The acute phase reaction detected in dogs by concanavalin A binding

Using a kinetic turbidimetric assay based on the binding of serum glycoprotein to concanavalin A the acute phase reaction has been detected in dogs. Raised levels of glycoprotein were found in dogs which had undergone surgery, had been treated with bacterial endotoxin and had various inflammatory conditions.     

The feline acute phase reaction

The acute phase reaction (APR) is a response to potentially pathogenic stimuli. It begins with the release of interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-alpha from inflammatory cells. These cytokines induce fever, leucocytosis and release of serum acute phase proteins (APPs). In this review, the characteristics of the feline APR are described. In cats with inflammatory conditions, fever is a common finding, with leucocytosis due to the release of cells from the marginal pool, followed by activation of myelopoiesis. Because excitement frequently causes leucocytosis in cats, a diagnosis of inflammation should therefore be supported by additional findings such as the presence of toxic neutrophils. The major APPs are serum amyloid A and alpha(1)-acid glycoprotein (AGP), which both increase a few hours after the inflammatory stimulus and remain elevated for as long as the inflammation persists. AGP plays an important role in the diagnosis of feline infectious peritonitis (FIP) and may also be useful also in studies of FIP pathogenesis.     

Serum concentrations of acute phase proteins in dogs with leishmaniasis

The concentrations of haptoglobin, C-reactive protein and ceruloplasmin were measured in symptomatic and asymptomatic dogs naturally infected by Leishmania infantum, and in healthy uninfected dogs to determine the potential value of these proteins for the diagnosis and prognosis of leishmaniasis. The concentrations of the acute phase proteins were significantly higher in the dogs with leishmaniasis than in the control dogs, and the concentration of C-reactive protein was significantly higher in the symptomatic dogs than in the asymptomatic dogs. There were no correlations between the acute phase proteins and the gamma globulins, the albumin/globulin ratio or the titre of anti-leishmanial antibodies.     

The role of acute phase proteins in diagnosis and management of steroid-responsive meningitis arteritis in dogs

Acute phase proteins (APPs) have become an important tool in the diagnosis, management and prognosis of inflammatory diseases in humans and are developing a similar utility in domestic species. Steroid-responsive meningitis arteritis (SRMA) is a well-recognised inflammatory disease of the dog, the diagnosis of which remains unsatisfactory based on clinical criteria and non-specific laboratory investigations. In this prospective pilot study the authors examined the acute phase response throughout the course of SRMA in serum and cerebrospinal fluid (CSF) by evaluating three key stages in disease management: presentation, treatment response and putative relapse.Serum APPs were found to be of value in supporting the diagnosis of SRMA and monitoring its treatment. C-reactive protein (CRP), serum amyloid-A (SAA), alpha-1-acid glycoprotein (AGP) and haptoglobin (Hp) all exhibited an increase above our laboratory reference range in nine patients at initial presentation. During treatment APPs decreased significantly compared to presentation except Hp which increased (Wilcoxon–Signed–Rank-test: CRP, SAA and AGP P < 0.05). Serum CRP and SAA were also found to be of clinical value in the identification of putative relapse (seven cases), particularly in the light of unperturbed CSF parameters where APP concentrations were elevated. CSF APPs were found to be less reliable markers in the management of this disease. The results indicate that SRMA causes a significant APP response in dogs, which although not disease specific, is of value in supporting the diagnosis of SRMA.     

Serum acute phase proteins concentrations in dogs during experimentally short-term induced overweight. A preliminary study

The purpose of the study was to analyse serum concentrations of four different positive acute phase proteins (APPs): C-reactive protein, haptoglobin, serum amyloid A and ceruloplasmin in a model of experimentally short-term developed obesity in Beagle dogs. All APPs were quantified by commercially available ELISA methods and C-reactive protein was also determined by a highly sensitive time-resolved fluorometric assay. There were no significant differences between APPs concentrations at the beginning and the end of the study in groups of dogs that increased their body condition scores. In addition, dogs with body condition scores of 4 and 5 did not shown significant differences for any of the acute phase proteins studied compared with control dogs of BCS of 3, with exception of a decrease in haptoglobin. It was concluded that overweight induced in the experimental conditions of this study does not produce a significant change in acute phase proteins.     

Effects of different glucocorticoid treatments on serum acute phase proteins in dogs

The serum concentrations of haptoglobin, caeruloplasmin, C-reactive protein and serum amyloid A were measured in three groups of seven healthy dogs. Group 1 received a single dose of 1.1 mg/kg methylprednisolone acetate, administered subcutaneously; group 2 received 1 mg/kg per day of prednisone administered orally for three weeks; and group 3 received 2.2 mg/kg per day of prednisone administered orally for seven days. Before the administration of the glucocorticoids the serum concentrations of all the acute phase proteins were within the authors' laboratory reference ranges. After the administration of the drugs there were significant increases in the concentration of haptoglobin in all three groups, the increases being larger in groups 2 and 3. In contrast, the concentrations of C-reactive protein, caeruloplasmin and serum amyloid A were not affected.     

Pathology of concanavalin A-induced cutaneous reaction in the chicken

Sequential study of permeability and cellular responses following intradermal concanavalin A in the chicken skin, using the colloidal carbon technique, revealed an increase in vascular permeability which was mostly confined to venules. A noteworthy feature of the reaction was marked accumulation of basophils, even in the later stages, and the early appearance of perivascular lymphoid aggregations. The occurrence of well formed giant cells, hypertrophy and hyperplasia of vascular endothelium and marked acanthosis of the epidermis were the other prominent changes. The findings suggest that Con A, in the chicken, appears to have a more general effect on the different types of cells and that it may act as a mitogen not only for T lymphocytes but also for endothelial and epithelial cells.     

In vitro lymphocyte stimulation by concanavalin A and with histamine as a co-mitogen in dogs with atopic dermatitis.

Cell-mediated immune function was assessed in a group of dogs with atopic dermatitis by measuring the responses of peripheral-blood lymphocytes (PBL) to various concentrations of Concanavalin A (Con A) and comparing them to those of normal dogs. No difference from normal was found in any of the stimulation indices neither was spontaneous tritium uptake of unstimulated cells different between the groups. We also measured the response to Con A stimulation in vitro of PBL preincubated for 24 h, either in cell-culture medium at 37 degrees C, or in whole blood containing EDTA at room temperature, as an indirect measure of function of a subgroup of suppressor cells. Preincubation caused enhancement of mitogenesis for normal dog lymphocytes but not for the atopic dog cells, particularly for suboptimal concentrations of Con A. No differences were found in the responsiveness following incubation in cell-culture medium between normal and atopic dog cells but for both groups the cells preincubated in whole blood were generally more responsive. Histamine, which is one of the mediators of type 1 hypersensitivities such as atopy, can modulate lymphocyte function. At 10(-4) and 10(-8) M histamine, when added simultaneously with Con A, enhanced mitogenesis of normal dog PBL but suppressed mitogenesis of atopic dog PBL. By using histamine H1 and H2 antagonists, we concluded that histamine enhanced mitogenesis via H1, receptors and suppressed it via H2 receptors. Our results suggest that there are abnormalities in lymphocyte function in dogs with atopic dermatitis which may be important in the pathogenesis of the disease.     

Evidence of an acute phase response in dogs naturally infected with Babesia canis

The erythrocyte sedimentation rate (ESR), white blood cell count (WBC), haematocrit (HCT) and platelet number (PLT) were quantified and compared with the acute phase proteins (APPs) in dogs naturally infected with Babesia canis and healthy dogs. Both groups were treated with imidocarb dipropionate on the day of admission and both groups were monitored for all parameters on the admission day and on the first, second, third, fourth and seventh days in order to determine the presence of an acute phase reaction, to assess the diagnostic value of these markers in uncomplicated canine babesiosis and to evaluate the use of APPs in treatment monitoring. It was demonstrated that an acute phase response occurs in dogs naturally infected with Babesia canis, with significant increases in the concentration of major acute phase proteins. The serum concentration of C-reactive protein (CRP), serum amyloid A (SAA) and the erythrocyte sedimentation rate (ESR) decreased daily after treatment and approached reference range values by the eighth day. PLT and haematocrit (HCT) increased daily after treatment and approached reference range values by the fourth day. WBC and haptoglobin increased after treatment and then decreased from the third and fourth days, respectively, to the eighth day. The diagnostic sensitivity of CRP, SAA and PLT was significantly higher compared to haptoglobin, ESR, HCT and the WBC count. CRP and SAA were of clinical use in monitoring the response to antibabesial treatment.     

Serial evaluation of thoracic radiographs and acute phase proteins in dogs with pneumonia

BackgroundAcute phase proteins (APP) may guide treatment of pneumonia in dogs but correlations with radiographic abnormalities are poorly characterized.ObjectivesDevelop a thoracic radiographic severity scoring system (TRSS), assess correlation of radiographic changes with APP concentrations, and compare time to APP and radiograph normalization with duration of antimicrobials treatment.AnimalsSixteen client‐owned dogs, 12 with aspiration pneumonia, and 4 with community‐acquired pneumonia.MethodsConcentrations of C‐reactive protein (CRP), serum amyloid A (SAA), and haptoglobin were measured on days 1, 3, 7, 14, 28, and 60 and orthogonal 2‐view thoracic radiographs were obtained on days 1, 7, 14, 28, and 60. Treatment was clinician‐guided and blinded to APP concentrations. Radiographic severity scores were assigned by blinded, randomized retrospective review by 2 board‐certified radiologists with arbitration by a third radiologist.ResultsMedian (interquartile range [IQR]) time to normalization of CRP (7 days [7‐14]) and SAA concentrations (7 days [7‐14]) were shorter than antimicrobial treatment duration (17.5 days [14.5‐33.5]; P = .001 and .002, respectively) and TRSS normalization (14 days [8.8‐52], P = .02 and .02, respectively). The CRP and SAA concentrations were positively correlated with TRSS (CRP r _s , 0.643; SAA r _s , 0.634; both P < .0001). Both CRP and SAA identified normal thoracic radiographs area under the curve (AUC) 0.873 and 0.817, respectively, both P < .0001. Interobserver agreement for TRSS assignment was moderate (κ, .499; P < .0001).Conclusion and Clinical ImportanceConcentrations of CRP and SAA normalized before radiographic resolution and before clinicians discontinued antimicrobial treatment. The CRP and SAA concentrations may guide duration of antimicrobial treatment for dogs with pneumonia.     

The distributions of phytohemagglutinin-P and concanavalin A binding sites on equine, bovine and canine peripheral blood lymphocytes

The distributions of phytohemagglutinin-P (PHA) and concanavalin A (ConA) binding sites were investigated for equine, bovine and canine peripheral blood lymphocytes (PBL). Non-B lymphocytes were collected from each PBL using a fluorescence-activated cell sorter (FACS), and the numbers of PHA and ConA binding sites on their surfaces were counted. Most PHA binding sites on PBL of the three species were shown on the surfaces of non-B lymphocytes. On the other hand, the ConA binding sites on equine and canine PBL existed mainly on the surfaces of non-B lymphocytes, but B lymphocytes of these two species had many ConA binding sites. These results were confirmed by the results of two-parameter fluorescence analysis using FACS. It is, therefore, concluded that the different optimum concentrations of PHA and ConA in PBL blastogenic responses of each animal depended on the different distributions of their binding sites.     

Serum acute phase protein concentrations in dogs with hyperadrenocorticism with and without concurrent inflammatory conditions

Background: Acute phase proteins (APPs) are promising markers of inflammation in dogs, because they are more sensitive than WBC counts in detecting clinical and subclinical inflammation. Endogenous corticosteroids can mask an acute phase response and make it more difficult to identify underlying inflammatory disease. Objective: The purpose of this study was to evaluate the acute phase protein response in dogs with spontaneous hyperadrenocorticism (HAC) with and without concurrent inflammatory conditions. Methods: Serum concentrations of C‐reactive protein (CRP), haptoglobin (Hp), fibrinogen, and albumin were measured in 44 healthy adult dogs and 39 dogs with HAC; the HAC group was further divided into dogs with and without concurrent infection/inflammation. A fourth group of dogs with severe sepsis and without HAC was compared with the dogs with HAC and severe sepsis. Results: Dogs with uncomplicated HAC had significantly higher Hp and fibrinogen concentrations compared with healthy control dogs (P<.001). Dogs with HAC and severe inflammatory disease also had significantly higher CRP and lower albumin concentrations than control dogs and dogs with HAC without concurrent inflammation. Dogs with sepsis but without HAC had significantly higher CRP concentrations than dogs with HAC and sepsis. Conclusions: Dogs with HAC had increases in the moderate APPs (Hp and fibrinogen), and no significant changes in CRP and albumin compared with healthy dogs. Although concurrent HAC appeared to blunt the CRP response in dogs with sepsis, increased serum CRP concentration in dogs with HAC is likely indicative of severe concurrent inflammation.     

Selective CD11a upregulation on neutrophils in the acute phase of steroid-responsive meningitis-arteritis in dogs

Steroid-responsive meningitis-arteritis (SRMA) is a systemic inflammatory disease of juvenile to young adult dogs with a relapsing course and most prominent manifestation in the cervical meninges. The most important laboratory finding is a marked neutrophilic pleocytosis. Integrin (CD11a, b, c) expression on polymorphonuclear cells (PMNs) was quantified by immunophenotyping and subsequent flow cytometric measurements. Values were determined for peripheral blood in the acute phase of SRMA (n=14) as well as during glucocorticosteroid treatment (n=16). Results were compared to those from dogs with other neurological diseases (n=49) and healthy individuals (n=7). Integrin expression was also investigated on PMNs deriving from cerebrospinal fluid (CSF) of dogs in the acute phase of SRMA (n=14). In a second part of the study PMNs of healthy dogs were incubated with sera of dogs in the acute phase of SRMA (n=12). The influence on integrin expression was studied and results were compared to those after incubation with pooled sera of dogs suffering from idiopathic epilepsy (n=3). PMNs in peripheral blood of dogs in the acute phase of SRMA showed higher values of CD11a expression when compared to dogs under treatment and to control groups, whereas CD11b and c expression was comparable among the different groups. In the acute phase of SRMA CD11b expression on PMNs in CSF was increased in comparison to that in peripheral blood. Incubation with SRMA sera caused a stronger upregulation of CD11a than did pooled epilepsy sera in 9/12 cases whereas an upregulation of CD11b and c was observed in single cases only. High CD11a expression on PMNs in peripheral blood appears to be an important factor in the pathogenesis of SRMA. This integrin is known to be essential for adhesion of PMNs within the neutrophil recruitment cascade and therefore might mediate the enhanced invasion of neutrophils into the subarachnoidal space eventually leading to meningitis and clinical signs. Since sera of dogs suffering from SRMA selectively induce an upregulation of CD11a it can be suspected that this fluid contains one or multiple factors being responsible for this.     

Detection of Ehrlichia canis by polymerase chain reaction in dogs from Portugal

Antibodies against Ehrlichia canis, the cause of canine monocytic ehrlichiosis, have been reported previously in clinically ill and stray dogs from Portugal. In this study, the 16S rRNA gene of E. canis was detected by the polymerase chain reaction (PCR) in 12/55 (22%) of dogs with suspected tick-borne disease in the Algarve region in Portugal.     

Specificities of antinuclear antibodies detected in dogs with systemic lupus erythematosus

Five hundred and eighty dogs with at least one clinical sign compatible with a systemic lupus erythematosus (SLE) were entered in a prospective study aimed at evaluating the prevalence of antinuclear antibodies (ANAb). SLE was diagnosed in 38 of these dogs (group A) which fulfilled at least four American Rheumatism Association (ARA) criteria; of these, sixteen had ANAb titers greater than or equal to 4096. The 23 dogs which met three or two ARA criteria (group B) had an ANAb geometric mean titer (GMT) of 259. Dogs (group C) with only 1 criterium had an ANAb GMT of 75. Anti-ds-DNA Ab were present in 6 dogs from group A (16%), and 2 dogs from group B (9%). Anti-histone Ab were present among dogs from group A, B and C with frequencies of 81%, 67% and 26%, respectively. Among dogs from group A, the ANAb titers and the levels of anti-histone Ab correlated positively when individual sera were considered. Antibodies against the soluble nuclear antigen (SNA) were detected in 74%, 39% and 13% of the dogs from groups A, B and C, respectively. Antibodies initially described in human SLE also exist in SLE dogs. Anti-Sm Ab were found in 24% of dogs in group A. With anti-RNP Ab the frequency was still lower (10%). However, two other types of anti-SNA Ab against RNAse and trypsin-resistant antigens, not found in human "reference sera", were often detected. The first type (anti-type 1 Ab) was found in 26% and 9% of group A and group B, The first type (anti-type 1 Ab) was found in 26% and 9% of group A and group B, respectively; the second type (anti-type 2 Ab) is less frequent, and was found in 13% and 17% of group A and B, respectively. It appears that testing for anti-Sm, anti-type 1 and anti-histone Ab should be performed in order to improve the diagnosis of SLE in dogs.