Ocular toxoplasmosis is a disease caused by the infection with Toxoplasma gondii through congenital or acquired routes. Once the parasite reaches the retina, it proliferates within host cells followed by rupture of the host cells and invasion into neighboring cells to make primary lesions. Sometimes the restricted parasite by the host immunity in the first scar is activated to infect another lesion nearby the scar. Blurred vision is the main complaint of ocular toxoplasmic patients and can be diagnosed by detection of antibodies or parasite DNA. Ocular toxoplasmosis needs therapy with several combinations of drugs to eliminate the parasite and accompanying inflammation; if not treated it sometimes leads to loss of vision. We describe here clinical features and currently available chemotherapy of ocular toxoplasmosis.
Animals ; Antiprotozoal Agents/therapeutic use ; Humans ; Toxoplasma/*isolation & purification ; Toxoplasmosis, Ocular/*drug therapy/parasitology

Animals ; Child, Preschool ; Diagnosis, Differential ; Humans ; Male ; Toxoplasma ; Toxoplasmosis ; diagnosis ; drug therapy ; parasitology

Although some reports have been published on the protective effect of antibodies to Toxoplasma gondii surface membrane proteins, few address the inhibitory activity of antibodies to dense granular proteins (GRA proteins). Therefore, we performed a series of experiments to evaluate the inhibitory effects of monoclonal antibodies (mAbs) to GRA proteins (GRA2, 28 kDa; GRA6, 32 kDa) and surface membrane protein (SAG1, 30 kDa) on the invasion of T. gondii tachyzoites. Passive immunization of mice with one of three mAbs following challenge with a lethal dose of tachyzoites significantly increased survival compared with results for mice treated with control ascites. The survival times of mice challenged with tachyzoites pretreated with anti-GRA6 or anti-SAG1 mAb were significantly increased. Mice that received tachyzoites pretreated with both mAb and complement had longer survival times than those that received tachyzoites pretreated with mAb alone. Invasion of tachyzoites into fibroblasts and macrophages was significantly inhibited in the anti-GRA2, anti-GRA6 or anti-SAG1 mAb pretreated group. Pretreatment with mAb and complement inhibited invasion of tachyzoites in both fibroblasts and macrophages. These results suggest that specific antibodies to dense-granule molecules may be useful for controlling infection with T. gondii.
Animals ; Antibodies, Monoclonal/*pharmacology/therapeutic use ; *Antigens, Protozoan ; Female ; Fibroblasts/parasitology ; Host-Parasite Relations ; Immunization, Passive ; Macrophages/parasitology ; Mice ; Mice, Inbred BALB C ; Protozoan Proteins/*immunology ; Support, Non-U.S. Gov't ; Toxoplasma/*pathogenicity ; Toxoplasmosis/parasitology/*therapy

OBJECTIVETo identify more effective and less toxic drugs to treat animal toxoplasmosis.

METHODSEfficacy of seven kinds of sulfonamides against Toxoplasma gondii (T. gondii) in an acute murine model was evaluated. The mice used throughout the study were randomly assigned to many groups (10 mice each), which either remained uninfected or were infected intraperitoneally with tachyzoites of T. gondii (strains RH and CN). All groups were then treated with different sulfonamides and the optimal treatment protocol was determined candidates. Sulfadiazine-sodium (SD) was used for comparison.

RESULTSThe optimal therapy involved gavaging mice twice per day with 250 mg/kg bw of sulfachloropyrazine-sodium (SPZ) for five days. Using this protocol, the average survival time and the time-point of 50% fatalities were prolonged significantly compared with SD treatment. Treatment with SPZ protected 40% of mice from death, and the heart and kidney tissue of these animals was parasite-free, as determined by nested-PCR. SPZ showed excellent therapeutic effects in the treatment of T. gondii in an acute murine model and is therefore a promising drug candidate for the treatment and prevention of T. gondii in animals.

CONCLUSIONSIt can be concluded that the effective drug sulfachloropyrazine may be the new therapeutic options against animal toxoplasmosis.

Administration, Oral ; Animals ; Antiprotozoal Agents ; administration & dosage ; DNA, Protozoan ; analysis ; isolation & purification ; Disease Models, Animal ; Female ; Heart ; parasitology ; Kidney ; parasitology ; Mice ; Polymerase Chain Reaction ; Sulfanilamides ; administration & dosage ; Survival Analysis ; Toxoplasma ; drug effects ; genetics ; isolation & purification ; Toxoplasmosis ; drug therapy ; Treatment Outcome

A 36-year old female with acute myelogenous leukemia presented with a sudden decrease in vision one month following bone marrow transplantation (BMT). She had been taking multiple immunosuppressants to treat her recently-developed graft-versus-host-disease (GVHD). Visual acuity was 20/60 in her right eye and 20/25 in her left. Ophthalmic examination revealed mild inflammatory reaction in both the anterior chamber and the vitreous of both eyes, as well as densely opaque yellow-white infiltrates with well-demarcated borders in the posterior retina of both eyes. She was originally diagnosed as CMV retinitis, but treatment with ganciclovir failed to improve her ocular condition. Subsequent work-up, including serology and brain MRI, led to a diagnosis of combined ocular and cerebral toxoplasmosis. After 6 weeks of antiparasitic therapy, her retinal lesions became inactive and her cerebral lesions improved. Immunosuppressed patients with necrotizing retinochoroiditis should be suspected of having toxoplasmosis. Accurate differentiation between this condition and CMV, and early intervention with the appropriate treatment may be critical to preserve the best vision.
Adult ; Anti-Bacterial Agents/therapeutic use ; *Bone Marrow Transplantation ; Chorioretinitis/*diagnosis/drug therapy/parasitology ; Clindamycin/therapeutic use ; Cytomegalovirus Retinitis/*diagnosis ; Drug Therapy, Combination ; Female ; Functional Laterality ; Humans ; Leukemia, Myeloid, Acute/*surgery ; Magnetic Resonance Imaging ; Tomography, Optical Coherence ; Toxoplasmosis, Cerebral/*diagnosis/drug therapy ; Toxoplasmosis, Ocular/*diagnosis/drug therapy ; Transplantation, Homologous ; Trimethoprim-Sulfamethoxazole Combination/therapeutic use

No abstract available.
Adult ; Anemia, Aplastic/*surgery ; Antiprotozoal Agents/therapeutic use ; Drug Therapy, Combination ; Encephalitis/diagnosis/drug therapy/*parasitology ; Female ; Hematopoietic Stem Cell Transplantation/*adverse effects ; Humans ; Immunosuppressive Agents/adverse effects ; Magnetic Resonance Imaging ; Parasitology/methods ; Polymerase Chain Reaction ; Republic of Korea ; Toxoplasma/genetics/*isolation & purification ; Toxoplasmosis, Cerebral/diagnosis/drug therapy/*parasitology ; Transplantation, Homologous ; Treatment Outcome

We report here the records of 10 consecutive Korean patients (10 eyes) with ocular toxoplasmosis which showed the typical clinical manifestations with seropositivity for Toxoplasma gondii specific IgG antibodies by micro-ELISA between 2006 and 2010. Nine patients were males and 1 was female; their age was 50.5+/-13.8 years. The most common accompanying signs were vitritis (100%), anterior uveitis (70%), and scattered white deposit (80%). Pre-existing retinochoroidal scar was found in 1 (10%) patient. All patients received antiparasitic chemotherapy and systemic corticosteroid treatment, which resolved the presenting attack and recovered the visual acuity better than initial one in 9 patients and worse in 1. Optic atrophy, cataract, and retinal neovascularization were observed during the follow-up period and recurrence was detected in 3 eyes (30%) 6 to 20 months after the initial attack. In Korea, although rarely detected and reported, ocular toxoplasmosis needs more attention in clinical field of retinal diseases.
Adrenal Cortex Hormones/administration & dosage ; Adult ; Age Distribution ; Aged ; Anti-Inflammatory Agents/administration & dosage ; Antibodies, Protozoan/*blood ; Antiprotozoal Agents/administration & dosage ; Cataract/pathology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/blood ; Korea ; Male ; Middle Aged ; Optic Atrophy/pathology ; Retinal Neovascularization/pathology ; Sex Distribution ; Toxoplasma/immunology/*isolation & purification ; Toxoplasmosis, Ocular/complications/*diagnosis/drug therapy/*pathology ; Uveitis, Anterior/complications/drug therapy/parasitology/pathology