Assessment of Aspergillus sensitization or persistent carriage as a factor in lung function impairment in cystic fibrosis patients.

BACKGROUND: Cystic fibrosis (CF) patients presenting with persistent carriage of, or sensitization to, Aspergillus fumigatus are often treated with antifungal therapies because the presence of the fungus is commonly thought to impede lung function, even in the absence of allergic bronchopulmonary aspergillosis (ABPA). The aim of this study was to assess Aspergillus-related status modulating the forced expiratory volume in 1 s (FEV1) of CF patients. METHODS: From 1995 to 2007, 251 patients were evaluated. Demographic data, cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations, body mass index, and FEV(1) were recorded. The presence of A. fumigatus and Pseudomonas aeruginosa in sputum and the levels of A. fumigatus precipitin, total IgE (t-IgE), and specific anti-A. fumigatus IgE (Af-IgE) were determined. Patients were divided into 3 groups: (1) ABPA: A. fumigatus precipitin ≥3 lines, Af-IgE > 0.35 IU/ml, and t-IgE ≥500 IU/ml; (2) sensitization: Af-IgE > 0.35 IU/ml but t-IgE < 500 IU/ml; and (3) persistent carriage: Af-IgE ≤ 0.35 IU/ml with either an A. fumigatus persistent positive culture or an A. fumigatus precipitin ≥3 lines, provided this serological finding had been found associated with at least 1 A. fumigatus-positive culture. The remaining patients represented the control group. A multivariate analysis was carried out with FEV(1) as the outcome variable. RESULTS: ABPA, sensitization, and persistent carriage were significantly associated with a larger decline in FEV1 compared with the control group, with odds ratios of 15.9, 14.9, and 10.7, respectively. This association was independent of other associated factors (P. aeruginosa transient detection, age, being underweight, and low FEV1 at baseline). CONCLUSIONS: In addition to ABPA, sensitization and persistent carriage appear to have an impact on pulmonary function in CF patients.

Impact of rituximab therapy on response to tetanus toxoid vaccination in kidney-transplant patients.

OBJECTIVES: Rituximab is used after kidney transplant to prevention or treat kidney-allograft rejection. However, the impact of rituximab on the ability of patients to respond to tetanus toxoid vaccination has not yet been studied. MATERIALS AND METHODS: The response to tetanus toxoid vaccination was analyzed in 39 kidney transplant recipients immunosuppressed by corticoids, antiproliferative agents, and/or calcineurin inhibitors. Thirteen patients had previously received rituximab (group 1), 26 patients had not (group 2). Response to control bacterial antigens and immunologic parameters (lymphocyte count, B-cell subsets, serum immunoglobulin level) were analyzed before and at 1 month after vaccination. Thirty healthy blood donors were used as controls for the before-vaccination immunologic parameters. RESULTS: Before vaccination, neither patient group differed from controls in serum levels of immunoglobulins and antibodies against bacterial antigens, but they did display lower levels of CD4 T cells and B cells compared with controls. Responders to the tetanus toxoid vaccination were slightly fewer in group 1 (4/13) than in group 2 (16/26), but the intensity of the anti-tetanus toxoid response was not significantly different between these 2 groups. None of the parameters studied at the time of vaccination (anti-tetanus toxoid level, peripheral B or CD4 T-cell count, memory B-cell subsets, treatment with rituximab, time since transplant) were associated with an ability to respond to vaccination. The ability to respond to vaccination and graft outcomes were not correlated in each patient group. CONCLUSIONS: Rituximab impaired the secondary immune response after tetanus toxoid vaccination, but did not abolish it in all patients.

Immune responses in adult female volunteers during the bed-rest model of spaceflight: antibodies and cytokines.

BACKGROUND: It is unknown whether a prolonged period of bed rest will affect human immune responses, particularly in female subjects. OBJECTIVE: We sought to measure immune responses in adult female subjects exposed to prolonged bed rest. METHODS: Adult (25-40 years) female volunteers (n = 24) were maintained in a supine (6 degrees tilt) head-down bed-rest (HDBR) position for 60 days: 8 with HDBR only, 8 with HDBR and regular muscular exercise, and 8 with HDBR and dietary protein supplementation. Subjects were immunized with bacteriophage phiX-174. Antibody production and plasma cytokine levels were determined. RESULTS: The rate of primary antibody production of the HDBR plus exercise group increased faster (P = .01) and to a higher level versus that of the HDBR-only group (P = .03) and that of the HDBR plus diet group (trend P = .08). The rates of secondary antibody production between the 3 groups were similar, but the level of antibody in the HDBR plus exercise group remained higher versus that in the HDBR-only group (P = .03). Both the HDBR (P = .001) and HDBR plus diet (P = .02) groups had time-related progressive increases in TNF-alpha receptor levels, but the HDBR plus exercise group remained at baseline. The HDBR plus exercise group experienced an acute increase in IL-1 receptor antagonist levels versus the HDBR (P = .02) and the HDBR plus diet (P = .02) groups, with similar increases in RANTES levels. CONCLUSIONS: The exercise countermeasure accelerated primary antibody production and increased antibody levels to bacteriophage phiX-174 and also opposed the potentially harmful effects of increased TNF-alpha levels caused by prolonged bed rest, possibly by activating the anti-inflammatory cytokine IL-1 receptor antagonist and the chemotactic factor RANTES.

Thymic output and peripheral T lymphocyte subsets in relapsing--remitting multiple sclerosis patients treated or not by IFN-beta.

We explored the parameters of central and peripheral tolerance in patients with stable relapsing-remitting multiple sclerosis, treated or not with IFN-beta. TREC-positive T cells were lower in patients compared with controls, mainly in CD4+ subset, compatible with a thymus dysfunction or an expansion of peripheral lymphocytes. Compared to controls, the frequency of activated CD4+CD25+ T cells was higher in patients without modification of the CD4+CD25(high) T cell proportion. The IFN-beta-treatment did not modify the TREC-positive cell frequency nor the naive/memory T cell subset percentage but was associated with lower blood lymphocyte count and a lower frequency of CD4+CD45RC(high) subset.

Effects of intraoperative versus postoperative administration of rabbit antithymocyte antibodies on 1-year renal function in renal transplant patients.

OBJECTIVES: The aim of our study was to prospectively assess 1-year allograft outcomes and the evolution of lymphocyte subsets in a group of renal transplant patients who had received intraoperative rabbit antithymocyte antibodies (RATG). MATERIALS AND METHODS: We compared 1-year allograft transplant outcomes in renal transplant recipients who had received intraoperative RATG (group 1, n=53) with the outcomes observed in patients in a historical control group who had received postoperative RATG (group 2, n=49). RATG were given at the same dosage (1 mg/kg) during the first 3 days, and then the dosage was adapted according to CD2 count, until calcineurin inhibitors were started. RESULTS: The overall dosage of RATG administered was significantly lower in group 1. At day 4, CD2, CD3, and CD19 T-cell subset counts were significantly higher in patients in group 1. From 3 months after transplantation, CD4/CD8 ratios were significantly lower in patients in group 1 because of a rapid regeneration of CD8 T cells. One-year total lymphocyte counts were significantly higher in patients in group 1. There were fewer severe infectious complications in patients in group 1. One-year renal function was better in patients in group 2. Donor age was the only independent factor associated with renal function at both 1 month and 1 year after transplantation. CONCLUSIONS: When RATG are infused intraoperatively, a lower total amount of RATG is required to prevent acute rejection as compared with postoperative RATG infusion. Consequently, fewer serious lymphopenia-associated complications are observed during the first year after transplantation.

Study of Cynomolgus monkey (Macaca fascicularis) MhcDRB (Mafa-DRB) polymorphism in two populations.

Cynomolgus monkey is one of the macaque species currently used as an animal model for experimental surgery and medicine, in particular, to experiment new drugs or therapy protocols designed for the prevention of allograft rejection. In this field, it is of utmost importance to select histoincompatible recipient-donor pairs. One way to ensure incompatibility between donor and recipient is to check their major histocompatibility complex (MHC) genotypes at the loci playing a determinant role in histocompatibility. We report in this paper on the cynomolgus monkey DRB polymorphism evidenced by sequencing of amplified exon 2 separated either by denaturing gradient gel electrophoresis (DGGE), or by cloning. By the study of 253 unrelated animals from two populations (Mauritius and The Philippines), we characterized 50 exon 2 sequences among which 28 were identical to sequences already reported in Macaca fascicularis or other macaque species (Macaca mulatta, Macaca nemestrina). By cloning and sequencing DRB cDNA, we revealed two additional DRB alleles. Out of the 20 haplotypes that we defined here, only two were found in both populations. The functional impact of DR incompatibility was studied in vitro by mixed lymphocyte culture.

A new classification of HLA-DRB1 alleles differentiates predisposing and protective alleles for rheumatoid arthritis structural severity.

OBJECTIVE: A new classification of HLA-DRB1 alleles supporting the shared epitope hypothesis of rheumatoid arthritis (RA) susceptibility was recently introduced. We investigated the relevance of this classification in terms of the structural severity of RA. METHODS: The study group comprised 144 patients who were included in a prospective longitudinal cohort of French Caucasoid patients with early RA. Progression of the total radiographic damage score (Sharp/van der Heijde method) was used to quantify the structural severity of RA after 4 years of followup. HLA-DRB1 typing and subtyping were performed by polymerase chain reaction, using a panel of sequence-specific oligonucleotide probes. HLA-DRB1 alleles were classified according to the above-mentioned new system. The association between the HLA-DRB1 allele groups (S1, S2, S3P, S3D, and X) and the structural severity of RA was analyzed with nonparametric statistical tests. RESULTS: The presence of S2 alleles (HLA-DRB1*0401 and HLA-DRB1*1303) was associated with severe forms of RA (P = 0.004); a significant dose effect was observed (P = 0.01). The presence of S3D alleles (HLA-DRB1*11001, HLA-DRB1*1104, HLA-DRB1*12, and HLA-DRB1*16) was associated with benign forms of RA (P < 0.0001), and a significant dose effect was observed (P < 0.01). CONCLUSION: The studied classification of HLA-DRB1 alleles is relevant in terms of RA outcomes. Compared with a previously described classification system, this system differentiates predisposing (S2) and protective (S3D) alleles for RA structural severity, which, respectively, correspond to KRRAA and DRRAA amino acid patterns at position 70-74 of the third hypervariable region of the HLA-DRbeta chain.

Analysis of CCR5, CCR2, CX3CR1, and SDF1 polymorphisms in HIV-positive treated patients: impact on response to HAART and on peripheral T lymphocyte counts.

Although polymorphisms of chemokine genes (SDF1, stromal cell-derived factor-1 and RANTES, regulated on activation, normal T cell expressed and secreted) and chemokine-receptor genes (CCR5, CCR2, CX(3)CR1) were shown to be associated with sensitivity to HIV infection and untreated HIV disease progression, their association with the response to highly active antiretroviral therapy (HAART) remains unclear. To explore the possible influence of such polymorphisms on the evolution of AIDS in treated patients, we have studied SDF1-3'A, CCR5Delta32, CCR2-64I, CX(3)CR1-249I, and CX(3)CR1-280M polymorphisms in HIV-infected patients under HAART (n = 169). We studied the evolution of plasma virus load and peripheral T lymphocyte counts in these patients up to 3 years after the initiation of HAART. We observed that some of the genetic polymorphisms studied had an impact on the evolution of these two parameters. After 1 year of HAART, patients with a virological response (undetectable plasma HIV-1 RNA) have a higher frequency of the homozygous SDF1-3'A genotype than other patients (p = 0.005). Similarly, patients with a CD4 increase of over 200/mm(3) from baseline after 1 year of HAART display higher frequencies of homozygous SDF1-3'A (p = 0.035) and homozygous CX(3)CR1-280M genotypes (p = 0.04) than other patients. Moreover, we showed that the CX(3)CR1- 280M allele was associated with higher peripheral CD4+ T cell counts not only in HIV+ patients but also in healthy controls (p = 0.003).

FOXP3 mRNA levels are decreased in peripheral blood CD4+ lymphocytes from HIV-positive patients.

The impact of HIV infection on regulatory CD4(+)CD25(high) (Treg) lymphocyte subpopulations was evaluated by FOXP3 quantitative reverse transcriptase polymerase chain reaction and by flow cytometry. FOXP3 mRNA was quantified in peripheral blood mononuclear cells or purified CD4(+) lymphocytes from HIV(+) lymphopenic patients. Patients were distributed among clinical stages A, B, and C and received highly active antiretroviral therapy. The frequency of CD4(+)CD25(high) lymphocytes, measured by flow cytometry, was decreased in HIV patients (n = 38) compared with the group of uninfected subjects (n = 39). FOXP3 mRNA levels were found decreased in HIV patients (n = 25) compared with controls (n = 17) when expression of CD3gamma or beta-actin but not that of TATA box binding protein 1 was used for data normalization. Our results are compatible with a decrease of the Treg lymphocytes during HIV infection. The consequences of a Treg decrease are discussed in the context of immunologic anomalies observed during HIV infection.

Decrease of Lewis frequency in HIV-infected patients: possible competition of fucosylated antigens with HIV for binding to DC-SIGN.

We explored the impact of human ABO glycosyltransferase and Lewis and secretor fucosyltransferase polymorphisms in HIV infection. We found that, compared with healthy blood donors, HIV-infected patients display a significant decrease in Le(a-b+) phenotype frequencies. We showed that HIV binding on DC-SIGN-transduced Jurkat cells was inhibited by fucosyl bovine serum albumin. Our results suggest a slight protective effect of Lewis b antigen on HIV infection, possibly by the competition of Lewis antigens with HIV for binding to DC-SIGN.

Cross-sectional association of 10 molecular markers of bone, cartilage, and synovium with disease activity and radiological joint damage in patients with hip osteoarthritis: the ECHODIAH cohort.

OBJECTIVE: To investigate the associations of molecular markers of joint tissue turnover with clinical and radiological variables in patients with hip osteoarthritis (OA). METHODS: Patients of the ECHODIAH trial cohort (60% female; mean age 63 yrs, disease duration 5 yrs) fulfilling the American College of Rheumatology criteria for hip OA were studied. Pain was assessed using a 100 mm visual analog scale, and the presence of night pain and morning stiffness was observed as the index of joint inflammation. Joint space width (JSW) and subchondral bone sclerosis were assessed on hip radiographs. Ten markers were measured, 8 in serum: N-propeptides of collagen type I (PINP) and type III (PIIINP), cartilage oligomeric matrix protein (COMP), YKL-40, hyaluronan (HA), matrix metalloproteases (MMP1 and MMP3), and ultrasensitive C-reactive protein (CRP); and 2 in urine: C-terminal crosslinking telopeptides of collagen type I (CTX-I) and type II (CTX-II). Analyses of 376 patients with measurements of all the markers included principal component analyses to identify independent clusters of markers; followed by stepwise multivariate regressions to determine associations between markers, clinical variables, and radiographic signs of joint damage. RESULTS: Markers could be segregated into independent clusters: CTX-II, PINP, and CTX-I for cartilage degradation and bone turnover; COMP, PIIINP, and HA as potential markers of synovitis; and CRP and YKL-40, which are likely to indicate systemic inflammation; plus MMP1 and MMP3. After adjustment for age, sex, and body mass index, pain was significantly associated with CTX-II (p = 0.0095) and CRP (p = 0.046) and joint inflammation with COMP (p = 0.013). Radiographic signs of joint damage were associated with CTX-II (p = 0.001 for JSW; p = 0.007 for bone sclerosis). CONCLUSION: This cross-sectional study of OA molecular markers in a large cohort may provide biological evidence of different pathophysiological processes involved in hip OA. Among the markers measured, CTX-II showed the most consistent association with the symptoms and joint damage of OA.

Immunomodulatory effect of human adipose tissue-derived adult stem cells: comparison with bone marrow mesenchymal stem cells.

Like mesenchymal stem cells from bone marrow (BM-MSCs), adipose tissue-derived adult stem cells (ADAS cells) can differentiate into several lineages and present therapeutical potential for repairing damaged tissues. The use of allogenic stem cells can enlarge their therapeutical interest, provided that the grafted cells could be tolerated. We investigate here, for the first time, the immunosuppressive properties of ADAS cells compared with the well-characterized immunosuppressive properties of BM-MSCs. ADAS cells did not provoke in vitro alloreactivity of incompatible lymphocytes and, moreover, suppressed mixed lymphocyte reaction (MLR) and lymphocyte proliferative response to mitogens. The impairment of inhibition when ADAS cells and BM-MSCs were separated from lymphocytes by a permeable membrane suggests that cell contact is required for a full inhibitory effect. Hepatocyte growth factor is secreted by both stem cells but, similar to interleukin-10 and transforming growth factor-beta (TGF-beta), the levels of which were undetectable in supernatants of MLR inhibited by ADAS cells or BM-MSCs, it did not seem implicated in the stem cell suppressive effect. These findings support that ADAS cells share immunosuppressive properties with BM-MSCs. Therefore, ADAS cell-based reconstructive therapy could employ allogenic cells and because of their immunosuppressive properties, ADAS cells could be an alternative source to BM-MSCs to treat allogenic conflicts.

Polymorphism of human and primate RANTES, CX3CR1, CCR2 and CXCR4 genes with regard to HIV/SIV infection.

Among genes that influence human susceptibility to HIV (human immunodeficiency virus) infection or AIDS (acquired immunodeficiency syndrome) progression, chemokine-receptor and chemokine genes were extensively studied because of their role as HIV co-receptors or co-receptor competitors, respectively. We have studied in non-human primates (chimpanzee, gorilla, gibbon, orang-utan, crab-eating and rhesus macaque, baboon and marmoset) the RANTES, CCR2 and CX3CR1 gene sequences in regions surrounding human mutations that were associated with susceptibility to HIV or AIDS progression: RANTES G-403A and C-28G, CCR2 V64I, CX3CR1 V249I and CX3CR1 T280M. Among these five dimorphisms, only RANTES G-403A is observed in one of the eight primate species studied here (gibbon). This suggests that these mutations appeared recently in humans and probably do not account for variable HIV/SIV disease progression in primates. It is noteworthy that chimpanzees, which are naturally resistant to HIV-1- and HIV-2-induced AIDS, do not have the human mutations associated with delayed disease progression. Inter-species and intra-species polymorphic positions are observed in primates and we discuss the potential impact of these mutations on HIV/SIV disease progression. Particularly, we identified polymorphisms in old-world monkey (OWM) genes, and it could be of great importance to analyse the possible association between these polymorphisms and disease progression in OWM species that are currently used in research for HIV vaccine and therapy.

Stromelysin 1 (matrix metalloproteinase 3) and HLA-DRB1 gene polymorphisms: Association with severity and progression of rheumatoid arthritis in a prospective study.

OBJECTIVE: To test the hypothesis of an association between a polymorphism in the matrix metalloproteinase 3 (MMP-3) gene promoter and the susceptibility, severity, and progression of rheumatoid arthritis (RA), and to further document the association between HLA-DRB1 alleles encoding the shared epitope (SE) and the severity and progression of RA. METHODS: Patients with early RA (n = 103) were included in this prospective study. A total radiographic damage score (TDS; by the Sharp/van der Heijde method) was used to quantify RA severity at baseline and after 4 years of followup. The 5A/6A biallelic polymorphism in the MMP-3 gene promoter was analyzed using fluorescence-based polymerase chain reaction (PCR). HLA-DRB1 genotyping was performed using PCR methods. Control subjects (n = 127) were unrelated healthy individuals. RESULTS: MMP-3 allele carriage rates and allele and genotype frequencies did not differ between patients and controls. The MMP-3 6A/6A genotype was associated with the highest TDS both at baseline and after a 4-year followup and with the highest progression of the TDS over the 4 years of followup. The DRB1 SE+/+ genotype was associated with the highest TDS after a 4-year followup and with the highest progression of the TDS over the 4 years of followup. Patients homozygous for MMP-3 6A and DRB1 SE had the highest progression of the TDS. CONCLUSION: This study provides the first evidence of an association between a polymorphism in the MMP-3 gene promoter and the severity and progression of RA, but not RA susceptibility. Investigation of this polymorphism could be combined with that of DRB1 gene polymorphism to improve the predictive accuracy and management strategy in early RA.

Improved screening for peanut allergy by the combined use of skin prick tests and specific IgE assays.

BACKGROUND: The diagnosis of peanut allergy must be based on reliable, safe criteria. Double-blind, placebo-controlled food challenges (DBPCFCs) are the gold standard but are costly and dangerous because they can trigger severe reactions. OBJECTIVE: The aim of this study was to develop a new strategy for diagnosing peanut allergy while reducing the need for DBPCFCs. METHODS: We studied 363 children referred for an evaluation of suspected food hypersensitivity. They all benefited from the same diagnostic strategy, which included, in order, clinical history, a skin prick test (SPT), and a specific IgE assay. DBPCFCs were performed on all the children by personnel who were unaware of the results of the other tests. To assess the performance characteristics of the SPT (comparing commercial and raw peanut extracts) and the specific IgE assay, we compared the results with those provided by the DBPCFCs. For SPTs and specific IgE assays, we sought to determine the cutoff values required to exclude false-positive and false-negative results. RESULTS: According to DBPCFC results, 177 children were allergic to peanut, and 186 were not. The performance characteristics of the SPTs were superior with the raw extract because the negative predictive value was 100% (95% confidence interval [CI], 97.5-100). If the skin reaction with the raw extract was less than 3 mm, we could be quite certain that the child was not allergic. On the other hand, if the SPT resulted in a wheal diameter of larger than 3 mm, we could only be 74% certain that the children were allergic. Furthermore, if the SPT resulted in a wheal diameter of 16 mm or larger, we could be quite certain that the child was allergic because the positive predictive value was 100% (95% CI, 86.8-100). Specific IgE concentrations of 57 kU(A)/L or greater were associated with a positive predictive value of 100% (95% CI, 87.2-100). The combined use of the tests resulting in a positive diagnosis if the SPT result was 16 mm or larger or specific IgE concentration was 57 kU(A)/L or greater and in a negative diagnosis if the SPT result was less than 3 mm and the specific IgE concentration was less than 57 kU(A)/L allowed us to classify subjects with almost complete certainty as being allergic or not because the predictive values were 100%. CONCLUSION: Commercial extracts could not be used to reliably predict tolerance of peanut. Peanut DBPCFCs can be avoided when SPTs with raw extracts resulted in wheals with a largest diameter of less than 3 mm and a specific IgE concentration of less than 57 kU(A)/L and also when wheal diameters were 16 mm or larger or specific IgE values were 57 kU(A)/L or greater. Otherwise, DBPCFCs were indispensable for the unequivocal diagnosis of peanut allergy.

Screening of blood from potential organ and cornea donors for viruses.

Prospective nucleic acid tests were carried out for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) using the COBAS Amplicor HIV-1 and HCV tests (Roche Diagnostics, Meylan, France) on potential organ (n=113) and cornea (n=368) donors in France to evaluate their performance and suitability for use as a complement to routine serological tests. Blood samples were collected from organ donors with preserved cardiac function after verification of cerebral death. Blood samples were collected from cornea donors post-mortem within 48 hr after death. An internal control was added to the samples before extraction to monitor each individual polymerase chain reaction (PCR). The nucleic acid tests were always interpretable in organ donors and negative in all except in 2 anti-HCV positive patients. One had an indeterminate HIV p24 antigen but was negative for HIV RNA. HIV and HCV RNA were not found in cornea donors with a negative serology but indeterminate molecular results were frequent in this group (17.6%). Cornea donors also gave significantly more (14.4%) indeterminate serological results than organ donors (1.8%) (P<0.001). This was due to the poor quality of the blood samples collected post-mortem. However, there was no correlation between indeterminate results of serological and molecular tests. There were 16/19 (84%) indeterminate serological results for HIV and 4/4 (100%) for HCV that were negative by PCR. Thus, nucleic acid tests could be useful for qualifying a donor whose serological results are indeterminate. The extraction procedures on post-mortem specimens and/or blood collection must be changed to improve the performance of nucleic acid tests.

Collagenase-1 (MMP-1) and HLA-DRB1 gene polymorphisms in rheumatoid arthritis: a prospective longitudinal study.

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by chronic synovitis leading to permanent damage of the joints. Collagenase-1 (MMP-1) is a matrix metalloproteinase involved in articular cartilage degradation. We investigated the association between a biallelic polymorphism in the MMP-1 gene promoter and the susceptibility to, and severity of, RA. We also investigated the association between HLA-DRB1 gene polymorphism and severity of RA. METHODS: One hundred and three patients with early RA were included in this prospective longitudinal study. A radiographic damage score was used to quantify disease severity at baseline and after 4 years of followup. MMP-1 polymorphism genotyping was analyzed using a fluorescent-based polymerase chain reaction (PCR). HLA-DRB1 genotypes were determined by PCR sequence-specific oligonucleotide probes. One hundred and thirty-three healthy individuals were used as controls. RESULTS: MMP-1 allele and genotype frequencies did not differ between RA patients and controls. The radiographic damage or its progression over the 4 years of followup did not differ across MMP-1 genotypes. The radiographic damage score and its progression over the 4 years of followup differed across HLA-DRB1 genotypes. The HLA-DRB I shared epitope +/+ genotype was associated with the highest radiographic damage score and the highest progression, while the shared epitope -/- genotype was associated with the lowest. CONCLUSION: Our results do not support the hypothesis of an association between this particular polymorphism in the MMP-1 gene promoter and susceptibility to, or severity of, RA. This study confirms the previous reports of an association between the HLA-DRB1 gene polymorphism and severity of RA.