Pemphigus foliaceus in two Shetland sheepdog littermates

Two female Shetland Sheepdog littermates simultaneously developed pemphigus foliaceus at 6 months of age. Three other littermates were not affected. One bitch (tricolored) was not treated, and the disease has remained active for 2 years. The other bitch (blue merle) has been successfully managed with glucocorticoids and gold salts.

Encephalitozoon cuniculi infection in MRL/MPJ-LPR (lymphoproliferation) mice

Experiments were conducted to determine (a) whether mice bearing the single autosomal recessive gene lpr (lymphoproliferation) are more susceptible to encephalitozoonosis than syngeneic mice without the lpr gene and (b) whether infection with Encephalitozoon cuniculi in autoimmune MRL/MPJ mice accelerates and/or exacerbates the development of hypergammaglobulinemia, a manifestation of encephalitozoonosis in dogs and foxes. The results suggested that the lpr gene does not influence susceptibility to murine encephalitozoonosis. Infection with E. cuniculi changed neither the onset nor the severity of the spontaneous, age-related hypergammaglobulinemia in MRL/MPJ mice. Hypergammaglobulinemic lpr mice with encephalitozoonosis did not develop more severe lesions than lpr mice without encephalitozoonosis nor was their death accelerated.

Advances in canine diabetes mellitus research: etiopathology and results of islet transplantation

Histopathologic and immunocytochemical alterations in the pancreas of 18 dogs with spontaneous diabetes mellitus were evaluated. In 5 of 18 dogs (28%), extensive pancreatic damage appeared to be responsible for the development of diabetes mellitus. In the other 13 dogs, there was substantial reduction in the number of well-granulated beta cells, but the number of well-granulated alpha and delta cells was normal in 70% and 85% of the dogs, respectively. Also, insulitis lesions composed of infiltrating mononuclear cells, predominantly lymphocytes, were observed in 6 of 13 dogs (46%), but evidence of islet-directed humoral autoimmunity was not detected. Each pancreas had dense Ia (class II antigen) expression on ductal epithelia but not on islet endocrine cells. The importance of the insulitis lesions and class II antigen expression on ductal epithelial cells remains unclear. Of the 18 dogs, 8 received multidonor intrahepatic islet allografts. Allograft rejection was prevented by administration of cyclosporin. Five dogs were administered cyclosporin continuously. One dog with an allograft failed to sustain euglycemia at 231 days after transplantation, and one dog with fasting euglycemia died of pneumonia at 186 days after transplantation. In the other dogs, euglycemia was sustained for periods that ranged from 253 to 716 days.

Neuromuscular histopathology in (New Zealand black x New Zealand white)F1 and MRL-lpr/lpr autoimmune mice: models for skeletal muscle involvement in connective tissue disease

Skeletal muscle from (New Zealand black x New Zealand white)F1 and MRL-lpr/lpr mice was examined for histopathologic abnormalities. Although young animals had no muscle abnormalities, older mice in both strains had the following histopathologic abnormalities: perimysial/endomysial inflammation, acute simple denervation, muscle degeneration/necrosis, and an increase in internal nuclei. MRL-lpr/lpr mice had the following additional histopathologic abnormalities: inflammatory vascular disease (vasculitis), central myofibrillar loss, fascial inflammation, and tubular aggregates. These abnormalities are comparable with those seen in human connective tissue diseases, particularly the association with inflammation. These mouse strains provide good animal models for the study of immunopathologic processes of skeletal muscle associated with connective tissue disease.

Systemic lupus erythematosus in a colony of dogs

A colony of dogs was obtained by the mating of a female German Shepherd Dog crossbred and a male Belgian Shepherd Dog crossbred, both with systemic lupus erythematosus (SLE). The colony also contained 16 dogs representing F1, F2, and F3 generations. Ten colony dogs had circulating antinuclear antibodies, and 5 of the 10 had clinical signs of SLE. Two F3-generation females had signs of severe SLE. Two dogs had antibodies to extractable nuclear antigen, notably 1 dog had antibodies to Smith (Sm) antigen and 1 had antibodies to Sjogren syndrome A (SSA) antigen. Thymulin (serum thymic factor associated with zinc) titers were generally low in the descendants, but fluctuations were detected within the same dog. In vitro response of lymphocytes from these colony dogs to concanavalin A was maximal for lower mitogenic concentrations, compared with response of lymphocytes from 10 healthy dogs. The suppressive lymphocyte activity in 6 autoimmune colony dogs was diminished in comparison with the activity in 5 nonautoimmune colony dogs and 6 healthy dogs.

Corticosteroid (methylprednisolone sodium succinate) pulse therapy in five dogs with autoimmune skin disease

Corticosteroid pulse therapy is the parenteral administration of suprapharmacologic doses of methylprednisolone sodium succinate for short periods. Five dogs diagnosed as having autoimmune skin disease were treated, using pulse therapy, with subsequent dramatic and rapid improvement of skin lesions. The dogs had no adverse clinical signs attributable to the treatment. All dogs had a relapse of clinical signs after a maintenance protocol (0.5 mg/kg, q 48 h) of orally administered prednisone was started. Skin lesions on 4 of 5 dogs eventually were controlled by prednisone, azathioprine, or gold therapy.

Lack of circulating thyroid stimulating immunoglobulins in cats with hyperthyroidism

Although feline hyperthyroidism has become a commonly diagnosed disorder of older cats, the underlying etiology remains unknown. Pathological findings of adenomatous hyperplasia involving both thyroid lobes in most hyperthyroid cats suggests the possibility that feline hyperthyroidism may be similar to human Graves' disease, which results from high circulating levels of thyroid stimulating immunoglobulins (TSIs). To exclude high circulating levels of TSIs as the cause of feline hyperthyroidism, we measured intracellular concentrations of cyclic adenosine monophosphate (cAMP) in functioning rat thyroid cells (FRTL-5) incubated with IgG extracted from hyperthyroid cat serum. Since TSIs stimulate thyroid hormone secretion through activation of cAMP, their presence can be evidenced in vitro by generation of high cAMP concentrations in cultured thyroid cells. No significant difference was found in intracellular cAMP concentrations in FRTL-5 cells incubated with IgG from normal versus hyperthyroid cats. In contrast, IgG from a human patient with Graves' disease caused substantially more cAMP generation than either normal human IgG or IgG from the cats of this study. These results indicate that feline hyperthyroidism does not result from high circulating concentrations of TSI and, in that respect, is not analogous to Graves' disease.

The laboratory identification of serum antinuclear antibody in the dog

An indirect immunofluorescence test with sections of rat liver as a substrate, proved useful in detecting antinuclear antibodies (ANA) in the dog. A specific anti-canine IgG reagent conjugated with fluorescein isothiocyanate was used. A proportion of normal dogs gave positive reactions at low titres. The presence of ANA was one of the criteria used to diagnose canine systemic lupus erythematosus. Some dogs within a general hospital population were also positive for the auto-antibody. The indirect immunofluorescence test with Trypanosoma brucei as a substrate was insensitive. The LE-cell test was laborious and insensitive. A commercial latex slide agglutination test used for detecting ANA in man gave false positive and false negative results in the dog. A commercial radioimmunoassay used in man gave many false positive results. A similar assay with synthetic DNA gave encouraging results and is worthy of further study.

Genetically determined murine models of immunodeficiency

We have discussed more than 30 mutant genes known to cause abnormalities in the development and regulation of the immune system. The loci defined by these deleterious alleles have been assigned to 13 different autosomal chromosomes in addition to X and Y. It is important to note that these single genes do not act alone but function in concert with the background genome. Studies of these mutations on different inbred strain backgrounds are contributing important information on the influence of background modifying genes. The development of stocks of mice carrying multiple mutations on an inbred strain background enables the use of a well-characterized mutation to explore a less-well-understood genetic model. Investigators are urged to assure proper conditions for studies with immunological mutants by using the appropriate methods of animal husbandry. A detailed guide for maintaining immunologically compromised rodents has been prepared. These experiments performed by nature provide a valuable resource for investigating the immune system in normal and pathologic states. As the gene products of the loci defined by these mutations become known, the information obtained will provide additional insight into mechanisms underlying normal immune function as well as immunologic disease processes in man.

Antinuclear antibody in chickens with reoviral arthritis

Antinuclear antibody (ANA) in chickens infected with reovirus was first detected at 3 weeks postinfection (PI). The antibody titer was greatest at 10 weeks PI (1:2560) and then declined. From 19 to 30 weeks PI, the birds were negative for ANA. The ANA was of both IgG and IgM types. The association between antinuclear factor and reoviral arthritis is discussed.

Diseases of the lips and oral cavity of domestic animals

Oral and lip lesions in domestic animals, as in man, may be due to a vast number of diseases. While some of these diseases are unique to each species, the majority of them are similar to human afflictions. These represent an untapped resource in comparative medicine, and research in this area can only benefit both man and the domestic animals he is dependent upon.

Avidin-biotin-peroxidase complex immunohistochemistry to detect immunoglobulin in formalin fixed skin biopsies in canine autoimmune skin disease

Avidin-biotin-peroxidase complex immunohistochemistry was used on formalin fixed, paraffin embedded, trypsin digested, skin biopsies to detect immunoglobulin deposition in dogs with autoimmune skin disease. Immunostaining by the avidin-biotin-peroxidase complex technique revealed intercellular and/or basement membrane immunoglobulin deposits in 27 of 28 dogs considered to have autoimmune skin disease by clinical and histological evaluation and in six of 19 dogs considered to have autoimmune skin disease by clinical evaluation but without histological confirmation. Similar immunostaining was not evident in five biopsies of normal skin or in biopsies from four dogs with noninflammatory dermatoses, but was present in biopsies from one of ten dogs considered by clinical and histological criteria to have an inflammatory dermatosis other than autoimmune skin disease. Detection of immunoglobulin deposits in skin biopsies by avidin-biotin-peroxidase complex immunohistochemistry offers numerous advantages over conventional immunofluorescence methods including the opportunity to precisely compare histological and immunological findings.

Localization of immunoglobulins and complement by the peroxidase antiperoxidase method in autoimmune and non-autoimmune canine dermatopathies

Formalin-fixed, paraffin embedded skin biopsy specimens from 44 dogs with various dermatopathies were examined for the presence of immunoglobulins (IgG, IgM, IgA) and complement (C3) by the peroxidase antiperoxidase method (PAP). Final diagnoses of the skin diseases were determined by clinical findings, fungal and bacterial cultures, skin scrapings, serum endocrinologic tests, and histologic features of cutaneous biopsies. The dermatopathies included examples of pyoderma (folliculitis/furunculosis), demodecosis, sarcoptic mange, dermatophytosis, endocrine dermatopathy, and autoimmune skin disease (AISD). In the latter category, 7 cases of pemphigus foliaceus, 1 pemphigus vulgaris, 4 discoid lupus erythematosus (DLE) and 4 examples of indeterminate AISD were examined. Immunoglobulins, C3, or both, were localized in tissue sections from AISD (15/16), pyoderma (7/11), demodecosis (4/8) sarcoptic mange (3/3), and dermatomycosis (2/3). Endocrine dermatopathy biopsies were consistently negative for Ig and C3 (0/3). The pattern of localization was most often intercellular (31/44 positive biopsies) with basement membrane immunoreactivity in 4 cases of DLE, and 1 case of indeterminate AISD. There was no consistent correlation between histologic features of hematoxylin and eosin-stained biopsies and the presence of Ig and C3. Clinical outcome was similar in both Ig and C3 positive and negative cases of non-AISD dermatitis. The high percentage (95%) of positive results in AISD biopsies indicates the usefulness and sensitivity of the PAP method for the localization of Ig and C3. Because of the high percentage of Ig localization in pyoderma (73%), biopsy specimens with extensive inflammatory skin disease are not suitable for diagnosis of AISD. The PAP method is useful in the diagnosis of AISD in biopsy specimens with minimal inflammation. Caution is warranted in the interpretation of immunoreactivity independent of clinical and histologic information.

A review of major histocompatibility complex-disease associations in man and dog

The organization and biology of the Major Histocompatibility Complexes (MHC) of man (HLA) and dog (DLA) are reviewed, and a summary is presented of laboratory techniques used to define allotypes. The nomenclature of this field and the mechanisms of disease association with the MHC are discussed. Currently recognized HLA-disease associations are enumerated, with emphasis on the value of the complement C4 marker. DLA-disease association studies into autoimmune disease, allergy and neoplasia are reviewed.

Lymphocytes and antibody in retrovirus-induced feline pure red cell aplasia

The possible role of antibody and T-lymphocytes was investigated in the pure red cell aplasia (PRCA) associated with feline leukemia virus, subgroup C (FeLV-C), infection. In previous studies, erythroid colony-forming cells were undetectable in marrow culture of cats with PRCA. Yet erythroid burst-forming cells (BFU-E) remained, suggesting that BFU-E were able to differentiate in vitro but not in vivo. It was inferred that immunologic suppression may contribute to the pathogenesis of feline PRCA, and the interactions of antibody and T-lymphocytes with erythroid and granulocyte-macrophage progenitors were studied. Incubation of normal or PRCA marrow cells with PRCA serum or IgG concentrated from this serum and then complement (C') failed to decrease hematopoietic colony growth when compared to the results obtained with cultures of marrow cells incubated with C' alone. In crossover coculture studies, T-cells from Safari cats with PRCA had no inhibitory effect on colony growth from normal or autologous PRCA marrow cells. For the determination of whether feline PRCAs were associated with a clonal T-cell process, lymphocytes were obtained periodically from glucose-6-phosphate dehydrogenase (Glc-6-PD) heterozygous cats following FeLV-C infection and were expanded with a crude preparation of interleukin-2. The ratios of Glc-6-PD enzyme types in these samples did not change as cats developed anemia, suggesting that the inhibition of erythropoiesis was not associated with the clonal expansion of T-cells. These studies, therefore, do not support the premise that feline PRCA results from the interaction of antibody or T-cells with erythroid progenitors.

Immune-mediated diseases of the dog and cat. III. Immune-mediated diseases of the integumentary, urogenital, endocrine and vascular systems

The first two articles in this series have covered the basis of the immune mediated diseases, systemic immune-mediated diseases and those that involve the haemolymphatic and musculoskeletal system. The purpose of this article is to cover the immune-mediated diseases that involve the integumentary, urogenital, endocrine and vascular systems.