Lipids and inflammation: serial measurements of the lipid profile of blood donors who later developed rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis is characterised by inflammation and an increased cardiovascular risk. It was recently shown that active early rheumatoid arthritis is associated with dyslipidaemia, which may partially explain the enhanced cardiovascular risk. However, it is unknown when this dyslipidaemia starts. OBJECTIVE: To investigate the progression of the lipid profile over time and the influence of inflammatory parameters on this lipid profile, in people who later developed rheumatoid arthritis. METHODS: Levels of total cholesterol, high-density lipoprotein cholesterol (HDLc), triglycerides, apolipoprotein AI (apo AI), apolipoprotein B (apo B) and lipoprotein(a) (Lp(a)) were determined in 1078 stored, deep-frozen, serial blood bank samples, collected between 1984 and 1999, of 79 blood donors who later developed rheumatoid arthritis. These samples were compared with 1071 control samples of unselected blood donors, matched for age, sex and storage time. RESULTS: Samples of patients who later developed rheumatoid arthritis showed, on average, 4% higher total cholesterol, 9% lower HDLc, 17% higher triglyceride and 6% higher apo B levels than matched controls (p< or =0.05). The magnitude of the differences in lipid levels between groups, explained by C reactive protein (CRP), was limited. For example, only 3.6% of the difference in HDLc levels between the groups was explained by the CRP concentrations. CONCLUSION: Patients who later develop rheumatoid arthritis have a considerably more atherogenic lipid profile than matched blood donors at least 10 years before onset of symptoms. As inflammation only marginally explains the differences between the two groups, a modulating effect of lipids on inflammatory processes is hypothesised.

Simultaneous development of acute phase response and autoantibodies in preclinical rheumatoid arthritis.

OBJECTIVE: To investigate the temporal relationship between onset of inflammation (as measured by secretory phospholipase A2 (sPLA2) and C reactive protein (CRP)) and the presence of autoantibodies (IgM rheumatoid factor (IgM RF) and antibodies against citrullinated peptides (anti-CCP)) in the preclinical phase of rheumatoid arthritis (RA). METHODS: For 79 patients with RA who had been blood donors before the onset of disease, a median of 13 serum samples per patient was available. sPLA2 was measured in patient and matched control samples and related to previous CRP, IgM RF, and anti-CCP measurements. The temporal relationship between the increased markers of inflammation and autoantibodies was analysed with time lag analysis. RESULTS: IgM RF and anti-CCP concentrations were significantly associated (p<0.001) with concentrations of sPLA2, CRP, and the combination of sPLA2 and CRP at the same time point. However, we found no stronger association between the two autoantibody tests and the three inflammation measures 1, 2, and 3 years before or after a time point than for measurements at the same time, in the whole group or in subgroups of IgM RF and anti-CCP positive patients. CONCLUSION: Both the acute phase response and autoantibody formation often develop years before the first symptoms of RA occur, and these phenomena are probably closely connected in time.

Evaluation of automated RNA-extraction technology and a qualitative HCV assay for sensitivity and detection of HCV RNA in pool-screening systems.

BACKGROUND: The objective of this study was the evaluation of NAT technology for the detection of HCV RNA in plasma pools according to the recommendations of the Paul Ehrlich Institute (5000 IU/mL/donation) and the Committee for Proprietary Medical Products (100 IU/mL/manufacturing pool). STUDY DESIGN AND METHODS: Serial dilutions of both the EUROHEP standard (3,800 genome equivalents [geq]/mL; HCV genotype 1) and the World Health Organization (WHO) international standard (100,000 IU/mL; HCV genotype 1) were made in S/D plasma (ESPEP plasma, OctaPharma), which was nonreactive in serologic tests. Serial dilutions of plasma (2 mL) were used for extraction of HCV RNA with an automated version of a nucleic acid isolation method (NucliSens Extractor, Organon Teknika). HCV RNA was co-extracted from 2 mL of plasma, together with 84 copies of an in vitro-synthesized single-strand RNA serving as internal extraction control (IC) to monitor the efficiency of extraction and PCR. Amplification and detection of both HCV RNA and IC RNA were performed with an automated PCR system and a qualitative HCV assay (COBAS Amplicor 2.0 HCV, Roche Diagnostics). RESULTS: A cutoff value of 16 geq per mL (10/10 runs [100% hit rate]) was found by using the EUROHEP standard, whereas the WHO international standard had a cutoff value of approximately 12 IU per mL (10/10 runs [100% hit rate]). The IC had a cutoff value of approximately 17.5 copies per mL (6/6 runs [100% hit rate]). Forty-two copies per mL of IC RNA were found in 282 of 284 runs (99% hit rate). The negative controls (ESDEP plasma) were negative in all experiments. Experiments with pool sizes of 12, 24, 48, and 96 using serial dilutions of the WHO international standard revealed a cutoff value of 8 IU per mL (100% hit rate). The EUROHEP standard and the WHO international standard were detected with a 50 percent detection endpoint of 5.2 geq per mL and 1.5 IU per mL, respectively. CONCLUSION: This test system (NucliSens Extractor, and the COBAS Amplicor 2.0 HCV assay) revealed a high sensitivity for HCV RNA; considering the proposed requirements for sensitivity of NAT assays for the detection of HCV RNA in donor plasma, pool sizes of about 400 donors are possible. These endpoint results indicated that 1 IU is equal to about 3.4 geq.

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.