Primary conjunctival herpetic geographic ulcer in an immunocompetent patient.

Herpes simplex virus ocular infections have been recognized as a major cause of corneal blindness in the developed world. The major signs of a primary infection are limited to the lids, conjunctiva, and cornea. Presence of a conjunctival dendrite without corneal involvement has been reported. Although conjunctival ulceration has been associated with recurrent attacks, it has not been documented as a manifestation of primary herpetic infection. We report a case of primary herpetic infection with geographic conjunctival ulcer with multiple corneal dendrites.

Primary conjunctival herpetic geographic ulcer in an immunocompetent patient.

Herpes simplex virus ocular infections are a major cause of corneal blindness in the developed world. Signs of a primary infection are limited to the lids, conjunctiva and cornea. The presence of a conjunctival dendrite without corneal involvement has been reported. Although conjunctival ulceration has been associated with recurrent attacks, it has not been documented as a manifestation of primary herpetic infection. We report a case of primary herpetic infection with geographic conjunctival ulcer with multiple corneal dendrites.

[The pathogenesis of herpetic keratitis]. / Zur Pathogenese der herpetischen Keratitis.

BACKGROUND: Viral infections of Herpes origin are the most commonly encountered ones in man. The most important member of this family is the Herpes simplex virus (HSV), two varieties of which are known to exist: HSV-1 affects predominantly the upper half of the body, whereas HSV-2 is associated mainly with diseases of the urogenital tract. In the immunocompetent host, viral replication is usually confined to cutaneous and mucocutaneous sites, invasion of subcutaneous tissues being impeded by an early onset of non-specific defence mechanisms. These are rapidly complemented by the specific, mainly cellular, immune response. PATIENTS: Epithelial dendritic keratitis is the first symptomatic clinical finding, and after several recurrences, the corneal stroma may become involved. This condition of herpetic stromal keratitis (HSK), which, in contrast to the epithelial one, is believed to be directed by a predominantly immunopathological process, is one of the leading causes of infectious blindness in developed countries. RESULTS: The mechanisms underlying HSK, and the establishment of viral latency and reactivation are poorly understood. But on the basis of studies with mice as well as clinical immunohistological observations, evidence is now accumulating in support of a cell-mediated mechanism being responsible for corneal destruction. CONCLUSION: Our present knowledge of the pathogenesis of herpetic keratitis is incomplete. The different pathophysiological aspects reflecting our current understanding, such as that of a virally induced autoimmune disease, form the basis of accepted clinical treatment concepts.

1,25-Dihydroxyvitamin D3 prolongs graft survival without compromising host resistance to infection or bone mineral density.

BACKGROUND: Recently, we have shown that 1,25-dihydroxyvitamin D3 prolongs graft survival in mice and rats when the donor and recipient differ at two or more major histocompatability loci. Among the most serious side effects encountered with the currently available transplantation antirejection drugs are an increased susceptibility to infection and decreased bone mineralization. Our results suggest that 1,25-dihydroxyvitamin D3 prolongs graft survival without these side effects of bone loss and susceptibility to infection. METHODS: We compared the ability of 1,25-dihydroxyvitamin D3-treated, nontreated, or cyclosporine (CsA)-treated mice to resist infection with Candida albicans and herpes simplex virus-1. To determine bone density, femurs were collected from nontreated, 1,25-dihydroxyvitamin D3-treated (50 ng/mouse/day), or CsA-treated (25 mg/kg/day) mice, and bone ash was determined. RESULTS: Here we show that 1,25-dihydroxyvitamin D3 treatment does not increase the susceptibility of the host to fungal or viral infection. Furthermore, CsA causes bone loss, whereas 1,25-dihydroxyvitamin D3 actually increases bone mass. CONCLUSIONS: The use of 1,25-dihydroxyvitamin D3 and its analogs to increase transplant survival will avoid bone loss and opportunistic infection, two important disadvantages of the most widely used transplant antirejection drugs--CsA and the glucocorticoids.

A therapeutic vaccine that reduces recurrent herpes simplex virus type 1 corneal disease.

PURPOSE: To investigate the therapeutic efficacy of periocular vaccination with herpes simplex virus (HSV) recombinant glycoprotein D from HSV-1 (gD1) or HSV-2 (gD2) in decreasing HSV-induced recurrent dendritic keratitis and HSV-induced recurrent ocular shedding in rabbits latently infected with HSV-1. METHODS: Rabbits latently infected with HSV-1 were vaccinated periocularly (by subconjunctival injection) with gD1 and adjuvant, gD2 and adjuvant, or adjuvant alone. Eyes were examined daily for 49 days for recurrent herpetic keratitis and for recurrent infectious HSV-1 shedding. RESULTS: In both vaccinated groups, a significantly decreased number of eyes exhibited recurrences of herpetic keratitis compared with recurrences in adjuvant-treated control eyes (gD1 group, 27/1372, [2%]; gD2 group, 24/1274, [2%]; and control, 54/1274 [4%]; P < 0.005). Eyes in the gD1-vaccinated group (44/1308 [3.4%]; P = 0.01), but not those in the gD2-vaccinated group (71/1274 [5.6%]; P = 0.93), had significantly decreased viral shedding (positive cultures compared with total cultures) compared with eyes in the adjuvant-treated control group (69 of 1275 [5.4%]). CONCLUSIONS: Recurrent HSV-1 corneal disease was significantly reduced by therapeutic local periocular vaccination. The vaccine may be more efficacious against HSV-1-induced recurrent corneal disease than against recurrent HSV-1 ocular shedding. Its efficacy against corneal disease appeared to be longer lasting than its efficacy against recurrent spontaneous shedding. The heterotypic gD2 vaccine was as efficacious as the homotypic gD1 vaccine against recurrent corneal disease, whereas the homotypic vaccine was much more efficacious than the heterotypic vaccine against recurrent HSV-1 shedding. This is the first report in any animal model of a successful therapeutic vaccine against recurrent HSV-1-induced corneal disease. These results support the concept that development of a therapeutic vaccine for ocular HSV-1 recurrence in humans may be possible.

Activation of NK cells in mice following corneal infection with herpes simplex virus type-1.

Natural killer (NK) cells are large granular lymphocytes that mediate antigen nonspecific, non-major histocompatibility complex (MHC) restricted lysis of virus infected cells. They are thought to play a role in innate resistance to herpes simplex virus (HSV) infections. In most animal studies reported to date, the virus was injected intraperitoneally, not a natural route of infection. Using a murine model of acute HSV-1 ocular infection, we demonstrate that increased splenic NK activity is induced in BALB/c mice following corneal infection with four different strains of HSV-1. The kinetics of NK cell activation depended on the strain of virus and was associated with virulence of the strain and with the ability of the viruses to grow in vivo. We also assessed the role of interferon-alpha/beta, IFN-gamma, and interleukin-2 (IL-2) in the HSV-1 induced NK cell activation by treating mice with antisera against these lymphokines prior to infection. Treatment with anti-IFN-alpha/beta or anti-IFN-gamma significantly reduced NK cell cytotoxicity, suggesting that these lymphokines were involved in the activation of NK cells following HSV-1 ocular infection. Treatment with anti-IL-2 resulted in increased NK cell activity, suggesting that in vivo, IL-2 is involved in the suppression of NK cell activity in infected mice. Treatment with a combination of anti-IL-2 and anti-IFN also increased NK cytotoxicity. Despite the induction of high levels of NK activity, mice developed severe ocular disease or died of encephalitis.

Endogenously produced interferon alpha protects mice from herpes simplex virus type 1 corneal disease.

Intravenous (i.v.) injection of u.v. light-inactivated herpes simplex virus type 1 (UV HSV-1) at the time of HSV-1 corneal infection reduced the cytotoxic T lymphocyte (CTL) response to HSV-1, and significantly reduced the incidence of HSV-1-induced corneal stromal disease in A/J mice. The spread of HSV-1 through the eye after corneal infection, detected using engineered HSV-1 (US3::Tn5-lacZ) with the lacZ gene under the transcriptional control of the viral late gene promoter for glycoprotein C, was also markedly reduced by i.v. UV HSV-1 injection. The restriction of HSV-1 corneal invasiveness in i.v. UV HSV-1-injected mice preceded the onset of a detectable specific cell-mediated or humoral immune response to HSV-1, and was accompanied by an elevated serum titre of interferon (IFN-alpha), reversed by anti-IFN-alpha/beta antibody, and mimicked by systemic IFN-alpha treatment. IFN-alpha-treated mice developed a normal CTL response to HSV-1 after corneal infection, but the corneal invasiveness of the virus was markedly reduced and none of the treated mice developed corneal stromal disease. Together with our previous findings that HSV-1-specific CTLs participate in the pathogenesis of corneal stromal disease, these results indicate that i.v. injection of UV HSV-1 at the time of corneal infection may prevent stromal disease by the combined effects of IFN-mediated reduction of the spread of virus in the cornea and inhibition of the activity of the HSV-specific T lymphocytes that induce tissue destruction in the corneal stroma.

[Recurrent herpetic keratitis in mice].

In order to investigate the mechanism of recurrence in herpes simplex keratitis, it is very important to establish an animal model. As a first step, mice were examined with the slit-lamp biomicroscope to determine whether they spontaneously showed recurrent epithelial keratitis after healing of primary herpetic keratitis. Among 90 eyes of 45 inbred C57BL/6 mice, recurrent epithelial keratitis stained with fluorescein was observed in 10 eyes of 9 mice during the observation period up to 50 days after the primary corneal infection with herpes simplex virus (HSV) type I Amakata strain (virulent strain). Recurrent epithelial keratitis was observed in 17 eyes of 15 mice among 116 eyes of 58 ddy mice infected with HSV-I Ska strain (avirulent strain). The epithelial lesions showed punctate or dendritic patterns and continued for one to 7 days. HSV antigen was detected by the fluorescent antibody technique in the cornea of 5 out of 8 eyes which showed recurrent epithelial keratitis using another ddy mice group tested. It was limited in the epithelium of the cornea. These results show that mice herpetic keratitis recurs spontaneously.

[Immunity status in patients with injuries and diseases of the cornea]. / Sostoianie immuniteta u bol'nykh s travmami i zabolevaniiami rogovitsy.

Clinical and immunologic examinations of 97 patients with leukoma after corneal injuries and diseases have shown that immunity disorders are present in leukoma of whatever origin. The authors claim that preoperative treatment of the patients before keratoplasty should include study of the background immunologic tests, the most informative of these being the leukocyte migration inhibition test with the corneal antigen.

Recurrent herpes simplex keratitis with concurrent epithelial and stromal involvement. Immunohistochemical and ultrastructural observations.

A 65-year-old man with recurrent herpetic keratitis underwent corneal transplantation for persistent nonimmunologic graft failure. Histopathologic examination of the corneal button revealed an epithelial dendrite containing Cowdry type A inclusion bodies, moderate stromal edema, and a retrocorneal fibrous membrane. Immunohistochemical studies demonstrated herpes simplex virus antigens in epithelial cells bordering the dendritic defect and in stromal keratocytes. The mean width of corneal epithelium displaying herpes simplex virus-positive epithelial cells on either side of the dendritic defect measured 200 +/- 46 microns. By electron microscopy, herpesvirus particles were identified in epithelial cells lining the dendrite as well as in stromal keratocytes. Infected keratocytes were scattered throughout the stroma but were not observed subjacent to the epithelial dendrite. This study demonstrates that a recurrent epithelial dendrite can be associated with subclinical stromal infection of the graft.

Ocular herpes simplex virus reactivation in mice latently infected with latency-associated transcript mutants.

A mouse model for ocular reactivation of herpes simplex virus type 1 (HSV-1) was modified and used to study the effect of strain difference on the frequency of ocular HSV reactivation. Outbred male NIH white mice were immunized with 1.0 ml of anti-HSV serum with a neutralizing titer of 1:400 24 hr before infection and bilaterally infected at 10(5) plaque-forming units/eye with one of three HSV-1 strains: 17 Syn+, LAT+ (XC-20), or LAT- (X10-13). Latency-associated transcripts (LAT) are produced by strain 17 Syn+ and LAT+ but not by LAT-. The primary infection was monitored by ocular swabbing for HSV. Reactivation was induced by intravenous (i.v.) injection of cyclophosphamide (5 mg) followed 24 hr later by i.v. dexamethasone (0.2 mg). These drugs significantly reduced the white cell count between 0 and 6 days post-administration. The eyes were swabbed for 7 consecutive days to monitor reactivation, and HSV-1 reactivation was induced at the following frequencies in individual eyes: 17 Syn+ (32.5%), LAT+ (18.5%), and LAT- (2.5%) (P less than or equal to 0.002). Co-culture of trigeminal ganglia was done, and random isolates were checked to ascertain their identity. The HSV was recovered from individual trigeminal ganglia at the following frequencies: 17 Syn+ (83%), LAT+ (100%), and LAT- (67%) (P less than or equal to 0.091). These results confirm that the mouse can be used as a reactivation model for ocular HSV infection and that the presence of LAT facilitates reactivation in vivo in the mouse.

[An investigation of HSV-1 antigen in human corneas with recurrent HSK].

The authors first report in China the detection of HSV-1 antigen in 36 human corneas with recurrent HSK, using the horse radish peroxidase staining technique. The results were that in 16 eyes of quiescent HSK, the HSV antigen was negative, and in 11 of 20 corneas with active HSK, the HSV antigen was positive. When 5 corneas with quiescent HSK were cultured in vitro, 3 again became HSV antigen positive. The findings may be useful in the treatment of HSK.

Herpes simplex keratitis: role of viral infection versus immune response.

The cumulative clinical and experimental data regarding the role of viral infection versus the immune response in the pathogenesis of herpes simplex stromal keratitis and central disciform endotheliitis are discussed. Ultrastructural and viral isolation studies have been performed in only a limited number of cases of human stromal keratitis and disciform endotheliitis. Virus has been isolated from the minority of corneas cultured, whereas viral particles have been demonstrated in selected cases of stromal keratitis, most of which had been treated with steroids at some point in time. The possibility of corneal latency in cases of quiescent herpetic stromal keratitis will require further systematic study. Review of the experimental and clinical findings suggests a dialectical role of the immune response in limiting viral infection, while contributing to corneal opacification and scar formation.

Mechanisms of protection against herpes simplex virus type 1-induced retinal necrosis by in vitro-activated T lymphocytes.

In BALB/c mice, acute retinal necrosis occurs in the uninoculated eye 8 to 10 days following uniocular anterior chamber inoculation of the KOS strain of herpes simplex virus type 1 (HSV-1). Retinitis in the uninjected eye can be prevented if HSV-1-specific immune effector cells that have been restimulated with virus in vitro are administered intravenously within 1 day of anterior chamber inoculation of virus. We explored further the mechanism of protection afforded by these activated immune effector cells. The results of our studies revealed that optimal protection from retinitis required in vitro restimulation, since infusion of 50 x 10(6) HSV-1-primed but nonrestimulated cells could not protect as well as 10 x 10(6) activated cells. Analysis of both restimulated and nonrestimulated cells showed that only in vitro-restimulated cells were cytotoxic to HSV-1-infected syngeneic target cells. From these studies, we concluded that the ability to kill virus-infected target cells contributed to optimal protection achieved by intravenous administration of activated immune effector cells. Furthermore, T-cell subset depletion of activated immune effector cells demonstrated that both L3T4+ and Lyt-2+ T cells in the transfer inoculum contributed to protection. Additional studies revealed that although the transferred immune effector cells reached the injected eye within 24 h, virus replication in the injected eye was not affected. In the uninjected eye, virus titers were low, consistent with protection of this eye from retinitis. Taken together, the virus recovery results suggest that the interaction of virus with intravenously administered HSV-1-specific immune effector cells which limits virus spread and/or replication of virus probably occurred within the central nervous system and prevented the second wave of virus from entering the uninoculated eye.

An analysis of the subpopulations in draining lymph node cells and MHC antigen induction in murine herpetic keratitis.

The protective role of T cell subsets in corneal herpes simplex virus type 1 (HSV-1) infection has been studied. However, the relative contribution of, and the role played by, each particular T cell subset still remain a controversial issue. We studied sequentially the appearance of major histocompatibility (MHC) and viral antigens in HSV-1 infected corneas of Balb/C mice and related them to induction of T cell subsets in local lymph nodes and corneal lesions. Immunohistochemical study has revealed a marked increase of expression of class II MHC antigen in the corneal stromal cells, while class I MHC antigen gradually increased in the corneal epithelium and stroma. Further immunohistochemical survey has revealed that L3T4 antigen bearing and Lyt 2 antigen bearing cells were induced to a similar extent with an equal rapidity in the local lymph nodes as well as in the corneal stroma. Transfer of these subpopulations to syngeneic nude mice showed that they played a role to prevent severe outcome of corneal herpetic infection. These results indicate that the corneal stroma is a major site of the host's immunological activities and both L3T4 and Lyt 2 bearing cells are equally important for the prevention of corneal herpetic infection.

HSV antigens and HSV DNA in avascular and vascularized lesions of human herpes simplex keratitis.

Fifty-one corneal buttons obtained by penetrating keratoplasty from patients with a preoperative clinical diagnosis of nonulcerative herpetic keratitis and/or disciform stromal scarring (44) as well as ulcerative necrotizing stromal keratitis (7) were processed for herpes simplex virus (HSV) antigens using an immunoperoxidase technique and for HSV DNA by the polymerase chain reaction (PCR). HSV antigens were detected significantly more often (p less than 0.025) in specimens with avascular nonulcerative keratitis than in those with vascularization. In contrast to HSV antigens, HSV DNA was identified at equal proportions in avascular and vascularized lesions. Both HSV antigens and HSV DNA were detected in all specimens from patients with ulcerative necrotizing stromal keratitis. The implications of these findings with regard to possible mechanisms underlying herpetic keratitis in man are discussed.

Herpetic stromal keratitis in mice: less reversibility in the presence of Langerhans cells in the central cornea.

Infection on the snout with HSV-1 in mice with normal corneas produced a mild ocular disease, characterized by a zosteriform skin lesion around the eye, enlargement of the pupil, hyperemia of the iris and, sporadically, transient keratitis. By contrast, snout infection after prior cauterization of the cornea induced significantly more frequent and more severe corneal disease, in which keratitis was usually permanent. Corneal cauterization also produced increased numbers of Langerhans cells in the central cornea. We speculate that the combination of virus and increased numbers of Langerhans cells within the cornea may lead to an exaggerated ocular immune response that is destructive to the cornea.

External ocular herpesvirus infections in immunodeficiency.

Infections of the eye with members of the herpes family of viruses (e.g. HSV, CMV, VZV) are frequent manifestations of acquired and inherited defects in cell mediated immunity. Herpesvirus infections in the immunocompromised may reflect frequent viral reactivation from the latent state, as well as extensive productive infection of ocular structures following reactivation or primary infection. A review of experimental and clinical studies of both acquired and inherited immune dysfunction implicates specific immune mechanisms influencing the establishment of latency, viral reactivation and the control of active viral replication in ocular tissues.