Immunophenotyping of lymphocyte subsets in the third eyelid tissue in dogs (Canis familiaris): morphological, microvascular, and secretory aspects of this ocular adnexa.

The third eyelid is an important adnexa of the eye. The objective of this study was to evaluate (i) morphological aspects (ii) vascularization, and (iii) the immunophenotype of lymphocyte subsets in the third eyelid of dogs. Flow cytometric analysis revealed the presence of three patterns concerning the immunophenotype of the third eyelid tissue. Dogs without ocular insult or deficient tear production might belong to one of the following immunophenotype patterns: I--the number of T-cells that expressed CD3(+) CD8(+) was higher than the number of cells that expressed CD3(+)CD4(+). II--the number of cells CD3(+)C4(+) was higher than the number of cells CD3(+)CD8(+) and in this case a higher number of cells that expressed CD19 were identified. III--Proximity of values of the cells that expressed CD3(+)CD4(+) and CD3(+)CD8(+). These data might suggest that the number of lymphocyte T cells alone should not be considered a direct indicator of the presence of an immune-based inflammation. Besides, a particular population of T-cells does not indicate a particular inflammatory state. The morphological study of the third eyelid revealed a rather uncommon angioarchitecture. The artery that irrigates the eyelid crosses almost the entire length of this structure to achieve its free border, and only then, ramificates deeply towards an inner segmental level. This spatial microvascular arrangement probably results from an adaptation to the fact that the third eyelid, in the medial cantus of the eye, is inwardly compressed into a tiny space. Efficient vascularization is achieved by allowing the first ramifications of the third eyelid artery to run straight to the top. Accini secretor cells of the third eyelid show a mucin content while tubuloacinar cells are mainly serous.

Nictitating membrane as a potentially useful postmortem diagnostic specimen for classical swine fever.

The gold standard for diagnosis of classical swine fever (CSF) is cell culture virus isolation combined with reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent antibody test (FAT) in cryosections of tonsils, spleen, various lymph nodes, ileum, and kidney. Autolytic and heterolytic samples render correct FAT evaluation difficult and can even yield false-negative or ambiguously positive results. To extend the spectrum of CSF diagnostic specimens, the authors tested whether the nictitating membrane (NM) might be a useful adjunct diagnostic specimen in wild boars and domestic pigs. To accomplish this, results of virus isolation, FAT, and RT-PCR were compared on NM samples and lymphoid tissues, which are the routine specimens of choice for CSF diagnosis. Wild boars (n = 30) and domestic pigs (n = 8) were experimentally challenged with various CSF virus (CSFV) strains or isolates of different virulence. The FAT revealed CSFV antigen in surface and tubular adenoid epithelium as well as in lymphatic follicles of the NM. In wild boars and domestic pigs with CSF, a strong agreement was found between results of FAT, virus isolation, and RT-PCR on NM and lymphoid tissues. These results suggest that NM is a useful additional specimen that can provide valuable data for postmortem diagnosis of CSF. The NM is relatively easy to sample at necropsy, and postmortem autolysis and heterolysis of this tissue is minimal compared with internal organs.

Russel bodies-containing cells in the Harderian gland of the chicken in relation to different immune conditions.

The modulation of the number of Russel bodies-containing plasma cells in the Harderian gland under different experimentally induced immune conditions is reported. The findings support the conception of an immunologic function of the Harderian gland which is similar to the function of the thymus on the one hand, and to the function of the bursa of Fabricius on the other.

Keratoconjunctivitis sicca: immunological evaluation of 62 canine cases.

The etiology of keratoconjunctivitis sicca (KCS) in 62 dogs was evaluated, using immunologic techniques. Using direct fluorescent antibody testing, autoantibodies within the lacrimal, salivary, or pancreatic glands were detected in 5 of 8 dogs tested. Circulating antibodies to the nictitating membrane gland, main lacrimal gland, parotid salivary gland, or mandibular salivary gland were detected using indirect fluorescent antibodies in 9 of 31, 3 of 31, 5 of 31, and 5 of 31 sera, respectively. Using radial immunodiffusion, hyper-gamma-globulinemia was detected in 21 of 30 dogs with KCS. Antinuclear antibodies, primarily in a nucleolar pattern, were demonstrated in 20 of 50 dogs with KCS. Lymphocytic infiltrates were evident in 5 of 9 labial salivary biopsies, 2 of 4 parotid gland specimens, 2 of 4 mandibular gland specimens, and 2 of 3 thyroid gland specimens taken from dogs with KCS. Autoimmune diseases had been previously documented in 4 of 62 dogs. Twenty-five of the 62 dogs (40%) had concurrent problems indicative of an underlying immunologic disorder.

Histologic characteristics and local cellular immunity of the gland of the third eyelid after topical ophthalmic administration of 2% cyclosporine for treatment of dogs with keratoconjunctivitis sicca.

OBJECTIVE: To evaluate the efficacy of topical administration of a 2% solution of cyclosporine (CsA) for treatment of dogs with keratoconjunctivitis sicca (KCS) and to correlate results with histopathologic characteristics and local cellular immunity of the gland of the third eyelid. ANIMALS: 24 dogs with bilateral KCS. PROCEDURE: Lacrimal secretion was measured, using Schirmer tear test (STT) strips. Leukocyte and T-lymphocyte subsets were determined in blood samples. Histopathologic changes as well as CD4+, CD8+, and alpha-naphthyl-acetate esterase-positive (ANAE+) lymphocytes were evaluated. RESULTS: Clinical signs resolved at the end of 1 month in conjunction with significantly increased STT values, compared with baseline values. Fifteen and 30 days after discontinuation of CsA treatment, a decrease was observed in STT values in both eyes; however, only values for the right eye were significantly different. There was a significant decrease in the number of lymphocytes and ANAE+ lymphocytes 15 and 30 days after discontinuation of CsA treatment, compared with baseline values. Differences were not observed in number of CD4+ lymphocytes among treatment groups. However, there was a significant decrease in number of CD8+ lymphocytes with reversal of the CD4+:CD8+ in both eyes after CsA treatment for 30 days, compared with the control group. Increased secretory activity and decreased lymphocyte infiltration were characteristic histopathologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: Topical administration of a 2% solution of CsA was effective for the treatment of dogs with KCS. Strict follow-up monitoring is required after the cessation of treatment because of the possibility of recurrence of KCS.

Orthotopic transplantation of alogeneic canine conjunctiva.

In previous papers it has been shown that simultaneous transplantation of conjunctiva to the corneal-scleral region, and skin to the inside of the pinna will afford good opportunities to follow both the onset and the terminal phase of the allograft reaction. It has also been stated that conjunctiva grafted alone will have a longer survival time (12.1 days), than when grafted simultaneously with skin (7.5 days). In order to find out whether the localization to the corneal-scleral region per se had anything to do with this prolongation of the survival time, conjunctiva was grafted in 8 dogs to the palpebral surface of the nictitating membrane, i.e. more peripherally in the type used as grafts in previous experiments were weighed and examined histologically to compare the "tissue doses" --quantitatively and quanlitatively--transferred to the recipient when transplanting conjunctiva plus skin, or conjunctiva alone. Conjunctiva alone grafted to the nictitating membrane had a mean survival time of 10.5 days which does not significantly differ from the mean survival time of conjunctiva grafted to the cornealscleral region. Various possible reasons for the significantly prolonged survival time of conjunctiva alone, compared with that of conjunctiva when grafted with skin, are discussed in some detail. The author suggests that the most likely explanation of the prolonged survival time of the conjunctival grafts applied alone is that this operation means transfer of an antigen dose so low that the mobilization of the immune defence system is delayed.