SAT0182 THE ASSOCIATION BETWEEN AUTOANTIBODIES AND RITUXIMAB RESPONSE IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic Lupus Erythematosus (SLE) is clinically and immunologically heterogeneous with a variable response to treatment. MASTERPLANS is an MRC-funded consortium that seeks to identify immunophenotypic subgroups of patients that predict response to therapy. Autoantibody profiles can differentiate subgroups of patients and have potential to predict response to treatment.

Objectives:

To determine whether known and novel autoantibodies are associated with response to rituximab (RTX), and analyse the association between these antibodies and disease involvement in various organ systems.

Methods:

Serum was obtained from 224 SLE patients in the BILAG Biologics Registry who received rituximab according to NHS England criteria (2). Patients were recruited if they were starting a first cycle of rituximab for active SLE (BILAG A or 2xBILAG B) despite previous cyclophosphamide or mycophenolate mofetil. Evidence of any single organ system involvement previous or current was taken as having a BILAG score of A-D but not E. Disease activity was measured using BILAG-2004. Clinical response was defined as improvement by >=1 grade in active BILAG-2004 systems with no worsening in other systems. Autoantibodies were measured by immunoprecipitation of proteins by sera from35S-labelled K562 cell lines, followed by SDS-PAGE separation and autoradiography. Autoantibodies not able to be detected by this technique (anti-Ro52, anti-dsDNA and aCL) were measured by ELISA. Autoantibody data was analysed in IBM SPSS and GraphPad Prism v8.2. Association between autoantibodies and RTX response was analysed using binary logistic interaction terms and Pearson’s Chi-Square test.

Results:

Of the 224 patients (201 female, 23 male, median age 40 years) the most common system involvement from the 9 BILAG domains was musculoskeletal (164 patients) and the least ophthalmic (11 patients). Patients with anti-Ro52 and anti-U1RNP/Sm had more frequent involvement of mucocutaneous (p<0.036,p<0.012) and musculoskeletal domains (p<0.015 for U1RNP) respectively.

There were 136 patients with sufficient data to define as either responders (n=67) or non-responders (n=69) to RTX at 6 months. RTX responders had a higher frequency of anti-U1RNP/Sm compared to non-responders (Figure 1). Further Pearson’s Chi-Square analysis showed a significant association between presence of anti-U1RNP/Sm and better response to RTX (p<0.018).

Conclusion:

Our findings suggest that the presence of U1RNP/Sm autoantibodies in a cohort of patients who have received treatment with RTX is associated with more frequent musculoskeletal and mucocutaneous involvement and predicts a more favourable response to treatment.

Acknowledgments :

Funded by a grant from the Medical Research Council, grant number MR/M01665X/1. BILAG BR has been funded by unrestricted educational donations from Roche, GSK and LUPUS UK. Part-funded by a grant from LUPUS UK.

Disclosure of Interests: :

Danyang Li: None declared, Hui Lu: None declared, Juliet Dunphy: None declared, Theresa Smith: None declared, Edward Vital Grant/research support from: AstraZeneca, Roche/Genentech, and Sandoz, Consultant of: AstraZeneca, GSK, Roche/Genentech, and Sandoz, Speakers bureau: Becton Dickinson and GSK, Ian N. Bruce Grant/research support from: Genzyme Sanofi, GSK, and UCB, Consultant of: Eli Lilly, AstraZeneca, UCB, Iltoo, and Merck Serono, Speakers bureau: UCB, Neil McHugh: None declared

MHC class II, tumour necrosis factor alpha, and lymphotoxin alpha gene haplotype associations with serological subsets of systemic lupus erythematosus

OBJECTIVE

To conduct a case-control study to investigate whether there are independent tumour necrosis factor alpha (TNFalpha) or lymphotoxin alpha (LTalpha) haplotype associations with SLE or with any of the major serological subsets of SLE.

METHODS

157 patients with SLE were genotyped for HLA-DRB1, HLA-DQB1, TNFalpha, and LTalpha alleles by polymerase chain reaction and compared with 245 normal white controls. For TNFalpha, six single nucleotide polymorphisms (SNPs) at positions -1031, -863, -857, -308, -238, and +488 and for LTalpha three SNPs at positions +720, +365, and +249 were studied to assign six TNFalpha haplotypes (TNF1-6) and four LTalpha haplotypes (LTA1-4). All SLE patients had full serological profiles on serial samples.

RESULTS

The most significant association with SLE overall was with HLA-DR3 (p<0.001; odds ratio (OR) = 2.5 (95% confidence interval, 1.6 to 3.8)) and the extended haplotype HLA-DQB1*0201;DRB1*0301;TNF2;LTA2 (p<0.001; OR = 2.3 (1.4 to 3.7)). Associations were strongest in the anti-La positive group (13%) of SLE patients (HLA-DR3, OR = 71 (9 to 539); HLA-DQB1*0201, OR = 35 (5 to 267); TNF2, OR = 10 (2.8 to 36), and LTA2, OR = 4.9 (1.1 to 21)). There was an increase in the HLA-DR2 associated extended haplotype (HLA-DQB1*0602;DRB1*1501;TNF1;LTA1) in patients with anti-Ro in the absence of anti-La (p<0.005; OR = 3.9 (1.5 to 10)). The HLA-DR7 extended haplotype (HLA-DQB1*0303;DRB1*0701/2;TNF5;LTA3) was decreased in SLE overall (p<0.02; OR = 0.2 (0.05 to 0.8)).

CONCLUSIONS

The strongest association in this predominantly white population with SLE was between HLA-DR3 and anti-La, which seemed to account for any associations with TNFalpha alleles on an extended DR3 haplotype.

Isolation, characterisation and expression of mRNAs encoding the ovine CC chemokines, monocyte chemoattractant protein (MCP)-1alpha and -2

CC chemokines are important mediators of immune responses, orchestrating the differential recruitment of various leukocyte populations. Despite the large number of known CC chemokines in other species, no cDNA encoding ovine CC chemokines have been isolated. A homology cloning strategy was utilised to isolate the cDNA of ovine CC chemokines. Full-length monocyte chemoattractant protein (MCP)-1alpha and -2 cDNA have been isolated. The predicted ovine MCP-1alpha amino acid sequence shares 87 and 75% identity with bovine MCP-1alpha and porcine MCP-1, respectively. The predicted ovine MCP-2 amino acid sequence shares 92 and 85% identity with bovine and porcine MCP-2, respectively. Northern blot analysis of MCP-1alpha revealed that it is strongly expressed in cells isolated from mammary lavage fluid (MAL) of ewes given intramammary infusions of Haemonchus contortus. Weak signals were detected in mammary and abomasal tissue. Southern blot analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) products indicates that MCP-1alpha mRNA levels increase in abomasum after challenge with H. contortus. MCP-1alpha mRNA levels were also increased in bronchoalveolar lavage (BAL) cells and lung tissue after house dust mite extract (HDME) challenge. Similarly, MCP-2 mRNA was detected by Northern blot analysis at high levels in MAL cells after H. contortus intramammary infusion, and increased in BAL cells and lung tissue in HDME-challenged sheep. MCP-2 mRNA was not detected by Northern blots in whole mammary or abomasal tissue, but Southern blot analysis of RT-PCR products also indicates that MCP-2 mRNA increases in abomasal tissue after challenge with H. contortus. Hence, two ovine CC chemokine mRNA have been isolated that are up-regulated in response to parasite infection and allergen challenge. Ultimately the isolation of these and other ovine CC chemokines will help elucidate a wide variety of immune responses in sheep.

Antineutrophil cytoplasmic antibodies and HLA class II alleles in minocycline-induced lupus-like syndrome

We report 14 patients with minocycline-induced lupus-like syndrome (four men, 10 women; mean age 27.8 years) who developed a lupus-like illness after chronic use of minocycline for acne (1-10 years, median 3.8). Clinical features resolved completely on drug withdrawal (mean follow-up 11 months) and reappeared in two patients who were rechallenged. Sera from all 14 patients contained antineutrophil cytoplasmic antibodies (ANCA) giving a perinuclear pattern on indirect immunofluorescence on ethanol-fixed human neutrophils (p-ANCA), whereas 14 control asymptomatic individuals taking minocycline for acne were ANCA-negative. Eleven of the 14 patients had elevated antimyeloperoxidase antibodies and 10 had antielastase antibodies on enzyme-linked immunosorbent assay, which diminished on extended follow-up, as did other serological abnormalities. Major histocompatibility complex class II typing demonstrated that all of the 13 patients tested were either HLA-DR4 (nine of 13) or HLA-DR2 (four of 13) positive, and all had an HLA-DQB1 allele encoding for tyrosine at position 30 of the first domain. Our findings suggest a model whereby the presence of p-ANCA may be a marker for the development of lupus-like symptoms in genetically susceptible individuals taking minocycline for acne.

Characterisation of anticytoplasmic antibodies and their clinical associations

OBJECTIVES

To characterise the cytoplasmic staining patterns identified by indirect immunofluorescence (IF) of human epithelial (HEp-2) cells and the antigens recognised using additional serological techniques. To define the disease associations of anticytoplasmic antibodies.

METHODS

Sera from 1173 patients were screened for cytoplasmic IF staining on HEp-2 cells and the patterns characterised. The presence of antimitochondrial antibodies (AMA) was evaluated by a sensitive anti-pyruvate dehydrogenase complex enzyme linked immunosorbent assay (ELISA) (IgG) and by immunoblotting. Detection of antibodies to extractable nuclear antigens (ENA) was performed by double immunodiffusion and the presence of anti-ribosomal P antibodies was determined by immunoblotting.

RESULTS

Cytoplasmic IF staining was demonstrated in 75 sera (6.4%). Six different patterns were recognised: coarse granular filamentous speckles (AMA, n = 9); condensed large speckles (anti-golgi apparatus antibodies, n = 3); cytoskeletal (n = 9); centriolar (n = 4); diffuse coarse speckles (n = 33); and fine speckles (n = 17). Of the nine sera with an AMA pattern, the presence of these antibodies was confirmed in seven by the ELISA (n = 6) and on immunoblotting (n = 7). One of the seven patients had primary biliary cirrhosis, and two had scleroderma. Two patients with anti-golgi antibodies had rheumatoid arthritis and two with anticentriolar antibodies had scleroderma. Of 33 sera that had cytoplasmic staining and were ANA negative, three were positive for anti-Ro and two were positive for anti-Jo-1 antibodies.

CONCLUSIONS

In general, defined cytoplasmic IF patterns have no specific disease associations. However, the finding of cytoplasmic fluorescence should not be ignored, as it may indicate the presence of antibodies to ENA in the absence of nuclear staining.