Mutations in human cytomegalovirus UL97 gene confer clinical resistance to ganciclovir and can be detected directly in patient plasma

Specific mutations in the UL97 region of human cytomegalovirus (HCMV) have been found to confer resistance to laboratory-adapted strains subjected to ganciclovir selection. In this study, mutations in the UL97 region of HCMV isolates obtained from patients receiving ganciclovir therapy were examined to determine whether they would confer ganciclovir resistance, and if these mutations could be detected directly in the plasma of AIDS patients with progressive HCMV disease despite ganciclovir treatment. A single nucleotide change within a conserved region of UL97 was found in five resistant isolates, resulting in an amino acid substitution in residue 595: from leucine to phenylalanine in one, and from leucine to serine in four resistant isolates. A sixth resistant isolate demonstrated a single nucleotide change, leading to a threonine to isoleucine substitution in residue 659. The role of the 595 amino acid substitution in conferring ganciclovir resistance was confirmed by marker transfer experiments. In further studies, direct sequencing of HCMV DNA present in plasma obtained from persons with resistant viruses revealed the identical amino acid substitutions in plasma as those present in the cultured viruses. These findings indicate that clinical resistance to ganciclovir can result from specific point mutations in the UL97 gene, and that the emergence of the resistant genotype can be detected directly in patient plasma.

An evaluation of serum soluble CD30 levels and serum CD26 (DPPIV) enzyme activity as markers of type 2 and type 1 cytokines in HIV patients receiving highly active antiretroviral therapy

This study evaluates serum CD26 (dipeptidyl peptidase IV, DPPIV) enzyme activity and serum levels of soluble CD30 as markers of T1 and T2 cytokine environments in HIV patients who achieved immune reconstitution after highly active antiretroviral therapy (HAART). Patients who had experienced inflammatory disease associated with pre-existent opportunistic infections after HAART (immune restoration diseases, IRD) were considered separately. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were compared with IFN-gamma production by PBMC cultured with cytomegalovirus (CMV) antigen in controls and patient groups. High sCD30 levels were associated with low IFN-gamma production after antigenic stimulation in control subjects and, to a lesser extent, in immune reconstituted HIV patients. There was no association between serum CD26 (DPPIV) enzyme activity and IFN-gamma production or sCD30 levels. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were significantly increased in immune reconstituted patients with high HIV viral loads. Patients who had experienced CMV retinitis as an IRD had significantly higher sCD30 levels than all other patient groups. Hence, high sCD30 levels may be a marker of a T2 cytokine environment in HIV patients with immune reconstitution and are associated with higher HIV viral loads and a history of CMV associated IRD.

Cytomegalovirus (CMV) retinitis activity is accurately reflected by the presence and level of CMV DNA in aqueous humor and vitreous

To evaluate the potential of ocular and systemic specimens to provide markers of active cytomegalovirus (CMV) retinitis, we examined the relationship between virologic and clinical aspects of CMV infections in AIDS patients with CMV retinitis. CMV polymerase chain reaction (PCR) analysis of 74 aqueous humor and vitreous specimens indicated that ocular specimens can provide accurate markers to differentiate active and inactive CMV retinitis (aqueous or vitreous PCR, P<.001). Moreover, these markers were superior to extraocular measures, including plasma PCR (P=.08) and blood and urine CMV cultures (P=.05). A direct correlation was identified between the quantity of CMV DNA in aqueous humor or vitreous specimens and the corresponding surface area of active CMV retinitis (r2=.69 and.44, respectively). Thus, qualitative and quantitative PCR-based analyses of aqueous humor can provide valuable markers of CMV retinitis activity. Such assays could provide rapid and reliable tools to assist in management of patients with CMV retinitis in whom the view of the retina is obscured.

Monitoring plasma levels of ganciclovir in AIDS patients receiving oral ganciclovir as maintenance therapy for CMV retinitis

OBJECTIVES

To investigate whether low ganciclovir serum levels in patients on maintenance oral ganciclovir therapy are associated with recurrence of CMV retinitis.

METHODS

A prospective study of the plasma concentration of ganciclovir after initiation of maintenance oral ganciclovir therapy in 14 AIDS patients who had recovered from acute cytomegalovirus (CMV) retinitis.

RESULTS

Five of the 14 patients exhibited a mean time to recurrence of 37 days. The mean trough plasma concentration of ganciclovir in these patients after 1 month of oral ganciclovir therapy, was 0.40 +/- 0.30 mg/L. Nine patients had a mean time of progression of 263 days. The mean trough plasma concentration of ganciclovir in the latter patients was 0.80 +/- 0.60 mg/L.

CONCLUSIONS

Patients exhibiting trough plasma levels of ganciclovir below 0.6 mg/L may be at higher risk of progression than patients who exhibited levels above 0.6 mg/L.

Hemorheologic Abnormalities Associated with HIV Infection: In Vivo Assessment of Retinal Microvascular Blood Flow

PURPOSE

To evaluate retinal microvascular blood flow in human immunodeficiency virus (HIV)-infected individuals using scanning laser Doppler flowmetry (SLDF) and to seek correlations between flow and various laboratory measures that may predict alterations in flow.

METHODS

The Heidelberg Retina Flowmeter and SLDF software were used to acquire in vivo retinal blood flow data from 24 HIV-infected individuals and 16 HIV-negative control subjects. In each subject, separate scans were performed in each of six retinal regions: nasal parapapillary retina; macula; and the superior, nasal, inferior, and temporal periphery. Erythrocyte aggregation (assessed in vitro by a fully automatic erythrocyte aggregometer and by zeta sedimentation ratio [ZSR, a hematocrit-independent sedimentation rate]), serum fibrinogen level, plasma viscosity, and leukocyte rigidity (assessed in vitro with a cell transit analyzer) were compared with flow in selected regions.

RESULTS

Flow was significantly higher in the periphery (superior, nasal, inferior, temporal) than in the posterior retina (nasal parapapillary retina, macula). Flow was highest in the temporal periphery for both HIV-infected subjects and control subjects. Flow in the posterior retina was significantly lower in HIV-infected subjects than in control subjects (P < 0.0001). Among HIV-infected individuals, flow in the macula correlated negatively with ZSR (r = -0.397, P = 0.0547) and leukocyte rigidity (r = -0.505, P = 0.0119).

CONCLUSIONS

Microvascular blood flow in the posterior retina is reduced in HIV-infected individuals. Both increased erythrocyte aggregation and increased leukocyte rigidity contribute to this hemorheologic abnormality.

A case of ganciclovir-resistant cytomegalovirus (CMV) retinitis in a patient with AIDS: longitudinal molecular analysis of the CMV viral load and viral mutations in blood compartments

OBJECTIVE

To study the temporal relationships between cytomegalovirus (CMV) viral load and specific UL97 mutations in polymorphonuclear leukocytes (PMNL) and plasma samples from a patient with AIDS who developed ganciclovir-resistant CMV retinitis.

METHODS

Sequential PMNL and plasma samples were analysed for determination of the CMV viral load using non-molecular methods and a quantitative polymerase chain reaction (PCR) assay. Screening of the same samples for the most common mutations conferring ganciclovir resistance was performed using nested PCR and restriction enzyme analysis.

RESULTS

At the time of progression of CMV retinitis (after 6 months of ganciclovir), a rapid increase in the CMV DNA load was found in both PMNL and plasma samples. This increase paralleled the emergence of a specific mutation (V594) in the same samples and recovery of ganciclovir-resistant blood isolates. In this patient, however, the only tests that substantially predicted the progression of CMV disease were the quantitative PCR assay using PMNL and to a lesser extent the pp65 antigenemia assay.

CONCLUSIONS

Quantitative evaluation of the CMV viral load in PMNL using sensitive assays such as PCR appears to be a promising approach for monitoring antiviral therapy in subjects with AIDS. In addition, common mutations conferring ganciclovir resistance can be detected directly in PMNL and plasma samples.

Cytomegalovirus (CMV) retinitis and CMV antigenemia as a clue to impaired adrenocortical function in patients with AIDS

OBJECTIVE

To elucidate the relationship between the activity of CMV disease and adrenocortical function in patients with AIDS.

DESIGN AND PATIENTS

CMV retinitis and CMV antigenemia assay (CMV-Ag: numbers of polymorphonuclear leukocytes positive for CMV pp65 antigen per 1.5 x 10(5) cells) are the least invasive and easily accessible examinations to assess the CMV disease activity. All HIV-infected patients with CD4+ lymphocyte counts < 50 x 10(6)/l who were admitted to the Research Hospital of the Institute of the Medical Science (University of Tokyo) between May 1995 to April 1996 were included in this study.

METHODS

Fundoscopic examination on CMV retinitis and CMV-Ag were chosen as methods to assess CMV activity because of their simplicity. Adrenocortical function was evaluated by basal plasma adrenocorticotropin, plasma cortisol, plasma aldosterone, plasma renin activity, and responses of plasma cortisol and plasma aldosterone to 250 micrograms intravenous cosyntropin [rapid adrenocorticotropin test (RAT)].

RESULTS

Thirty patients were enrolled in this study with a maximum CD4+ lymphocyte count of 32 x 10(6)/l. Eleven out of 30 patients showed impaired RAT response (37%). Fourteen out of 30 patients had CMV retinitis. A significant correlation was found between the presence of CMV retinitis and subnormal cortisol response (P < 0.005). Sixteen out of the 30 patients were CMV-Ag-positive. A significant correlation was found between CMV-Ag positivity and subnormal cortisol response to RAT (P < 0.005). CMV-Ag levels in the patients with subnormal cortisol response to RAT were significantly higher than those with normal response (P < 0.001). Importantly, five patients with subnormal cortisol response but not overt adrenal insufficiency at the time of RAT developed overt disease shortly afterwards. Autopsy was performed in six patients with subnormal cortisol response and showed multiple inclusion bodies indicative of CMV adrenitis.

CONCLUSION

The adrenal gland is most frequently affected by CMV in AIDS patients. Our result suggests that CMV retinitis or CMV-Ag positivity independently serve as an indication of possible adrenal dysfunction.

Foscarnet and ganciclovir pharmacokinetics during concomitant or alternating maintenance therapy for AIDS-related cytomegalovirus retinitis

INTRODUCTION

The use of foscarnet and ganciclovir as a combination treatment for cytomegalovirus retinitis is increasing because of limitations associated with single agent therapy.

METHODS

The pharmacokinetics of foscarnet and ganciclovir were determined in 13 patients receiving either concomitant therapy (regimen A) or daily alternating therapy (regimen B) for maintenance of cytomegalovirus disease. For regimen A, 60 mg/kg intravenous foscarnet and 3.75 mg/kg ganciclovir were sequentially administered daily; for regimen B, 120 mg/kg foscarnet and 6 mg/kg ganciclovir were administered on alternating days. For both regimens, serial blood sampling for pharmacokinetic analysis was performed for each drug alone (day 1 or 2) and after 2 weeks of combination therapy. Plasma samples for foscarnet and ganciclovir analysis were performed by means of high-performance liquid chromatography. Pharmacokinetic analysis was performed with noncompartmental methods.

RESULTS

For regimen A, the plasma clearance (CL) of foscarnet did not change in the presence of ganciclovir, averaging 0.12 +/- 0.08 and 0.11 +/- 0.02 L/hr/kg on study days 2 and 14, respectively (p = 0.34). The volume of distribution (VSS) and mean residence time (MRT) also did not change significantly. CL and MRT of foscarnet did not change for regimen B, although a slight increase in VSS was observed before (0.38 +/- 0.05 L/kg) and after (0.46 +/- 0.07 L/kg) alternating therapy (p = 0.03). Ganciclovir CL did not change for either regimen, with mean values of 0.21 +/- 0.10 and 0.25 +/- 0.10 L/hr/kg (regimen A, p = 0.17) and 0.32 +/- 0.10 and 0.34 +/- 0.11 L/hr/kg (regimen B, p = 0.24). MRT and VSS were also not significantly different.

CONCLUSION

These plasma data suggest that further dosage adjustments are unnecessary for or alternating maintenance therapy.

Cytokine profile in response to Cytomegalovirus associated with immune recovery syndrome after highly active antiretroviral therapy

BACKGROUND

Several changes have occurred in the presentation and course of cytomegalovirus (CMV) retinitis in patients with AIDS since the introduction of HAART (highly active antiretroviral therapy). In some individuals who take HAART, retinitis is kept under control even after the discontinuation of anti-CMV therapy. However, many of these patients develop intraocular inflammation. Uveitis, cataract, vitreitis, cystoid macular edema, epiretinal membrane, and disc edema may occur in patients with immune recovery syndrome (IRS).

METHODS

We evaluated the CMV-specific immune response in 55 patients by assessing CMV-specific lymphocyte proliferation, cytotoxicity, and cytokine production and correlated it with the clinical outcome.

RESULTS

Our data suggest that control of CMV retinitis is associated with acquisition of cytotoxic and lymphoproliferative responses to CMV. In addition, the upsurge of macular and disc edema seems associated with the production of interleukin-4 and tumor necrosis factor-alpha, whereas vitreitis is associated with the production of interleukin-2 and interferon-gamma.

INTERPRETATION

The type of T-cell response that develops after HAART may determine the side effects of immune recovery and these effects are predictable based on the lymphokine profile produced by CMV-specific cells.

Cytomegalovirus (CMV) strain differences between the eye and blood in AIDS patients with CMV retinitis

OBJECTIVE

To investigate possible differences in cytomegalovirus (CMV) strain distribution between the eye and blood in AIDS patients with CMV retinitis.

METHODS

CMV DNA sequences from aqueous humour and peripheral blood leukocytes (PBL), obtained from 13 AIDS patients with CMV retinitis, were compared. DNA was isolated and the CMV IE-1 sequence (part of the immediate early-1 gene) and the a-sequence (located in the a-region) were amplified by polymerase chain reaction (PCR). The PCR products of the a-sequence were analysed by Southern blotting for amplified fragment-length polymorphisms. The level of divergence between the a-sequences of aqueous humour- and PBL-derived CMV was studied in two patients by cloning these sequences followed by sequence analysis.

RESULTS

CMV DNA could be detected in all aqueous humour samples and in 10 out of 13 paired blood samples. In the 10 patients, with CMV DNA detectable in both aqueous humour and PBL, seven cases showed differences between the amplified products of both compartments. Sequence analysis in two patients revealed that the aqueous humour and PBL of the same patient can harbour both identical, similar and highly divergent CMV a-sequences.

CONCLUSION

These results indicate that despite the haematogenous spread of CMV, the eye, being a relatively shielded organ, may contain CMV strains different from those found in the blood.

Quantitation of peripheral blood cytomegalovirus DNA for monitoring recurrent cytomegalovirus retinitis in pediatric solid organ transplant recipients

Cytomegalovirus (CMV) infection is a major concern following solid organ transplantation, especially in the pediatric population who remain at high risk of primary infection. CMV disease leads not only to increased patient and graft morbidity, but also to increased health care costs. This study describes the usefulness of a quantitative CMV polymerase chain reaction (PCR) technique for monitoring peripheral blood CMV DNA in pediatric recipients of kidney and liver allografts who had recurrent CMV retinitis. The incidence of CMV disease in 28 pediatric transplant recipients was 28.6%, one-half of whom developed retinitis. Two of these patients had recurrent retinitis on cessation of anti-viral treatment. A peripheral blood CMV DNA copy number of > or =500/microg of DNA was associated with recrudescence of the retinitis in these patients. We conclude that the measurement of peripheral blood CMV DNA by PCR is a useful tool for the surveillance of disease resolution and recurrence. This is particularly important in patients with CMV retinitis, who may remain asymptomatic for a period of time, despite recurrences.

CMV retinitis after cessation of ganciclovir therapy for CMV antigenemia in an unrelated BMT recipient

An 11-year-old boy with severe aplastic anemia underwent unrelated BMT following TBI, antithymocyte globulin and CY. On day +23, CMV antigenemia was detected which resolved with ganciclovir. Eight days after discontinuing ganciclovir, he complained of impaired visual acuity. Ophthalmologic findings and a positive PCR study using anterior chamber fluid from the right eye confirmed the presumptive diagnosis of CMV retinitis, although CMV antigenemia and PCR studies using PBMC were then negative. He was successfully re-treated with ganciclovir. CMV retinitis should be considered even when CMV antigenemia is not present or PCR using PBMC is negative.

Role of the cytomegalovirus (CMV)-antigenemia assay as a predictive and follow-up detection tool for CMV disease in AIDS patients

Forty-two patients were evaluated to determine the value of the CMV antigenemia (CMV-Ag) test as a follow-up marker as well as a prediction marker of CMV disease. Twenty patients were positive for at least one positive CMV-Ag assay and 9 of them developed CMV retinitis. With the threshold value (10 positive cells), sensitivity was 56% and specificity was 94%. The CMV-Ag assay, with the threshold value, produced high specificity, positive predictive value and negative predictive value but relatively poor sensitivity. Eight patients experienced CMV disease relapse a total of 16 times. At relapse, 8 of the 16 times showed negative for CMV-Ag assay; 7 underwent systemic maintenance while 1 underwent local maintenance. It is inferred that the CMV-Ag test is a poor follow-up marker to detect the relapse of CMV disease, particularly in patients undergoing systemic maintenance.

Influence of filgrastim (granulocyte colony-stimulating factor) on human immunodeficiency virus type 1 RNA in patients with cytomegalovirus retinitis

Filgrastim, or granulocyte colony-stimulating factor, reverses neutropenia associated with human immunodeficiency virus type 1 (HIV-1) and cytomegalovirus (CMV) infections. During a trial of anti-CMV retinitis therapies coadministered with antiretroviral therapy, 2-4 plasma specimens of HIV-1 RNA were collected from 36 HIV-1-infected patients receiving filgrastim to prevent neutropenia and from 36 patients not receiving filgrastim. For both groups, the crude mean and mean rate of change of HIV-1 log(10) RNA levels were similar. Adjustment for covariates (CD4(+) T cell lymphocytes, virus load at enrollment, level of neutropenia and antiretroviral therapy [mainly non-highly active antiretroviral therapy], and anti-CMV therapy during follow-up) resulted in a mean log(10) HIV-1 RNA level for individuals receiving filgrastim versus those not receiving the drug of 5.11 versus 4.87 (P=.12) and respective log mean rates of change per month of -0.08 versus -0.21 (P=.08). This latter difference has borderline statistical significance, which suggests that filgrastim may reduce the decline of HIV-1 RNA loads.

The analysis of correlated panel data using a continuous-time Markov model

We consider the analysis of correlated panel data in which two or more correlated multistate processes are periodically observed on each individual and the exact transition times between states are unknown. We describe a procedure that models each process marginally under a time-homogeneous Markov model allowing for covariates. The resulting estimators are shown to be asymptotically jointly normal with a covariance matrix that can be consistently estimated. Simultaneous inference procedures are also proposed. Methods are illustrated using data from an AIDS clinical trial to compare the toxic effects of two treatments on two hematologic variables, hemoglobin and absolute neutrophil count.

Cytomegalovirus glycoprotein B genotyping in ocular fluids and blood of AIDS patients with cytomegalovirus retinitis

PURPOSE

To determine the frequency of cytomegalovirus glycoprotein B (gB) genotypes in clinical samples of ocular fluids of patients with acquired immune deficiency syndrome (AIDS) who have cytomegalovirus retinitis and to compare these with the cytomegalovirus gB genotype in paired peripheral blood leukocytes.

METHODS

Glycoprotein B genotypes of cytomegalovirus genomic DNA were determined in 29 ocular and 9 paired blood samples of 27 patients, by polymerase chain reaction amplification followed by restriction fragment length polymorphism analysis.

RESULTS

In the 29 ocular samples, 30 gB genotypes were determined: Glycoprotein B1 was found in 8 samples (27%), gB2 in 9 samples (30%), gB3 in 6 samples (20%), and gB4 in 3 samples (10%). In one sample, a mixed genotype was observed. In addition to these previously characterized gB genotypes, a new gB variant was observed in the ocular fluid of four patients. Partial sequence analysis revealed that this new gB genotype is closely related to gB3, and it was therefore named gB3'. In the blood samples, only gB1, gB2, and gB3 genotypes were observed. In the nine paired samples of ocular fluid and blood, four showed a difference in gB genotype between these compartments.

CONCLUSIONS

The distribution of cytomegalovirus glycoprotein B genotypes gB1-gB4 in ocular fluids of patients with AIDS who have cytomegalovirus retinitis was determined in this study. The predominance of gB2, as described by others, was not confirmed. The glycoprotein B genotype in the eye can be different from the genotype found in the blood of the same patient. A new gB variant, gB3', was found in the ocular samples of 4 of 27 patients, but not in the blood samples tested.

Morbidity and toxic effects associated with ganciclovir or foscarnet therapy in a randomized cytomegalovirus retinitis trial. Studies of ocular complications of AIDS Research Group, in collaboration with the AIDS Clinical Trials Group

BACKGROUND

The Foscarnet-Ganciclovir Cytomegalovirus Retinitis Trial compared the use of either ganciclovir or foscarnet for the initial treatment of cytomegalovirus retinitis in patients with the acquired immunodeficiency syndrome. We previously reported that patients treated with foscarnet lived longer but were more likely to have their treatment switched, the latter suggesting foscarnet may not have been as well tolerated as ganciclovir. This study compared the morbidity and toxic reactions reported during the trial.

METHODS

Two hundred thirty-four patients with the acquired immunodeficiency syndrome and previously untreated cytomegalovirus retinitis at 11 university centers were randomly assigned to receive intravenously either foscarnet (n = 107) or ganciclovir (n = 127). Medical histories, laboratory tests, and drug treatment histories during the first 6 months of treatment were analyzed.

RESULTS

Neutropenia was more common in patients assigned to ganciclovir than to foscarnet (34% vs 14%; P = .001). Patients assigned to foscarnet reported more infusion-related symptoms (58% vs 24%; P < .001) and, in male patients, more genitourinary symptoms (36% vs 16%; P > .001); they also experienced a trend toward more nephrotoxic effects (13% vs 6%; P = .082) and electrolyte abnormalities. The incidence of seizures was similar in both groups (foscarnet, 12%; ganciclovir, 9%; P = .511). Patients assigned to foscarnet were more likely to be switched to the alternative treatment (foscarnet to ganciclovir, 46%; ganciclovir to foscarnet, 11%; P < .001), and most of this excess was attributable to toxic reactions. In 88% of cases in which treatment was switched as a result of toxic reactions and in which follow-up data were available, the toxic reaction resolved after the switch. No permanent disability or death resulted from toxic reactions.

CONCLUSIONS

Compared with ganciclovir, the use of foscarnet was more frequently limited by the occurrence of toxic reactions. However, these toxic reactions rarely had long-term sequelae. In light of the previously reported survival benefit seen in patients treated with foscarnet, these data support the use of foscarnet for the initial treatment of cytomegalovirus retinitis.

[Anterior uveitis and cidofovir]

PURPOSE

This retrospective study was designed to determine the different parameters involved in the occurrence of uveitis during treatment with codofovir.

PATIENTS AND METHODS

This study included 10 patients out of 13 treated with cidofovir for cytomegalovirus (CMV) disease. Ocular examination, CD4+ lymphocyte count, and creatinine clearance were performed for each case of uveitis.

RESULTS

During the 17-month study, 20 uveitis cases were analyzed. The first attack occurred after a median interval of 7.6 doses. At the time of ocular inflammation, 65% of the cases had a CD4+ lymphocyte count >=100x10(6)/L, the patients thus had an improved immune function. Half of the patients had a normal creatinine clearance. The patients with a CD4+ lymphocyte count<100x10(6)/L who presented one or more incidents of uveitis had an abnormal clearance, thus probably inducing intraocular storage of the drug.

CONCLUSION

The occurrence of anterior uveitis during treatment with cidofovir is induced by the association of several parameters: a previous history of CMV retinitis, improvement of the immune function state, and intraocular storage of the drug.

Quantitative CMV antigenemia correlated with ophthalmoscopic screening for CMV retinitis in AIDS patients

To assess the efficacy of the cytomegalovirus (CMV) antigen test in detecting the clinical presence of CMV retinitis. A retrospective chart review was conducted on 86 HIV positive patients who underwent dilated fundus exams for CMV retinitis. All patients had a CMV antigen assay performed within three months of their retinal exam. At a level of 45, the antigen test has a sensitivity of 96% in correctly detecting CMV retinitis and a specificity of 90.2%. The negative and positive predictive values of the antigen test were 98.2% and 80%, respectively. CMV antigen blood test provides a useful screening tool in detecting the presence or absence of CMV retinitis. An antigen level less than 45 strongly suggests the absence of retinitis.

Human cytomegalovirus glycoprotein B genotypes in blood of AIDS patients: lack of association with either the viral DNA load in leukocytes or presence of retinitis

It has been suggested that human cytomegalovirus (HCMV) glycoprotein B (gB) genotypes could be used as a marker for viral virulence in patients with AIDS. The present study was designed to evaluate a possible association between specific gB genotypes, the presence of HCMV retinitis, and the HCMV viral load. Fifty-four blood samples were obtained from 54 HIV- and HCMV-infected patients. Twenty-seven of these patients were asymptomatic for HCMV, whereas the other 27 patients had been diagnosed recently with HCMV retinitis. HCMV gB genotyping was carried out by using restriction enzyme analysis of PCR-amplified PMNL extracts. Determination of the HCMV viral load in the same specimens was carried out using a quantitative-PCR. HCMV gB genotype 2 was found more frequently than other genotypes in PCR-amplified polymorphonuclear leukocytes (PMNL) of patients with AIDS (P < 0.05) but not more frequently in samples from patients with HCMV retinitis. No significant association was found between any HCMV gB genotypes and the viral load in blood. In conclusion, the actual HCMV gB genotyping system using PMNL provides no additional benefit over the viral load in blood for identification of HIV-infected subjects at risk of HCMV disease.