Towards cytokine insight in sight

Cytokine Concentrations Measured by Multiplex Assays in Canine Peripheral Blood Samples

Cytokines are known to play important roles in a wide range of pathologic conditions spanning all organ systems in every species studied. As our knowledge of the physiology of individual cytokines expands and our ability to measure multiple cytokines in smaller biological samples increases, we gain more insight into the significance and function of each cytokine and the importance of cytokine networks. Previous studies that reported measurements of cytokine concentrations from serum or plasma in dogs with infectious, autoimmune, metabolic, endocrine, and neoplastic diseases yield an appreciation for the complexity of cytokine control and potential applications for cytokine measurements in the diagnosis, prognosis, and therapy of a variety of disease conditions. In this review, we highlight the benefits of multiplex cytokine analysis, summarize clinical and experimental reports that have used this technology in dogs, and discuss the strengths and limitations of data analysis for the interpretation of results in these studies. We describe how differences in technical acuity, data reporting tactics, statistical analysis, study population selection criteria, and cross-sectional experimental design methods may affect interpretation of results from this technology. We also suggest methods for analysis in future studies, such as reporting median fluorescence intensity values, analyzing the proportion of patients above population medians, and performing longitudinal studies.

Recent developments in the treatment of posterior uveitis

Uveitis is an intraocular inflammation that can be caused by infection, autoimmune disease, trauma or malignancy. It is a serious cause of visual handicap and therapy is targeted at: removal of possible infectious agents, the immunological processes that lead to or sustain the inflammation and finally to prevent or treat the destructive effects of the inflammation on the delicate ocular structures. In this review the latest developments concerning the treatment of posterior uveitis are illuminated, e. g., new approaches concerning the treatment of infectious uveitis including the therapy of herpes virus (VZV, HSV and CMV), bacterial and toxoplasma infections of the eye. Several new ways to influence the immune response and inflammation are described including the use of interferons, modulation of cytokines, soft steroids, other new immunosuppressive drugs and treatment of autoimmune uveitis by oral tolerization. An overview is given to illustrate new ways to administer drugs into eyes, such as intravitreal devices. Finally new developments in the field of the treatment of the various complications of uveitis (cystoid macular edema) are described.

Treatment of uveitis with recombinant human interleukin-13

AIM

To evaluate the anti-inflammatory cytokine interleukin-13 (IL-13) for the treatment of uveitis.

METHODS

Uveitis was induced in monkeys by immunisation with human retinal S-antigen. Starting at the onset of disease, the animals were treated with IL-13 at 25 micrograms/kg, or vehicle control, injected subcutaneously once a day for 28 days. Intraocular inflammation was scored by indirect ophthalmoscopy for a period of 56 days. Circulating leucocyte levels were monitored.

RESULTS

Uveitis started unilaterally in all but one animal. IL-13 inhibited inflammation both in the eyes in which the disease was present when the treatment was initiated (p = 0.0001), and in the contralateral initially negative eyes (p = 0.0001). After cessation of therapy, there was a progressive increase of inflammation in the IL-13 treated group. However, the beneficial effect of IL-13 extended into the 4 week follow up period. IL-13 produced an increase in circulating polymorphonuclear neutrophils and a decrease in lymphocytes.

CONCLUSION

Administration of IL-13 appears to be a promising modality of treatment for severe uveitis.

Drug-induced uveitis. Incidence, prevention and treatment

Drug-induced uveitis is a relatively rare occurrence. For example, the patient database at the tertiary referral Uveitis Clinic at the Casey Eye Institute, Oregon Health Sciences University records an incidence of less than 0.5%. Despite this, the frequency of uveitis secondary to rifabutin therapy in AIDS patients has brought greater recognition to the potential role of medications as a cause of intraocular inflammation. A brief review of uveitis including its classification, causes, symptoms and signs is presented along with a review of systemic medications associated with uveitis. These medications include cidofovir, cobalt, diethylcarbamazepine, pamidronic acid (disodium pamidronate), interleukin-3 and interleukin-6, oral contraceptives, quinidine, rifabutin, streptokinase and sulfonamides. Other systemic medications may cause uveitis. Topical ocular medications such as beta-blockers and corticosteroids as well as other topical ocular medications have been associated with uveitis. Cidofovir, pamidronic acid, sulfonamides, rifabutin and topical metipranolol can 'probably' cause uveitis. The remainder of the medications discussed have a 'possible' cause-and-effect relationship with uveitis. Treatment begins with recognition of a drug-related event and usually subsequent avoidance of the drug. Therapy depends on the severity and likelihood of the reaction. Drug-induced uveitis is almost always reversible within weeks of discontinuation of the drug and treatment of the inflammation.