Cytomegalovirus infection in AIDS. Patterns of disease, response to therapy and trends in survival

Clinical Features and CD4+ T Cells Count in AIDS Patients with CMV Retinitis: Correlation with Mortality

PURPOSE

To explore the all-cause mortality in patients with acquired immune deficiency syndrome (AIDS) and Cytomegalovirus (CMV) retinitis.

METHODS

A retrospective cohort study of patients with CMV retinitis (CMVR) presented to a tertiary referral center in Singapore from January 1, 2004, through December 31, 2015.

RESULTS

A total of 144 patients were studied (87 survived, 11 lost to follow up, 46 died). Patients with bilateral CMVR and six-month follow up CD4 + T cell count < 50 cells/mm³ have shorter time to mortality, compared to patients with CD4 + T cell count > 50 cells/mm³ (p < .001) and unilateral disease (p = .043). Baseline CD4 + T cell count, size and zone of initial primary retinitis lesions, recurrences of retinitis, and timing of combined antiretroviral therapy (cART) are not significantly associated with mortality.

CONCLUSION

Bilateral ocular involvement and lack of immune recovery in patients with AIDS and CMVR are associated with shorter survival time.

Polymerase chain reaction analysis of aqueous humor specimens in the diagnosis of cytomegalovirus retinitis in AIDS patients

PURPOSE

To determine the value of the polymerase chain reaction analysis of aqueous humor specimens as a tool to diagnose cytomegalovirus retinitis in AIDS patients.

METHODS

In all, 63 AIDS patients were evaluated in this study. They were sorted into two diagnostic categories: eyes with active cytomegalovirus retinitis and eyes without active cytomegalovirus retinitis. The aqueous humor and blood samples were collected and analyzed by polymerase chain reaction.

RESULTS

A total of 49 patients had active cytomegalovirus retinitis (77.8%) and 14 patients had inactive cytomegalovirus retinitis or normal fundus (22.2%). The mean average of patients was 39 years (range: 22-59). The majority of patients were male (90.5%). Cytomegalovirus DNA was detected in 46 and 7 of 49 aqueous and blood samples, respectively, from AIDS patients with active cytomegalovirus retinitis. We did not detect cytomegalovirus DNA in any of the eyes without active cytomegalovirus retinitis. The sensitivity of polymerase chain reaction in the detection of cytomegalovirus in aqueous humor and blood samples was 93.5% and 14.3%, respectively.

CONCLUSIONS

The polymerase chain reaction analysis is a safe, highly specific, and sensitive method to diagnose cytomegalovirus retinitis.

Spectrum of Newly Diagnosed Cytomegalovirus Retinitis in a Developing Country in the HAART Era

Purpose: To characterize the presenting features of cytomegalovirus (CMV) retinitis in HIV-positive patients in a developing country in the HAART era.Methods: Retrospective chart review of all patients with CMV retinitis seen at a tertiary-care referral center between January 2006 to June 2017. Demographic and clinical data were collected to study the presenting features and risk factors for blindness.Results: Fifty-five patients with treatment-naïve CMV retinitis were enrolled; 75% were males. CD4 counts were below 50 cells/µL in 51.1%. Bilateral presentation was seen in 61.5%. Half (50.6%) of the eyes were blind at first examination. Zone 1 involvement was present in 46% of the eyes. Retinal area involvement > 25% was the only factor associated significantly with higher incidence of blindness (p = 0.016).Conclusions: There was extensive and bilateral presentation of CMV retinitis due to delayed presentation. Screening for CMV retinitis, irrespective of CD4 counts, may help in developing nations.

Impact of Depression and Inflammation on the Progression of HIV Disease

The human immunodeficiency virus type 1 (HIV-1) epidemic has negatively affected over 40 million people worldwide. Antiretroviral therapy (ART) has improved life expectancy and changed the outcome of HIV-1 infection, making it a chronic and manageable disease. However, AIDS and non-AIDS comorbid illnesses persist during the course of infection despite the use of ART. In addition, the development of neuropsychiatric comorbidities (including depression) by HIV-infected subjects significantly affects quality of life, medication adherence, and disease prognosis. The factors associated with depression during HIV-1 infection include altered immune response, the release of pro-inflammatory cytokines, and monoamine imbalance. Elevated plasma pro-inflammatory cytokine levels contribute to the development of depression and depressive-like behaviors in HIV⁺ subjects. In addition, comorbid depression influences the decline rates of CD4⁺ cell counts and increases plasma viral load. Depression can manifest in some subjects despite their adherence to ART. In addition, psychosocial factors related to stigma (negative attitudes, moral issues, and abuse of HIV⁺ subjects) are also associated with depression. Both neurobiological and psychosocial factors are important considerations for the effective clinical management of HIV and the prevention of HIV disease progression.

Entry of human cytomegalovirus into porcine endothelial cells depends on both the cellular vascular origin and the viral strain

BACKGROUND

Primary infection and reactivation of human cytomegalovirus (HCMV) is associated with allograft rejection. Pig-to-human xenotransplantation is regarded as an alternative to circumvent donor organ shortage and inevitably, porcine endothelial cells (pEC) will be exposed to human pathogens, among them HCMV. Infection of pEC with HCMV induces apoptosis and entry is sufficient to induce phenotypic alterations, which have the potential to result in rejection and vasculopathy. We investigated the mechanisms used by HCMV to enter pEC from different anatomical origins and compared them with the entry mechanisms used to enter human endothelial cells (hEC).

METHODS

Immortalized porcine aortic (PEDSV.15) and porcine microvascular bone marrow derived EC (2A2) as well as primary human aortic (HAEC) and microvascular EC (HMVEC) were inoculated with the endotheliotropic (TB40/E) or the fibroblast propagated (TB40/F) HCMV strains at multiplicity of infection (MOI) ranging from 0.3 to 5. EC were analyzed for receptor expression and their involvement in HCMV entry. The role of endocytosis was evaluated by treating EC with specific inhibitors, and the involvement of the endolysosomal pathway was investigated by confocal microscopy.

RESULTS

Silencing of platelet-derived growth factor receptor alpha resulted in a reduced expression of viral immediate early (IE) antigen only in pEC infected with either TB40/E or TB40/F whereas silencing of β1 integrins reduced expression of IE proteins in all EC except for TB40/F-infected microvascular pEC. TB40/E enters hEC and pEC by a similar mechanism dependent on dynamin-2, lipid rafts, actin and pH, whereas entry of TB40/F in pEC occurs mainly by a dynamin-2-dependent, clathrin-, lipid rafts-independent mechanism and in a pH-dispensable manner. When actin polymerization was prevented, TB40/F could enter pEC in an actin-independent fashion. Disturbance of the microtubule cytoskeleton resulted in an inhibition of infection of TB40/E-infected EC, whereas infection of TB40/F-infected pEC was not modified. Finally, viral particles located in vesicles of the endolysosomal pathway, suggesting that HCMV uses this pathway for intracellular trafficking following entry.

CONCLUSIONS

Our findings demonstrate that HCMV uses a variety of entry mechanisms that are dependent on the strain and on the vascular origin of the cells. Given the profound effect of pEC infection with HCMV, prevention of such an infection will be crucial for clinical application of xenotransplantation. A potential avenue is to render porcine grafts resistant to HCMV infection by blocking viral entry and propagation.

Therapy for HIV: past, present, and future

Initial therapies for HIV infection comprised nucleoside analogues, but as single or dual agents, they failed to prevent disease progression. When a new class of drug was introduced, the protease inhibitors, an effective triple therapy became possible-namely, highly active antiretroviral therapy, or HAART. HAART reduced viral replication almost completely and enabled immune system recovery. The probability of classical infections and tumors attributed to HIV were dramatically reduced, and life expectancy correspondingly increased. The initial disadvantages of HAART included the need for strict adherence to prevent drug resistance, the cost that initially precluded their widespread use in the developing world, and the short- and long-term side effects. One of the most disabling long-term complications was HIV lipodystrophy, which in extreme cases lead to severe peripheral fat wasting and central fat gain. In recent years, many of these disadvantages have been addressed: Once-daily drug combinations improve adherence; global access to HAART has been markedly improved; and new drugs enable patients to avoid many of the initial side effects. Future research will determine at what CD4 count HAART should be initiated, and new approaches such as immunotherapeutic HIV vaccines are being tested with the aim to delay or obviate the need for antiretroviral drugs.

Gastrointestinal cytomegalovirus disease in patients with cancer: a two decade experience in a tertiary care cancer center

Although gastrointestinal cytomegalovirus disease (GI-CMVd) is not common in cancer patients, it is associated with high morbidity and mortality. Herein, we review our 2-decade experience with GI-CMVd in such patient population at The University of Texas M.D. Anderson Cancer Center. Forty-seven patients were identified. Thirty-four patients (72%) had an underlying haematological malignancy, and 18 patients (38%) developed GI-CMVd following hematopoietic stem cell transplantation (HSCT). Nine (25%) of the 36 cancer patients with data available had AIDS. Upper-GI tract involvement was more common in patients with haematological malignancies than in those with solid tumours (P=0.02). Patients with AIDS were more likely to have colonic involvement than were those without AIDS (67% vs. 15%, P=0.006), and patients without AIDS were more likely to have gastric involvement (59% vs. 11%, P=0.01). The CMV-attributable mortality rate was 42%. Independent predictors of death by multivariate analysis included disseminated CMV and AIDS (P<0.01). The presentation of GI-CMVd varies according to the type of cancer, and AIDS. GI-CMVd is associated with a high mortality among cancer patients, particularly those with disseminated CMV disease or AIDS.

Self-limited colitis during the course of rubella and cytomegalovirus infection in an immunocompetent adult

We report a case of self-limited colitis in cytomegalovirus (CMV) infection in an immunocompetent adult. A 22-year-old man developed a high fever and diarrhea. Laboratory data revealed an increased number of lymphocytes and liver damage. Enzyme immunoassays for anti-virus antibodies revealed that the patient was recently infected with CMV and rubella. Colonoscopy revealed severe erosive and edematous mucosa that resembled ulcerative colitis (UC). The symptoms, laboratory data and colonoscopic findings improved without any medical treatment. This case indicates that UC-like self-limited colitis can occur in an immunocompetent individual during the course of CMV infection.

Mortality risk for patients with cytomegalovirus retinitis and acquired immune deficiency syndrome

We prospectively followed up 589 patients to evaluate the relationship of anti-cytomegalovirus (CMV) treatment and immune reconstitution in response to highly active antiretroviral therapy (HAART) on the mortality risk of patients with CMV retinitis and acquired immune deficiency syndrome. The use of HAART was associated with an 81% lower mortality rate (95% confidence interval [CI], 74%-86%); it was 96% lower (95% CI, 92%-98%) for those who developed immune recovery and 49% lower (95% CI, 30-63%) for those who did not. Using time-updated multivariate analysis, current systemic anti-CMV treatment was independently associated with a 28% lower mortality rate (95% CI, 8%-43%). On the basis of these results, for patients who continue to have profound immunodeficiency despite HAART, the continued use of HAART and systemic anti-CMV therapy is predicted to reduce the risk of mortality by 65%, over and above the benefits of Pneumocystis carinii and Mycobacterium avium prophylaxis.

Persistent rat cytomegalovirus (RCMV) infection of the salivary glands contributes to the anti-RCMV humoral immune response

The salivary glands are the major sites of persistent replication of rat cytomegalovirus (RCMV). At several months post infection (pi), infectious RCMV is usually still produced in the salivary glands but not in any other organ or tissue of the rat. To investigate whether the persistence of RCMV in the salivary glands is crucial to the pathogenesis of viral infection, we monitored the progression of RCMV-induced disease in rats from which the salivary glands had been surgically removed (desalivated) as well as in sham-operated rats, both after a lethal and sublethal challenge with RCMV. Desalivation did not have a significant effect on either RCMV-induced morbidity or mortality. As expected, at 1 year pi, relatively high levels of infectious virus were detected in the salivary glands of sham-operated rats, whereas neither infectious virus nor RCMV DNA could be detected in liver, spleen and lungs of these animals. Infectious virus and viral DNA were also undetectable in organs from desalivated animals at 1 year pi. Surprisingly, a difference was found between desalivated and sham-operated rats in the titers of anti-RCMV IgG antibodies, which were significantly higher in sham-operated rats than in desalivated animals at 183, 295 and 365 days pi. This finding indicates that the persistence of RCMV in the salivary glands may contribute significantly to the anti-RCMV humoral immunity of infected rats.

Efficient identification of HLA-A*2402-restricted cytomegalovirus-specific CD8(+) T-cell epitopes by a computer algorithm and an enzyme-linked immunospot assay

Antigenic peptides recognized by virus-specific cytotoxic T lymphocytes (CTLs) are useful tools for studying the CTL responses exclusively among those who own the major histocompatibility complex (MHC) class I molecules that present the peptides. For widening the application, an efficient strategy to determine such epitopes in the context of a given MHC is highly desirable. A rapid and efficient strategy is presented for the determination of CTL epitopes in the context of given MHC molecules of interest through multiple screenings consisting of a computer-assisted algorithm and MHC stabilization and enzyme-linked immunospot assays. A major cytomegalovirus (CMV)-specific CTL epitope, QYDPVAALF, in the amino acid sequence of its lower matrix 65 kd phosphoprotein (pp65) presented by HLA-A*2402 molecules was identified from 83 candidate peptides. The results indicate that the CMV-specific CTL response is highly focused to pp65 in the context of HLA-A*2402. Endogenous processing and presentation was confirmed using a peptide-specific CD8(+) T-cell clone as the effectors and autologous fibroblast cells infected with recombinant vaccinia virus expressing pp65 gene or CMV as antigen-presenting cells. Flow cytometric analysis of intracellular interferon-gamma production revealed 0.04% to 0.27% of CD8(+) T cells in peripheral blood of HLA-A24(+) and CMV-seropositive donors to be specific for the peptide. The tetrameric MHC-peptide complexes specifically bound to the reactive T-cell clone and 0.79% of CD8(+) T cells in peripheral blood from a seropositive donor. The peptide could be a useful reagent to study CTL responses to CMV among populations positive for HLA-A*2402.

Isolation of cytomegalovirus-specific cytotoxic T-lymphocytes from gut-associated lymphoid tissue (GALT) of HIV type 1-infected subjects

Cytomegalovirus (CMV) can be an important opportunistic infection in HIV-1-infected patients, particularly when the CD4+ T-cell count drops below 50 lymphocytes/mm3. CMV-associated disease, including retinitis, pneumonitis, gastroenteritis, and encephalitis, is estimated to affect up to 40% of AIDS patients. We have studied the cellular immune response to CMV in gut-associated lymphoid tissue (GALT) of HIV-1-infected patients. Two patients with chronic diarrhea of unknown etiology were examined by flexible sigmoidoscopy and upper endoscopy. Biopsy specimens were obtained from lymphoid-associated tissue sites in rectum and duodenum. Both patients were seropositive for CMV IgG, but had not been treated with ganciclovir, and neither had clinical signs of CMV disease. Mononuclear cell cultures were established from GALT and blood and assayed for the presence of CMV-specific CD8+ T cells. CD8+ T-cell phenotype and function were assessed by MHC Class I tetramer staining, using an HLA-A*0201 tetramer complex specific for peptide 495-503 (NLVPMVATV) of CMV lower matrix protein pp65, and by a standard 51Cr release assay. CMV pp65-specific cytotoxic lymphocytes (CTL) were detected in GALT and blood MNC from both patients. These results demonstrate that HIV-1-infected subjects seropositive for CMV, but without active CMV gastrointestinal disease, harbor CMV-specific CTL in intestinal lymphoid tissue. This is the first report of isolation of CMV-specific CTL in GALT and will lead to greater understanding of the pathogenesis of CMV disease in human mucosal tissue.

Prognostic factors of survival of HIV-infected patients with cytomegalovirus disease: Aquitaine Cohort, 1986-1997. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine (GECSA)

OBJECTIVE

To analyse survival of HIV-infected patients who developed cytomegalovirus (CMV) disease and to identify prognostic factors of their survival.

METHODS

Cases of CMV disease diagnosed in the Aquitaine Cohort of HIV-infected patients (n = 4297) during the 1986-1996 period, were reviewed using standardised definitions. Follow-up was extended to December 1997. Cox model was used to determine factors associated with survival after the initial manifestations of CMV disease, considering protease inhibitor (PI) prescription and anti-CMV treatment as time dependent covariates.

RESULTS

253 patients presented a CMV disease of which 221 (87.3%) died (median survival: 7 months). A better prognosis for survival was associated with: PI prescription [relative hazard (RH): 0.26; 95% confidence interval (CI): 0.11-0.59], anti-CMV treatment (RH: 0.37; CI: 0.25-0.54), CD4+ lymphocyte cell count > 50/mm3 (RH: 0.66; CI: 0.47-0.94) and absence of neoplasia (RH: 0.70; CI: 0.52-0.94) whereas the disseminated CMV disease worsened prognosis (RH: 1.83; CI: 1.20-2.80).

CONCLUSION

Antiretroviral treatment including PI, improved short-term prognosis of CMV disease regardless of its clinical manifestations.

Effect of desferrioxamine (DFO) and calcium trinatrium diethylenetriaminepentaacetic acid (DTPA) on rat cytomegalovirus replication in vitro and in vivo

Cytomegalovirus (CMV) infection is a major problem in the immunosuppressed patient. It is thought that besides direct CMV induced cell lysis, immunological damage is part of CMV pathogenesis. New antiviral drugs, which combine immunomodulating and antiviral qualities, could be beneficial. Recently, it has been described that desferrioxamine (DFO) and calcium trinatrium diethylenetriaminepentaacetic acid (DTPA) exhibit both properties. In this report the antiviral effects of both compounds against rat CMV (RCMV) are described in vitro and in vivo using a generalised and local infection model. In vitro, both compounds exhibited a significant antiviral effect, DTPA being more potent than DFO. However, in the generalised infection model no effect was seen on mortality, morbidity or presence of virus in internal organs. In rats infected subcutaneously in the hind paw, no effect was seen locally on paw thickness, presence of viral antigens and inflammatory response. In addition, these rats suffered from a generalised infection of low magnitude at 15 days post infection, although both DFO and DTPA were able to lower the level of viral replication. In conclusion, our data indicate that despite in vitro activity, in vivo usage of DFO or DTPA for acute CMV infection is not warranted.

Nonnucleoside pyrrolopyrimidines with a unique mechanism of action against human cytomegalovirus

Based upon a prior study which evaluated a series of nonnucleoside pyrrolo[2,3-d]pyrimidines as inhibitors of human cytomegalovirus (HCMV), we have selected three active analogs for detailed study. In an HCMV plaque-reduction assay, compounds 828, 951, and 1028 had 50% inhibitory concentrations (IC(50)s) of 0.4 to 1.0 microM. Similar results were obtained when 828 and 951 were examined by HCMV enzyme-linked immunosorbent assay (IC(50)s = 1.9 and 0.4 microM, respectively) and when 828 was tested in a viral DNA-DNA hybridization assay (IC(50) = 1.3 microM). In yield-reduction assays with a low multiplicity of infection (MOI), all three compounds caused multiple log(10) reductions in virus titer, and the activities of these compounds were comparable to the activity of ganciclovir (GCV; IC(90) = 0.2 microM). In contrast to the reduction of viral titers by GCV, the reduction of viral titers by 828, 951, and 1028 decreased with increasing MOI. Cytotoxicity in human foreskin fibroblasts and KB cells ranged from 32 to >100 microM. In addition, 828 (the only compound tested) was less toxic against human bone marrow progenitor cells than GCV. Time-of-addition and time-of-removal studies established that the three pyrrolopyrimidines inhibited HCMV replication before GCV had an effect on viral DNA synthesis but after viral adsorption. Compound 828 was equally effective against GCV-sensitive and GCV-resistant HCMV clinical isolates. Combination studies with 828 and GCV showed that the effects of the two compounds on HCMV were additive but not synergistic. Taken together, the data indicate that these pyrrolopyrimidines target a viral protein that is required in an MOI-dependent manner and that is expressed early in the HCMV replication cycle.

Human CD28−CD8+ T Cells Contain Greatly Expanded Functional Virus-Specific Memory CTL Clones

At birth, almost all human peripheral blood CD8+ T cells express the costimulatory molecule CD28. With increasing age, the proportion of CD8+ T cells that lack CD28 increases. Because the Ag specificity of CD28−CD8+ T cells has not previously been defined, we studied the contribution of CD28−CD8+ T cells to the memory CD8+ CTL response against two human persistent viruses, human CMV (HCMV) and HIV. From PBMC of healthy virus carriers we generated multiple independent CTL clones specific for defined viral peptides and sequenced their TCR β-chains. We designed clonotypic oligonucleotides complementary to each β-chain hypervariable sequence and quantified the size of individual immunodominant CTL clones in PBMC. Some individual CTL clones were very large, comprising up to 3.1% of all CD8+ T cells in PBMC, and were generally maintained at a stable level for months. Individual virus-specific CTL clones were consistently more abundant in purified CD28− cells than in the CD8+ population as a whole. Because CD28−CD8+ cells as a population have been reported to proliferate poorly in response to mitogen, we studied the function of these virus-specific CD28− CTL clones by quantifying the frequency of peptide-specific CTL precursors using limiting dilution analysis. CD28−CD8+ T cells contained high frequencies of functional memory CTL precursors specific for peptides of HCMV or HIV, generally higher than in the CD8+ T cell population as a whole. We conclude that in asymptomatic HCMV and HIV infection, human CD28−CD8+ T cells contain high frequencies of functional virus-specific memory CTL clones.

TORCH testing in HIV-infected women

The issue of TORCH testing in pregnant women infected with the HIV virus remains confusing, even more so than it is in the non-HIV-infected gravida. Unfortunately, the data presented in this article make the recommendations of how to test for these various infections in pregnancy that much more difficult. Patients who are newly diagnosed as being HIV-infected and referred for prenatal care or who have not had TORCH testing probably should be tested. Thus, the prenatal patient with newly diagnosed HIV infection should be tested for T. gondii IgG antibodies. If positive for IgG antibodies, IgM antibodies should be obtained in an attempt to rule out acute T. gondii infection. Patients who test negative do not require any further testing until after the pregnancy unless they are severely immunocompromised and show signs and symptoms of toxoplasmosis. Antibodies (IgG) to CMV should be obtained in the HIV-infected gravida who is at high risk for CMV disease, i.e., patients with CD4+ T cell counts less than 100/mm3. Unfortunately, the previously described problems with antibody detection make this testing less than ideal; thus, it is not routinely recommended in the HIV-infected pregnant patient who presents for prenatal care except for those at risk of disease reactivation. As for herpes simplex virus testing, there is no value in routinely testing patients prenatally for evidence of the disease. Finally, syphilis testing in the HIV-infected gravida is of major importance. Once tested, the patient who tests negative and who remains at risk for infection should probably be retested in the third trimester. Patients who are found to have the disease and who are treated need to be tested serially to rule out re-infection or treatment failure.

The memory cytotoxic T-lymphocyte (CTL) response to human cytomegalovirus infection contains individual peptide-specific CTL clones that have undergone extensive expansion in vivo

Human cytomegalovirus (HCMV)-specific CD8(+) cytotoxic T lymphocytes (CTL) appear to play an important role in the control of virus replication and in protection against HCMV-related disease. We have previously reported high frequencies of memory CTL precursors (CTLp) specific to the HCMV tegument protein pp65 in the peripheral blood of healthy virus carriers. In some individuals, the CTL response to this protein is focused on only a single epitope, whereas in other virus carriers CTL recognized multiple epitopes which we identified by using synthetic peptides. We have analyzed the clonal composition of the memory CTL response to four of these pp65 epitopes by sequencing the T-cell receptors (TCR) of multiple independently derived epitope-specific CTL clones, which were derived by formal single-cell cloning or from clonal CTL microcultures. In all cases, we have observed a high degree of clonal focusing: the majority of CTL clones specific to a defined pp65 peptide from any one virus carrier use only one or two different TCRs at the level of the nucleotide sequence. Among virus carriers who have the same major histocompatibility complex (MHC) class I allele, we observed that CTL from different donors that recognize the same peptide-MHC complex often used the same Vbeta segment, although other TCR gene segments and CDR3 length were not in general conserved. We have also examined the clonal composition of CTL specific to pp65 peptides in asymptomatic human immunodeficiency virus-infected individuals. We have observed a similarly focused peptide-specific CTL response. Thus, the large population of circulating HCMV peptide-specific memory CTLp in virus carriers in fact contains individual CTL clones that have undergone extensive clonal expansion in vivo.

Diagnosis and treatment of colonic disease in AIDS

The colon is a frequent site of gastrointestinal complications in patients with HIV infection, and these colonic disorders increase in frequency as immunodeficiency worsens. The most common clinical manifestations of colonic disease in AIDS are diarrhea, lower gastrointestinal bleeding, and abdominal pain. Toxic megacolon, intussuseption, typhlitis, idiopathic colonic ulcer, and pneumatosis intestinalis also have been described. In the HIV-infected patient with preserved immunity, the most common cause of colitis is bacterial, but as the degree of immunodeficiency worsens, opportunistic pathogens (CMV, protozoa, mycobacteria, fungi) and neoplasms become more frequent. The frequent use of antibiotics, chemotherapeutic agents, and frequent hospitalization increase the susceptibility to cf2Clostridium difficule cf1colitis. Endoscopy plays an integral role in the management of many colonic disorders in AIDS.

High-dose (2000-microgram) intravitreous ganciclovir in the treatment of cytomegalovirus retinitis

OBJECTIVE

The authors prospectively studied visual outcome, relapse, complications, and survival of patients with acquired immune deficiency syndrome (AIDS)-related cytomegalovirus (CMV) treated with high-dose intravitreous ganciclovir (2 mg/0.1 ml) injections. The outcomes were compared with those of patients treated with standard doses of intravenous ganciclovir in the same institution. The histopathologic and electrophysiologic effects of high-dose intravitreous ganciclovir injections in rabbits also were studied.

DESIGN

A nonrandomized case series.

PARTICIPANTS

A total of 42 patients (74 eyes) were treated with intravitreous injections and 18 patients (27 eyes) were treated with intravenous ganciclovir. Five eyes of three New Zealand white rabbits were injected with ganciclovir, and the sixth eye was a control specimen.

INTERVENTION

Patients treated with intravitreous injections received twice-weekly doses of 2 mg/0.1 ml ganciclovir for 3 weeks, then weekly injections. Patients treated with intravenous ganciclovir received standard doses. Patients were monitored with regular examinations. Rabbit eyes were given intravitreous injections of 1 mg/0.1 ml of ganciclovir weekly for 4 weeks.

MAIN OUTCOME MEASURES

Assessments of vision, retinal inflammation, and survival were made. Electroretinograms were performed on the rabbit eyes, and they were processed for light and electron microscopy.

RESULTS

In the intravitreous group, visual acuity (VA) was stable in 64 of 74 eyes, 5 improved, and 5 deteriorated. Sixty-three (85%) of 74 eyes had final VA of 20/20 to 20/40. Relapse occurred in five eyes (7%; median time, 42 weeks). There were three cases of endophthalmitis. Median survival after diagnosis of CMV retinitis was 36 weeks. In the intravenous group, VA was stable in 18 eyes, 0 improved, and 9 deteriorated. Sixteen (59%) of 27 eyes had final VA of 20/20 to 20/40. Relapse occurred in 15 eyes (56%) at a median time of 21 weeks. Median survival was 21 weeks. The rabbit studies showed no evidence of toxicity.

CONCLUSION

High-dose intravitreous ganciclovir effectively suppressed CMV retinitis, preserved vision, and prevented relapse without deterioration in survival.

Increasing survival in AIDS patients with cytomegalovirus retinitis treated with combination antiretroviral therapy including HIV protease inhibitors

OBJECTIVE

To assess the effect of combination antiretroviral therapy including HIV protease inhibitors on the survival of patients with cytomegalovirus retinitis (CMVR).

DESIGN AND PARTICIPANTS

A longitudinal study of patients with CMVR diagnosed between October 1992 and May 1996 and followed to May 1997.

SETTING

UK National Health Service specialist HIV medicine department.

OUTCOME MEASURE

Time to death from first diagnosis of CMVR. Data were censored on 31 May 1997.

RESULTS

Data were available on 147 patients with CMVR. Median survival of CMVR patients before December 1995 was 256 days [95% confidence interval (CI), 197-315]. Following the introduction of protease inhibitors in December 1995 this rose to 555 days (95% CI, 351-759). By 31 May 1996 median survival for the entire group of patients alive with CMVR had risen to 720 days (95% CI, 551-889). The mean survival after CMVR diagnosis was 224 days (n=89; 95% CI, 186-261; 1-year survival, 16%) in those who took no further antiretroviral therapy, 353 days in those who took nucleoside reverse transcriptase inhibitors but no protease inhibitors (n=34; 95% CI, 289-418; 1 -year survival, 50%), and 914 days in those who took a protease inhibitor (n=24; 95% CI, 768-1059; 1-year survival, 83%; P < 0.0001). Multivariate analysis showed that the strongest independent predictor of improved survival was having ever received a protease inhibitor after CMVR (relative risk of death, 0.063; 95% CI, 0.027-0.149; P < 0.0001).

CONCLUSIONS

The use of HIV protease inhibitors in combination antiretroviral therapy has been associated with a marked increase in the survival of patients with CMVR.

Molecular diagnosis of gastrointestinal infections associated with HIV infection

Developments in medical microbiology in the past 20 years have had a profound impact on our understanding of infectious diseases and have led the way in the development of new diagnostic techniques. Molecular diagnostic techniques are generally more sensitive, specific, and rapid than conventional methods by which infectious agents are detected. For many of the opportunistic infectious agents of the gastrointestinal tract found in HIV-infected individuals, the application of molecular diagnostic techniques to the clinical laboratory is in its infancy. In this article, methods by which these techniques can be evaluated are demonstrated, and the current status and potential future application of these techniques for each gastrointestinal opportunistic pathogen are described.

Agents of diarrhea

Diarrhea is a common problem for AIDS patients, and is chronic and debilitating. A thorough evaluation will reveal a pathogen in the majority of patients, and the organisms most frequently identified in AIDS patients with chronic diarrhea are Cryptosporidium, microsporidia, and Mycobacterium avium complex. Bacterial pathogens are more common in AIDS patients than in the general population and may present in different ways from infections in immunocompetent hosts. Other pathogens, including Cryptosporidium and microsporidia, are difficult to diagnose and have no effective therapy. Moreover, enteric viruses and HIV itself may contribute to the diarrhea. In addition to microbes, other factors such as medication, immune dysregulation, automatic dysfunction, and nutritional supplementation play a substantial role in diarrhea of AIDS patients.

Synthesis of non-nucleoside analogs of toyocamycin, sangivamycin, and thiosangivamycin: the effect of certain 4- and 4,6-substituents on the antiviral activity of pyrrolo[2,3-d]pyrimidines

A number of 4-substituted 7-(ethoxymethyl)- and 7-[(2-methoxyethoxy)methyl]pyrrolo[2,3-d]-pyrimidine-5-carbonitrile and -5-thiocarboxamide derivatives and several 7-substituted 4,6-diaminopyrrolo[2,3-d]pyrimidine-5-carbonitrile, -5-carboxamide, and -5-thiocarboxamide analogs related to the nucleoside antibiotics toyocamycin and sangivamycin were prepared and tested for activity against human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1). Biologically, modifications at the 4-position were not well tolerated in cell culture, and in almost all cases no activity against HCMV or HSV-1 was observed. Furthermore, none of the compounds inhibited the growth of L1210 murine leukemic cells in vitro. In sharp contrast to the 4-substituted compounds, all of the 4,6-diamino 5-nitrile and the 5-thioamide analogs were active against HCMV, whereas the 5-carboxamides were inactive. The corresponding 4-amino 6-methylamino and 6-dimethylamino 5-nitrile analogs were inactive against HCMV, establishing that an amino group at both C-4 and C-6 is a likely requirement for antiviral activity. Overall, our results demonstrate that an amino group at C-4 and a thioamide moiety at C-5 of a 7-substituted pyrrolo[2,3-d]pyrimidine are essential for activity against HCMV, whereas a 4,6-diamino analog does not necessarily require a thioamide group at C-5 for activity against HCMV.

Fluorescence in situ hybridization with cosmid clones for the detection of human cytomegalovirus DNA in peripheral blood leukocytes

Radioactive in situ hybridization techniques or enzymatic detection procedures of hapten-modified human cytomegalovirus (HCMV) probes have been widely used for studying the infection of peripheral blood leukocytes with HCMV. This report describes significant improvements in terms of signal resolution which can be obtained by applying a highly sensitive fluorescence in situ hybridization (FISH) technique in conjunction with a large subgenomic HCMV DNA probe. Three cosmid clones spanning 119.1 kb of the HCMV genome (230 kb) were used to construct the digoxigenin-11-dUTP-labeled probe which was found to be superior to a total HCMV probe representing the entire genome. Crucial hybridization parameters were analyzed systematically in order to ensure optimal resolution power and sensitivity. The protocol was successfully applied to HCMV-infected fibroblasts and peripheral blood leukocytes of 12 transplant patients and unambiguously facilitated the precise intracellular localization of HCMV genomes in infected cells. Because of its excellent resolution properties, accompanied by the virtual absence by any background staining, we recommend the use of this protocol as a sensitive approach for further virological analyses of the interactions between HCMV and peripheral blood leukocytes at the single-cell level.

Synthesis of non-nucleoside analogs of toyocamycin, sangivamycin, and ++thiosangivamycin: influence of various 7-substituents on antiviral activity

A number of 7-substituted 4-aminopyrrolo[2,3-d]pyrimidine-5-carbonitrile, -5-carboxamide, and -5-thiocarboxamide derivatives related to the nucleoside antibiotics toyocamycin and sangivamycin were prepared and tested for their activity against human cytomegalovirus (HCMV) and herpes simplex virus type-1 (HSV-1). Treatment of 2-amino-5-bromo-3,4-dicyanopyrrole (1) with triethyl orthoformate followed by alkylation via the sodium salt method with a variety of alkylating agents furnished the corresponding 1-substituted pyrroles 2a-k. Ring annulation was achieved with methanolic ammonia affording the 7-substituted 4-amino-6-bromopyrrolo++-[2,3-d]pyrimidine-5-carbonitrile derivatives 3a-k. Debromination of 3a-k, via catalytic hydrogenation, gave the corresponding 7-substituted 4-aminopyrrolo[2,3-d]pyrimidine-5-carbonitrile analogs 4a-j,l. A selective reduction of 4-amino-6-bromo-7-allylpyrrolo[2,3-d]-pyrimidine-5-carbon ril e (3k) in zinc and acetic acid furnished 4-amino-7-allylpyrrolo-[2,3-d]pyrimidine-5-carbonitrile (4k). Conventional functional group transformations involving the 5-cyano group of 4 furnished the 5-carboxamide derivatives 5a-1 and the 5-thio-amide analogs 6a-l. A similar transformation of the aglycone of toyocamycin (4m) furnished the corresponding aglycone of thiosangivamycin (6m). Several of the new compounds (4-6a-ej-l) were evaluated for their ability to inhibit the growth of L1210 murine leukemic cells. Whereas a number of the carboxamide (5) and thioamide (6) derivatives had modest activity, the corresponding nitrile analogs (4) were all inactive. All compounds were tested for activity against HCMV and HSV-1. The non-nucleoside nitrile analogs 4a-m and carboxamide derivatives 5a-l were, with a few exceptions, essentially inactive against HCMV and HSV-1 and relatively nontoxic. In direct contrast, nearly all of the thioamide derivates 6a-1, including the aglycone of thiosangivamycin (6m), were good inhibitors of HCMV and HSV-1. Most were noncytotoxic in their antiviral concentration range. Cytotoxicity which was observed appeared to be a consequence of DNA synthesis inhibition. Several of these compounds, such as 6b,e, were particularly interesting inhibitors of HCMV with IC(50)'s ranging from 0.1 to 1.3 muM. The antiviral activity of both compounds was well separated from cytotoxicity in KB, HFF, and L1210 cells.

Visual prognosis of AIDS patients with cytomegalovirus retinitis

A prospective study of visual acuity (VA) was performed in a cohort of 147 AIDS patients with cytomegalovirus retinitis (CMVR). Patients were treated according to standard regimes, and corrected VA was recorded at regular intervals from presentation until death. Follow-up was 6 weeks to 5 years (mean 30 weeks). Fifty patients (34%) had bilateral CMVR at initial presentation; at death 81 patients (55%) had bilateral disease. Thirty-one eyes initially uninfected developed CMVR during follow-up. Of 228 infected eyes, VA at presentation was 6/12 or better in 182 eyes (80%) and 6/60 or better in 215 eyes (94%) At death, VA was 6/12 or better in 112 eyes (49%) and 6/60 or better in 171 eyes (75%). VA in the better eye at death was 6/12 or better in 113 of 147 patients (77%), 6/24 or better in 135 patients (92%) and worse than 6/60 in only 7 patients (5%). Treatment of AIDS-related CMVR minimises loss of vision and may protect previously uninfected eyes, prolonging visual independence.

Cytomegalovirus viraemia in HIV infection: association with intercurrent infection

The aim of this retrospective study was to investigate the clinical significance of cytomegalovirus (CMV) viraemia in HIV-infected subjects (with or without AIDS) who had attended this hospital during a 45 month period. They were reviewed regularly and, when clinically indicated, tested for CMV viraemia. The blood of 105 subjects was cultured for CMV and 34 had at least one episode of CMV viraemia during the review period. The viraemia was present during CMV disease in nine of the 34 positive patients and was the only detectable infection in another two. In the remaining 23 patients, CMV viraemia occurred in association with intercurrent opportunistic infection. Among these 23 patients, the viraemia resolved in 12 after treatment (or natural resolution) of the intercurrent infection and only one of these 12 developed CMV disease (mean review period: 8 months). In another seven patients, CMV viraemia persisted despite treatment (or natural resolution) of the intercurrent infection and four subsequently developed CMV disease (mean review period: 4 months) (P = 0.08, Fisher's exact test). From the remaining four patients, no specimens for CMV culture were obtained after treatment of the intercurrent infection. The CD4 count was higher in the 12 patients in whom there was resolution of the viraemia [mean CD4 60 x 10(6)/l] compared with the seven in whom the viraemia persisted [mean CD4 45 x 10(6)/l]. These findings suggest that in some HIV-positive patients, CMV viraemia was potentiated by intercurrent infection with another micro-organism and that its treatment was sufficient to mitigate the CMV disease.

Cytomegalovirus esophagitis in AIDS: a prospective evaluation of clinical response to ganciclovir therapy, relapse rate, and long-term outcome

PURPOSE

Although cytomegalovirus (CMV) esophagitis is an important complication of acquired immunodeficiency syndrome, there has been little study specifically addressing the response to currently available antiviral therapy, relapse rate without maintenance therapy, and long-term outcome.

PATIENTS AND METHODS

Over a 45-month period, 44 patients with CMV esophagitis established endoscopically and histopathologically were prospectively identified from among all human immunodeficiency virus (HIV)-infected patients undergoing endoscopy. Induction therapy consisted of intravenous ganciclovir at 10 mg/kg per day for approximately 14 days. Foscarnet was given at 60 mg/kg every 8 hours for nonresponders to ganciclovir.

RESULTS

Of these patients, 35 completed induction ganciclovir therapy, resulting in a complete response in 17 (49%) and a partial response in 10 (29%), yielding a 77% overall response rate. Seven of 8 nonresponders were subsequently treated with foscarnet, with a clinical response seen in 5 patients. In the 18 eventual complete responders to ganciclovir or foscarnet followed up without maintenance therapy, 7 (39%) relapsed at a median of 4 months (range 2 to 18 months). In all cases, relapse was manifested by recurrent odynophagia. Reinduction ganciclovir therapy yielded a complete response in 1 patient and a partial response in 2, and induction foscarnet treatment resulted in a complete response in the other treated patients. During long-term follow-up, 1 complete responder developed CMV colitis with concurrent retinitis, and 4 other patients developed retinitis. The median survival after diagnosis was 8.2 months, although survival for greater than 1 year was seen in 4 patients. No patient died as a direct result of esophageal disease, although ulcer-related bleeding may have contributed to death in 2 patients with end-stage liver diseases and hepatic encephalopathy.

CONCLUSIONS

CMV esophagitis has a favorable response to induction ganciclovir therapy, and a long-term remission may occur after induction therapy alone. Despite the favorable response to ganciclovir therapy, the long-term survival is poor, reflecting the severe immunodeficiency of these patients.

Retinal findings in Malawian patients with AIDS

The purpose of this study was to determine the prevalence of retinal disease in a group of patients with AIDS in Malawi. Indirect ophthalmoscopy was performed on 99 patients with AIDS who were admitted consecutively to a medical ward at a central hospital. Necrotising retinitis was present in one eye of one patient examined. Non-infectious retinopathy was present in 13%. Retinitis is less common in AIDS patients from Africa compared with those from developed countries; it is believed that most patients die before acquiring it. Non-infectious retinopathy may also be less common.

Cytomegalovirus retinitis: diagnosis and treatment

Cytomegalovirus (CMV) is a non-pathogenic organism in the immunocompetent, but is a major cause of morbidity and mortality amongst patients with AIDS, and the retina is the commonest site of infection. If left untreated, patients with CMVR will develop disease in their second eye and ultimately become blind. However, with correct diagnosis and treatment useful vision can be maintained in the majority of cases. Fifteen to 20% of patients with AIDS will contract cytomegalovirus retinitis (CMVR) and this may be the AIDS-defining diagnosis though more commonly it occurs months after the diagnosis of AIDS. Given the increasing number of HIV positive patients and their longer survival, it is likely that CMVR will become an increasingly prevalent condition. In these patients loss of sight from CMVR has devastating consequences in terms of loss of independence and quality of life and therefore ophthalmologists and physicians should be aware of the presenting characteristics of CMVR, be familiar with therapy and its complications, and be able to recognize relapsing infection.

Cytomegalovirus retinitis and AIDS in Edinburgh

The medical records, retinal drawings and fundus photographs of all patients with cytomegalovirus retinitis (CMVR) and AIDS in Edinburgh between 1986-1992 were reviewed to determine the efficacy of treatment in preserving vision. Ophthalmoscopic features of CMVR were observed in 32 eyes of 24 patients with AIDS, 19 males and 5 females. HIV transmission in this group was by homo/bisexual contact (16), injection drug use (7) and blood transfusion (1). Unilateral blurring was the commonest visual symptom although 9 (38%) patients had no visual symptoms. All patients presented with a corrected visual acuity of 6/12 or better in at least one eye. Following treatment with systemic ganciclovir or foscarnet 16 patients (66%) developed toxic side-effects of therapy and 13 (54%) experienced a recurrence of CMVR. Four (17%) patients developed a retinal detachment in one eye. The mean survival was 8.3 months after the diagnosis of CMVR. At final follow-up, between 2-26 months after the diagnosis of CMVR, 21 (87.5%) patients retained useful vision (6/18 or better) although 3 (12.5%) were effectively blind (less than 6/60). We conclude that with prompt diagnosis and treatment of CMVR vision can be preserved in the majority of cases.

Bacterial, fungal, parasitic, and viral colitis

Colitides of bacterial, fungal, parasitic, and viral origin require an organized approach for diagnosis and treatment. Many colitides are transmitted through poor hygienic practices. However, increasing numbers of patients are at risk because of immunocompromise. This population includes the elderly, individuals taking steroids or immunosuppressive agents, and HIV-seropositive individuals. This latter group of individuals is at high risk not only because of immunocompromise but also because of practices such as oroanal intercourse with infected partners. These facts suggest that both the prevalence and the geographic scope of infectious colitides will continue to expand. Undoubtedly, the surgeon will be called on to assist in the diagnosis and management of the complications.

Muscle disease, HIV and zidovudine: the spectrum of muscle disease in HIV-infected individuals treated with zidovudine

Eleven patients with AIDS or AIDS-related complex who developed muscle-related symptoms whilst taking zidovudine were investigated. The clinical details of a further ten patients who did not undergo muscle biopsy are also outlined. The clinical features, quantitative muscle strength testing, electromyographic findings, serial creatine kinase levels, muscle biopsy appearance on light microscopy and the effects of zidovudine withdrawal and rechallenge are described. The spectrum of muscle disease encountered included four cases of frank myopathy diagnosed using clinical, electrophysiological and histological criteria, four patients with mild weakness and myalgia in whom muscle biopsies were normal, three patients with myalgia only and a mild increase in the interstitial cell infiltrate shown by biopsy. The patients presenting with myopathy showed no improvement on withdrawal of zidovudine but responded to immunosuppressive therapy with steroids and, in one case, thalidomide prescribed incidentally. At present, it is not yet possible to clinically define a specific zidovudine-induced myopathy that is distinct from the other effects of HIV infection on muscle structure and function. Our experience suggests that zidovudine may be implicated as a myotoxin in some patients, particularly those with myalgia and mild weakness. In those patients with severe weakness, and with biopsy findings of necrosis and inflammation, the drug effects may be difficult to separate from the primary effects of HIV.

Cytomegalovirus disease in AIDS: the Edinburgh experience

Retrospective analysis of medical records of 557 HIV positive patients (including 113 with AIDS) revealed 17 patients with an antemortem clinical diagnosis of cytomegalovirus (CMV) disease. This group comprised 7 injection drug users (2 male and 5 female) and 10 homosexual men. Males were significantly older than females, and homosexual men were significantly older than drug users at the time of diagnosis of CMV. All 17 patients had evidence of retinitis, and 6 also had evidence of extraocular disease. CMV retinitis was the AIDS defining diagnosis in two patients, and the attack rate of CMV in all AIDS patients progressively increased with time, with a 3-year CMV-free survival of 57%. Fifteen patients with CMV disease had evidence of previous CMV infection (CMV IgG positive), with 7 also having a positive CMV IgM and 10 a positive viral culture. The mean CD4+ lymphocyte count at diagnosis of CMV was 17 cells/mm3, compared with 68 cells/mm3 at diagnosis of AIDS. Therapy was unsatisfactory, often being complicated by marrow suppression. Relapse occurred in 11 patients after initial improvement but despite this only 3 patients died with severe visual impairment. The mean survival after a diagnosis of CMV was 10.5 months. This study confirms that disease caused by CMV is usually a late manifestation of AIDS, and the increasing prevalence among patients with AIDS implies that, the longer the survival, the greater the risk of disease. Frequent fundoscopy in HIV positive patients is of paramount importance particularly in patients who have a CD4+ lymphocyte count of less than 100 cells/mm3.