Synovial White Blood Cell Count Research Articles

Effects of intra-articularly administered endotoxin on clinical signs of disease and synovial fluid tumor necrosis factor, interleukin 6, and prostaglandin E2 values in horses

SUMMARY In each of 4 horses, sterile synovitis was induced by intra-articular injection of 3 μg of Escherichia coli endotoxin (lipopolysaccharide, LPS) into one antebrachiocarpal joint; an equal volume (2 ml) of phosphate-buffered saline solution (PBSS) was injected into the opposite, control carpus. Blood and 1.5 ml of synovial fluid were obtained at postinjection hours (pih) 0, 2, 4, 8, 12, 18, 42, 66, and 144. Synovial fluid sample collection was accomplished by use of an indwelling, intra-articular catheter through pih 12, and by arthrocentesis subsequently. Joint fluid samples were analyzed for cell counts, protein concentration, cytologic variables, and tumor necrosis factor (tnf), interleukin 6 (IL-6), and prostaglandin E2 (PGE2) values. Tumor necrosis factor and 1L-6 activities and WBC count were also measured in blood. To monitor local inflammation, skin temperature of each carpus was imaged, using a thermographic scanner prior to each sample collection time. Horses had minimal systemic effects. Mean (± SEM) rectal temperature increased significantly to 39 02 ± 0.15 C only at pih 18 after intra-articular injection of LPS. One horse had signs of mild depression from pih 7 to 18, but its vital signs did not change appreciably. Each horse had mild signs of discomfort in the LPS-injected limb from pih 1 to 3 until pih 8 to 10. Mean peak surface temperature of the LPS-injected carpi was significantly higher than that of control carpi from pih 8 to 144 (P < 0.05). Mean synovial fluid WBC count in the LPS-injected and control carpi increased after injection and peaked by pih 8 (193,125 ± 8,528 cells/μl, LPS-treated; 16,425 ± 8,336 cells/μl, controls). Mean values for LPS-treated (principal) joints were significantly greater than values for control joints from pih 2 until after pih 66 (P < 0.05). Mean synovial fluid protein concentration increased in the principal and control joints, with values for the principal joints remaining significantly greater than values for control joints from pih 4 to 144 (P < 0.05). Mean TNF activity in synovial fluid was maximal at pih 2 (10,573 ± 5,924 U/ml). Interleukin-6 activity increased more gradually and peaked at pih 8 (1.78 ± 0.71 × 106 U/ml). Tumor necrosis factor activity did not increase above the minimal detectable value of 6 U/ml in the control joints. Mean PGE2 concentration in the principal joints peaked by pih 2 (3.6 ± 0.37 ng/ml) and remained significantly (P < 0.05) greater than the value for control joints from pih 2 through 66. These results indicate that a humane model of synovitis was created by intra-articular injection of LPS and can be used to establish the basic responses of synovial TNF, IL-6, and PGE2 in horses with early inflammatory joint disease.

Evaluation of sodium hyaluronate therapy in induced septic arthritis in the horse.

This study was conducted to determine the efficacy of sodium hyaluronate (SH) with antibiotic therapy and joint lavage for reducing acute inflammatory and degenerative changes induced by septic arthritis. Septic arthritis was induced in six adult horses by inoculating the tarsocrural joints with 1 x 10(4) colony-forming units of Staphylococcus aureus. When clinical signs appeared, trimethoprim-sulphamethoxazole (30 mg/kg bodyweight [bwt] daily) and phenylbutazone (4.4 mg/kg bwt sid) were administered and continued until termination of the study (Treatment Day 18). Twenty-four hours post inoculation, all joints were lavaged with sterile lactated Ringer's solution. Following lavage, one joint of each horse was injected with 10 mg of SH, and the contralateral joint served as the control. Sodium hyaluronate treated joints showed significant reductions in lameness, tarsal circumference and synovial fluid protein and WBC concentrations. The synovial membrane of the SH-treated joints contained less cellular infiltrate, less granulation tissue formation and retained a more normal villous structure compared with controls. The total glycosaminoglycan loss from the articular cartilage in the SH treated joints was consistently less than that from the control joints; however, this difference was not statistically significant. Sodium hyaluronate with joint lavage appears to be more beneficial than lavage alone for treatment of septic arthritis.

Effects of intra-articular administration of dimethylsulfoxide on chemically induced synovitis in immature horses

SUMMARY The effects of intra-articular administration of dimethylsulfoxide (dmso) on chemically induced synovitis in the middle carpal joint of 6 weanling horses were evaluated. Following aseptic collection of synovial fluid, the middle carpal joint of each forelimb was injected with 50 mg of Namonoiodoacetate to induce synovitis. Eight days after injection, synovial fluid was obtained and the right middle carpal joints were injected with 2 ml of 40% dmso in lactated Ringer solution. The corresponding joints of the left limb (control) were injected with 2 ml of lactated Ringer solution. Sampling and treatments were repeated on postinjection days 11 and 14, for a total of 3 treatments. Horses were visually evaluated daily for lameness and joint effusion. Synovial fluid was evaluated for color and clarity, differential and total WBC count, total protein content, and hyaluronic acid concentration. The Kaegi gait analysis system provided an objective assessment of lameness prior to inducing synovitis, again on day 7, and on day 17. At necropsy (day 17), synovial fluid, synovial membrane, and articular cartilage specimens were collected. Joint effusion was evident 12 hours after injection of Namonoiodoacetate in all joints. Mild lameness was evident at 24 hours; however, the lameness resolved by 72 hours. Objective assessment of lameness did not reveal significant differences between treatment or control limbs. Hyaluronic acid concentrations increased significantly (P = 0.023) above baseline values in most joints over the study period. Synovial fluid wbc counts increased significantly (P = 0.002) following Na-monoiodoacetate injection and remained significantly (P = 0.002) above baseline values throughout the study. There was a significantly greater decrease (P = 0.04) in total wbc counts between the pretreatment and final sampling period in the dmso-treated joints, compared with the controls. Histologic evaluation of synovial membrane samples revealed a significantly less inflammatory response in 4 of 6 dmso-treated joints, compared with that in the controls. Histochemical staining of articular cartilage did not reveal any observable difference between treated or control specimens.

Evaluation of use of dimethyl sulfoxide for intra-articular lavage in clinically normal horses

SUMMARY The antebrachiocarpal and tarsocrural joints of 10 adult horses were randomly assigned to 1 of 4 groups. Groups were formulated and were treated as follows: group 1, control (arthrocentesis only); group 2, buffered lactated Ringer solution; group 3, 10% dimethyl sulfoxide (dmso; w/v) in lactated Ringer solution; and group 4, 30% dmso (w/v) in lactated Ringer solution. Joints were lavaged once with the respective solution. Prior to lavage and on days 1, 4, and 8 after lavage, all horses were evaluated for lameness and joint effusion; synovial fluid total and differential wbc counts, synovial fluid total protein concentration, and mucin clot quality were determined. Horses were euthanatized on day 8, and joints were evaluated grossly, histologically, and histochemically. Significant difference was not observed in effect of lactated Ringer solution, 10% dmso, and 30% dmso on any measured variable. At 24 hours after treatment, significant (P < 0.05) difference in synovial fluid wbc numbers and total protein concentration was detected between control and treated joints. Eighty percent of lavaged joints had effusion 24 hours after treatment, compared with 30% of control joints. Gross, histopathologic, or histochemical differences were not detected between treated and control joints. Results of the study indicate that buffered lactated Ringer, 10% dmso, and 30% dmso solutions induce similar inflammatory changes in articular structures and significantly greater inflammatory reaction than does arthrocentesis alone.

Treatment of Nongonococcal bacterial septic arthritis.

Septic arthritis carries significant morbidity and mortality, necessitating prompt, appropriate therapy with joint fluid aspiration, intravenous antibiotics, and occasionally, surgical intervention. The initial choice of antimicrobial agent is guided by the results of synovial fluid gram stain, by identification of the pathogenesis of the primary focus, or by epidemiologic factors. Adequacy of therapy is assessed by serial synovial fluid white blood cell counts and by determining antimicrobial concentrations in the joint space. The goal of treatment is a clinically normal and sterile joint. Factors that may affect antimicrobial joint penetration include the degree of joint tissue inflammation, the degree of drug protein binding, and the chemical characteristics of the drug. Perhaps most important in determining the extent of joint penetration are factors that may affect serum antibiotic concentrations, for example, dose, route of administration, volume of distribution, but rate of elimination.

Reciprocal relationship of synovial fluid volume and oxygen tension.

To investigate the impact of synovial fluid volume on oxygen tension (PO2) and other metabolic correlates, 24 specimens of synovial fluid from the knees of 22 patients were analyzed for volume, number of leukocytes (WBC), pH, PO2, PCO2, glucose, protein, and complement (CH50) levels. Concurrent arterial blood samples were obtained in 21 instances. Synovial fluid PO2 values varied inversely with volumes of synovial fluid (r = -0.54, P less than 0.01), but when patients with rheumatoid arthritis were excluded, the correlation was more significant (r = -0.76, P less than 0.001). When synovial fluid PO2 dropped below 45 mm Hg, intraarticular acidosis resulted. The decrease in pH (r = 0.93, P less than 0.001), the lowering of glucose values (r = 0.89, P less than 0.001), and the rise in PCO2 (r = -0.79, P less than 0.01) can be explained by a shift toward anaerobic metabolism coupled with the impaired elimination of its products. Systemic acidosis and hypoxia were not found. Intraarticular hypoxia most likely represents circulatory imbalance at the level of the synovial membrane, although an inverse relationship of synovial fluid PO2 and WBC was also noted. Complement and protein levels had no correlation with volume, pH, or respiratory gas tensions of synovial fluids. Our data support the importance of the effective blood flow to the joint in maintaining homeostasis. The volume of synovial effusion and the compliance of the joint capsule appear to be important determinants of the articular blood supply.

Rheumatic Fever and Gonococcal Pharyngitis in an Adult

The arthritis of rheumatic fever in adults may mimic acute gonococcal arthritis. To further characterize this clinical picture the features of six patients presenting with the migratory polyarthritis of acute rheumatic fever have been analyzed. There were two men and four women, ranging in age from 18 to 43; in five the initial clinical impression was gonococcal arthritis. In all patients, however, the diagnosis of acute rheumatic fever was subsequently established. Characteristics of acute rheumatic fever not commonly described included tenosynovitis in all six and an erythematous rash in three. In three patients synovial fluid WBC exceeded 28,000/cu mm, with greater than 90% neutrophils. In five of the six, gonococcal arthritis was ruled out by appropriate studies and by failure to respond to antibiotics in all patients. The one patient with serum antigonococcal antibodies had gonococcal pharyngitis and acute rheumatic fever.