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Biomedical subjects

M B Raizman

Publications and source records attributed to M B Raizman.

At least 37 records · Page 2Linked to original sources

Dapsone-induced neutropenia in patients treated for ocular cicatricial pemphigoid.

BACKGROUND: Dapsone is used widely in treating ocular cicatricial pemphigoid, leprosy, and dermatologic disorders. Hemolysis is a well-known complication of dapsone therapy. Rarely, neutropenia or agranulocytosis may occur, resulting in up to a 50% mortality rate. To the authors' knowledge, agranulocytosis has not been reported in patients treated with dapsone for ocular cicatricial pemphigoid. METHODS: The authors report two cases of dapsone-induced neutropenia with bone marrow suppression in patients with ocular cicatricial pemphigoid. RESULTS: Neutropenia was detected on routine laboratory examination 8 and 10 weeks after initiating dapsone therapy. Bone marrow biopsy showed acellular or hypocellular marrow. Leukocyte count returned to baseline value after cessation of dapsone. CONCLUSION: Patients with ocular cicatricial pemphigoid who were treated with dapsone are at increased risk for agranulocytosis. Dapsone-induced neutropenia may not be a dose-dependent phenomenon. The authors indicate that there is a need for routine monitoring of leukocyte counts, especially 8 to 10 weeks after initiating therapy. Signs or symptoms of infection require immediate investigation.

Aged↗

Intracellular degradation of Fc gamma RIII in mouse bone marrow culture-derived progenitor mast cells prevents its surface expression and associated function.

Although mouse interleukin-3-dependent, bone marrow culture-derived progenitor mast cells (BMMC) and a Kirsten sarcoma virus (KiSV)-immortalized mouse mast cell line (MC4w) both express on their surfaces receptors for the Fc portion of IgG (Fc gamma R), only MC4w degranulate upon Fc gamma R perturbation. As shown by surface iodination and SDS-polyacrylamide gel electrophoresis analysis of deglycosylated proteins immunoprecipitated with the Fc gamma R-specific monoclonal antibody 2.4G2, a 26-kDa protein, identified as Fc gamma RIII by immunoblotting with antibody to Fc gamma RIII, was predominantly expressed on the surface of MC4w but minimally on BMMC. However, both BMMC and MC4w expressed mRNA for Fc gamma RIII as determined by RNA blot analysis, and both translated Fc gamma RIII as assessed by intrinsic radiolabeling and SDS-polyacrylamide gel electrophoresis analysis of deglycosylated monoclonal antibody 2.4G2 immunoprecipitates. Pulse-chase analysis showed that intrinsically radiolabeled Fc gamma RIII was stable in MC4w cells but was degraded rapidly in BMMC and that newly synthesized Fc gamma RIII remained sensitive to digestion by endoglycosidase H in BMMC but rapidly became resistant in MC4w. These data suggest that the deficiency in surface Fc gamma RIII expression on BMMC is due to the degradation of Fc gamma RIII in the endoplasmic reticulum. Immunoprecipitation of surface Fc gamma R and Fc receptors for IgE (Fc epsilon RI) from digitonin-extracted cells followed by immunoblotting with antibody to Fc epsilon RI gamma-chain showed that gamma-chain is associated with surface Fc epsilon RI and Fc gamma R in MC4w, but only with Fc epsilon RI in BMMC, which lack surface Fc gamma RIII. Inasmuch as BMMC are progenitors of serosal mast cells, which, like MC4w, express surface Fc gamma RIII and undergo Fc gamma R-mediated activation, the data suggest that maturation of BMMC enables Fc gamma RIII to bypass degradation in the endoplasmic reticulum, resulting in the acquisition of functional Fc gamma RIII/gamma-chain complexes on the cell surface.

Amino Acid Sequence↗

Spontaneous hyphema associated with anterior uveitis.

Few reports have described hyphema in association with anterior uveitis. Five cases of anterior chamber haemorrhage are reported in patients with five different anterior uveitic entities: Reiter's syndrome, juvenile chronic arthritis, ankylosing spondylitis, idiopathic anterior uveitis, and herpes simplex. Hyphema has been reported in association with idiopathic non-granulomatous anterior uveitis, but not with the other four entities. In three cases, iris rubeosis was present. In two cases the patients were taking non-steroidal anti-inflammatory agents. The hyphemas occurred at times of heightened inflammation and resolved spontaneously without complication in all but one case, a boy with idiopathic uveitis who required surgery to remove the blood. The clinical outcome of these cases provides evidence that conservative medical management is usually sufficient.

Adult↗

Six cases of scleritis associated with systemic infection.

Isolated scleritis (without keratitis) associated with infections is uncommon, and correct diagnosis and appropriate therapy for it are often delayed. Six patients with infection-associated scleritis were seen at our institution between May 1983 and May 1990 (these patients represented 4.6% of all patients with scleritis [six of 130 patients] in that period). Three of these cases were associated with systemic infections. One was associated with syphilis, one was associated with tuberculosis, and one was associated with toxocariasis. Three cases resulted from local infections. One was associated with infection with Proteus mirabilis, one was associated with infection with herpes zoster virus, and one was associated with infection with Aspergillus. The Aspergillus infection developed after trauma and the P. mirabilis-induced infection developed after strabismus surgical procedures. Four of the six cases were initially misdiagnosed and inappropriately managed. Correct diagnosis was made seven days to four years after onset of symptoms. Review of systems, scleral biopsy, culture, and laboratory investigation were used to make the diagnosis. Differential diagnosis of scleritis must include infective agents.

Aged↗

Secretory granule mediator release and generation of oxidative metabolites of arachidonic acid via Fc-IgG receptor bridging in mouse mast cells.

The releases of beta-hexosaminidase, LTC4, LTB4, and PGD2 after the bridging of Fc gamma R3 were assessed in mouse IL-3-dependent bone marrow-derived progenitor mast cells (BMMC), BMMC maintained in coculture with 3T3 fibroblasts separated by a filter to achieve maturation of the granules toward those of a serosal mast cell (SMC), and SMC that are the prototype of a mouse connective tissue mast cell. Bridging of Fc gamma R on BMMC with the 2.4G2 rat anti-Fc gamma RII/III mAb and anti-rat IgG elicited only 4% net release of beta-hexosaminidase and 4, 2, and 1 ng/10(6) cells of immunoreactive LTC4, LTB4, and PGD2, respectively. Bridging of Fc-IgE receptors (Fc epsilon R) on BMMC yielded 35% net release of beta-hexosaminidase and 9, 4, and 3 ng/10(6) cells of immunoreactive LTC4, LTB4, and PGD2, respectively. BMMC maintained in coculture responded to the bridging of Fc gamma R with statistically significant increases in the net percent release of beta-hexosaminidase to 16% and in the generation of immunoreactive LTC4 to 11 ng/10(6) cells, but without a significant change in the production of either LTB4 or PGD2. Bridging of Fc epsilon R on cocultured mast cells yielded a net percent release of beta-hexosaminidase and lipid mediator amounts and profile similar to those for BMMC. Bridging of Fc gamma R on purified mouse SMC resulted in a maximal net percent release of beta-hexosaminidase of 10% and the generation of 4, 1, and 17 ng/10(6) cells of immunoreactive LTC4, LTB4, and PGD2, respectively; the net percent release of beta-hexosaminidase and PGD2 generation were significantly greater than those obtained from BMMC. The Fc epsilon R-mediated net percent release of beta-hexosaminidase from purified SMC was 34%, with PGD2 being the predominant metabolite of arachidonic acid. That the predominant lipid mediator generated with activation by either Fc gamma R or Fc epsilon R is LTC4 for cocultured mast cells and PGD2 for SMC suggests that the mast cell phenotype rather than the receptor class being bridged determines the lipid mediator profile. The responsiveness to Fc gamma R bridging elicited by coculture of BMMC with fibroblasts in vitro and present in SMC derived in vivo relative to BMMC may relate to the previously measured increases in receptor number per cell, but may also involve the acquisition of an enhanced signal transduction capability, possibly through the increased expression of Fc gamma RIII.

Antigens, Differentiation↗

Medical therapy for ocular allergy.

The ocular manifestations of allergy have traditionally been classified into four categories--namely, hay fever conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, and contact lens-associated giant papillary conjunctivitis. Typically, hay fever conjunctivitis is characterized by mild conjunctival inflammation, whereas the other disorders may have severe inflammation and clinical manifestations. Potentially blinding corneal complications may result from vernal keratoconjunctivitis and atopic keratoconjunctivitis. Although hay fever conjunctivitis is clearly an immediate hypersensitivity reaction, the immunologic mechanisms that cause vernal keratoconjunctivitis, atopic keratoconjunctivitis, and giant papillary conjunctivitis are primarily unknown and speculative. Treatment of patients with ocular allergies is often challenging and may necessitate collaborative efforts of an ophthalmologist and an allergist. Herein we discuss conventional therapy and new, promising antiallergy drugs.

Anti-Inflammatory Agents↗

Diagnostic value of anti-neutrophil cytoplasmic antibodies in scleritis associated with Wegener's granulomatosis.

Serum antineutrophil cytoplasmic antibodies (ANCAs) are a sensitive and specific marker for generalized Wegener's granulomatosis. However, ANCA sensitivity and specificity in identifying patients in whom ophthalmic signs constitute the presenting or only definitive manifestation of Wegener's granulomatosis have not been tested. The authors report on 7 patients in whom scleritis was the initial manifestation leading to the diagnosis of Wegener's granulomatosis. Six had the limited form of Wegener's granulomatosis. Results of serum ANCA tests were positive in all these patients. In contrast, the serum ANCA was negative in 54 patients with ocular inflammation due to other disorders; 16 of these patients had scleritis. Serial ANCA titers reverted to normal in only two of the four patients with Wegener's granulomatosis who attained clinical remission. One of the patients who did not revert to normal experienced relapse 2 months after discontinuation of therapy. Antineutrophil cytoplasmic antibodies appear to be both sensitive and specific for Wegener's granulomatosis-associated scleritis, and testing is useful in the evaluation of patients with scleritis.

Adolescent↗

Tectonic keratoplasty for peripheral ulcerative keratitis.

Peripheral ulcerative keratitis (PUK) is a destructive, inflammatory process that can lead to corneal perforation and visual loss. Successful control of PUK has been reported with conjunctival resection, cyanoacrylate adhesive, and systemic immunosuppression. Cases with impending or actual corneal perforation may require more extensive surgery, including lamellar or penetrating keratoplasty, to maintain the integrity of the globe. We report on 17 eyes of 14 patients with PUK that required tectonic keratoplasty because of progressive ulceration. Surgery with concomitant immunosuppression preserved the eyes in all but two cases, and 8 of 17 eyes maintained or improved preoperative visual acuity. Six eyes had final visual acuities of 20/200 or better. This therapeutic strategy can preserve eyes that might otherwise be lost to progressive inflammation.

Adult↗

Mast cell heterogeneity. Differential synthesis and expression of glycosphingolipids by mouse serosal mast cells as compared to IL-3-dependent bone marrow culture-derived mast cells before or after coculture with 3T3 fibroblasts.

The synthesis and intracellular expression of glycosphingolipids by mouse serosal mast cells (SMC) have been characterized by radiolabeling and TLC and by immunodetection in situ. Chromatographic analysis of purified glycosphingolipids from SMC intrinsically labeled with [14C]galactose and [14C]glucosamine hydrochloride revealed the predominant synthesis of only the simplest neutral glycosphingolipid and ganglioside, glucosylceramide and ganglioside GM3, respectively. Intracellular indirect immunofluorescence staining of permeabilized SMC demonstrated the absence of the more complex neutral glycosphingolipids lactosylceramide, globotriosylceramide, globotetraosylceramide, and globopentaosylceramide, the absence of ganglioside GM1, and the presence of ganglioside GM3. By contrast, permeabilized mouse IL-3-dependent bone marrow culture-derived mast cells (BMMC) and mast cells recovered after 21 days of coculture of BMMC with mouse 3T3 fibroblasts expressed lactosylceramide, globotriosylceramide, globotetraosylceramide, ganglioside GM1, and ganglioside GM3, but not globopentaosylceramide intracellularly as determined by immunofluorescence. The findings indicate a loss of biosynthetic capacity and epitope maintenance for glycosphingolipids with in vivo differentiation of SMC from IL-3-dependent BMMC progenitors. Thus, although mast cells derived after coculture of these progenitors for 21 days with fibroblasts assume multiple SMC-like properties in terms of their histochemical staining and their secretory granule proteoglycan and neutral protease constituents, they do not lose the ability to express complex glycosphingolipids. The finding that glycosphingolipid composition does not change coordinately with other secretory granule markers defines a new stage of mouse mast cell development between the BMMC and SMC and provides evidence that mast cell development is more complex than previously appreciated.

Animals↗

Discoid lupus keratitis.

Two patients with long-standing discoid lupus erythematosus developed acute, unilateral, corneal stromal infiltration and edema. No evidence of infection was found, and both responded rapidly to topical corticosteroid therapy. To our knowledge, only one case of stromal keratitis associated with discoid lupus erythematosus has been published previously. We describe the first cases, to our knowledge, in which a satisfactory response to corticosteroid therapy is demonstrated.

Adult↗

Plasma exchange in the therapy of Behçet's disease.

Present therapies for Behçet's disease are unsatisfactory in many cases. We investigated the role of plasma exchange in four patients with severe Behçet's retinitis who were unresponsive to standard medical therapies. Plasma exchange induced a rapid reduction of ocular inflammation with improved visual acuity in all cases. In patients with severe Behçet's retinitis, plasma exchange is able to interrupt the acute inflammatory activity, but relapses may occur.

Adolescent↗

Mast cells in conjunctiva affected by cicatricial pemphigoid.

Ocular cicatricial pemphigoid (OCP) is characterized by progressive conjunctival subepithelial fibrosis often leading ultimately to corneal blindness. Mast cells have been shown to play a role in several fibrotic disorders, but the role of mast cells in OCP is unknown. The authors compared the mast cell population in conjunctival biopsy specimens from 14 OCP patients and from six controls by using specific histochemical stains for mast cell subsets. The total mast cell number and the ratio of connective tissue mast cells to mucosal mast cells (MMCs) were significantly higher in OCP than in normal conjunctiva (P less than 0.05). This report is the first analysis of mast cell subsets in human ocular tissue. The results suggest that connective tissue mast cells (CTMCs) may play an important role in OCP and that therapy directed toward mast cells and their mediators may be an appropriate avenue for further exploration.

Adult↗

Effects of blood transfusion and cyclosporin on rabbit corneal graft survival.

Blood transfusion prolongs renal, cardiac, and skin allograft survival, but promotes rejection of bone marrow allografts. At present, it is unclear whether transfusion induces allograft tolerance or sensitization in corneal transplants. We performed eccentric penetrating keratoplasty on New Zealand albino rabbits, using Dutch rabbits as donors. Twenty-four recipient rabbits were randomly allocated into four groups. The control group received no pretreatment. The other three groups received a donor-specific whole-blood transfusion and/or cyclosporin seven days before the corneal transplants. A single blood transfusion accelerated allograft rejection by an average of 8.8 days (p = 0.0005). In contrast, a single cyclosporin pretreatment prolonged graft survival by an average of 5.3 days (p = 0.02). There was no evidence of interaction effects between transfusion and cyclosporin (p = NS). Therefore, unlike renal, cardiac, and skin allografts and similar to bone marrow allografts, prior blood transfusion accelerates corneal allograft rejection in our rabbit model. Although our data can not be extrapolated to human corneal transplants, our results raise the question whether blood transfusion can sensitize humans to corneal allografts.

Animals↗

Chorioretinal disease patterns in congenic mice following intraocular inoculation with HSV-1.

Disease patterns and immunologic parameters were studied employing inbred and Igh-1 disparate congenic mice to determine the role of host genetics and Igh-1-linked gene products in the von Szily model of viral chorioretinitis. Following intracameral inoculation of 1.5 x 10(4) PFU HSV-1 (KOS), 100% of BALB/c (Igh-1a), 62% of A/J (Igh-1e) and none of the C57BL/6J (Igh-1b) inbred mice developed contralateral necrotizing chorioretinitis. Multigenic differences between inbred mice prohibit conclusions about the specific role of Igh-1-linked immune regulation in this model. In order to more exactly define Igh-1-specific restriction of HSV-1-mediated chorioretinitis, Igh-1-disparate, congenic BALB/c mice were studied following both anterior chamber and intravitreal inoculation protocols. Anterior chamber inoculation resulted in contralateral retinal necrosis in 75% of BALB/c (Igh-1a) mice, 30% of C.AL-20 (Igh-1d) and 5% of the C.B-17 (Igh-1b) congenic mice; all strains showed ipsilateral retinal sparing. Following intravitreal inoculation of HSV-1 a similar restricted disease pattern was found in contralateral eyes. Contralateral chorioretinitis developed in 30% of BALB/c, 15% of C.AL-20 and 6% of C.B-17 mice. Ipsilateral disease, however, was found in all murine strains. These disease patterns developed despite equivalent suppression of systemic DTH and equivalent RPE permissivity to viral replication. These data demonstrate that host genetics strongly regulates contralateral HSV-1-mediated chorioretinal disease patterns by a mechanism unrelated to the development of systemic suppression of DTH and specifically support a dominant role for gene products linked to the Igh-1 locus in the immunomodulation of ocular disease.

Animals↗

Passive transfer of anti-HSV-1 IgG protects against stromal keratitis in mice.

Cellular immune mechanisms are felt to play a primary role in modulating responses to herpes simplex virus (HSV) infections, but the role of anti-HSV antibody is less clear. We first investigated the effects of passive transfer of murine serum containing anti-HSV antibody and then fractionated IgG subclasses on the development of HSV stromal keratitis in mice. Both immune sera and fractionated IgG's from these sera were effective in preventing stromal keratitis in susceptible mice. Non-IgG immunoglobulins and other serum proteins are unnecessary and inadequate in transferring protection; transfer of sera depleted of IgG had no influence on the development of keratitis. These results suggest an important role for anti-HSV antibody in modulating destructive corneal responses to HSV.

Animals↗