Investigation of synovial fluid lubricants and inflammatory cytokines in the horse: a comparison of recombinant equine interleukin 1 beta-induced synovitis and joint lavage models

BACKGROUND

Lameness is a debilitating condition in equine athletes that leads to more performance limitation and loss of use than any other medical condition. There are a limited number of non-terminal experimental models that can be used to study early inflammatory and synovial fluid biophysical changes that occur in the equine joint. Here, we compare the well-established carpal IL-1β-induced synovitis model to a tarsal intra-articular lavage model, focusing on serial changes in synovial fluid inflammatory cytokines/chemokines and the synovial fluid lubricating molecules lubricin/proteoglycan 4 and hyaluronic acid. The objectives of this study were to evaluate clinical signs; synovial membrane and synovial fluid inflammation; and synovial fluid lubricants and biophysical properties in response to carpal IL-1β synovitis and tarsal intra-articular lavage.

RESULTS

Hyaluronic acid (HA) concentrations, especially high molecular weight HA, and synovial fluid viscosity decreased after both synovitis and lavage interventions. Synovial fluid lubricin concentrations increased 17-20-fold for both synovitis and lavage models, with similar changes in both affected and contralateral joints, suggesting that repeated arthrocentesis alone resulted in elevated synovial fluid lubricin concentrations. Synovitis resulted in a more severe inflammatory response based on clinical signs (temperature, heart rate, respiratory rate, lameness and joint effusion) and clinicopathological and biochemical parameters (white blood cell count, total protein, prostaglandin E2, sulfated glycosaminoglycans, tumor necrosis factor-α and CC chemokine ligands - 2, - 3, - 5 and - 11) as compared to lavage.

CONCLUSIONS

Synovial fluid lubricin increased in response to IL-1β synovitis and joint lavage but also as a result of repeated arthrocentesis. Frequent repeated arthrocentesis is associated with inflammatory changes, including increased sulfated glycosaminoglycan concentrations and decreased hyaluronic acid concentrations. Synovitis results in more significant inflammatory changes than joint lavage. Our data suggests that synovial fluid lubricin, TNF-α, CCL2, CCL3, CCL5, CCL11 and sGAG may be useful biomarkers for synovitis and post-lavage joint inflammation. Caution should be exercised when performing repeated arthrocentesis clinically or in experimental studies due to the inflammatory response and loss of HA and synovial fluid viscosity.

Leucoreduced platelet concentrates in additive solution: an evaluation of filters and storage containers

BACKGROUND AND OBJECTIVE

Buffy coat (BC) pooling sets are integrated systems, consisting of a pooling bag, a filter and a platelet storage container, for the production of leucoreduced platelet concentrates (LR-PCs) from pooled BCs. It was our aim to compare various pooling sets that are currently marketed.

MATERIALS AND METHODS

LR-PCs were made by pooling five BCs and adding 250 g of PAS-II. In study I, filters were compared: four BC pools (of five BCs each) were mixed and divided, and after centrifugation the platelet-rich supernatant (PRS) was expressed through one of the following filters: CLX-5, BioP-plus, Autostop or Imugard. In study II, storage containers were compared: five LR-PCs were mixed and divided over the following storage containers: 1300-ml PL-2410, 1000-ml and 1500-ml polyolefin, 1500-ml CLX or 1000-ml DnDP-PVC. These LR-PCs were stored for 9 days with sampling performed on days 1, 2, 5, 7 and 9. We required that the pH remained between 6.8 and 7.4, and that the swirling effect was present at the end of the storage period.

RESULTS

All filters gave LR-PCs that contained uniformly < 1 x 106 leucocytes (n = 12 experiments) with a recovery of, on average, 70% of the platelets originally present in the BC pools, except for the BioP-plus filter, which had a recovery of 43 +/- 10%. The 1500-ml CLX bag had, in two of nine cases, a pH < 6.8 on day 5 of storage, while the other storage containers were able to maintain a pH of > 6.8 until day 9. With the CLX container, the oxygen level remained adequate until day 9, but low glucose, high lactate and high lactate dehydrogenase (LDH) levels suggested high platelet metabolism and/or activation.

CONCLUSIONS

BC pooling sets have various benefits, such as less welding, resulting in a lower work-load, but not all combinations of filters and storage containers tested were suitable. Therefore, validation prior to routine use in a blood centre is necessary.

Automated separation of whole blood in top and bottom bags into components using the Compomat G4

BACKGROUND AND OBJECTIVES

Whole blood can be separated by hard spin centrifugation into layers of blood components according to their specific gravity. The aim was to develop a program for an automatic separator to subsequently express the various components into their respective satellite bags in top and bottom systems with the following requirements: a red cell concentrate with a low leukocyte and platelet contamination, a 'cell-free' plasma, and a buffy coat with a volume of about 50 ml with an acceptable loss of red cells.

MATERIALS AND METHODS

The Compomat G4 possesses an independently moving upper and lower press, to automatically express plasma or red cells to satellite bags of top and bottom systems. The influence of the extension of the lower press was studied by pooling and dividing two units of whole blood, and separating these units after centrifugation (2,960 g, 10 min) either with a program where the lower press was completely extended (program C), or with a program that left approximately 1 mm between the door and the lower press (program D).

RESULTS

The program (program D), where the lower press was not completely extended, yielded a buffy coat with a volume of 52+/-1 ml (mean +/- SD, n = 36), which contained >75% leukocytes and >90% platelets of the original whole blood unit, with a red cell loss in the buffy coat of 21+/-1 ml (10.8+/-0.8% of the original volume). The leukocyte content of the red cell concentrates was 775+/-379x10(6) per unit, whereas the plasma contained 3+/-3x10(6) leukocytes and 4+/-3x10(9) platelets per unit. The pooling experiment indicated that complete extension of the lower press (program C) resulted in a significantly higher leukocyte contamination of the red cell concentrate (788+/-431x10(6 ) vs. 658+/-419x10(6); n = 12; p = 0.03), while there was no difference in the yield of red cells or plasma. The buffy coat produced with program D contained significantly more leukocytes (2,242 +/-396x10(6) vs. 2,065+/-327x10(6), p = 0.005) and more platelets (96+/-14x10(9) vs. 92+/-17x10(9), p = 0.02) per unit than with program C, probably because buffy coat cells sticking to the container wall are not expressed to the red cell concentrate, and thus remain in the buffy coat bag. Therefore, program D met our specifications for blood products.

CONCLUSIONS

The Compomat G4 warrants reproducible separation of whole blood in top and bottom bags into red cells, buffy coat and plasma meeting our specifications.

Comparison of four HTLV-I and HTLV-I + II ELISAs

BACKGROUND

Various countries require blood donor screening using assays applying specific HTLV-I and HTLV-II antigens. We evaluated the sensitivity and specificity of 4 anti-HTLV-I + II ELISAs (Abbott, Murex, Organon Teknika and Ortho).

METHODS

Panel A consisted of HTLV-I-positive individuals (n = 41), panel B of Mixed Titer Performance Panel 204 (Boston Biomedica Inc. panels C and D of dilution series from HTLV-I-positive (n= 30) and HTLV-II-positive (n =20) individuals and panel E of sera from first-time blood donors (n = 1,055).

RESULTS

In HTLV-I- and -II-positive samples, a sensitivity of 100% could be observed in all 4 ELISAs. In diluted HTLV-I- and -II-positive samples, probit analysis revealed that the Murex assay had the highest analytical sensitivity, followed by the ELISAs from Ortho, Abbott and Organon Teknika. In specimens from first-time donors, a specificity of 100% was observed in ELISAs from Murex, Organon Teknika and Ortho, and of 99.7% in the assay from Abbott.

CONCLUSION

The 4 anti-HTLV-I + II ELISAs studied were appropriate as screening tests.

Evaluation of RNA and E2 antibodies in prospectively followed recipients of hepatitis G virus-infected blood

BACKGROUND

Hepatitis G virus (HGV) has recently been cloned and tests for HGV RNA and envelope antibodies (anti-E2) have been developed. HGV infection is widespread among blood donors worldwide, but the clinical and serologic outcome of transfusion-associated HGV infection has not been fully characterized.

STUDY DESIGN AND METHODS

Consecutive blood donors (n = 2210) were investigated for HGV markers (RNA and anti-E2). The recipients of HGV RNA-positive blood were followed for 1 year after transfusion.

RESULTS

Forty-two blood donors (1.9%) were positive for HGV RNA. Eight recipients of HGV RNA-positive blood were retrospectively identified within 2 weeks of transfusion and prospectively followed. In four patients, the presence of anti-E2 before transfusion or an early antibody response protected them from reinfection or prevented HGV persistence, while, in the remaining four patients, transient or persistent viremia was detected shortly after exposure. None of the infected recipients had any evidence of liver disease.

CONCLUSION

These results do not support the screening of donors to prevent transfusion-associated HGV infection.

Ribavirin treatment for patients with chronic hepatitis C: results of a placebo-controlled study

BACKGROUND/AIMS

Small, uncontrolled studies of ribavirin for patients with chronic hepatitis C have reported efficacy in chronic hepatitis C. We have evaluated the efficacy and safety of a 24-week course of oral ribavirin in patients with chronic hepatitis C, compared to placebo.

METHODS

A total of 114 patients were randomised to ribavirin or placebo. Ribavirin was administered in doses of 1000 or 1200 mg/day for 24 weeks. Efficacy was determined in the intention-to-treat population: 76 received ribavirin and 38 placebo.

RESULTS

Ribavirin was significantly more effective than placebo in reducing and normalising serum ALT levels: 42/76 (55%) of ribavirin-treated patients vs 2/38 (5%) placebo recipients had either normalisation of the ALT levels or a reduction from baseline of at least 50% (p < 0.001). ALT levels were normal in 22/76 (29%) of ribavirin-treated patients vs 0/38 placebo recipients (p < 0.001). Twenty-four weeks after stopping ribavirin, the majority of patients had abnormal ALT levels. There was no difference between the treatment groups in reduction or disappearance of HCV-RNA levels. HCV RNA disappeared during treatment in 3% of ribavirin-treated patients and 3% of placebo recipients. More ribavirin than placebo patients showed improvement in total Knodell score (45% vs 31%), but these differences were not statistically significant. Analysis of each component of a histology activity index revealed no statistically significant differences between treatment groups. Ribavirin patients had fewer lymphoid aggregates than did placebo recipients at the post-treatment assessment (p = 0.05). Ribavirin was associated with reversible haemolytic anaemia: a fall in haemoglobin occurred in 3% of placebo- and 32% (25/78) of ribavirin-treated patients, respectively (p < 0.001).

CONCLUSIONS

These data indicate that ribavirin was no more effective than placebo in reducing or eliminating HCV-RNA levels, and was not significantly more effective than placebo in improving hepatic histology after 6 months of treatment. The role of a 6-month treatment of chronic hepatitis C with ribavirin alone, without a significant effect on HCV RNA, is therefore limited.

Prevention of HIV infection by passive immunization with HIV immunoglobulin

The use of a human immunodeficiency virus (HIV) immune globulin (HIVIG) in prevention of HIV infection in chimpanzees was investigated in the hope of ultimate application to interruption of vertical transmission. In previous experiments, no protection was observed when relatively high challenge doses were used. This study shows that HIVIG protected against a challenge dose (10 CID50) tenfold lower than that used previously. The protected animal remained free of HIV infection as determined by cocultivation and by polymerase chain reaction (PCR), and did not mount a primary immune response detectable by enzyme-linked immunosorbant assay (ELISA) and neutralization assays. These results imply that HIV vaccines should induce neutralizing antibody and may not need to induce cell-mediated immunity in order to be protective against exposure to HIV. They also provide an experimental basis for the conduct of clinical trials to evaluate prevention of maternal-infant transmission by HIVIG.

Risk factors in hepatitis C virus-infected blood donors

Risk factors of parenteral and nonparenteral exposure to hepatitis C virus (HCV) infection were studied in 125 blood donors in The Netherlands who were positive for anti-HCV on enzyme-linked immunosorbent assay (ELISA). Risk factors were related to confirmatory test results of four-antigen recombinant immunoblot assay (4-RIBA) and polymerase chain reaction (PCR) of the HCV 5' untranslated region. Twelve (10%) of the 125 anti-HCV C100 ELISA-positive blood donors were 4-RIBA positive. Eleven (92%) of 12 4-RIBA-positive blood donors were PCR positive, and all 113 remaining 4-RIBA-negative or -indeterminate donors were PCR negative. Eleven (92%) of 12 4-RIBA-positive blood donors had a risk factor of parenteral exposure, as compared to 17 (15%) of 113 4-RIBA-negative or -indeterminate donors. The prevalence of confirmed HCV infection among Amsterdam blood donors is calculated at 0.04 percent; parenteral exposure appears to be the major risk factor for HCV infection.