Antibiotic treatment for ocular toxoplasmosis: a systematic review and meta-analysis: study protocol

Recurrence of Ocular Toxoplasmosis after Vitrectomy: Case Report and Review

PURPOSE

The purpose of this study is to report one case of ocular toxoplasmosis (OT) recurrence after vitrectomy and review the scientific basis about it.

CASE REPORT

A 58-year-old male patient with previous OT, properly treated, underwent vitrectomy due to macular hole. During follow-up, patient evolved with recurrence of the OT. After 1 year, patient presents visual acuity of 20/200 and extensive macular scar.

CONCLUSION

There is no consensus on using perioperative antiparasitic therapy aiming recurrence prophylaxis. Studies with better statistical design are necessary to evaluate the recurrence risk after ocular surgeries and the possible recommendation of prophylaxis, especially in countries where the strains are more virulent and the recurrence more common.

A Novel Combined DNA Vaccine Encoding Toxoplasma gondii SAG1 and ROP18 Provokes Protective Immunity Against a Lethal Challenge in Mice

PURPOSE

Antigens expressed by Toxoplasma gondii (T. gondii) during its life cycle trigger various immune responses in the host. Recently, toxoplasma vaccine research focused on T. gondii surface antigen 1 (SAG1) and Rhoptry Protein 18 (ROP18) to establish a safe and efficacious DNA vaccine.

METHOD

We constructed two eukaryotic expression plasmids: p3 × FLAG-Myc-CMV™-24-SAG1 and p3 × FLAG-Myc-CMV™-24-ROP18. BALB/c mice were randomly divided into six groups and immunized with these DNA vaccines either separately or in combination. The combination vaccine was administered at either the full dose or at half-strength dose. Control mice were immunized with empty vector or with phosphate-buffered saline.

RESULTS

The frequency of CD4⁺ cells in the spleen was consistent among all groups, whereas that of CD8⁺ T cells was the highest in the group immunized with the combination vaccine at half-strength dose (p < 0.05). Importantly, the mRNA expression levels of interleukin-12 (IL-12) and interferon-gamma (INF-γ) were closely correlated (r = 0.6, p < 0.0001) and both were upregulated in the group that was immunized with the combination vaccine at half-strength dose (p < 0.0001). The survival time of the mice subjected to a lethal dose of toxoplasma was significantly extended by prior immunization with DNA vaccines expressing either SAG1 or ROP18 or a combination of both (p < 0.05). The group that was immunized with the combination vaccine at half-strength dose demonstrated the best efficacy (p < 0.05).

CONCLUSION

These results showed that the combination DNA vaccine provided better immune protection than the single gene vaccines, and that optimizing the dosing of the vaccine can improve the immune response.

Safety and efficacy of different antibiotic regimens in patients with ocular toxoplasmosis: systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis (OT) is the most common cause of posterior uveitis, which leads to visual impairment in a large proportion of patients. Antibiotics and corticosteroids lower the risk of permanent visual loss by controlling infection and inflammation. However, there remains disagreement regarding optimal antibiotic therapy for OT. Therefore, this systematic review and meta-analysis were performed to determine the effects and safety of existing antibiotic treatment regimens for OT.

METHODS

MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, LILACS, WHO International Clinical Trials Registry Platform portal, ClinicalTrials.gov, and Gray Literature in Europe ("OpenGrey") were searched for relevant studies; manual searches of reference lists were performed for studies identified by other methods. All published and unpublished randomized controlled trials that compared antibiotic schemes known to be effective in OT at any dosage, duration, and administration route were included. Studies comparing antibiotics with placebo were excluded. This review followed standard methodological procedures recommended by the Cochrane group.

RESULTS

Ten studies were included in the narrative summary, of which four were included for quantitative synthesis (meta-analysis). Interventions were organized into three groups: intravitreal clindamycin versus pyrimethamine + sulfadiazine, trimethoprim + sulfamethoxazole versus other antibiotics, and other interventions. The first comparison favored intravitreal clindamycin (Mean difference (MD) = 0.10 logMAR; 95% confidence interval = 0.01 to 0.22). However, this finding lacks clinical relevance. Other outcomes showed no statistically significant differences between the treatment groups. In general, the risk of performance bias was high in evaluated studies, and the quality of the evidence found was low to very low.

CONCLUSIONS

No antibiotic scheme was superior to others, and the selection of a treatment regimen depends on multiple factors; therefore, treatment should be chosen based on safety, sulfa allergies, and availability.

Heerfordt-Waldenström syndrome, a rare presentation of sarcoidosis in a patient with old ocular toxoplasmosis

BACKGROUND

There are similarities between ophthalmic presentation of toxoplasmosis and sarcoidosis and there are some concerns of immunosuppressive treatments for sarcoidosis may lead to T. gondii reactivation. We report a rare case with acute sarcoidosis (Heerfordt-Waldenström syndrome) and past history of ocular toxoplasmosis from the North of Iran.

CASE PRESENTATION

The patient was a 36-year-old woman, with left painful eye and swollen parotid, right facial paresis, maculopapular rash in left eyebrow and erythema nodosa on both legs. Anti-Toxoplasma IgG antibody was positive and IgM was not detectable. Radiographic findings on chest revealed bilateral hilar lymphadenopathy. The initial treatment was sulfamethoxazole-trimethoprim to prevent recurrence of retinal toxoplasmosis and corticosteroid and mycophenolate mofetil for sarcoidosis. The patient showed clinical and vision improvement without recurrences during three months follow-up.

DISCUSSION

Ophthalmological examinations and laboratory test to rule out toxoplasmosis could be considered in known cases of sarcoidosis particularly in ocular sarcoidosis status. To the best of our knowledge this is first report of co-morbidity of ocular toxoplasmosis / sarcoidosis from Iran and possibly the world.