Barbara Baird

CD4 Counts as Predictors of Opportunistic Pneumonias in Human Immunodeficiency Virus (HIV) Infection

STUDY OBJECTIVE To determine if circulating CD4+ lymphocyte counts are predictive of specific infectious or neoplastic processes causing pulmonary dysfunction. DESIGN Retrospective, consecutive sample study. SETTING Referral-based clinic and wards. PATIENTS We studied 100 patients infected with human immunodeficiency virus (HIV) who had had 119 episodes of pulmonary dysfunction within 60 days after CD4 lymphocyte determinations. MEASUREMENTS AND MAIN RESULTS Circulating CD4 counts were less than 0.200 X 10(9) cells/L (200 cells/mm3) before 46 of 49 episodes of pneumocystis pneumonia, 8 of 8 episodes of cytomegalovirus pneumonia, and 7 of 7 episodes and 19 of 21 episodes of infection with Cryptococcus neoformans and Mycobacterium avium-intracellulare, respectively. In contrast, circulating CD4 counts before episodes of nonspecific interstitial pneumonia were quite variable: Of 41 episodes, 11 occurred when CD4 counts were greater than 0.200 X 10(9) cells/L. The percent of circulating lymphocytes that were CD4+ had a predictive value equal to that of CD4 counts. Serum p24 antigen levels had no predictive value. CONCLUSIONS Pneumocystis pneumonia, cytomegalovirus pneumonia, and pulmonary infection caused by C. neoformans or M. avium-intracellulare are unlikely to occur in HIV-infected patients who have had a CD4 count above 0.200 to 0.250 X 10(9) cells/L (200 to 250 cells/mm3) or a CD4 percent above 20% to 25% in the 60 days before pulmonary evaluation. Patients infected with HIV who have a CD4 count below 0.200 X 10(9) cells/L (or less than 20% CD4 cells) are especially likely to benefit from antipneumocystis prophylaxis.

A randomized, controlled trial of foscarnet in the treatment of cytomegalovirus retinitis in patients with AIDS

OBJECTIVE To evaluate foscarnet sodium in treating cytomegalovirus retinitis in patients with AIDS. PATIENTS Twenty-four previously untreated persons with AIDS and cytomegalovirus retinitis who were at low risk for loss of their visual acuity. INTERVENTION PATIENTS were randomly assigned to receive either no therapy (delayed treatment, control group) or immediate treatment with intravenous foscarnet at a dose of 60 mg/kg body weight three times a day for 3 weeks (induction regimen) followed by a maintenance regimen of 90 mg/kg once a day. MEASUREMENTS PATIENTS were examined weekly until they reached the primary clinical end point, defined as progression of their retinitis border by 750 microns or the development of a new retinal lesion due to cytomegalovirus. Progression was evaluated using retinal photographs by masked readers. Secondary evaluations included changes in visual acuity, cytomegalovirus shedding in the blood and urine, serum levels of human immunodeficiency virus type 1 (HIV-1) p24 antigen, and total CD4 T lymphocyte counts. RESULTS The mean time to progression of retinitis was 3.2 weeks in the control group (n = 11) compared with 13.3 weeks in the treatment group (n = 13) (P less than 0.001). Nine of 13 patients in the treatment group had positive blood cultures for cytomegalovirus at entry and all nine cleared their blood of cytomegalovirus by the end of the induction period (P = 0.004) compared with one of six patients in the control group. No reductions in p24 levels were seen in the control patients compared with a reduction of more than 50% in p24 levels for all four patients on treatment for whom follow-up levels were available. The main adverse effects of foscarnet treatment were seizures (2 of 13 patients), hypomagnesemia (9 of 13), hypocalcemia (11 of 13), and elevations in serum creatinine above 176.8 mumol/L (2.0 mg/dL) (3 of 13). The control patients received an average of 0.2 units of blood per week compared with an average of 0.6 units of blood per week for the patients on treatment. CONCLUSIONS The administration of foscarnet decreases the rate of progression of cytomegalovirus retinitis in persons with AIDS. Its judicious use is likely to prevent loss of vision in these patients. In this study, however, there was little change in visual acuity in patients in either the immediate or delayed treatment group because only patients with non-sight-threatening disease were selected.

Trimetrexate for the Treatment of Pneumocystis carinii Pneumonia in Patients with the Acquired Immunodeficiency Syndrome

Preclinical studies have demonstrated that trimetrexate is a potent inhibitor of dihydrofolate reductase from Pneumocystis carinii. On the basis of this evidence, this lipid-soluble antifolate was used as an antipneumocystis agent in 49 patients with the acquired immunodeficiency syndrome (AIDS) and pneumocystis pneumonia. Simultaneous treatment with the reduced folate leucovorin was used as a specific antidote to protect host tissues from the toxic effects of the antifolate without affecting the antipneumocystis action of trimetrexate. Patients were assigned to three groups and treated for 21 days: in Group I, trimetrexate with leucovorin was used as salvage therapy in patients in whom standard treatments (both pentamidine isethionate and trimethoprim-sulfamethoxazole) could not be tolerated or had failed (16 patients); in Group II, trimetrexate with leucovorin was used as initial therapy in patients with a history of sulfonamide inefficacy or intolerance (16 patients); and in Group III, trimetrexate with leucovorin plus sulfadiazine was used as initial therapy (17 patients). The response and survival rates were, respectively, 69 percent and 69 percent in Group I; 63 percent and 88 percent in Group II; and 71 percent and 77 percent in Group III. Trimetrexate therapy had minimal toxicity; transient neutropenia or thrombocytopenia occurred in 12 patients and mild elevation of serum aminotransferases in 4. We conclude that the combination of trimetrexate and leucovorin is safe and effective for the initial treatment of pneumocystis pneumonia in patients with AIDS and for the treatment of patients with intolerance or lack of response to standard therapies.

Effect of 9-(1,3-Dihydroxy-2-Propoxymethyl) Guanine on Serious Cytomegalovirus Disease in Eight Immunosuppressed Homosexual Men

Eight immunosuppressed homosexual men with cytomegalovirus viremia--seven with serious bilateral retinitis, one with colitis in addition to retinitis, and one with pneumonitis only--were treated with a new acyclovir derivative, 9-(1,3-dihydroxy-2-propoxymethyl) guanine, which has excellent in-vitro activity against cytomegalovirus. All patients had virologic and clinical improvement, but substantial leukopenia developed in three patients. Both clinical relapses and viral relapses occurred frequently, usually within 30 days after cessation of treatment. 9-(1,3-Dihydroxy-2-propoxymethyl) guanine represents the first clinically and virologically effective agent for the treatment of cytomegalovirus disease, but more effective and less toxic therapeutic regimens for both acute and chronic use must be developed.

Treatment of Cytomegalovirus Retinitis With Dihydroxy Propoxymethyl Guanine

Eight patients with cytomegalovirus retinitis in one or both eyes were treated with 9-(1,3 dihydroxy 2-propoxymethyl) guanine. Of the 14 eyes with retinitis, eight demonstrated more than 90% resolution, four had partial improvement, one failed to respond, and one could not be evaluated. Two of the eight patients had chemotherapy-induced immunosuppression and had ocular remissions for at least several months. The remaining six patients had AIDS or probable AIDS and relapsed in five weeks or less after discontinuation of therapy. Dihydroxy propoxymethyl guanine appears to be effective biologically in treating human cytomegalovirus retinitis without the development of unacceptable side effects but a single course of therapy is not capable of eradicating the virus.

Anticytomegaloviral activity and safety of cidofovir in patients with human immunodeficiency virus infection and cytomegalovirus viruria.

Cidofovir (HPMPC; (S)-1-[3-hydroxy-2-(phosphonylmethoxy)propyl]cytosine) is a nucleotide analog with activity against human cytomegalovirus (CMV). A phase I/II dose escalation trial was conducted with asymptomatic human immunodeficiency virus (HIV)-infected patients with CMV viruria to determine its pharmacokinetics, maximally tolerated dose, and preliminary antiviral activity against CMV. Qualitative CMV blood and urine cultures were monitored weekly to assess anti-CMV activity. Twenty-one HIV-infected persons with CD4 counts from 0 to 389 cells per microliters (median, 39) were enrolled in six dose-ranging groups. The first five groups enrolled four patients each to receive cidofovir infusions either weekly or biweekly for 4 weeks or every 3 weeks for 12 weeks. The sixth group enrolled one patient who received infusions of 5 mg/kg of body weight every other week. Patients receiving 0.5 or 1.5 mg/kg twice weekly experienced no serious toxicity. The first two patients who received 5 mg/kg twice weekly developed glycosuria and 2+ proteinuria. Subsequent patients received concomitant probenecid to attempt to ameliorate renal toxicity. Seventeen patients experienced proteinuria on one or more occasions; 6 of them experienced at least 2+ proteinuria. Four patients did not complete the study as planned because of renal toxicity. Positive CMV urine cultures reverted to negative in 2 of 8 patients receiving doses of < or = 1.5 mg/kg twice weekly and 11 of 13 patients receiving higher doses. Cidofovir has in vivo anti-CMV activity demonstrated by prolonged clearing of CMV viruria, although this observation is tempered by the fact that clearance of viremia could not be demonstrated. The dose-limiting toxicity is renal; however, concurrent administration of probenecid may be protective. The maximally tolerated weekly intravenous dose with probenecid is approximately 5 mg/kg. Efficacy trials with CMV disease will define the therapeutic utility and optimal dosing interval for cidofovir.

Nonspecific Interstitial Pneumonitis without Evidence of Pneumocystis carinii in Asymptomatic Patients Infected with Human Immunodeficiency Virus (HIV)

STUDY OBJECTIVE To assess how often Pneumocystis carinii organisms, P. carinii pneumonia, or other pulmonary pathologic processes were present in persons infected with human immunodeficiency virus (HIV) without pulmonary symptoms or previous history of P. carinii, and with a normal chest roentgenogram. DESIGN Serial, prospective assessment of eligible HIV-seropositive patients over 21 months. PATIENTS Twenty-four HIV-seropositive patients with either a nonpulmonary manifestation of the acquired immunodeficiency syndrome (AIDS) (n = 12) or an absolute CD4 lymphocyte count of 0.200 X 10(9) cells/L or less (n = 12), no pulmonary symptoms, a normal chest roentgenogram, no history of P. carinii pneumonia, and no history of treatment with antipneumocystis prophylaxis. INTERVENTIONS Pulmonary assessment with arterial blood gases, pulmonary function tests, gallium-67 citrate scans, and bronchoscopy with bronchoalveolar lavage and transbronchial biopsies. MEASUREMENTS AND MAIN RESULTS Mean alveolar-arterial gradient was 11.1 mm Hg +/- 8.5 and mean diffusion capacity was 73.0% +/- 20.0% of predicted. None of the 24 patients showed P. carinii or other pathogens on stains of bronchoalveolar lavage fluid. No patient had histologic evidence of P. carinii pneumonia. Transbronchial biopsy specimens showed chronic, nonspecific interstitial pneumonitis (11 of 23) and no pathologic abnormality (12 of 23). Six patients have developed P. carinii pneumonia during 2 to 18 months of follow-up. CONCLUSIONS HIV-infected patients without pulmonary symptoms did not have detectable Pneumocystis organisms in bronchoalveolar lavage fluid or transbronchial biopsy specimens; but 11 of 23 had evidence of chronic, nonspecific interstitial pneumonitis. Pneumocystis organisms in a pulmonary specimen from a symptomatic patient probably indicate the cause of the pulmonary dysfunction even if only a few are detected.

Heterozygosity for a defective gene for CC chemokine receptor 5 is not the sole determinant for the immunologic and virologic phenotype of HIV- infected long-term nonprogressors

HIV-1-infected long-term nonprogressors are a heterogeneous group of individuals with regard to immunologic and virologic markers of HIV-1 disease. CC chemokine receptor 5 (CCR5) has recently been identified as an important coreceptor for HIV-1 entry into CD4+ T cells. A mutant allele of CCR5 confers a high degree of resistance to HIV-1 infection in homozygous individuals and partial protection against HIV disease progression in heterozygotes. The frequency of CCR5 heterozygotes is increased among HIV-1- infected long-term nonprogressors compared with progressors; however, the host defense mechanisms responsible for nonprogression in CCR5 heterozygotes are unknown. We hypothesized that nonprogressors who were heterozygous for the mutant CCR5 gene might define a subgroup of nonprogressors with higher CD4+ T cell counts and lower viral load compared with CCR5 wild-type nonprogressors. However, in a cohort of 33 HIV-1-infected long-term nonprogressors, those who were heterozygous for the mutant CCR5 gene were indistinguishable from CCR5 wild-type nonprogressors with regard to all measured immunologic and virologic parameters. Although epidemiologic data support a role for the mutant CCR5 allele in the determination of the state of long-term nonprogression in some HIV-1- infected individuals, it is not the only determinant. Furthermore, long-term nonprogressors with the wild-type CCR5 genotype are indistinguishable from heterozygotes from an immunologic and virologic standpoint.

Increased survival of a cohort of patients with acquired immunodeficiency syndrome and cytomegalovirus retinitis who received sodium phosphonoformate (Foscarnet)

PURPOSE To evaluate the impact of foscarnet on the longevity of persons with human immunodeficiency virus, type 1 (HIV-1) infection and cytomegalovirus (CMV) retinitis. PATIENTS AND METHODS A cohort of 24 patients with acquired immunodeficiency syndrome (AIDS) and CMV retinitis received sodium phosphonoformate (foscarnet) as part of a controlled efficacy trial at the National Institutes of Health. Foscarnet was continued for as long as it was tolerated. Antiretroviral therapy was given to the patients as tolerated. Long-term follow-up was available on all patients. RESULTS Seventeen patients received zidovudine during or after receiving foscarnet, 2 patients received dideoxyinosine, 2 patients zidovudine and dideoxyinosine, and 3 patients received no specific antiretroviral agent. Patients received foscarnet for a mean of 6.2 months (median, 4 months; range, 10 days to 22 months). Ten patients required a change to ganciclovir therapy at some time after receiving foscarnet. The median time from the diagnosis of CMV retinitis until death was 13.5 months (range, 3 to 34 months). Patients lived longer than untreated or ganciclovir-treated historical controls with AIDS and CMV retinitis. There was no difference in the survival of patients treated with foscarnet at the time of diagnosis and those patients treated with foscarnet only after progression of their CMV retinitis. CONCLUSIONS These data suggest that foscarnet may prolong the survival of persons with AIDS and CMV retinitis and should be the initial treatment of choice in these patients.

Evaluation of Lymph Node Virus Burden in Human Immunodeficiency Virus-Infected Patients Receiving Efavirenz-Based Protease Inhibitor-Sparing Highly Active Antiretroviral Therapy

Although efavirenz-containing regimens effectively suppress plasma levels of human immunodeficiency virus (HIV) RNA, it is now clear that undetectable plasma viremia may not reflect a lack of viral replication. Because lymphoid tissue is an active site of HIV replication, the lymph node virus burden was analyzed in persons who received highly active antiretroviral therapy (HAART) containing either efavirenz or a protease inhibitor (PI). Testing with in situ hybridization revealed no detectable follicular dendritic cell-associated HIV RNA in either group, and only 2 of 8 persons in the efavirenz group and 1 of 4 in the PI group had detectable RNA in lymph node mononuclear cells (LNMC) when tested by use of nucleic acid sequencebased amplification. Low levels of replication-competent HIV were identified in both groups by use of quantitative coculture assays. There was no evidence of development of resistance to either regimen in virus isolated from LNMC. These data support the use of efavirenz as an alternative to a PI in initial HAART regimens.