Invariant natural killer cells change after an oral allergy desensitization protocol for cow's milk.

BACKGROUND: Cow milk (CM) allergy (CMA) affects up to 3% of the paediatric population and recent data suggest that only about 50% will outgrow by age 8. Oral immunotherapy (OIT) is a type of immune-modulating treatment that is able to induce desensitization to food allergens, to increase tolerance threshold, to reduce the risk of anaphylaxis, and to improve the patient's quality of life. The examination of the immunological changes observed during the establishment of food allergy (FA) desensitization in FA patients is a window into the pathogenesis of food allergy and food tolerance development. In this pathway, we have previously found that invariant natural killer T cells (iNKTs) are involved in CM allergy sensitization and now examine their role in OIT. METHODS: In this study, 10 of the 11 children with CM induced anaphylaxis enrolled in a CMA OIT clinical trial and completed the protocol. Peripheral blood iNKTs were quantitatively and qualitatively via flow cytometry characterized ex vivo and after culture with milk lipids before and after completing the OIT protocol. RESULTS: After completing OIT for CM, children were able to reintroduce CM in their diet. For the first time, we demonstrated that OIT induced a significant increase in the peripheral blood iNKT, as well as their switch from a T helper (Th-2; ie IL-4, IL-13) to Th-1 (ie IFN-γ) cytokine profile. CONCLUSIONS AND CLINICAL RELEVANCE: This study confirms the efficacy and safety of CM-OIT as well as the role of iNKT cells in CM allergy.

Profiling penciclovir susceptibility and prevalence of resistance of herpes simplex virus isolates across eleven clinical trials.

Asusceptibility testing program was established to determine the prevalence of resistance to penciclovir among herpes simplex virus isolates collected from patients participating in 11 world-wide clinical trials involving penciclovir (topical or intravenous formulations) or famciclovir, the oral prodrug of penciclovir. These trials represented nine randomised double blind, placebo or aciclovir-controlled studies and two open-label studies. Groups surveyed included immunocompetent or immunocompromised patients receiving 2 to 12 months chronic suppressive therapy for genital herpes, immunocompetent patients with recurrent herpes labialis treated for four days, and immunocompromised patients with mucocutaneous herpes simplex virus (HSV). Another subset of patients had been identified as non-responders to aciclovir or to valaciclovir. This program assessed the susceptibility profile for a total of 2145 herpes simplex virus isolates from 913 immunocompetent and 288 immunocompromised patients treated with penciclovir, famciclovir, aciclovir or placebo (depending on trial design). HSV isolates were tested for susceptibility to penciclovir using the plaque reduction assay (PRA) in MRC-5 cells. Resistance was defined as an IC(50)>or=2.0 microg/ml or an IC(50)> 10-fold above the wild type control virus IC(50) within that particular assay. Penciclovir-resistant HSV was isolated from 0.22% immunocompetent patients, and 2.1% of immunocompromised patients overall and therefore the frequency of penciclovir-resistant herpes simplex virus in the immunocompetent population approximates that of aciclovir-resistant herpesvirus reported previously. Penciclovir-resistant HSV isolates were more common in isolates from immunocompromised patients, consistent with aciclovir clinical experience. Treatment with penciclovir (intravenous formulation) was associated with the development of resistant HSV in only one severely immunocompromised patient (day 7 isolate IC(50) = 2.01 microg/ml), although treatment was effective and resulted in the complete clearance of the lesion by day 8. No patients receiving topical penciclovir developed treatment-associated penciclovir-resistant HSV, and a single immunocompromised patient developed resistant HSV upon treatment with oral famiciclovir.

Famciclovir for ophthalmic zoster: a randomised aciclovir controlled study.

AIMS: To compare the efficacy and safety of famciclovir with aciclovir for the treatment of ophthalmic zoster. METHODS: Randomised, double masked, aciclovir controlled, parallel group in 87 centres worldwide including 454 patients with ophthalmic zoster of trigeminal nerve (V(1)) comprised the intent to treat population. Oral famciclovir 500 mg three times daily or oral aciclovir 800 mg five times daily for 7 days. Assessments included day 0 (screening), days 3 and 7 (during treatment), days 10, 14, 21, 28 and monthly thereafter, up to 6 months (follow up). Proportion of patients who experienced ocular manifestations, severe manifestations and non-severe manifestations; loss of visual acuity was the main outcome measure. RESULTS: The percentage of patients who experienced one or more ocular manifestations was similar for famciclovir (142/245, 58.0%) and aciclovir (114/196, 58.2%) recipients, with no significant difference between groups (OR 0.99; 95% CI 0.68, 1.45). The percentage of patients who experienced severe and non-severe manifestations was similar between groups, with no significant difference. The prevalence of individual ocular manifestations was comparable between groups. There was no significant difference between groups for visual acuity loss. CONCLUSION: Famciclovir 500 mg three times daily was well tolerated and demonstrated efficacy similar to aciclovir 800 mg five times daily.

A randomized, double-blind trial of famciclovir versus acyclovir for the treatment of localized dermatomal herpes zoster in immunocompromised patients.

In this randomized, double-blind, multicenter, acyclovir-controlled study, the efficacy and safety of famciclovir were evaluated for the treatment of herpes zoster in patients who were immunocompromised following bone marrow or solid organ transplantation or oncology treatment. A total of 148 patients, 12 years or older with clinical evidence of localized herpes zoster, received either oral famciclovir, 500 mg three times daily, or acyclovir, 800 mg five times daily, for 10 days. Famciclovir was equivalent to acyclovir with respect to the numbers of patients reporting new lesion formation while on therapy (77% vs. 73%, respectively). There were no significant differences between the groups in the time to cessation of new lesion formation, full crusting, complete healing of lesions, or loss of acute phase pain. Treatment with famciclovir was well tolerated, with a safety profile comparable to that of acyclovir. Thus oral famciclovir is a convenient, effective, and well-tolerated regimen for immunocompromised patients with herpes zoster.

Efficacy and safety of famciclovir for treating mucocutaneous herpes simplex infection in HIV-infected individuals. Collaborative Famciclovir HIV Study Group.

OBJECTIVE: To compare the efficacy and safety of 7 days' treatment with famciclovir 500 mg twice a day versus acyclovir 400 mg five times a day, for mucocutaneous herpes simplex virus (HSV) infection in HIV-infected individuals. DESIGN: Randomized, double-blind, parallel-group study to demonstrate equivalence for the primary efficacy parameter. SETTING: Forty-eight hospital-based or specialist public-health clinics in 12 countries. PATIENTS: Two-hundred and ninety-three HIV-positive patients with recurrent HSV infection (orolabial or genital) starting treatment within 48 h of first appearance of herpetic lesions. MAIN OUTCOME MEASURES: Proportion of patients developing new lesions during treatment (primary outcome measures); Time to complete healing of lesions, time to cessation of viral shedding, time to loss of lesion-associated symptoms, number of withdrawals due to treatment failure (secondary outcome measures). RESULTS: Equivalence was defined prospectively and famciclovir was equivalent to acyclovir in preventing new lesion formation: new lesions occurred in 16.7% and 13.3% of patients, respectively [difference, 3.4%; 95% confidence interval (CI), -4.8-11.5]. The groups were comparable in time to complete healing (median 7 days for both groups; hazard ratio, 1.01; 95% CI, 0.79-1.29; P = 0.95), cessation of viral shedding (median of 2 days [hazard ratio = 0.93; 95% C.I. 0.68, 1.27; p = 0.64]), and loss of lesion-associated symptoms (median 4 days; hazard ratio, 0.99; 95% CI, 0.75-1.30; P = 0.93). Similar numbers in each group withdrew because of treatment failure. There were no differences between groups in the incidence of adverse events. CONCLUSIONS: Famciclovir given twice a day is as effective and well tolerated as high-dose acyclovir for mucocutaneous HSV infections in HIV-infected individuals, and has the convenience of less frequent dosing.

Oral famciclovir for the suppression of recurrent genital herpes: a randomized controlled trial. Collaborative Famciclovir Genital Herpes Research Group.

CONTEXT: Recurrent genital herpes simplex virus (HSV) may be treated episodically, but this may not be sufficient for patients with frequent recurrences. OBJECTIVE: To determine the efficacy and safety of famciclovir in the suppression of recurrent genital HSV infection. DESIGN: A randomized, double-blind, placebo-controlled, parallel-group study. SETTING: Thirty university, hospital, or private outpatient referral centers in Canada and Europe. PATIENTS: A total of 455 patients (223 men, 232 women) aged 18 years or older with a history of 6 or more episodes of genital herpes during 12 of the most recent 24 months, in the absence of suppressive therapy, received study medication. INTERVENTION: Oral famciclovir, 125 mg or 250 mg 3 times daily or 250 mg twice daily, or placebo for 52 weeks. MAIN OUTCOME MEASURES: Time to the first recurrence of genital HSV infection; the proportion of patients remaining free of HSV recurrence at 6 months; frequency of adverse events. RESULTS: In an intent-to-treat analysis, famciclovir significantly delayed the time to the first recurrence of genital herpes at all dose regimens (hazard ratios, 2.9-3.3; P<.001); median time to recurrence for famciclovir recipients was 222 to 336 days compared with 47 days for placebo recipients. The proportion of patients remaining free of HSV recurrence was approximately 3 times higher in famciclovir recipients (79%-86%) than in placebo recipients (27%) at 6 months (relative risks, 2.9-3.1; P<.001); efficacy was maintained at 12 months. Famciclovir was well tolerated with an adverse experience profile comparable to placebo. CONCLUSIONS: Oral famciclovir (125 mg or 250 mg 3 times daily or 250 mg twice daily) is an effective, well-tolerated treatment for the suppression of genital HSV infection in patients with frequent recurrences.

Famciclovir for the suppression of symptomatic and asymptomatic herpes simplex virus reactivation in HIV-infected persons. A double-blind, placebo-controlled trial.

BACKGROUND: Herpes simplex virus (HSV) infection is one of the most common opportunistic infections in HIV-infected persons. However, most documentation of the effectiveness of antiviral therapy in reducing HSV reactivation is anecdotal. OBJECTIVE: To evaluate the quantitative effect of antiviral therapy on the frequency of HSV reactivation in HIV-infected persons. DESIGN: Double-blind, placebo-controlled, crossover trial. SETTING: Research clinic at a university hospital. PATIENTS: 48 persons (45 men and 3 women) who were HIV positive and HSV seropositive. INTERVENTION: Patients were randomly assigned to receive famciclovir, 500 mg orally twice daily, or placebo for 8 weeks. They then crossed over to receive the other regimen after a 1-week washout period. MEASUREMENTS: Patients obtained daily cultures of their perirectal, urethral, oral, and genital areas and kept dairy records of signs and symptoms of genital and oral-labial herpes. RESULTS: The median CD4 cell count at study entry was 384 cells/mm3. In the intention-to-treat analysis of the first study period, HSV was isolated on 122 of 1114 (11%) placebo days compared with 9 of 1071 (1%) famciclovir days (relative risk, 0.15; P < 0.001). For patients who completed the crossover, the median difference in days with symptoms between placebo and famciclovir was 13.8% of days and the median difference in days on which HSV was isolated was 5.4% of days (P < 0.001 for both). Percentage of days with HSV-2 shedding was reduced from 9.7% to 1.3%. Breakthrough reactivations that occurred while patients were receiving famciclovir were infrequent, short, and often asymptomatic, HSV-2 isolates from these reactivations were susceptible to penciclovir in vitro. CONCLUSIONS: Antiviral chemotherapy with famciclovir results in clinically and statistically significant reductions in the symptoms associated with HSV infection and the symptomatic and asymptomatic shedding of HSV among HIV-positive persons.

Penciclovir cream for the treatment of herpes simplex labialis. A randomized, multicenter, double-blind, placebo-controlled trial. Topical Penciclovir Collaborative Study Group.

OBJECTIVE: To compare the safety and efficacy of topical 1% penciclovir cream with vehicle control cream (placebo) for the treatment of a recurrent episode of herpes simplex labialis (cold sores) in immunocompetent patients. DESIGN: Randomized, double-blind, placebo-controlled, patient-initiated, 2-armed, parallel clinical trial. Patients were prospectively dispensed study medication, and treatment was self-initiated by the patient within 1 hour of the first sign or symptom of a recurrence. SETTING: A total of 31 ambulatory clinics in the United States in a variety of settings, including private practices, public health facilities, and universities. PATIENTS: Otherwise healthy individuals with a history of frequent episodes of herpes simplex labialis. A total of 2209 patients were enrolled and given study medication, and 1573 initiated treatment for a recurrence. INTERVENTIONS: Topical 1% penciclovir cream or vehicle control cream. Subjects applied treatment every 2 hours while awake for 4 consecutive days. MAIN OUTCOME MEASURES: Lesion healing was the primary efficacy variable. Secondary end points included time to loss of lesion pain and time to cessation of viral shedding. RESULTS: Healing of classical lesions (vesicles, ulcers, and/or crusts) was 0.7 day faster for penciclovir-treated patients compared with those who received vehicle control cream (median, 4.8 days vs 5.5 days; hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.18-1.49; P<.001). Pain (median, 3.5 days vs 4.1 days; HR, 1.22; 95% CI, 1.09-1.36; P<.001) and lesion virus shedding (median, 3 days vs 3 days; HR, 1.35; 95% CI, 1.10-1.64; P=.003) also resolved more quickly for penciclovir-treated patients compared with patients who applied the vehicle control. The efficacy of penciclovir cream was apparent when therapy was initiated early (prodrome or erythema lesion stage) and when initiated late (papule or vesicle stage). The incidence of adverse events was comparable between penciclovir and placebo groups. CONCLUSIONS: Penciclovir cream is the first treatment to clearly demonstrate an impact on the course of recurrent herpes labialis in immunocompetent patients. Efficacy was seen in all clinical and laboratory measures of the disease (lesion healing, pain resolution, and cessation of viral shedding). Faster healing and pain resolution occurred both among patients who first applied penciclovir cream in the prodrome and erythema stages and among those who started treatment in the papule and vesicle lesion stages.

Famciclovir for the treatment of acute herpes zoster: effects on acute disease and postherpetic neuralgia. A randomized, double-blind, placebo-controlled trial. Collaborative Famciclovir Herpes Zoster Study Group.

OBJECTIVE: To document the effects of treatment with famciclovir on the acute signs and symptoms of herpes zoster and postherpetic neuralgia. DESIGN: A randomized, double-blind, placebo-controlled, multicenter trial. SETTING: 36 centers in the United States, Canada, and Australia. PATIENTS: 419 immunocompetent adults with uncomplicated herpes zoster. INTERVENTION: Patients were assigned within 72 hours of rash onset to famciclovir, 500 mg; famciclovir, 750 mg; or placebo, three times daily for 7 days. MEASUREMENTS: Lesions were assessed daily for as long as 14 days until full crusting occurred and then weekly until the lesions healed. Viral cultures were obtained daily while vesicles were present. Pain was assessed at each of the visits at which lesions were examined and then monthly for 5 months after the lesions healed. Safety was assessed throughout the study. RESULTS: Famciclovir was well tolerated, with a safety profile similar to that of placebo. Famciclovir accelerated lesion healing and reduced the duration of viral shedding. Most importantly, famciclovir recipients had faster resolution of postherpetic neuralgia (approximately twofold faster) than placebo recipients; differences between the placebo group and both the 500-mg famciclovir group (hazard ratio, 1.7 [95% CI, 1.1 to 2.7]) and the 750-mg famciclovir group (hazard ratio, 1.9 [CI, 1.2 to 2.9]) were statistically significant (P = 0.02 and 0.01, respectively). The median duration of postherpetic neuralgia was reduced by approximately 2 months. CONCLUSIONS: Oral famciclovir, 500 mg or 750 mg three times daily for 7 days, is an effective and well-tolerated therapy for herpes zoster that decreases the duration of the disease's most debilitating complication, postherpetic neuralgia.

Safety of famciclovir in patients with herpes zoster and genital herpes.

Safety reporting from individual ongoing and completed clinical studies has demonstrated that famciclovir, the well-absorbed oral form of the antiherpesvirus agent penciclovir, has been well tolerated by more than 3,000 individuals worldwide. An integrated safety evaluation has been performed and includes over 1,600 patients from 11 completed, randomized, double-blind clinical trials and 2 open trials. The famciclovir population consisted of 816 herpes zoster patients (four trials), 409 patients with acute genital herpesvirus infections (seven trials), and 382 patients from two genital herpes suppression studies. Overall, the famciclovir-treated patient population was 57.7% female and ranged in age from 15 to 102 years (mean, 42.6 years), with 31.2% aged 50 years or more and 15.7% aged 65 years or more. The mean duration of exposure to famciclovir was 28.8 days (5.8 days excluding suppression studies). The total daily doses ranged from 125 mg to 2.25 g. The most common adverse experiences reported as related to study medication (famciclovir and placebo) were headache, nausea, and diarrhea. The frequencies of adverse experiences and laboratory abnormalities (hematology, clinical chemistry, and urinalysis parameters) were similar in both famciclovir and placebo recipients. Thus, safety data from the analysis of 13 completed clinical studies demonstrate that famciclovir is tolerated well by patients with either herpes zoster or genital and has a safety profile comparable to that of placebo.

High levels of circulating cytomegalovirus DNA reflect visceral organ disease in viremic immunosuppressed patients other than marrow recipients.

Although viremia is a hallmark of disseminated cytomegalovirus (CMV) infection, not all viremic patients have visceral organ CMV disease. We used blot hybridization with a cloned subgenomic probe to quantitate viral DNA in blood leukocytes of 60 viremic patients (25 with solid organ transplants, 20 with AIDS, and 15 marrow recipients) who had different clinical manifestations of CMV infection. The results are expressed as pg of viral DNA/10 micrograms of leukocyte DNA. Patients with AIDS or with solid organ transplants who had CMV visceral organ disease had the largest amounts of viral DNA in their granulocytes (median 632 and 237 pg, respectively). These amounts were significantly greater than those in similar viremic patients without CMV visceral disease (17 and 21 pg; P < 0.005 and 0.002, respectively). All patients in the study with > 150 pg of CMV DNA in their granulocytes had visceral CMV disease. The amounts of viral DNA in granulocytes of AIDS and organ transplant patients with CMV retinitis were low (median 22 pg). Marrow transplant patients were unique in that the amounts of CMV DNA in granulocytes were low whether CMV visceral organ disease was present (17 pg) or absent (14 pg). We conclude that high levels of circulating CMV DNA in viremic AIDS and solid organ transplant patients reflect viral involvement of visceral organs but not the retina. In marrow recipients, the severity of CMV disease, even when fatal, is not reflected quantitatively in peripheral blood leukocytes.

Quantitation of cytomegalovirus DNA by blot hybridization in blood leukocytes of viremic patients.

We describe a technique for quantitation of viral DNA in blood leukocytes during viremic infection with human cytomegalovirus (CMV). Using a cloned subgenomic DNA probe and a blot hybridization assay, small amounts of viral DNA within samples of leukocyte DNA could be quantitated reproducibly using a videodensitometer. Critical components of the assay were: (1) a direct relationship between optical density and known amounts of viral DNA diluted in cellular DNA as positive standard samples and, (2) determination of the proper duration of autoradiographic exposure. The technique was sufficiently sensitive to detect 10 picograms of CMV DNA in the presence of microgram quantities of host cell DNA. In addition, samples containing minute amounts of CMV DNA could reliably be distinguished from samples that were negative. We have used the technique to characterize the pathogenesis of CMV viremia and to monitor the effects of antiviral chemotherapy. This procedure could easily be applied to pathogenetic studies of a variety of other infectious agents.

The spectrum of clinical and laboratory findings resulting from human herpesvirus-6 (HHV-6) in patients with mononucleosis-like illnesses not resulting from Epstein-Barr virus or cytomegalovirus.

Recently, the morphologic, immunologic, and molecular makeup of a new virus designated human herpesvirus-6 (HHV-6) has been described. Because cell cultures of HHV-6-infected mononuclear cells showed prominent lymphocytic changes, it could be anticipated that mononucleosis-like illnesses or lymphoproliferative disorders would turn out to be manifestations of active HHV-6 infection. In the present study, blood samples from 27 patients previously categorized as having non-Epstein-Barr virus (non-EBV)/noncytomegalovirus (non-CMV) heterophil-negative mononucleosis-like illnesses were tested for IgM and IgG antibodies to HHV-6. Eight of these patients (30%) had serologic evidence of active HHV-6 infection. The clinical spectrum includes a short-lived febrile illness, mild cervical lymphadenopathy, laboratory data suggestive of active viral hepatitis in two patients, and a prolonged febrile illness in a single patient with previously documented positive anti-HIV serology. The viral studies revealed the presence of fourfold HHV-6-specific IgG titer increases by immunofluorescent assay (IFA) in seven serially studied cases and positive IgM serology on one or more samples tested by IFA or enzyme-linked immunosorbent assay (ELISA) in all eight cases. The authors could not determine whether the illnesses represented primary HHV-6 infections in susceptible individuals or reactivation of latent virus. HHV-6 serologic studies may be indicated in patients with mononucleosis-like illnesses with atypical lymphocytosis when EBV and CMV test results are nondiagnostic.

Fetal parts embolization during termination of pregnancy: report of a case.

A 19-year-old woman underwent termination of pregnancy by dilatation and evacuation at 19 weeks of gestation. She subsequently developed persistent massive hemorrhage, with laboratory evidence of a consumption coagulopathy. Attempts to control bleeding were unsuccessful, and the patient underwent a hysterectomy. Pathologic evaluation of the uterus revealed embolization of fetal tissues and placental fragments in the uterine and parametrial veins. This is the first reported case of such a finding, and its importance in relation to the patient's clinical presentation is discussed.

Cadmium exposure on day 12 of gestation in the Wistar rat: distribution, uteroplacental blood flow, and fetal viability.

The effects of cadmium exposure (40 mumole CdCl2/kg, s.c.) on day 12 of gestation were evaluated in the Wistar rat. At 16-18 hours following such cadmium exposure, blood flow (as determined by radiolabeled microspheres) to the chorioallantoic placenta (CAP) was significantly reduced by 35%; at 24-26 hours, blood flow to the CAP had returned to control levels and was still unaffected at 38-43 hours. Uterine blood flow was not significantly altered at any of these timepoints. Between 16-18 and 24-26 hours after cadmium exposure, the concentration of cadmium in the placenta decreased significantly, while total cadmium content did not change. By 38-43 hours after cadmium exposure, total cadmium content of the placenta had increased significantly, although cadmium concentration was unchanged. There were no adverse effects on fetal viability or growth, as determined on day 20 of gestation. In sharp contrast, near-term (day 18) exposure to 40 or 50 mumole CdCl2/kg (s.c.) resulted in 53% and 82% mean incidences of fetolethality, respectively, within 24 hours. Administration of 50 mumole CdCl2/kg (sc) on day 12 also had no effect on fetal growth but resulted in increased fetolethality (12%). Thus midgestational cadmium exposure and its accompanying alterations in placental blood flow do not compromise fetal viability or growth. The differential response to cadmium at mid- and late gestation, in terms of fetolethality, is not due to maternal cadmium dose.

Human choriocarcinoma (JAr) cells grown as multicellular spheroids.

JAr choriocarcinoma cells grew as multicellular spheroids, and exhibited a logarithmic pattern of growth, reaching geometric mean diameters of at least 1200 microns after 21 days in culture. HCG, E2 and P4 were secreted into the culture medium throughout the entire culture period, in proportion to spheroid size. This, along with the presence of lipid droplets, non-staining glycogen, Golgi apparatus and microvilli on the spheroid surface and in intercellular spaces indicated that the JAr cells within spheroids were functionally active. While spheroids of less than 800 microns GMD attached to culture dishes and produced cellular outgrowth, larger spheroids showed impaired attachment, and a delay in the subsequent production of outgrowth, which was not correlated with the development of a necrotic core. This outgrowth contained more multinucleated cells and cellular projections than that of smaller spheroids, suggesting that the cells in larger spheroids had undergone early differentiative changes. The spheroid culture system will be applied to the study of processes, such as implantation, which may require a three-dimensional arrangement of placental cells.

Disseminated cytomegalovirus infection. Molecular analysis of virus and leukocyte interactions in viremia.

Viremia is a hallmark of disseminated cytomegalovirus (CMV) infection and disease. Using conventional virus culture and a subgenomic cloned CMV DNA probe to detect viral DNA within leukocytes, we studied the virus-cell interactions involved in immunocompromised patients with viremic CMV infection. CMV was recovered by culture in 17/17 samples enriched for polymorphonuclear leukocytes. Viral DNA was detected by dot-blot hybridization in 16/17 (94%). In contrast, samples enriched for mononuclear cells yielded infectious CMV in culture in only 7/15 (47%) instances; nonetheless, viral DNA was present in 16/17 samples probed. The quantity of CMV DNA in polymorphonuclear cells was significantly greater than in mononuclear leukocytes (mean 13.1 vs. 9.1 estimated viral genome equivalents per 100 cells, respectively), and CMV was always recovered from these cells regardless of the amount of viral DNA present. Yet, when the amounts of CMV DNA were virtually identical in granulocytes and mononuclear cells (6.3 and 7.1 genomic equivalents, respectively) collected simultaneously, infectious CMV could not be recovered from mononuclear cells. Although several interpretations are possible, these data are consistent with the view that CMV exists within granulocytes in a mature infectious form during viremia. The virus interactions with mononuclear cells appear to be more complex, particularly in those cells that contain CMV DNA but do not yield infectious virus.

Immunodeficiency of the elderly.

The elderly are at risk for an increased incidence and severity of certain infections. The contribution of age-related immunologic impairment to the pathogenesis of these infections has been difficult to determine because of a number of confounding variables associated with aging. Nevertheless, studies in vitro and in animals support the hypothesis that immunodeficiency accompanies the aging process. Multiple factors may be responsible for altered cell-mediated immunity in the elderly, including thymic involution, reduced levels of thymic hormones, and an increase in the number of immature T lymphocytes. While studies of T cell subpopulations have yielded conflicting results, it appears that T cell proliferative responses are diminished. Aging is also associated with abnormalities of humoral immunity. Although the number and functional activities of neutrophils from healthy elderly persons are relatively intact, diminished bactericidal activity and altered oxygen metabolism have been reported in extremely old individuals. While the relative importance and clinical impact of these immunologic abnormalities remain unclear, future studies may provide new strategies for the prevention and treatment of infections in this rapidly growing segment of the population.