Immunoglobulins IgG and IgM in synovial fluids of swine with erysipelothrix polyarthritis

Concentrations of IgG and IgM immunoglobulins in synovial fluids and sera from a group of swine with experimentally produced Erysipelothrix rhusiopathiae polyarthritis were measured to determine if there was local synthesis of these immunoglobulins by plasma cells in arthritic synovial tissue. IgG and, to a lesser extent, IgM were significantly higher in arthritic than in nirmal synovial fluids from the same group of swine and this increase could only partly be explained by the increased permeability of the arthritic synovial membrane to plasma proteins. When synovial fluid values of IgG and IgM were calculated on the basis of companion serum concentration it was found that 82% of IgG, and 25% of IgM estimations were significantly elevated above levels in normal joints indicating that IgG was the dominant immunoglobulin synthesized.     

Successful treatment of infectious (Salmonella type III: 44) polyarthritis and osteomyelitis in a 4‐week‐old foal

This article describes the acute onset of infectious polyarthritis and osteomyelitis in a 4‐week‐old foal. Analysis of synovial fluid obtained from the left femoropatellar and right tarsocrural joints combined with clinical signs consisting of joint effusion and lameness yielded a diagnosis of septic arthritis. Bacterial culture of synovial fluid from the left stifle revealed Salmonella type III: 44. Rapid, sustained clinical improvement was noted following discontinuation of empirical antimicrobial therapy (potassium penicillin and amikacin sulphate) and initiation of treatment with ceftiofur and ampicillin. The importance of combining knowledge of veterinary pharmacology and microbiology so that appropriate antimicrobials may be selected with regard to the local environment in which they are to eradicate infection is emphasised. Despite frequent reference to amikacin sulphate as an effective antimicrobial for treating infections in foals caused by Salmonella, factors are discussed that explain why amikacin may not be clinically effective for treating infectious arthritis caused by Salmonella.     

Erosive polyarthritis associated with Mycoplasma gateae in a cat

Erosive polyarthritis was diagnosed in an 11-month-old neutered male Egyptian Mau-cross cat with concurrent glucocorticoid-responsive dermatitis. Clinical signs, synovial fluid analysis, serological tests and radiographic appearance could not differentiate between immune-mediated and infective arthritis. Mycoplasma gateae was isolated by strictly anaerobic culture of the synovial fluid. Treatment with Enrofloxacin led to a rapid improvement of the cat's condition. Two months later the cat was euthanased because of severe glomerulonephritis and direct Coombs' test positive anaemia, possibly caused by mycoplasma infection. M gateae could not be isolated at post-mortem examination.     

Bovine and ovine mycoplasmal arthritis and synovitis (abstract)

The pathology of mycoplasmal gonitis in a Friesian cow aged 15 months, and polyarthritis in a 3-week-old East Friesian sheep was described. Both stifle joints of the cow, which was 1/63 calves that developed polyarthritis after being fed milk contaminated with Mycoplasma mycoides mycoides large colony type (MmmLC), were distended with yellow flocculent fluid. The capsular and synovial tissues and their associated tendon sheaths were greatly thickened due to chronic active fibrinopurulent inflammation with ulceration of synovial membranes and progressive organisation of the exudate by granulation tissue and fibrosis. Nodular aggregates of lymphocytes and plasma cells studded the membrane. Articular surfaces were unremarkable. Mycoides cluster organisms were demonstrated on polymerase chain reaction (PCR) analysis of the joint tissues and these were confirmed on culture as MmmLC. The lamb was the offspring of an agalactic ewe whose progeny of the previous 3 years developed polyarthritis. The carpal and hock joints had periarticular nodular swellings and there was mild haemarthrosis of all appendicular skeletal joints. Lesions were characterised as subacute active fibrinopurulent synovitis and periarthritis with haemorrhage. Articular surfaces were normal. Joint tissue was positive by PCR for the mycoides cluster of organisms. Mycoplasma was not isolated in culture.     

Effect of Repeated Arthrocentesis on Cytologic Analysis of Synovial Fluid in Dogs

Background: Serial arthrocentesis and synovial fluid examination can be used to monitor treatment efficacy in immune-mediated polyarthritis (IMPA), but whether this procedure induces inflammation that interferes with test result interpretation is unknown.
Objectives: The aim of this study was to determine the effect of repeated arthrocentesis on synovial fluid cytology in healthy dogs.
Animals: Nine healthy client-owned dogs.
Methods: Prospective study. Arthrocentesis was performed under sedation on 4 joints (both carpi, 1 tarsus, 1 stifle) on each dog every 3 weeks, a total of 4 times. Automated cell counts were done on stifle fluid, smears were made, and differential cell counts done on smears from all joints. Slides were evaluated microscopically for erythrocyte numbers, total nucleated cell count, differential cell count, and cell morphology. Data were analyzed by 2-way analysis of variance.
Results: A total of 144 synovial fluid samples were examined. Repeated arthrocentesis was not associated with increases in synovial fluid neutrophil numbers. Mild mononuclear inflammation was detected in 13 samples from 6 dogs.
Conclusions and Clinical Importance: Serial arthrocentesis at 3-week intervals can rarely be associated with mild mononuclear joint inflammation, but does not appear to induce neutrophilic inflammation, at least in healthy dogs, and can be useful to monitor treatment response in canine IMPA.     

The Physiopathological Changes in Synovial Fluid in Arthritic Swine

There was produced with Ery. rhusiopathiae a rheumatoid-like arthritis in swine, which passed successively through acute, sub-acute and chronic stages. This was typically a non-suppurative proliferative change with concurrent changes in the joint fluid.

The arthritis was shown to persist even though the initial inciting agent could not be isolated from the advanced cases of chronic polyarthritis. This strongly suggests that the pathological process responsible for this arthritis can become autonomic and probably is related to a state of hypersensitivity.

The cellular changes observed in the synovial fluid did not differ markedly from those of rheumatoid arthritis in man. Synovial fluid mucinous changes were apparent in the decreased viscosity observed grossly. Definite changes in the character of the precipitate produced by acetic acid treatment of the fluid were also observed.

     

Orally administered doxycycline accumulates in synovial fluid compared to plasma

Reasons for performing study: Tetracycline compounds have been used to slow the progression of osteoarthritis (OA) and rheumatoid arthritis but the concentration of doxycycline attained in synovial fluid following oral, low‐dose administration has yet to be determined. Objective: To determine the concentration of doxycycline in synovial fluid following oral, low‐dose administration. Methods: Six mature horses received doxycycline (5 mg/kg bwt q. 12 h for 5 doses). Venous blood and synovial fluid samples were collected at t = 0, 0.25, 0.5, 1, 12, 24, 48 and 72 h. Doxycycline concentrations were measured using reverse phase high pressure liquid chromatography with ultraviolet detection. Results: Doxycycline concentrations at all time points after t = 0 were above the lower limit of quantification for the assay. Plasma concentrations of doxycycline were above 0.21 µg/ml at t = 0.5 h. The mean ± s.d. peak concentration (C_max) of doxycycline in plasma was 0.37 ± 0.22 µg/ml and time to peak concentration was 0.54 ± 0.19 h. Synovial fluid concentrations of doxycycline were above 0.12 µg/ml 1 h after drug administration. The mean C_max of doxycycline in the synovial fluid was 0.27 ± 0.10 µg/ml. The penetration factor of doxycycline from plasma into synovial fluid, as determined by a ratio of the area‐under‐the‐curve for synovial fluid:plasma during the sampling period, was 4.6. Potential relevance: Orally administered doxycycline distributes easily into synovial fluid with a penetration factor of 4.6. Terminal half‐life of the drug in synovial fluid was longer than in the plasma, indicating possible accumulation in this compartment. Further in vivo studies are warranted to define a medication protocol prior to routine clinical use of doxycycline for the treatment of OA.     

我国发生Leachii支原体引起的犊牛多发性关节炎

2009年2月～6月我国某奶牛场发生严重的犊牛多发性关节炎,发病犊牛的症状与最早发生于澳大利亚的犊牛Leachii支原体关节炎非常相似。为确定病原,我们无菌采集2份具有典型症状犊牛的关节液样品进行实验室诊断,2份样品中均检测和分离出支原体。将2个分离菌株的16S rRNA基因和LppA基因与参考支原体菌株进行核苷酸序列比对,发现这2株支原体的16S rRNA基因和LppA基因均与Leachii支原体具有最高的核苷酸序列同源性,分别为99.9%和99.6%。结果显示,本研究分离的2株支原体为Leachii支原体,分别命名为GN407和GN408。综合分析发病犊牛的临床病理学观察和关节液样品的实验室诊断结果,我们确定Leachii支原体为该奶牛场犊牛多发性关节炎的病因。     

Clinical and radiographic study of bone and joint lesions in 26 dogs with leishmaniasis

Twenty-six dogs with parasitologically confirmed leishmaniasis and abnormalities of gait were studied to determine the most common radiological patterns of bone and joint lesions. The clinical findings included either lameness, joint pain and crepitation, soft tissue swelling and/or muscle atrophy. Bone lesions were observed radiographically in 12 of the 26 dogs; the radius and ulna were affected in seven, the tibia in six and the femur in six. Joint lesions were observed radiographically in 15 of the 26 dogs; the carpus and stifle were affected in all 15, and the tarsus in nine. There was a tendency for the bones and joints to be affected bilaterally. The radiographic patterns observed were different in the long bones and the joints. In the long bones, the most common pattern was periosteal and intramedullary proliferation, involving the diaphyses and related to the nutrient foramen; in the joints, two patterns, either non-erosive or erosive polyarthritis with soft-tissue swelling, were observed. The changes observed in the synovial fluid were associated in most cases with osteolytic lesions. However, Leishmania organisms were identified in the synovial fluid from joints without bony radiographic changes.     

Polyarthritis in a young cat

A 3-year-old cat had polyarthritis involving both tarsal joints and the right carpal joint. The condition was associated with pyrexia and regional lymphadenopathy. The aetiology of the arthritis was not determined, but no bacterial or mycoplasmal agent could be isolated from the synovial fluid obtained from one of the affected joints. Prednisolone, administered on a reducing dosage schedule, induced lasting remission of the clinical signs.     

Ehrlichia canis-related polyarthritis in a dog

Ehrlichia canis-related polyarthritis was diagnosed in a 7-month-old Boxer. The diagnosis was based on intraneutrophilic morulae found in synovial fluid specimens, thrombocytopenia, a positive result for indirect fluorescent antibody testing for E canis, the presence on the dog of the known vector of E canis infection (Rhipicephalus sanguineus), and a favorable response to treatment with tetracycline hydrochloride. The dog has had no recurrence of lameness for 18 months after cessation of treatment.     

Synovial fluid D-dimer concentration in foals with septic joint disease

Background: Increased synovial fibrinolytic activity (detected by increases in synovial D‐Dimer concentrations) has been observed in different joint diseases in humans and adult horses, presumably in order to minimize fibrin deposition within the joint and thus avoid its detrimental effects. Objective: To investigate fibrinolytic pathway activation in joint sepsis in foals by measuring synovial D‐Dimer concentrations. Animals: Eighteen septic foals with septic joints, 9 septic foals without septic joints, 9 systemically healthy foals with septic joint, and 3 controls are included. Methods: Prospective observational clinical study of foals admitted for septic arthritis. Synovial D‐Dimer concentration and routine synovial fluid analysis were performed. Diagnosis of joint sepsis was made whenever synovial total nucleated cell count was >30,000 cells/μL, synovial total protein >4 g/dL, and neutrophil percentage of >80%, or synovial fluid culture resulted positive. Results were compared among groups by general lineal models. Results: Synovial D‐Dimer concentration was significantly (P < .001) higher in the foals with septic joints compared with foals without joint disease (P < .001). Conclusions and Clinical Importance: Septic joint disease is associated with a marked increase of synovial D‐Dimer concentration (marked activation of the fibrinolytic activity) within the affected joint. Although further studies are needed, the measurement of synovial D‐Dimer concentration may be considered a complementary diagnostic marker of septic joint disease.     

Automated counting of nucleated cells in equine synovial fluid without and with hyaluronidase pretreatment

Background: Microscopy is usually used to obtain manual total and differential cell counts in equine synovial fluid. A faster, more precise method is desirable. Objectives: The objectives were to compare an automated impedance method with a manual method for obtaining total and differential cell counts in equine synovial fluid and to evaluate the effect of pretreatment with hyaluronidase on automated results. Methods: Synovial fluid samples (n=48) were collected into EDTA and analyzed within 48 hours. Automated total and differential cell counts were evaluated using a Medonic CA620‐VET hematology analyzer before and after pretreatment for 5–30 minutes with hyaluronidase (final concentration 0.01 mg/mL). A hemacytometer count and microscopic evaluation of a direct smear were used as the reference method. Intra‐assay coefficients of variation (CV) were determined. Results: Thirty‐one of 46 untreated samples and 0/46 hyaluronidase‐treated samples were error‐flagged by the analyzer. Correlation between automated (ANCC) and manual (MNCC) nucleated cell counts in untreated samples (n=15; R²=0.93) and pretreated samples (n=46; R²=0.94) was high, and pseudomedian difference was low. Intra‐assay CVs for samples with medium and high cellularity were significantly lower for ANCC (1.5–2.7%) compared with MNCC (6.1–15.7%) (P<.01). Valid automated differential cell counts were not obtained. Conclusions: Automated total cell counts obtained on the Medonic analyzer correlate well with manual counts in equine synovial fluid; however, pretreatment with hyaluronidase is required to minimize error flags. Automated differential counts are not accurate for synovial fluid.     

Bacterial culture of septic synovial structures of horses: Does a positive bacterial culture influence prognosis?

Reasons for performing study: The influence of synovial fluid culture on short‐ and long‐term prognosis of cases with septic synovitis requires study. Hypotheses: Horses with a positive bacterial culture from septic synovial fluid are less likely to survive or return to successful athletic function than those with a negative bacterial culture from septic synovial fluid. Methods: Records of mature horses presented to 2 equine referral hospitals for investigation of suspected septic synovitis were examined. Horses (n = 206) were included in the study if synovial fluid was submitted for full laboratory examination, including bacterial culture. A diagnosis of septic synovitis was based on a nucleated cell count >30 × 10⁹ cells/l or >90% neutrophils and other clinical, cytological and bacteriological parameters. Long‐term follow‐up was obtained by telephone questionnaire. Univariate analysis, using the Fisher's exact test, was used for all outcomes. Results: Fourteen (20.9%) of 67 horses with a positive bacterial culture from synovial fluid were subjected to euthanasia because of persistent synovial sepsis compared to 2 (1.44%) of 139 with negative bacterial cultures (P<0.001). Overall survival and successful long‐term return to function in horses with a positive bacterial culture was 50% (24/48 horses) compared to 70.5% (74/105) in culture negative horses (P = 0.01). In horses that survived to be discharged, successful long‐term return to function was not significantly different between culture positive and culture negative groups. Growth of Staphylococcus aureus from synovial fluid did not affect short‐term survival to discharge from the hospital compared to other positive bacterial culture; however, successful long‐term return to function was only 30.4% (4/13) in horses from which S. aureus was cultured compared to 73.9% (17/23) of horses in which other bacteria were cultured (P = 0.015). Conclusions and potential clinical relevance: Horses with a positive bacterial culture from a septic synovitis have a poorer prognosis for survival to discharge from hospital and overall long‐term return to function than horses that yielded no bacterial growth. When S. aureus was cultured, the long‐term prognosis was poorer.     

Synovial fluid eosinophilia: a case report in a dog and review of the literature

The first known report of synovial fluid eosinophilia in a dog is described here. The occurrence of eosinophils in joint fluid is rare. Sporadic cases have been recorded in humans and most can be related to immunemediated reactions, both parasitic and non- parasitic. The dog in this case report had 20-52% eosinophils in multiple joints, as well as hemarthrosis and marked mononuclear cell reactivity. An intense peripheral eosinophilia was demonstrated one week later. The associated lameness resolved with non-steroidal anti-inflammatory therapy. Lack of remarkable history or other clinical symptoms led to a diagnosis of idiopathic, eosinophilic, polyarthritis, likely immune-mediated.     

Cartilage-derived retinoic acid-sensitive protein in equine synovial fluid from healthy and diseased joints

Reasons for performing study: More sensitive and specific diagnostic methods for early detection of changes in the joint cartilage are needed. Cartilage‐derived retinoic acid‐sensitive protein (CD‐RAP) is a potential marker of cartilage synthesis and regeneration. This is the first study on equine CD‐RAP. Objectives: To evaluate the ability of a commercially available human sandwich ELISA assay to detect equine CD‐RAP in synovial fluid from healthy and diseased joints. Methods: Synovial fluid was collected from 28 horses with no signs of joint disease and from 5 with induced inflammatory arthritis. CD‐RAP concentrations were measured using a human CD‐RAP ELISA. Intra‐ and interassay imprecision of the assay were evaluated by multiple measurements on pools of equine synovial fluid. Assay inaccuracy was determined by linearity under dilution. Results: The assay showed moderate to large intra‐ and interassay variation when applied to equine synovial fluid. Equine CD‐RAP was detected in synovial fluid from healthy horses ranged at 8.2–52 ng/ml. Repeated arthrocentesis (after injection of isotonic saline), age, joint or gender did not significantly affect CD‐RAP concentrations. Twelve hours after intra‐articular injection of lipopolysaccharide, concentrations of CD‐RAP were significantly lower than after injection of isotonic saline and remained significantly lower until the end of the study at 144 h. Conclusion and potential relevance: The assay is suitable for longitudinal monitoring of CD‐RAP concentration in individual horses. Disease significantly influenced CD‐RAP levels. Similar to previous results obtained in man, CD‐RAP seems to be a marker of cartilage synthesis and/or regeneration in horses.     

Bacterial infective arthritis in the dog

Bacterial infections of joints produce an inflammatory arthropathy. Most cases appear to be due to the haematogenous localisation of bacteria in a joint and trauma may predispose a joint to infection. Two clinical syndromes are identified; the classic acute onset case and a more chronic local grade infection syndrome. Affected joints are usually thickened and show pain on manipulation. The synovial fluid has increased numbers of white cells, most of which are polymorphonuclear leucocytes. Peripheral blood analysis may be normal and only a few dogs show systemic illness. Radiography in the early stage, will only show soft tissue changes; periosteal new bone and bony destruction are seen in longer standing cases. The carpus was the most frequently affected joint and the larger breeds, particularly the males, were over-represented. Various organisms were isolated but haemolytic Streptococcus and Staphylococcus intermedius were the most common. Culture of the synovial membrane was more sensitive than the synovial fluid. Antibiotic therapy for several weeks was generally successful providing an early diagnosis was made. In a few cases, steroid responsive synovial inflammation persisted in the absence of viable bacterial organisms.     

Pharmacokinetics of tetracycline in plasma,synovial fluid and milk using single intravenous and single intravenous regional doses in dairy cattle with papillomatous digital dermatitis

Rodrigues, C. A., Hussni, C. A., Nascimento, E. S., Esteban, C., Perri, S. H. V. Pharmacokinetics of tetracycline in plasma, synovial fluid and milk using single intravenous and single intravenous regional doses in dairy cattle with papillomatous digital dermatitis. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2009.01138.x. The purpose of this study was to compare the pharmacokinetics of tetracycline in plasma, synovial fluid, and milk following either a single systemic intravenous (i.v.) injection or a single i.v. regional antibiosis (IVRA) administration of tetracycline hydrochloride to dairy cattle with papillomatous digital dermatitis (PDD). To this end, plasma and synovial fluid tetracycline concentrations were compared with the minimal inhibitory concentration (MIC) values of the major bacteria, which are known to cause digital diseases and thus assess its efficacy in PDD. Residual tetracycline concentrations in milk from cows treated by both methods were also determined. Twelve Holstein cows with various stages of PDD were randomly assigned to two groups of six animals. Group 1 received a single systemic i.v. injection of 10 mg/kg of tetracycline hydrochloride. Group 2 received 1000 mg of tetracycline hydrochloride by IVRA of the affected limb. Blood, synovial fluid and milk samples were taken prior to tetracycline administration (time 0 control), and then at 22, 45 and 82 min, and 2, 3, 4, 6, 8, 12, 24, 48, 72, 96, and 120 h following drug administration. Tetracycline concentrations were determined by high‐performance liquid chromatography. Mean tetracycline plasma and milk concentrations in Group 1 were higher than Group 2. The opposite was observed for synovial fluid concentrations. Group 2 synovial fluid concentrations were higher than the MIC value over 24 h for the bacteria most frequently responsible for claw disease. Compared with i.v. administration, IVRA administration of tetracycline produced very high synovial fluid and low plasma and milk concentrations.     

Synovial fluid total protein concentration as a possible marker for canine idiopathic polyarthritis

Idiopathic polyarthritis (IPA) is a very common inflammatory arthropathy in the dog. Canine IPA is diagnosed mainly by detecting increased number of leukocytes in the synovial fluid (SF), which is easily influenced by glucocorticoid therapy. We obtained 31 SF samples from 24 IPA dogs prior to (n=19) and/or after (n=12) 1 to 10 weeks of glucocorticoid therapy. The SF total protein concentrations of IPA dogs were significantly higher than those of dogs with non-arthritis diseases (n=34) and healthy controls (n=10). Our data revealed that the SF total protein concentrations are not influenced by several weeks of glucocorticoid therapy. Hence, the SF total protein concentration is applicable as a diagnostic marker of canine IPA even when the patients are receiving glucocorticoid therapy.     

Urea as a measure of dilution of equine synovial fluid

This paper tests the hypothesis that serum and synovial urea concentrations are similar and that urea concentration can be used as an accurate marker for synovial fluid dilution in normal equine joints. Serum and synovial fluid urea concentrations were compared in 42 horses and were equivalent for individual horses (P<0.0001). Mean +/- s.e. serum concentration was 6.1+/-0.552 mmol/l and synovial concentration 6.0+/-0.459 mmol/l. The normal range for synovial urea concentration was determined as 2.5-7.7 mmol/l. The synovial urea concentration from different synovial structures in individual horses were compared and were equivalent (P = 0.002). Known dilutions of synovial fluid with saline were made. The actual and expected synovial urea concentrations were compared and were equivalent (P<0.001). An accurate method of calculating synovial fluid dilution has been determined.