IL)-12 was conducted in medically stable human immunodeficiency virus (HIV)-infected patients with 100-500/microL absolute CD4(+) T lymphocytes. Subjects at each dose level were randomly assigned (3:1) to receive rhIL-12 or placebo. Among the 47 subjects enrolled, rhIL-12 was well tolerated at doses of 3-300 ng/kg, but 4 of 5 subjects who received rhIL-12 at 1000 ng/kg had severe adverse events. Dose-related increases in serum interferon-gamma occurred after rhIL-12 administration at doses > or =30 ng/kg. There was no effect of rhIL-12 on plasma HIV RNA or absolute CD4(+) T cell counts. However, dose-related increases in absolute CD8(+) T and NK cells were observed in subjects assigned to rhIL-12 doses of 30-300 ng/kg. Single rhIL-12 doses of 30-300 ng/kg were well tolerated and had biologic activity that could potentially be of benefit in the treatment of HIV disease or its complications.

Dianion aggregates derived from lithiation of N-silyl allylamine.

[reaction: see text] Three different N-silyl-protected allylamines, i.e., N-TMS, N-TBDMS, and N-TIPS allylamine, were lihtiated by reaction with excess n-butyllithium. Crystallization of the resulting dianions and X-ray structure determination yields three uniquely different aggregates.

Adenosine and inosine increase cutaneous vasopermeability by activating A(3) receptors on mast cells.

Adenosine has potent effects on both the cardiovascular and immune systems. Exposure of tissues to adenosine results in increased vascular permeability and extravasation of serum proteins. The mechanism by which adenosine brings about these physiological changes is poorly defined. Using mice deficient in the A(3) adenosine receptor (A(3)AR), we show that increases in cutaneous vascular permeability observed after treatment with adenosine or its principal metabolite inosine are mediated through the A(3)AR. Adenosine fails to increase vascular permeability in mast cell-deficient mice, suggesting that this tissue response to adenosine is mast cell-dependent. Furthermore, this response is independent of activation of the high-affinity IgE receptor (FcepsilonR1) by antigen, as adenosine is equally effective in mediating these changes in FcepsilonR1 beta-chain-deficient mice. Together these results support a model in which adenosine and inosine induce changes in vascular permeability indirectly by activating mast cells, which in turn release vasoactive substances. The demonstration in vivo that adenosine, acting through a specific receptor, can provoke degranulation of this important tissue-based effector cell, independent of antigen activation of the high-affinity IgE receptor, supports an important role for this nucleoside in modifying the inflammatory response.

Disruption of the A(3) adenosine receptor gene in mice and its effect on stimulated inflammatory cells.

The A(3) adenosine receptor (A3AR) is one of four receptor subtypes for adenosine and is expressed in a broad spectrum of tissues. In order to study the function of A3AR, a mouse line carrying a mutant A(3) allele was generated. Mice homozygous for targeted disruption of the A3AR gene, A3AR(-/-), are fertile and visually and histologically indistinguishable from wild type mice. The lack of a functional receptor in the A3AR(-/-) mice was confirmed by molecular and pharmacological analyses. The absence of A3AR protein expression in the A3AR(-/-) mice was demonstrated by lack of N(6)-(4-amino-3-[(125)I]iodobenzyl)adenosine binding to bone marrow-derived mast cell membranes that were found to express high levels of A3AR in wild type mice. In A3AR(-/-) mice, the density of A(1) and A(2A) adenosine receptor subtypes was the same as in A3AR(+/+) mice as determined by radioligand binding to brain membranes. Additionally, A(2B) receptor transcript expression was not affected by ablation of the A3AR gene. A3AR(-/-) mice have basal heart rates and arterial blood pressures indistinguishable from A3AR(+/+) mice. Functionally, in contrast to wild type mice, adenosine and the A3AR-specific agonist, 2-chloro-N(6)-(3-iodobenzyl)-adenosine-5'-N-methyl-carboxamide (2-Cl-IB-MECA), elicit no potentiation of antigen-dependent degranulation of bone marrow-derived mast cells from A3AR(-/-) mice as measured by hexosaminidase release. Also, the ability of 2Cl-IB-MECA to inhibit lipopolysaccharide-induced tumor necrosis factor-alpha production in vivo was decreased in A3AR(-/-) mice in comparison to A3AR(+/+) mice. The A(2A) adenosine receptor agonist, 2-p-(2-carboxyethyl)phenylamino)-5'-N-ethylcarboxamidoadenosine, produced inhibition of lipopolysaccharide-stimulated tumor necrosis factor-alpha production in both A3AR(-/-) and A3AR(+/+) mice. These results show that the inhibition in vivo can be mediated by multiple subtypes, specifically the A(3) and A(2A) adenosine receptors, and A3AR activation plays an important role in both pro- and anti-inflammatory responses.

A multicenter, randomized, double-blind, placebo-controlled trial of recombinant human interleukin-10 in HIV-infected subjects.

OBJECTIVE: To determine the effect of multiple subcutaneous doses of recombinant human interleukin (rhuIL)-10 on plasma HIV RNA levels and CD4 T-cell counts, and to evaluate its safety and tolerability in HIV-infected subjects. DESIGN: Prospective, randomized, double-blind, placebo-controlled, multicenter trial. SUBJECTS: Thirty-nine HIV-infected subjects with CD4 T-cell counts > 200 x 10(6)/l, plasma HIV RNA concentrations > or = 3.18 log10 copies/ml and on stable antiretroviral therapy were recruited from six centers. INTERVENTION: Subjects received (subcutaneously) rhuIL-10 1 microg/kg daily, 4 microg/kg daily, 8 microg/kg three times per week, placebo daily or placebo three times per week for 4 weeks. MAIN OUTCOME MEASURES: Prospectively defined outcomes included safety and tolerability, plasma HIV RNA levels and CD4 T-cell counts. Outcomes were assessed at baseline, weeks 1, 2, 3 and 4 during treatment and weeks 2 and 4 following completion of therapy. RESULTS: Baseline characteristics were similar in all groups. Compared to baseline, no significant change in plasma HIV RNA concentrations or CD4 T-cell counts was observed in any of the groups. RhuIL-10 was generally well tolerated. Two patients receiving rhuIL-10 4 microg/kg required discontinuation due to thrombocytopenia. One patient receiving rhuIL-10 4 microg/kg who had chronic hepatitis B and C infections discontinued drug because of elevated liver function tests. One patient receiving placebo discontinued study drug because of depression. CONCLUSION: The lack of a demonstrable virological benefit, as assessed by plasma viral load, with 4 weeks of rhuIL-10 does not support the development of this immune-based therapy for treatment of HIV infection.

Nonpeptide oxytocin antagonists: analogs of L-371,257 with improved potency.

Structure-activity studies on the oxytocin antagonist 1 (L-371,257; Ki = 9.3 nM) have led to the identification of a related series of compounds containing an ortho-trifluoroethoxyphenylacetyl core which are orally bioavailable and have significantly improved potency in vitro and in vivo, e.g., compound 8 (L-374,943; Ki = 1.4 nM).

Phase I study of combination therapy with intravenous cidofovir and oral ganciclovir for cytomegalovirus retinitis in patients with AIDS.

Ganciclovir and cidofovir, two antiviral agents used in the treatment of cytomegalovirus (CMV) retinitis, have a synergistic effect inhibiting CMV replication in vitro. In a phase I study, seven patients with AIDS-related CMV retinitis were treated with cidofovir (5 mg/kg intravenously every 2 weeks) combined with ganciclovir (1 g orally three times a day). During a median of 5.5 months (range, 1-12 months) of combined therapy, only one patient had retinitis progression, and only two of 28 blood cultures (specimens of which were obtained on a monthly basis) yielded CMV. Dose-limiting adverse ocular effects (anterior uveitis [two patients] and hypotony [two patients]) occurred in three of seven patients. The results suggest that combination therapy with intravenous cidofovir and oral ganciclovir (a regimen that does not require indwelling central venous catheter access) might enhance clinical efficacy. Less frequent administration of cidofovir in combination with oral ganciclovir should be prospectively studied to determine if the incidence of treatment-associated toxicity might be reduced.

Effect of renal disease and hemodialysis on foscarnet pharmacokinetics and dosing recommendations.

BACKGROUND: Foscarnet is an antiviral agent commonly used for managing patients with cytomegalovirus infection. Despite its clinical usefulness, foscarnet is associated with substantial adverse effects including nephrotoxicity. Moreover, foscarnet is primarily eliminated unchanged through the kidneys, thus requiring aggressive dose adjustment during kidney failure. To develop specific dosage guidelines, information on the disposition of this compound in patients with varying degrees of renal function and those requiring dialysis is essential. DESIGN: Twenty-six subjects were enrolled in this study and divided into five groups depending on their degree of renal dysfunction. Group 1 included subjects with normal renal function; group 5 included subjects requiring maintenance hemodialysis. Nondialysis study subjects received a single 60-mg/kg intravenous dose of foscarnet whereas hemodialysis subjects received two intravenous doses, separated by 1 week, to compare the effects of conventional and high-flux dialysis methods. RESULTS: Mean plasma clearance in control subjects averaged 2.1+/-0.7 ml/minute/kg and declined proportionally with changing renal function as indicated by the regression equation: Clp (ml/minute/kg) = 1.48 [CrCl (ml/minute/kg)]-0.08 (r2 = 0.82). Mean half-life averaged 1.9+/-0.1 hours in normal subjects and increased to a mean of 25+/-19 hours in study subjects with severe impairment not on dialysis. Foscarnet dialysis clearance (based on dialysate recovery) averaged 183 ml/minute with conventional dialysis methods and 253 ml/minute during high-flux procedures, which resulted in removal of 37% and 38% of a dose for the two methods, respectively. CONCLUSIONS: These data indicate that substantial dosage adjustments must be made in renal failure patients. Therefore, a patient-specific dosage nomogram has been developed.

Effect of antiviral drugs used to treat cytomegalovirus end-organ disease on subsequent course of previously diagnosed Kaposi's sarcoma in patients with AIDS.

OBJECTIVE: To evaluate the association of ganciclovir (GCV) and foscarnet (PFA) therapy with the outcome of previously diagnosed Kaposi's sarcoma (KS) after initiating antiviral therapy for cytomegalovirus (CMV) end-organ disease. DESIGN: Retrospective study. METHODS: KS progression was defined as a clinically obvious increase in size of baseline cutaneous or mucosal lesions, a new diagnosis of visceral KS, or initiation of a new systemic antineoplastic regimen or radiation therapy to treat KS. Multivariate analyses of risk of KS progression were calculated for prior duration of KS before initiating CMV treatment, treatment with PFA or GCV, number of weeks treated with PFA or GCV, absolute CD4 lymphocyte count at time of CMV-related disease diagnosis, diagnosis of KS prior to 1991, visceral KS, prior systemic chemotherapy, and prior radiation therapy. RESULTS: Among 66 patients who received > or = 14 days PFA (N=20) or only GCV (N=46), median time to progression of KS was 211 days (95% confidence interval [CI], 46-578) for patients who received PFA versus 22 days (95% CI, 15-41) for those who received only GCV (p < .001). In the stepwise multivariate analysis, only prior visceral KS (rate ratio [RR]=2.80; 95% CI, 1.07-7.35) and foscarnet therapy (RR = 0.24; 95% CI, 0.11-0.53) were significantly associated with risk of KS progression. CONCLUSION: PFA may be an effective therapy for AIDS-related KS; prospective trials are indicated.