Correction of iron-deficient erythropoiesis in the treatment of anemia of chronic disease with recombinant human erythropoietin.

Anemia of chronic disease (ACD) is a frequent complication of chronic inflammation in rheumatoid arthritis (RA). Recombinant human erythropoietin (rHuEpo) has been shown to be effective in correcting ACD, although with a variable rate of nonresponders. The first aim of this trial was to improve the response to rHuEpo by parenteral iron supplementation in cases of iron-deficient erythropoiesis (IDE). An additional goal was the evaluation of the zinc protoporphyrin content of erythrocytes (ZnPP), the soluble transferrin receptor (sTrfR) serum concentration, and the hemoglobin (Hb) content of reticulocytes (CHr) in stimulated erythropoiesis as diagnostic and prognostic parameters. Thirty RA patients with ACD were treated with subcutaneous 150 IU rHuEpo/kg body weight twice weekly. Intravenous iron supplementation (200 mg iron sucrose once weekly) was added in cases of IDE (n=23), which was defined by the presence of two of three criteria: saturation of transferrin (TrfS) < or =15%, hypochromic erythrocytes (HypoE) > or =10%, and a serum ferritin (Fn) concentration < or =50 microg/l. All 28 completers met the treatment goal, with an increase of the median Hb concentration from 10.3 g/dl to 13.3 g/dl. Epo treatment and iron supplementation was safe and well tolerated in all patients. Monitoring of Fn, TrfS, and HypoE every other week allowed a successful correction of anemia. Retrospective analysis of the evaluable parameters (CHr, sTrfR, and ZnPP) revealed no additional benefit for predicting or monitoring IDE in this setting, although the one or other may be advantageous in other therapeutic situations.

Interferon-gamma induces expression of interleukin-18 binding protein in fibroblast-like synoviocytes.

OBJECTIVE: To investigate expression of the endogenous antagonist of interleukin 18 (IL-18) bioactivity, IL-18 binding protein isoform a (IL-18BPa), in fibroblast-like synoviocytes (FLS). METHODS: Long-term cultured FLS from rheumatoid arthritis (RA), osteoarthritis (OA) and spondylarthropathy patients were analysed for spontaneous and cytokine-induced IL-18BPa expression. Messenger RNA and release of IL-18BPa were assessed by semi-quantitative and quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) as well as immunoblot analysis, respectively. RESULTS: All investigated FLS cultures expressed low amounts of IL-18BPa transcripts. However, there was no detectable release of IL-18BPa from unstimulated synoviocytes. Of the investigated cytokines, only interferon (IFN)-gamma markedly up-regulated IL-18BPa mRNA levels. Induction was accompanied by release of IL-18BPa immunoreactivity from FLS. Conditioned media from IFN-gamma-stimulated FLS cultures reduced IL-12/IL-18-dependent IFN- production by peripheral blood mononuclear cells. CONCLUSION: The present data imply that IFN--activated synoviocytes mediate a negative feedback loop via IL-18BPa, which may limit IL-18 biological activity in arthritis.

Prednisolone induces interleukin-18 expression in mononuclear blood and myeloid progenitor cells.

OBJECTIVE: Interleukin (IL)-18 is involved in host defense mechanisms and inflammatory diseases, among them rheumatoid arthritis (RA). High levels of IL-18 expression in RA joints are contrasted by reduced IL-18 expression in RA peripheral blood mononuclear cells (PBMC). Here, we investigated a putative IL-18 regulating role of corticosteroids. METHODS: IL-18 transcript and protein levels in PBMC from untreated and prednisolone treated RA patients, and from healthy donors were assessed by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting. IL-18 regulation was determined in PBMC and U937 cells upon exposure to prednisolone in vitro by RT-PCR and Northern Blot analysis, by ELISA in cell culture supernatants, and in transiently transfected THP-1 cells by IL-18 promoter activity luciferase assays. RESULTS: In RA PBMC, IL-18 transcript levels were dose dependently restored, in parallel with administered prednisolone treatment, to subnormal levels. The corresponding intracellular IL-18 deposits in contrast were depleted. In cultured PBMC and promonocytic cell lines, prednisolone up-regulated IL-18 transcription in parallel with increasing the IL- 18 protein release into cell culture supernatants. CONCLUSION: Prednisolone increases IL-18 expression and release in PBMC and monocytic cell lines.

Assessment of intestinal absorption of trace metals in humans by means of stable isotopes.

This study is aimed to demonstrate the feasibility of stable isotopes for the assessment of reliable data on fractional intestinal absorption of trace metals in healthy humans. Among the various methods available, the double isotope technique, i.e. one isotope given orally together with the test substance to be investigated and another isotope injected intravenously to correct for retention and endogenous excretion of the particular trace metal, provides quantitative figures of intestinal absorption at reasonable expenses with regard to costs for materials and number of samples to be evaluated. The trace metals exemplarily included in this study, i.e. iron, cobalt and molybdenum show diverging relations between absorbed fractions and amounts administered which are indicative for different regulatory mechanisms of their body content. Food ligands influence the fractional absorption significantly so that the uptake from a composite meal cannot be derived from results on uptake from particular foodstuffs. Therefore, validated data on the behaviour of intestinal absorption will significantly contribute to a better understanding of human trace metal metabolism.

Long term efficacy and safety of cyclosporin versus parenteral gold in early rheumatoid arthritis: a three year study of radiographic progression, renal function, and arterial hypertension.

OBJECTIVE: To compare the three year safety and efficacy of cyclosporin and parenteral gold in the treatment of early, active, severe rheumatoid arthritis (RA), and to study the reversibility of cyclosporin associated renal dysfunction in patients who discontinued cyclosporin treatment. METHODS: The patients continued to receive cyclosporin or parenteral gold in an 18 month open extension to an 18 month randomised, parallel group study. The main efficacy variable was blinded evaluation of radiographic progression of joint damage. Safety variables included serum creatinine, calculated creatinine clearance, and blood pressure. RESULTS: Radiographic progression during follow up was similar in both groups. About 60% of the patients in the intention to treat groups (n=272) and about half of the patients in the completer groups (n=114) had definite radiographic progression in joint damage (increases >6 in the Larsen-Dale score), and about one in three also had substantial progression (>18 increase in Larsen-Dale score). Both systolic and diastolic blood pressure were significantly increased in the cyclosporin group compared with the gold group, and 12/139 (9%) versus 3/139 (2%) (p=0.03) had notably raised blood pressure. The mean serum creatinine increased by 28% at the treatment end point in the cyclosporin group as compared with 7% in the gold group. The mean calculated creatinine clearance was reduced by 16% and increased by 1% in the cyclosporin and gold groups, respectively, at the end of the study. At the final follow up visit after discontinuation of cyclosporin (at least three months after treatment was stopped) the mean serum creatinine was increased by 15% and creatinine clearance reduced by 16%. Sustained increases in serum creatinine at this post-treatment end point were mostly seen in patients with a raised serum creatinine during treatment of at least 50%. CONCLUSION: Three year changes in radiographic damage during cyclosporin and parenteral gold were similar in patients with early, active RA. Abnormal renal function and raised blood pressure were often seen in the cyclosporin treated patients.

[Analysis of immunoglobulins and complement factors in synovial fluid and serum in rheumatoid arthritis, seronegative spondyloarthropathies and osteoarthritis: pathophysiology and retrospective analysis of clinical value]. / Analyse der Immunglobuline und Komplementfaktoren in Synovialflüssigkeit und Serum bei rheumatoider Arthritis, seronegativen Spondylarthropathien und Osteoarthritis: Pathophysiologie und retrospektive Analyse der klinischen Wertigkeit.

UNLABELLED: Synovial fluid (SF) analysis was a mandatory investigation in rheumatological practice. In recent time, synovial fluid analysis lost importance predominantly due to unclear defined guidelines for the practical use. OBJECTIVE: To evaluate the clinical value of the determination of the complement components C'3c and C'4 and immunoglobulines IgG, IgA and IgM synovial fluid concentrations with regard to pathophysiology and currently used RA and SpA classification criteria. METHODS: Synovial fluid samples were obtained from 22 patients fulfilling ACR criteria for rheumatoid arthritis (RA), and 18 patients suffering from seronegative spondyloarthropathy (SpA) according to the ESSG criteria. Sixteen osteoarthritis (OA) SF samples were used as controls. IgG, IgA, IgM, C'3c and C'4 in SF and sera were determined by nephelometry. Comparison of the diseases, and linear as well as stepwise logistic regression analyses were performed in order to determine the interrelation of the determined parameters and a ranking of their diagnostic value for the identification of RA or SpA synovial fluids. RESULTS: SF-IgA, SF-IgG and SF-IgM concentrations were closely correlated with their corresponding serum levels (p < 0.01), while SF-C'3c and SF-C'4 depended on articular factors (p < 0.01). Determination of SF-C'3c (accuracy = 80.4%, improved chi 2 = 22.02, p < 0.001) and SF-C'4 (accuracy = 75.0%, improved chi 2 = 21.81, p < 0.001) both provided a good predictive value for the diagnosis of SpA when exceeding the cut off level of about 40 mg/dl (C'3c) or 15 mg/dl (C'4), respectively. Calculation of the C'-SF/S ratios did not provide an additional diagnostic benefit. SF-IgG, IgA and IgM as well as the calculated SF/S ratios were within the same range in RA and SpA fluids. CONCLUSIONS: SF concentration of complement components primarily depends on local articular factors. Significant differences of SF complement concentrations in established RA and SpA give reason for prospective analysis of these parameters in early undifferentiated oligoarthritis and evaluation in large studies, e.g. when re-evaluating the preliminary criteria for spondyloarthropathy.

Interleukin-10 expression: is there a neglected contribution of CD8+ T cells in rheumatoid arthritis joints?

OBJECTIVE: To search for RA specific processes among T cell accumulation, T cell activation, or cytokine expression in CD4+ and CD8+ synovial fluid (SF) T cells. METHODS: Flow cytometry of CD4+, CD8+, CD45RA+, CD45RO+, CD69 double or triple stained peripheral blood (PB) and SF T cells. IL-2, IL-10, and IFN-gamma expression was determined in PMA + ionomycin stimulated T cells on the single cell level. Concentrations of secreted IL-2, IL-4, IL-10, and IFN-gamma were quantified in the sera and synovial fluids by enzyme linked immunosorbent assay (ELISA). RESULTS: A preferential recruitment of CD45RO+ memory T cells was found for CD4+ helper T cells, and in similar also for CD8+ suppressor T cells. An elevated CD69 expression was detected in memory, but also in CD45RA+ naive CD4+ and CD8+ SF T cells, whilst IL-2 expression was only demonstrable in a minor proportion of T cells populations. Preferential recruitment of memory T cells, but incomplete activation of naive and memory, CD4+ and CD8+ T cells were in similar found in RA and control patients. In RA but not in the control patients, a relevant proportion of CD4+ and CD8+ PB and SF T cells expressed IL-10 and IFN-gamma. High concentrations of IL-10, that were correlated with the amounts of secreted TNF-alpha, were only detected in RA joints. CONCLUSION: Memory and naive T cell state of CD4+ and CD8+ T cell accumulates in the joints, and early T cell activation occur in similar patterns in RA and control patients. High IL-10 SF concentrations in contrast, and elevated percentages of IFN-gamma and IL-10 expressing CD4+ and CD8+ T cells in the PB and SF were characteristic for RA. Here, CD8+ T cells may contribute to high IL-10 concentrations in RA joints.

Effect of recombinant human erythropoietin and intravenous iron on anemia and disease activity in rheumatoid arthritis.

OBJECTIVE: To investigate whether treatment of anemia of chronic disease (ACD) in patients with rheumatoid arthritis (RA) with recombinant human erythropoietin (rHu-Epo) in combination with intravenous (i.v.) iron influences health related quality of life (HRQoL) and clinical outcome including disease activity. METHODS: Thirty patients with ACD and RA were treated with 150 IU/kg rHu-Epo twice weekly for 12 weeks. As well, in case of functional iron deficiency 200 mg of iron-sucrose per week was given intravenously. Vitality and fatigue as dimensions of HRQoL were evaluated by the vitality subscale of the Short Form-36 (SF-36-VT) and the Multidimensional Assessment of Fatigue (MAF). Muscle strength was measured by the Muscle Strength Index. RESULTS: All 28 patients completing the study responded to treatment; 23/28 patients developed functional iron deficiency and received i.v. iron (mean absolute dose 710 +/- 560 mg). Average hemoglobin concentration increased from 10.7 +/- 1.1 to 13.2 +/- 1.0 g/dl after a mean treatment period of 8.7 +/- 2.3 weeks. Muscle strength increased from 43.5 +/- 11.2 to 49.1 +/- 12.9 and SF-36-VT from 28.2% +/- 14.3% to 47.1% +/- 20.8%. while fatigue decreased (MAF from 34.7 +/- 9.3 to 25.0 +/- 11.3). Among the disease activity variables the number of swollen/tender joints, erythrocyte sedimentation rate, Disease Activity Score, and RA Disease Activity Index improved significantly during treatment. CONCLUSION: Treatment of ACD in RA patients with rHu-Epo and i.v. iron is safe and effective in correction of anemia, increases muscle strength. improves vitality, and lowers fatigue. In addition we observed a reduction of disease activity.

Protection against severe disease is conferred by DERAA-bearing HLA-DRB1 alleles among HLA-DQ3 and HLA-DQ5 positive rheumatoid arthritis patients.

Experimental studies in transgenic mice have suggested that HLA-DQ predisposes to rheumatoid arthritis (RA), but could also modulate disease severity by presenting peptides derived from self-DR molecules. In particular, a short amino acid sequence, (70)DERAA(74), in the third hypervariable region of HLA-DRB1 confers protection for the disease, while particular HLA-DQ [DQB1*0501/DQA1*01 (DQ5) and DQB1*03/DQA1*03 (DQ3)] molecules predispose to the disease. We have therefore analyzed the allelic distribution of HLA-DRB1, DQA1, and DQB1 and the presence of rheumatoid factor and nodules among 199 German RA patients and 196 healthy controls. Our results show that HLA-DQB1*03/DQA1*03 (or DRB1*04) predisposes to RA more than HLA-DQB1*0501/DQA1*01 (i.e., DRB1*01 and DRB1*10). Homozygosity for DQ3 confers the strongest genetic risk for RA (OR = 19.79 compared to OR = 10.05 for two doses of shared epitope (SE) positive HLA-DRB1 alleles). Furthermore, patients carrying both predisposing DQ and (70)DERAA(74)-positive HLA-DRB1 alleles are more often rheumatoid factor (RF) negative than patients carrying predisposing DQ alleles alone. Only one out of 14 patients (7%) with a protective combination (DQ3/(70)DERAA(74) and DQ5/(70)DERAA(74)) had rheumatoid nodules compared to 67 out of 144 patients (46.5%) with predisposing DQ alleles alone (OR = 0.12, 95% CI: 0.02-0.72, p = 0.004). These results demonstrate a protective role of (70)DERAA(74)-positive DRB1 alleles against disease severity among RA patients.

Expression of interleukin-18 and its monokine-directed function in rheumatoid arthritis.

OBJECTIVES: To investigate the expression of and monokine induction by interleukin 18 (IL-18; also called interferon-gamma inducing factor, IGIF), in peripheral blood mononuclear cells (PBMC) and cultured synoviocytes from rheumatoid arthritis (RA) patients. METHODS: We carried out IL-18 Western blotting and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) of cytokines in PBMC [IL-18, IL-1beta and tumour necrosis factor alpha (TNF-alpha)] and long-term cultured fibroblast-like synoviocytes (FLS) [IL-18, IL-1beta, TNF-alpha, IL-6, interferon gamma (INF-gamma) and [granulocyte-macrophage colony stimulating factor (GM-CSF)] from RA patients and controls. FLS were isolated from RA synovial membranes (FLS(SM)) and RA synovial fluids (FLS(SF)), osteoarthritis (OA) FLS(SM) and FLS(SF) from spondyloarthropathy patients. FLS were characterized by fluorescence-activated cell sorting of the FLS. PBMC and FLS from RA patients and control subjects were stimulated with recombinant human IL-18 and IL-1beta (rHuIL-18/rHuIL-1beta), and TNF-alpha, IL-1beta and MMP-1 were measured by ELISA in supernatants. RESULTS: Constitutive expression of IL-18 mRNA was significantly reduced whereas that of TNF-alpha was enhanced in RA PBMC. Persistent low expression of IL-18, TNF-alpha, GM-CSF and IL-1beta was observed in RA and OA FLS(SM) as well as spondyloarthropathy FLS(SF). In contrast, high constitutive expression of IL-18 in FLS (CD90/Thy-1- and CD54-positive, CD14- and CD86-negative), accompanied by persistent high levels of TNF-alpha, GM-CSF and IL-1beta expression, was restricted to synovial fluid-derived FLS obtained from RA patients. IFN-gamma was not detectable in any culture, but IL-6 mRNA was equally expressed in all FLS cultures. rHuIL-18 was effective in stimulating TNF-alpha and IL-1beta secretion in PBMC from healthy controls, but failed to stimulate TNF-alpha and IL-1beta secretion from PBMC in 11 of 12 RA patients, and all FLS cultures. rHu-IL-1beta, but not rHu-IL-18, induced interstitial collagenase (MMP-1) in FLS. CONCLUSIONS: Persistent high production of proinflammatory cytokines in RA-FLS(SF) may be relevant for chronic progression in RA synovitis. Levels of TNF-alpha and IL-1beta expression are increased in RA-FLS(SF), but are independent of IL-18. The pathological function of enhanced IL-18 expression in RA-FLS(SF) remains to be further elucidated.

Iron-overload and genotypic expression of HFE mutations H63D/C282Y and transferrin receptor Hin6I and BanI polymorphism in german patients with hereditary haemochromatosis.

Gene variations of HFE, a HLA-class I like molecule, are highly associated with hereditary haemochromatosis (HH). Functional as well as molecular studies of the HFE protein have indicated that the molecule is involved in iron metabolism and that the HFE gene variations observed among HH patients affect its interaction with the transferrin receptor (TfR). In the present study, we have therefore analysed the relationship between the HFE gene variants, C282Y and H63D, and body iron status among 85 German HH patients. In addition, two TfR gene polymorphism, TfR-Hin6I and TfR-BanI, were typed that have been reported to define ethnically distinct haplotypes. As controls we used 251/159 healthy German blood donors. Seventy-eight (92%) patients were C292Y homozygous, the H63D mutation was present in five (6%) patients with none of the patients being H63D homozygous. Serum transferrin, transferrin saturation and liver iron content were determined prior to therapeutic intervention. Among C282Y homozygous patients serum ferritin levels (2294 +/- 3174 vs. 463 +/- 224 microg L-1, P < 0.0001) and transferrin saturation (86 +/- 18% vs. 62 +/- 25%, P = 0.048) were elevated significantly compared with C282Y and/or H63D heterozygous patients. In addition, the liver iron content (291 +/- 165 vs. 138 +/- 95 micromol g-1, P = 0.028) and liver iron index (6.4 +/- 2.8 vs. 3.2 +/- 2.3, P = 0.019) were increased among C282Y homozygotes compared with C282Y heterozygotes. In contrast, no difference was observed between patients and controls regarding the distribution of TfR-Hin6I and TfR-BanI alleles. These data indicate that the iron intake is higher among C282Y homozygous patients compared with C282Y heterozygous or C282Y/H63D compound heterozygous individuals and supports the functional role of the HFE protein in iron metabolism whereas the TfR gene variants seem to have no influence on iron uptake.

A comparison of the efficacy and safety of leflunomide and methotrexate for the treatment of rheumatoid arthritis.

OBJECTIVE: To compare the clinical efficacy and safety of leflunomide and methotrexate for the treatment of rheumatoid arthritis (RA). METHODS: In this multicentre, double-blind trial, 999 subjects with active RA were randomized to leflunomide (n = 501; loading dose 100 mg/day for 3 days, maintenance dose 20 mg/day) or methotrexate (n = 498; 10-15 mg/week) for 52 weeks. After 1 yr the subjects could choose to stay for a second year of double-blind treatment. The primary end-points were tender and swollen joint counts and overall physician and patient assessments. Analyses were of the intent-to-treat group. RESULTS: After 1 yr, the mean changes in the leflunomide and methotrexate groups, respectively, were -8.3 and -9.7 for tender joint count; -6.8 and -9.0 for swollen joint count; -0.9 and -1.2 for physician global assessment; -0.9 and -1.2 for patient global assessment; -14.4 and -28.2 for erythrocyte sedimentation rate. Improvements seen with methotrexate were significantly greater than those with leflunomide. No further improvement occurred after the second year of treatment and the distinction between the two treatments in terms of tender joint count and patient global assessment was lost. During the first year of treatment, a small and equivalent degree of radiographically assessed disease progression was seen with both drugs. After 2 yr, disease progression was significantly less with methotrexate. The most common treatment-related adverse events in both groups were diarrhoea, nausea, alopecia, rash, headache, and elevated plasma liver enzyme levels. Over 2 yr, 21 subjects receiving methotrexate were withdrawn due to elevated plasma liver enzymes vs eight subjects taking leflunomide. Two drug-related deaths from pulmonary causes were recorded with methotrexate vs no drug-related deaths among the subjects receiving leflunomide. CONCLUSIONS: Both leflunomide and methotrexate are efficacious for prolonged treatment of RA. At the doses used, some clinical benefit of methotrexate over leflunomide was observed in the first year of treatment. This benefit must be weighed against the potential toxicity of this drug when used without folate supplementation.

[Clinical day care treatment of patients with rheumatoid arthritis: concept of a new outcome-oriented evaluation project]. / Tagesklinische Behandlung von Patienten mit rheumatoider Arthritis: Konzeption eines outcome-orientierten Evaluationsprojektes.

Patients with rheumatic diseases are commonly treated as an outpatient in their local environment or are referred to specialized centers. Two recently founded day-patient clinics in Berlin and Frankfurt/Rhein-Main (Germany) for patients suffering from rheumatic diseases will be evaluated for their medical outcome and cost-effectiveness of comprehensive treatment of RA patients in stages of high inflammatory activity and progressive disability. The study design will be prospective, controlled, and randomized to compare outpatient and day-patient treatment. The case-control study design with matched pairs within the network of collaborative arthritis centers will be used to compare day-patient and inpatient treatment. The paper contains a review of studies published in English or German language dealing with day-patient treatment of RA patients.

Total iron-binding capacity and serum transferrin determination under the influence of several clinical conditions.

In this study TIBC and serum-transferrin concentrations were determined by immunochemical turbidimetry, immunochemical nephelometry and radial immunodiffusion under normal and pathological clinical conditions. A total of 246 (123 male/123 female) patients were included [iron deficiency: 60 (18/42), iron overload: 56 (39/17), chronic inflammation: 47 (23/24), undefined diseases: 35 (16/19), healthy volunteers 48 (27/21)]. The data show that determination of TIBC from conversion of transferrin values using a constant factor results in significantly higher values compared to conversion with a function of first degree. For clinical practice the influence of different diseases is negligible. This study indicates that it is not possible to develop a universal algorithm for the conversion of transferrin values into TIBC.

Association of (Q)R/KRAA positive HLA-DRB1 alleles with disease progression in early active and severe rheumatoid arthritis.

OBJECTIVE: We have shown that HLA-DRB1 alleles influence inflammatory activity in patients with early active and severe rheumatoid arthritis (RA). Therefore, we analyzed the effect of HLA-DRB1 alleles on disease progression in patients with early RA during a clinical followup period of 18 months. METHODS: Disease progression was defined by the Larsen Score, the Ritchie Index (RI), and the Health Assessment Questionnaire (HAQ) score. RESULTS: Patients carrying arthritogenic HLA-DRB1 alleles on one or both haplotypes are characterized by increased radiological joint destruction (Larsen Score). Further, (Q)R/KRAA homozygous patients were characterized by worse overall disease course (higher RI and HAQ). However, analysis of changes in joint effects (delta-RI) and personal disability (delta-HAQ) did not reveal significant differences between patients with or without disease associated HLA-DRB1 alleles. CONCLUSION: The predisposing genetic pattern with disease associated HLA-DRB1 alleles did not profoundly influence the therapeutic outcome. Our data support the role of the HLA-DRB1 gene locus in disease modulation of RA. The genetic predisposition due to HLA-DRB1, however, may have only a limited influence on the therapeutic outcome in clinically severe cases of RA.

Erythropoietin and iron.

Serum ferritin concentration is most informative in estimating the amount of storage iron available for a particular individual. The serum transferrin receptor concentration, in contrast to serum ferritin, provides direct information about any deficit in the adequacy of iron supply to the erythropoiesis. The combination of serum transferrin receptor and serum ferritin provides complete information about storage and functional iron compartments. Using this combination along with the hemoglobin concentration, it is possible to define the iron nutritional status completely. Inflammatory conditions as well as parenteral iron administration interfere, however, with the direct and quantitative ferritin to storage iron relationship and, therefore, have to be considered carefully with respect to diagnostic purposes. The diagnostic use of the serum transferrin receptor is presently limited because of limitations in methodology and definition (standardization) of reference ranges.

HLA-DR/DQ interaction in patients with erosive rheumatoid arthritis presenting articular and extraarticular disease manifestations.

In the present study we have analysed the effect of HLA-DRB1 and -DQB1 alleles on disease progression and genetic predisposition among 201 RA patients. We clearly confirm the association of RA with HLA class II alleles sharing the (Q)R/KRAA amino acid (AA) cassette in the third hypervariable region (HVR3) of the DR beta-chain. The HVR3 (Q)R/KRAA motif was significantly overrepresented among RA patients (79% vs. 40%, P < 0.001), with one third of the patients homozygous (28% vs. 6.7%, P < 10(-9)) and the number of rheumatoid factor positive (RF+) patients was significantly increased among HVR3 (Q)R/KRAA homozygous in comparison to HVR3 (Q)R/KRAA negative individuals. Erosive disease defined by the Larsen Score and personal disability determined using the Health Assessment Questionnaire (HAQ) was significantly increased among patients positive for the HVR3 motif with the worst outcome among HVR3 (Q)R/KRAA homozygous patients. In contrast, there was no association of the shared HVR3 AA cassette and disease severity in the majority of patients presenting systemic (extraarticular) disease. Homozygosity for the shared HVR3 motif was only marginally increased among patients presenting 'severe' extraarticular disease in comparison to patients with articular disease (33% vs. 43%, P = ns). Similarly, patients with nodular disease were not more often homozygous for the HVR3 (Q)R/KRAA motif. Furthermore, we observed no HLA-DR independent association of DQB1 alleles among HVR3 (Q)R/KRAA positive patients and controls. Our analysis supports the predominant role of HLA-DR for genetic susceptibility to RA. In the clinical setting, however, HLA-DR typing may be limited to assess the individual risk of patients for disease progression.

An endogenous retroviral long terminal repeat at the HLA-DQB1 gene locus confers susceptibility to rheumatoid arthritis.

Human endogenous retrovirus (HERV) long terminal repeat (LTR) elements contain regulatory sequences that can influence the expression of adjacent cellular genes, which may contribute to breakdowns of the immune function leading to autoimmune disease. Rheumatoid arthritis (RA) is associated with particular HLA-DR/DQ haplotypes that modulate the pathogenesis of this autoimmune disease. We have therefore studied a solitary LTR element (DQ-LTR3) of the HERV-K family at the HLA-DQB1 locus for a possible disease association among 228 RA patients and 311 unrelated blood donors. The DQ-LTR3 was significantly more frequent among patients (76% vs 33%, OR = 5.07,p < 0.0001), with the majority of patients being heterozygous for the DQ-LTR3 (61% vs 22%, p < 0.0001). HLA-DRB1*04 positive patients did still differ for the presence of the DQ-LTR3 (88% vs 70%, OR = 3.03, p < 0.001), with an increase of both DQ-LTR3 homozygous and heterozygous patients, when compared to DRB1*04 positive controls (p = 0.0015). HLA-DR/DQ genotype analysis among HLA-DRB1*04 positive individuals revealed significantly more DQ-LTR3 homozygotes among HLA-DRB1*04-DQBI*03 homozygous patients (72% vs 27%, P = 0.015), and the number of DQ-LTR3 homozygous (23% vs 19%) and heterozygous (66% vs 53%) individuals was also increased among HLA-DRB1*04 heterozygous patients (p = 0.034). The presence of the DQ-LTR3 element increased both the relative risk and the positive predictive value for either DRB1*04-DQB1*03 positive/negative individuals when compared to the presence of HLA-DRB1*04-DQB1*03 alone. In conclusion, these data suggest that this DQ-LTR3 enhances susceptibility to RA.