HIV-associated retinopathy in the HAART era

Ocular manifestation of HIV/AIDS and correlation with CD4+ cells count among adult HIV/AIDS patients in Jimma town, Ethiopia: a cross sectional study

BACKGROUND

HIV/AIDS is one of twenty first century's challenges to human being with protean manifestation affecting nearly all organs of our body. It is causing high morbidity and mortality especially in sub-Saharan Africa with numerous ocular complications and blindness. The purpose of this study was to determine the patterns of ocular manifestations of HIV/AIDS and their correlation with CD4+T cells count.

METHODS

A cross-sectional study was done on 348 HIV-positive patients presented to Anti-Retroviral Therapy clinics. Data were collected using face-to-face interview, clinical examination and laboratory investigation, and analyzed using SPSS version 13 software. Statistical association test was done and p<0.05 was considered significant. Other statistical tests like student t-test and logistic regression were also done.

RESULTS

Of 348 patients, 175 were on antiretroviral therapy and 173 were not on therapy. The mean duration of therapy was 27 months. The overall prevalence of ocular manifestations was 25.3%. The commonest ocular manifestation was keratoconjunctivitis sicca (11.3%) followed by blepharitis (3.2%), molluscum contagiosum (2.6%), conjunctival squamous cell carcinoma (2.3%), conjunctival microvasculopathy (2.3%), cranial nerve palsies (2%), herpes zoster ophthalmicus (HZO) (1.2%), and HIV retinopathy (0.6%). HIV retinopathy and conjunctival microvasculopathy were common in patient with CD4+ count of <200 cells/μl while HZO and molluscum contagiosum were common in patients with CD4+ count of 200-499 cells/μl. Prevalence of ocular manifestation was higher among patients on HAART (32.6%) than those patients not on HAART (17.9%) (p<0.05). There was statistically significant association between ocular manifestation and sex, CD4+Tcells count, and age (p<0.05). CD4+ count, <200 cells/μl and age >35 years were independent risk factors for ocular manifestations.

CONCLUSION

The study showed that the prevalence of ocular manifestation of HIV/AIDS is lower than previous studies and could be due to antiretroviral therapy. Lower CD4 count is a risk as well as predictor for ocular manifestations.

Unravelling the Gordian knot: diagnostic dilemma in an HIV-positive patient with neurological involvement

We report a case of a 40-year-old seropositive-HIV patient with a CD4 count of 120 who presented with fever, severe headache and neck stiffness. Suspecting a case of tubercular meningitis (TBM; as tuberculosis is the commonest opportunistic infection in HIV/AIDS patients in India), a lumbar puncture was performed and a cerebrospinal fluid study revealed TBM. The patient was started on combination antitubercular drug therapy from directly observed treatment, short course (DOTS) (Cat 1 regimen) along with pyridoxine 40 mg/day and adjunctive corticosteroid therapy. However, despite adequate antitubercular therapy for 4 weeks, the patient did not show any improvement in his clinical condition. On the contrary, in the process he developed cytomegalovirus (CMV) retinitis. So we question our learned readers if the coinfection of Mycobacterium tuberculosis and CMV should be implicated for the failure to respond to isolated antitubercular therapy contrary to our expectation.

Protein-Loosing Entropathy Induced by Unique Combination of CMV and HP in an Immunocompetent Patient

Protein-losing gastroenteropathies are characterized by an excessive loss of serum proteins into the gastrointestinal tract, resulting in hypoproteinemia (detected as hypoalbuminemia), edema, and, in some cases, pleural and pericardial effusions. Protein-losing gastroenteropathies can be caused by a diverse group of disorders and should be suspected in a patient with hypoproteinemia in whom other causes, such as malnutrition, proteinuria, and impaired liver protein synthesis, have been excluded. In this paper, we present a case of protein-losing enteropathy in a 22-year-old immunocompetent male with a coinfection of CMV and Hp.

CMV retinopathy in the antiretroviral therapy era: prevention, diagnosis, and management

Before the advent of antiretroviral therapy (ART), CMV retinitis was a common, debilitating opportunistic infection in the HIV-infected population. ART has had such a favorable impact on the prevention and management of CMV retinitis that it can be considered in some ways to be CMV therapy. Currently available CMV directed antiviral therapies are quite successful at limiting vision loss, but in resource limited settings there is still significant morbidity associated with the disease. This review summarizes the pathology, diagnosis, clinical course and treatment of retinitis in the pre-ART era to provide context for the contemporary clinical scenario, and highlights current management strategies. Important questions concerning host correlates of susceptibility and ideal therapy in the context of drug resistance are also briefly reviewed.

Ocular manifestations of acquired immunodeficiency syndrome in Korea

The clinical features of HIV/AIDS-related ocular manifestations in Korean patients were investigated in this study. Data on 200 consecutive Korean patients diagnosed with AIDS who visited the Seoul National University Hospital from January 2003 to June 2008 were reviewed. Fifty-seven patients (28.5%) had ocular manifestations, and they showed significantly lower CD4+ T cell count than patients without ocular manifestations. Among them, 23 (40.3%) patients showed retinal microvasculopathy, and 22 (38.5%) patients showed cytomegalovirus (CMV) retinitis. Other manifestations included retinal vein occlusion (n = 4), herpes zoster ophthalmicus (n = 4), syphilitic uveitis (n = 2), acute retinal necrosis (n = 1), and progressive outer retinal necrosis (n = 1). The mean CD4+ lymphocyte counts of the patients with retinal microvasculopathy and cytomegalovirus retinitis were 108.5 cells/µL and 69.4 cells/µL, respectively. In conclusion, ocular manifestations including CMV retinitis are common complications in Korean patients with AIDS even in the era of highly active anti-retroviral therapy. Compared to previous reports in western countries, prevalence of CMV retinitis is relatively low and CD4+ lymphocytes count at the time of diagnosis is relatively high.

Human immunodeficiency virus and its effects on the visual system

During the first 15 years of the AIDS epidemic patients experienced a high incidence of blindness due to cytomegalovirus (CMV) retinitis and other severe ocular opportunistic infections. Highly active anti-retroviral therapy, introduced in 1996, dramatically decreased the incidence of CMV retinitis. Though CMV retinitis still causes 40% of vision loss in AIDS patients, other conditions such as immune reconstitution uveitis, cataracts, and a significant othercategory -which most investigators believe is directly due to HIV - comprise the majority of cases. HIV causes vascular abnormalities of the conjunctiva and retina in the majority of AIDS patients, as well as retinitis, anterior and posterior uveitis and vasculitis. HIV frequently causes an optic neuropathy and is responsible for the majority of eye movement disorders among HIV patients. Physicians need to be aware that these problems may be the initial manifestation of HIV infections or a sign of highly active anti-retroviral therapy (HAART) failure. Therefore, patients with identifiable risk factors for AIDS who present with ophthalmologic conditions of unknown etiology should be considered for HIV testing. Finally, anti-retroviral therapy has been reported to cause asymptomatic deposits as well as degenerative conditions of both the anterior and posterior segments of the eye.

Prevalence and clinical management of cytomegalovirus retinitis in AIDS patients in Shanghai, China

Background

Cytomegalovirus retinitis is a common AIDS-associated illness, leading to blindness in up to 30% of patients. This study was to investigate the prevalence and clinical management of the cytomegalovirus retinitis associated with AIDS in a large municipality of China.

Methods

Clinical and laboratory data from 23 cytomegalovirus retinitis patients (35 eyes) out of 303 hospitalized AIDS individuals in a single medical center were analyzed retrospectively. Two of 23 patients were diagnosed cytomegalovirus retinitis just before hospitalization without anti-CMV therapy. Ganciclovir combined with the high active anti-retroviral therapy was installed for treatment of cytomegalovirus retinitis after diagnosis was confirmed. The data were analyzed by specialists and statistics was also applied.

Results

The prevalence of cytomegalovirus retinitis in hospitalized AIDS patients was 7.6% in this study. The level of CD₄⁺ T lymphocytes was correlated well with the occurrence of cytomegalovirus retinitis, showing 16.8% (19/113) (95% confidence interval: 10.4,25.0), 5.4% (3/56) (95% confidence interval: 1.1,14.9), and 1.4% (1/69) (95% confidence interval: 0.0,7.8) occurrence in the patients with CD₄⁺ T lymphocyte counts < 50, 50~99, and 100~199 cells/μl, respectively. The mean CD₄⁺ T lymphocyte counts was 31.7 ± 38.6 cells/μl in 23 AIDS patients with cytomegalovirus retinitis. Median CD₄⁺ T lymphocyte count is 20 cells/μl with inter-quartile range as (5, 36). Seven patients died (11 eyes) and 16 patients (24 eyes) survived. The proportion of blindness and low vision in eyes infected with cytomegalovirus retinitis respectively was 20.8% (5/24) and 29.2% (7/24) when they were diagnosed in survivors. The ganciclovir therapy was effective in 16 patients (24 eyes). Clinical recovery of cytomegalovirus retinitis was 41.7% (10/24) and clinical improvement 58.3% (14/24). After anti-CMV treatment, the proportion of blindness or low vision was 16.7% (4/24).

Conclusions

The AIDS patients with CD₄⁺ T lymphocyte < 50 cells/μl had increased susceptibility to cytomegalovirus associated retinitis. Cytomegalovirus retinitis is a serious disease causing blindness. The cytomegalovirus retinitis in the AIDS patients was response well to ganciclovir therapy. We should check their eyes routinely such as dilated fundus examination with an indirect ophthalmoscope in the AIDS patients with CD₄⁺ T lymphocyte counts < 50 cells/μl.

Fluocinolone acetonide implant (Retisert) for chronic cystoid macular edema in two patients with AIDS and a history of cytomegalovirus retinitis

PURPOSE

To report the authors' experience using fluocinolone acetonide (Retisert) to treat cystoid macular edema (CME) resulting from immune recovery uveitis (IRU) in 2 acquired immunodeficiency syndrome (AIDS) patients with a history of cytomegalovirus (CMV) retinitis.

DESIGN

Interventional case series.

METHODS

Medical records were reviewed of 2 patients who received Retisert implantation in 3 eyes for IRU-associated inflammation and CME. Suppression of CMV disease was achieved with oral medication in one patient and with simultaneous implantation of a ganciclovir implant in the other patient.

RESULTS

After Retisert implantation in 3 eyes in AIDS patients on HAART, improvement in CME was seen in 2 eyes. No CMV reactivation was detected during the several-month follow-up period.

CONCLUSIONS

Retisert may be an effective treatment for CME in AIDS patients with IRU reactivation and a history of CMV retinitis.

Cytomegalovirus infection causes morbidity and mortality in patients with autoimmune diseases, particularly systemic lupus: in a Chinese population in Taiwan

To investigate the clinical outcome of cytomegalovirus (CMV) infection in febrile hospitalized patients with autoimmune diseases, mostly systemic lupus erythematosus (SLE). Fifty-four febrile patients were analyzed retrospectively. Half were diagnosed as CMV infection, by positive CMV pp65 antigenemia assay. Clinical and laboratory data between two groups were compared. Correlation between laboratory data and SELENA-SLEDAI scores/mortality were analyzed in the CMV infection group. Receiver operating characteristic analysis was performed to determine the cutoff points of different parameters for predicting mortality or morbidity. The CMV infection group received a higher corticosteroid dosage (mean 26.3 mg/day) and a higher percentage of azathioprine use before admission than the non-CMV infection group. In the former, the deceased subgroup had a significantly higher number of infected leukocytes for CMV (shortened as CMV counts, P = 0.013), more cases of bacterial infection (P = 0.090), and a higher SLE disease activity index score (P = 0.072) than the alive subgroup. The CMV infection group had lower lymphocyte count and more positive bacterial infection than the non-CMV infection group did (P = 0.013 and P = 0.027, respectively). A level of 25 CMV particles/5 × 10(5) polymorphonuclear neutrophils (PMN) was the best cutoff point for predicting CMV-associated mortality, with a sensitivity of 75.0% and specificity of 72.2%. Moderate dose (30 mg/day) of prednisolone or azathioprine use predisposes patients with autoimmune diseases to CMV infection with concurrent bacterial infection. In particular, peak CMV counts at 25/5 × 10(5) PMN or low lymphocyte counts predict mortality or morbidity, respectively.

Reactivity of white blood cell flux to hyperoxia in patients infected with human immunodeficiency virus

PURPOSE

The aetiology of the apparently vasoocclusive phenomena in human immunodeficiency virus (HIV)-related retinopathy is not well understood. Several hypotheses, including infectious damage of the retinal vasculature and altered retinal haemodynamics, have been postulated. Direct measurement of oxygen tension in the retina is not possible in vivo and indirect methods have to be employed. The objective of this study was to investigate the retinal vascular response to 100% oxygen breathing in patients with HIV.

METHODS

Twelve patients infected with HIV and 12 healthy individuals, matched for age, sex and smoking habits, were studied in an open study using the blue-field entoptic technique for the measurement of retinal white blood cell (WBC) flux. Reactivity in retinal blood flow during 100% O(2) breathing over 15 min was measured and expressed as percentage change over baseline.

RESULTS

WBC velocity during oxygen inhalation decreased over baseline by 9.0 ± 5.8% in HIV-infected patients and by 18.6 ± 5.4% in healthy participants (p < 0.04 between groups, ANOVA). The decrease in WBC velocity was paralleled by a decrease in WBC density. This decrease tended to be more pronounced in healthy participants (13.6 ± 7.9%) than in HIV-infected patients (8.0 ± 10.8%), but the difference was not statistically significant (p = 0.1 between groups, ANOVA). WBC flux decrease was 16.2 ± 11.4% in HIV-infected patients and 29.5 ± 9.5% in the control group and was significant between groups (p = 0.007 between groups, ANOVA).

CONCLUSION

Our results indicate a reduced reactivity of WBC flux to systemic hyperoxia in patients with HIV. Whether abnormal retinal haemodynamics in HIV-infected persons contributes to the pathogenesis of HIV-related microvascular diseases or is a consequence of the structural changes associated with the disease is unknown.

Pattern recognition can detect subtle field defects in eyes of HIV individuals without retinitis under HAART

Objectives

To use machine learning classifiers (MLCs) to seek differences in visual fields (VFs) between normal eyes and eyes of HIV+ patients; to find the effect of immunodeficiency on VFs and to compare the effectiveness of MLCs to commonly-used Statpac global indices in analyzing standard automated perimetry (SAP).

Methods

The high CD4 group consisted of 70 eyes of 39 HIV-positive patients with good immune status (CD4 counts were never <100/ml). The low CD4 group had 59 eyes of 38 HIV-positive patients with CD4 cell counts <100/ml at some period of time lasting for at least 6 months. The normal group consisted of 61 eyes of 52 HIV-negative individuals. We used a Humphrey Visual Field Analyzer, SAP full threshold program 24-2, and routine settings for evaluating VFs. We trained and tested support vector machine (SVM) machine learning classifiers to distinguish fields from normal subjects and high and CD4 groups separately. Receiver operating characteristic (ROC) curves measured the discrimination of each classifier, and areas under ROC were statistically compared.

Results

Low CD4 HIV patients: with SVM, the AUROC was 0.790 ± 0.042. SVM and MD each significantly differed from chance decision, with p < .00005. High CD4 HIV patients: the SVM AUROC of 0.664 ± 0.047 and MD were each significantly better than chance (p = .041, p = .05 respectively).

Conclusions

Eyes from both low and high CD4 HIV+ patients have VFs defects indicating retinal damage. Generalized learning classifier, SVM, and a Statpac classifier, MD, are effective at detecting HIV eyes that have field defects, even when these defects are subtle.

Structural and functional assessment in HIV-infected patients using optical coherence tomography and frequency-doubling technology perimetry

PURPOSE

To assess retinal nerve fiber layer (RNFL) and macular thickness using optical coherence tomography (OCT) on HIV-infected patients without ocular manifestations and to correlate these findings with frequency-doubling technology perimetry (FDT).

DESIGN

Cross-sectional study.

METHODS

setting: Single center. study population: Seventy-three patients (146 eyes) with clinically normal examination classified in 3 groups: group A, HIV-infected patients with CD4 count <100 cells/mm(3) for at least 6 months; group B, HIV-infected patients with CD4 count >100 cells/mm(3) since diagnosis; and group C, HIV-negative control subjects. observation procedures: Fast RNFL and fast macula scan strategies on Stratus OCT and Humphrey Matrix 24-2 full-threshold program. main outcome measures: OCT RNFL and macular thicknesses and FDT indices (mean deviation [MD], pattern standard deviation [PSD], and glaucoma hemifield test [GHT]).

RESULTS

Group A had a significantly thinner average RNFL, temporal outer macula, and inferior outer macula thicknesses when compared to groups B and C (P < .05). Statistically significant differences were observed in the FDT MD between groups A and C (P = .034) and in PSD in group A compared to groups B and C (P = .011). Eyes of HIV patients with GHT and PSD results outside normal confidence limits had thinner average RNFL thickness measures than eyes with results within normal limits in the same group of patients (P < .05).

CONCLUSIONS

HIV-infected patients with low CD4 count have a significant RNFL and macular thinning. Functional loss detected by FDT is related to RNFL thinning in HIV-infected patients.

Avaliação oftalmológica em pacientes com AIDS e neurotoxoplasmose

INTRODUÇÃO: Descrever os achados fundoscópicos em pacientes com AIDS e neurotoxoplasmose em fase ativa. MÉTODOS: Foi desenvolvido estudo prospectivo tipo série de casos incluindo 70 pacientes, de ambos os sexos, com idade variando de 20 a 63 anos, internados nas enfermarias de três hospitais públicos da Cidade do Recife, Pernambuco, com diagnósticos de AIDS e neurotoxoplasmose firmados segundo os critérios do Centers for Disease Control and Prevention (1992), no período de janeiro a outubro de 2008. Os pacientes se caracterizavam por: primeiro episódio de neurotoxoplasmose (65; 92,9%) ou recidiva (5; 7,1%); desconhecimento de ter AIDS (23; 32,9%), contagem média de linfócitos T CD4 de 139,8 ± 3,04 células/mm3 e carga viral média igual a 137.080 ± 39.380 cópias/mL. Todos foram submetidos a exame oftalmológico, consistindo de: inspeção ocular; aferição da acuidade visual; investigação da função muscular extrínseca ocular e fundoscopia, empregando oftalmoscópio indireto binocular (modelo OHN 3.5 (Eyetec®) e lente externa de 20 dioptrias (Volk®). RESULTADOS: Os achados consistiram em: exsudatos algodonosos retinianos (8,6%), constricção arteriolar difusa leve (8,6%); lesões de retinocoroidite cicatricial, características de toxoplasmose ocular (5,7%), atrofia do epitélio pigmentar retiniano (2,9%), descolamento da retina (2,9%), aumento de escavação papilar (1,4%), degeneração periférica retiniana (1,4%), macroaneurisma (1,4%), papiledema bilateral (1,4%), tração vítreo-retiniana (1,4%). CONCLUSÕES: Pacientes com AIDS e neurotoxoplasmose podem apresentar alterações fundoscópicas características da toxoplasmose ocular, na forma ativa ou cicatricial, relacionadas ao HIV ou, ainda, a outras doenças oportunistas ou sistêmicas, podendo ser de grande auxílio num tratamento integral do paciente por uma equipe multiprofissional.

Imaging of long-term retinal damage after resolved cotton wool spots

PURPOSE

Patients infected with the human immunodeficiency virus (HIV) develop noninfectious retinopathy characterized by retinal cotton wool spots (CWS) and microvascular abnormalities. Ophthalmoscopically, CWS fade with time. We hypothesized that structural changes should be permanent and possibly visible well after ophthalmoscopic resolution. We used simultaneous spectral domain optical coherence tomography (SD-OCT)/scanning laser ophthalmoscope (SLO) to allow colocalization of the lesions and determine the extent and location of residual damage after ophthalmoscopic resolution of the lesions.

DESIGN

Retrospective, noninterventional case series.

PARTICIPANTS

Eight eyes of 7 HIV patients with 19 resolved retinal CWS.

METHODS

Nineteen retinal CWS were imaged between 2 and 16 years (median, 7.84) after the acute lesions using simultaneous SD-OCT and SLO examinations. The areas of the previous CWS were scanned by overlaying the color retinal image over the SLO image and scanning at high resolution in the horizontal plane through the resolved lesion. Each CWS lesion had a control area taken from the same eye within 2 disc diameters of the lesion. The thickness of each of the retinal layers was compared between lesions and control areas using a paired t-test with multitest correction.

MAIN OUTCOME MEASURES

Thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL).

RESULTS

The greatest loss of thickness was seen in the retinal GCL with a 43% reduction in thickness. There was a statistically significant thinning of the RNFL, GCL, IPL, INL, and OPL. The median thickness differences ranged from 5 to 7 microns. This difference was highly significant. Another striking finding was the displacement of the ONL toward the retinal surface resulting in an apparent increase in thickness of the ONL by >15% (median difference, 12 microns).

CONCLUSIONS

Our data, using ultrahigh resolution and high-speed SD-OCT/SLO, show and quantify the presence of permanent retinal destruction associated with retinal CWS in HIV disease.

Multifocal electroretinography in HIV-positive patients without infectious retinitis

PURPOSE

To evaluate early changes in the central retinal response in human immunodeficiency virus (HIV)-positive patients without infectious retinitis using multifocal electroretinography (mfERG).

DESIGN

Case control study.

METHODS

We evaluated three cohorts: HIV-negative controls and two groups of HIV-positive patients separated according to their nadir CD4 counts (>or= 100 cells/mm(3) and < 100 cells/mm(3) for a minimum of six months). mfERG first-order kernels (FOKs) and second-order kernels (SOKs) were analyzed separately by areas of rings, quadrants, and individual hexagons for each cohort.

RESULTS

Of 103 hexagon locations of FOK results, there were no significant differences in amplitudes of P1 and N1 across the groups (.05 < P < .50), although there was a trend for an overall reduction in the amplitudes. Similarly, latency N1 did not differ (.28 < P < .95). There were significantly delayed latencies of P1 between cohorts across 103 hexagons in both kernels. SOK results also showed significant delay in latencies of P1 and a trend of reduced P1 amplitudes across studied locations among cohorts (.24 < P < .08).

CONCLUSIONS

The results demonstrate widespread delay in latency in HIV-positive patients, especially in those with prolonged low (below 100 cells/mm(3)) CD4 nadir counts. These findings suggest early diffuse dysfunction of the inner retina results from severe HIV disease even in the HAART era.

Intraocular inflammation: its causes and investigations

Intraocular inflammation, or uveitis, incorporates a diverse group of infectious and immune-mediated disorders. In addition, some conditions masquerade as uveitis. However, classifying uveitis according to anatomic location in adult and pediatric populations, and appreciating the effect of immune status and regional differences, refines the list of potential causes. In this way, a select few investigations can be performed, rather than a nondirected battery of tests.

Murine cytomegalovirus infection and apoptosis in organotypic retinal cultures

PURPOSE

An organotypic retinal culture model was used to determine the pattern of murine cytomegalovirus (MCMV) infection and whether apoptosis is induced in MCMV-infected cultured retinas.

METHODS

Retinas harvested from C57BL/6 mice were individually cultured at 37 degrees C on 3-microm filter inserts placed in 24-well plates. Some retinas were infected with MCMV (5 x 10(5) PFU/well). At days 4, 7, and 11 after infection (pi), the culture medium and cultured retinas were collected for examination.

RESULTS

Replicating virus was recovered and viral early antigen (EA)- and late antigen (LA)-positive cells were observed in the MCMV-infected retinal cultures. Most MCMV-infected cells were glia and horizontal cells. Infection resulted in atrophy of the photoreceptor cells and cytomegaly. Apoptosis of uninfected bystander cells, including photoreceptor cells and horizontal cells, was observed. TNF-alpha was produced by activated microglia during MCMV infection of the retina. Mouse apoptosis microarray studies, caspase activity studies, and RT-PCR studies showed that the genes involved in both the death receptor-mediated apoptotic pathway and the mitochondrial pathway were upregulated.

CONCLUSIONS

Many aspects of MCMV infection of retinal cultures parallel those observed during MCMV retinitis in mice. Thus, this in vitro system may be used to explore the role of apoptosis of uninfected retinal cells and the contribution of cytokines and other modulators to the pathogenesis of CMV retinitis.

Human Eye Infections

The eye contains a variety of cell and tissue types. Conjunctivitis due to respiratory RNA viruses represents by far the most common viral eye disorder. However, any ocular tissue can sustain infection by human viruses, including those viruses with predilection for neural sites. As elsewhere in the body, ocular pathologic changes induced by viruses tend to follow stereotypical patterns. Classical viral mechanisms of infection, including latency, reactivation, and carcinogenesis, can all be demonstrated in the eye. The eye's tissues also demonstrate a wide variety of immune responses, including those of mucosa-associated lymphoid tissue and immune privilege. The ocular complications of AIDS, including viral retinitis and ocular surface squamous carcinoma, remain significant causes of morbidity throughout the world.

Intraocular Properties of An Alkoxyalkyl Derivative of Cyclic 9-(S)-(3-Hydroxyl-2-Phosphonomehoxypropyl) Adenine, An Intravitreally Injectable Anti-HCMV Drug in Rabbit and Guinea Pig

PURPOSE

The aim of this study was to investigate intraocular properties and determine the highest nontoxic dose of hexadecyloxypropyl-cyclic-HPMPA (HDP-cHPMPA), a novel, potent, intravitreally injectable, slow-releasing crystalline drug for long-acting treatment of cytomegalovirus (CMV) retinitis.

METHODS

Various concentrations of HDP-cHPMPA were first studied in vitro in a human foreskin fibroblast (HFF) cell line infected with human cytomegalovirus (HCMV) to determine the EC50. In vivo, 9 pigmented rabbits and 3 doses (55, 100, and 550 microg/eye) were tested in triplicate in 1 eye of each animal. The eyes were monitored with slit lamp, tonopen, indirect ophthalmoscopy, electroretinography (ERG), and histology. A confirmation toxicity study with the dose equivalent to the highest nontoxic dose in rabbit was performed in 9 guinea pig eyes (a second species) to study the potential adverse effect on intraocular pressure (IOP).

RESULTS

In vitro testing in HFF cells showed an EC50 against HCMV of 0.02 microM, which is 75- and 60-fold greater than that of ganciclovir and cidofovir, respectively. All eyes injected with 550 microg/eye and 1 eye injected with 100 microg/eye of HDP-cHPMPA showed toxicity clinically (e.g., vitreous cells, disc edema, and retinal inflammation) as well as histologically (e.g., inflammatory cells in iris, vitreous, and retinal layers with disorganization). None of the eyes injected with 55 microg/eye of HDP-cHPMPA showed toxicity clinically (including ERG) and histologically. The equivalent dose (9.2 microg/eye) in the guinea pig eyes did not show toxicity either, including IOP evaluation (P > 0.05 at all time points after injection).

CONCLUSIONS

Intravitreal injection of the highest nontoxic dose of 55 microg/eye of HDP-cHPMPA in rabbit eyes yields a calculated intravitreal concentration of 65 microM, which is 3250-fold greater than the EC50 against HCMV (0.02 microM). Also, it does not cause hypotony in rabbit and guinea pig eyes and has a vitreous residence time of over 4 months.

Withdrawal of maintenance therapy for cytomegalovirus retinitis in AIDS patients exhibiting immunological response to HAART

BACKGROUND: Before the introduction of highly active antiretroviral therapy (HAART), CMV retinitis was a common complication in patients with advanced HIV disease and the therapy was well established; it consisted of an induction phase to control the infection with ganciclovir, followed by a lifelong maintenance phase to avoid or delay relapses. METHODS: To determine the safety of CMV maintenance therapy withdrawal in patients with immune recovery after HAART, 35 patients with treated CMV retinitis, on maintenance therapy, with CD4+ cell count greater than 100 cells/mm³ for at least three months, but almost all patients presented these values for more than six months and viral load < 30000 copies/mL, were prospectively evaluated for the recurrence of CMV disease. Maintenance therapy was withdrawal at inclusion, and patients were monitored for at least 48 weeks by clinical and ophthalmologic evaluations, and by determination of CMV viremia markers (antigenemia-pp65), CD4+/CD8+ counts and plasma HIV RNA levels. Lymphoproliferative assays were performed on 26/35 patients. RESULTS: From 35 patients included, only one had confirmed reactivation of CMV retinitis, at day 120 of follow-up. No patient returned positive antigenemia tests. No correlation between lymphoproliferative assays and CD4+ counts was observed. CONCLUSION: CMV retinitis maintenance therapy discontinuation is safe for those patients with quantitative immune recovery after HAART.

Blindness and low vision in a tertiary ophthalmologic center in Thailand: the importance of cytomegalovirus retinitis

PURPOSE

To determine the causes of blindness and low vision in patients consulting a tertiary ophthalmologic center in northern Thailand.

METHODS

The study population included 2,951 new consecutive patients from the Department of Ophthalmology at University Hospital in Chiang-Mai, Thailand. Main outcome measures were blindness and low vision, which were defined according to World Health Organization criteria.

RESULTS

Of 2,951 patients, 369 (12.5%) had blindness and/or low vision (bilateral blindness in 73, unilateral blindness in 129, bilateral low vision in 77, and unilateral low vision in 90). Of the etiological causes of visual loss, age-related ocular disease was the most frequent (128 patients [35%]) followed by infections (66 patients [18%]) and trauma (43 patients [12%]). Although infections and trauma were the predominant causes of blindness, age-related disorders were frequently found in patients with low vision. Of anatomical sites, the lens (134 patients [36%]) was the main location of visual loss, closely followed by disorders of the retina and/or uvea (126 patients [34%]). Blindness and low vision were considered avoidable in 70% of cases. Of 73 patients with bilateral blindness, 14 had active cytomegalovirus retinitis, accounting for 19% of all patients with bilateral blindness.

CONCLUSION

The most common causes of blindness and low vision in a tertiary center in northern Thailand were age-related ocular disorders and infections, which were predominantly cases of cytomegalovirus retinitis in human immunodeficiency virus-infected patients.

Effect of highly active antiretroviral therapy (HAART) on the natural history of ocular manifestations in HIV-infected children

PURPOSE

To determine the effect of highly active antiretroviral therapy (HAART) on the natural history of ocular manifestations in HIV-infected children.

METHODS

All of the HIV-infected children attending the Institute of Pediatrics, University of Milan, Milan, Italy, between 1982 and 2004 were studied. Every 3 months, they were physically examined and underwent indirect fundoscopy conducted by an experienced ophthalmologist; if diagnosed as having eye disease, they were evaluated by the ophthalmologist every week while on specific therapy and monthly thereafter. The clinical and laboratory findings before and after the introduction of HAART were compared.

RESULTS

The cohort consisted of 117 HIV-infected children (61 males), with a follow-up ranging from 0.09 to 22.31 years (median, 16.33 years). A total of nine cases of ocular involvement (7.7%) were diagnosed between 1983 and 1994, before the introduction of HAART. All nine children died 4-24 months (median, 15 months) after the diagnosis of ophthalmic disease. No case of ocular involvement was observed after the introduction of HAART (P=0.011 vs. before HAART).

CONCLUSION

The introduction of HAART has had a significant impact on the natural history of ocular manifestations in HIV-infected children, thus suggesting that a reduction in the frequency of ophthalmologic follow-up should be considered for HAART-treated HIV-infected children with immune reconstitution and no visual symptom.

Therapy Insight: CNS manifestations of HIV-associated immune reconstitution inflammatory syndrome

The introduction of combination antiretroviral therapy for HIV infection has prolonged the lives of patients with AIDS. It is increasingly being recognized, however, that following initiation of this therapy some patients can develop a paradoxical neurological deterioration, despite dramatic improvements in HIV viral load and CD4+ T-cell counts. This immune reconstitution inflammatory syndrome (IRIS) in the CNS is emerging as an important neurological complication, particularly as antiretroviral therapy is now becoming readily available worldwide. Currently, there are no guidelines for prevention, diagnosis or treatment of the CNS manifestations of IRIS. Even in patients with an acute presentation, the diagnosis can be challenging. Furthermore, it is possible that more-chronic forms of the syndrome exist but remain unrecognized. Here, we review the various clinical presentations of CNS IRIS, and discuss options for their management.

Discovery of a novel series of inhibitors of human cytomegalovirus primase

Infection by human cytomegalovirus (hCMV) remains a potent threat to susceptible people throughout the world. We have discovered a series of imidazolyl-pyrimidine compounds, which were found to be irreversible inhibitors of the hCMV UL70 primase based on results from radiolabeling and SAR studies. Two promising analogs are described that rival ganciclovir and cidofovir in antiviral potency and possess improved cytotoxicity profiles.

Immune reconstitution inflammatory syndrome in HIV

PURPOSE OF REVIEW

The purpose of this review is to describe the epidemiology, clinical features, putative immune mechanisms and management of immune reconstitution inflammatory syndrome (IRIS) using data published in the last 2 years.

RECENT FINDINGS

Ever more conditions are reported as IRIS events. These most frequently occur with mycobacterial (tuberculosis or Mycobacterium avium complex infection) or cryptococcal disease (each in approximately 30% of cases). Definitions have been proposed for its clinical diagnosis. These suffer from a lack of prospective studies to support their predictive value. The immunopathogenesis of IRIS appears to be related to the interaction between HAART-induced changes in host immune response and the presence of (usually microbial) antigen. Increasing evidence exists that this might be an anatomically compartmentalized phenomenon, such that immune responses may be localized to specific tissue sites such as the brain. This has implications for the use of simple blood tests, such as CD4 count or change in viral load, when assessing risk of IRIS. Treatment options include immune modulation, though supportive care is typically all that is required, unless symptoms are prolonged, significant or life-threatening.

SUMMARY

IRIS is common and will become more so as HAART is rolled out worldwide. Clear clinical definitions are required to avoid its over-diagnosis due to misclassification of other conditions.

Long-term Study of Intraocular Pressure Changes in Patients with Human Immunodeficiency Virus Treated with Highly Active Antiretroviral Therapy

PURPOSE

To characterize a longitudinal relationship between highly active antiretroviral therapy immune recovery as defined by an increase in CD4 cell counts and any associated changes in intraocular pressure (IOP) in both patients with and patients without a history of cytomegalovirus (CMV) retinitis and to determine if human immunodeficiency (HIV)-induced reduction in IOP is reversible.

DESIGN

Retrospective analysis of patient data collected from 1997 through 2004.

PARTICIPANTS

Cohort of patients from one eye center, including patients from the Longitudinal Study of Ocular Complications of Acquired Immunodeficiency Syndrome.

METHODS

Linear regression analyses were conducted within the CMV and non-CMV groups to determine the change in IOP per 100-unit change in CD4 count. Average changes in IOP per change in CD4 count were compared between the CMV and the non-CMV groups using a Wilcoxon rank-sum test. Linear regression analyses were conducted within the CMV and non-CMV groups to determine the linear relationship between the 12-month change in IOP per 12-month 100-unit change in CD4 count.

MAIN OUTCOME MEASURE

Intraocular pressure in relation to changes in CD4 cell counts.

RESULTS

Compared with the non-CMV group, the median IOP change per change in CD4 count was not statistically different from the CMV group (0.9 vs. 1.7 mmHg/100 CD4 cells, respectively; P = 0.20). Analysis of the linear relationship between the 12-month change in IOP and the 12-month change in CD4 count within both the CMV and non-CMV groups showed a strong linear relationship: 67% of the variability in a 12-month IOP change for the CMV group (P<0.0001) and 36% of the variability in a 12-month IOP change for the non-CMV group (P<0.001).

CONCLUSIONS

Reduction in T-lymphocyte count in HIV infection is accompanied by a decrease in IOP in both CMV-infected and non-CMV-infected eyes, and immune recovery is associated with an increase in IOP.