Marzia Quinzanini

Anti-MJ/NXP-2 autoantibody specificity in a cohort of adult Italian patients with polymyositis/dermatomyositis

IntroductionAutoantibodies in patients with polymyositis/dermatomyositis (PM/DM) are associated with unique subsets, clinical course and outcome. Anti-MJ antibodies, which recognize the nuclear protein NXP-2/MORC3, are reported in ~25% of juvenile DM. Prevalence and clinical significance of anti-MJ antibodies in adult Italian PM/DM patients were studied.MethodsSera from 58 consecutive adult Italian PM/DM patients were analyzed by immunoprecipitation of 35S-labeled K562 cells extract, ELISA (anti-MJ, Jo-1), Western blot and indirect immunofluorescence. Clinical associations were analyzed using information from medical charts.ResultsAnti-MJ antibodies were the most prevalent specificity (17%) found mainly in DM (30%, 8 cases) vs 8% of PM (2 cases, P = 0.02). Comparing 10 anti-MJ (+) vs 48 anti-MJ (-) cases, DM was more common (P = 0.03), and age at onset was younger in anti-MJ (+) (P = 0.0006). In anti-MJ (+), heliotrope rash (P = 0.01) and calcinosis (P = 0.09) were more frequent. None of them had heart or lung involvement, or malignancy. Myopathy in anti-MJ (+) patients responded well to therapy and none of them had elevated CPK at last visit (0% vs 25% in anti-MJ (-)). Only 60% of anti-MJ (+) showed immunofluorescent nuclear dots staining, despite PML localization of NXP-2/MORC3.ConclusionsAnti-MJ antibodies are the most frequent specificity in our cohort of adult Italian PM/DM. Anti-MJ (+) were associated with young onset DM, calcinosis, no internal organ involvement and good response of myopathy to therapy. Anti-MJ reported in juvenile DM is also found in adult PM/DM, and could be a new useful biomarker.

CHILBLAIN LUPUS ERYTHEMATOSUS IS ASSOCIATED WITH ANTIBODIES TO SSA/RO

Chilblain lupus erythematosus (CL) of Hutchinson is a subtype of lupus erythematosus (LE) characterized by erythematous lesions induced by cold, damp climates. A number of patients affected by CL eventually develop features of systemic lupus erythematosus (SLE). We report here 9 patients with chilblain cutaneous lesions, 6 of them were affected by SLE and 2 by SCLE. The onset of CL preceded the diagnosis of LE, from 1 to 10 years in 3 cases, it was concurrent in one case and was subsequent in the remaining 4 cases. Raynauds phenomenon and photosensitivity were other prominent clinical features in patients with CL. Nailfold capillaroscopy revealed pathological changes in every patient examined. ANA and anti-SSA/Ro antibodies were detected in all nine patients. Anti-SSB/La were detected in 2 cases, anti-Sm in one case, and anti-Sm and anti-RNP in a one case. Antibodies to dsDNA and complement consumption were found in the six patients with SLE. The fine specificity of anti-SSA/Ro was determined by immunoblotting: anti-60kD and anti-52 kD were detected in three sera, anti-60kD alone in 5 sera, while one serum did not blot. In conclusion, the present study suggests that chilblain LE is associated with SSA/Ro autoantibodies, as is SCLE, hypergammaglobulinemic purpura and neonatal lupus erythematosus.

Prevalence and clinical associations of anti-Ku antibodies in systemic autoimmune diseases

We retrospectively analysed the prevalence and clinical features associated to anti-Ku antibodies in patients affected by different autoimmune diseases. Anti-Ku antibodies are detected in 147 sera out of 7239 anti-ENA positive sera (2%). They are found in 2% of patients with systemic sclerosis (SSc) (8 out of 379), 1.8% of systemic lupus erythematosus (SLE) (7 out of 372) and 1.8% of undifferentiated connective tissue disease (UCTD) (9 out of 496) and more rarely in Sjögren Syndrome and rheumatoid arthritis. Most of anti-Ku positive patients were affected by UCTD and overlap syndromes, including polymyositis, SSc and SLE. Interstitial lung disease, myositis, articular symptoms, Raynaud’s phenomenon and sicca represents the main clinical features detected in our cohort. The rate and severity of pulmonary disease is similar to those found in other SSc patients. Isolated anti-Ku were detected in about 47% of sera. No clinical differences were observed between these patients and subjects with multiple anti-nuclear specificities. However, anti-Ku are usually detected in association with other serological markers in SLE and Sjögren Syndrome, while they occurred isolated in SSc and polymyositis.

Deforming Arthropathy of the Hands in Systemic Lupus Erythematosus is Associated with Antibodies to SSA/Ro and to SSB/La

Thirteen patients with systemic lupus erythematosus and deforming arthropathy (DA) of the hands were compared with 111 patients with SLE without deforming arthropathy. Clinical features were comparable in the two groups. Patients fulfilling criteria for mixed connective tissue disease (MCTD) were not included in the present study. A higher prevalence of antibodies to SSA/Ro (P < 0.0125) and SSB/La (P < 0.004) were found in the SLE-DA group. The detection of antibodies to SSA/Ro and SSB/La was even more strictly associated with DA in SLE antibodies to SSA/Ro alone (P < 0.002). Regarding the fine specificity of anti-SSA/Ro, a prevalent response to the 52 kD protein of the Ro antigen was found. We conclude that patients with SLE developing deformities of the hands belong to a subset of patients with circulating antibodies to SSA/Ro, particularly to the 52 kD component, and to SSB/La.

DNA typing of maternal HLA in congenital complete heart block: comparison with systemic lupus erythematosus and primary Sjögren's syndrome.

OBJECTIVE To investigate which maternal HLA allele or haplotype is primarily associated with isolated congenital complete heart block (CCHB) in offspring. METHODS HLA class II typings were assessed by line probe assay and polymerase chain reaction-sequence-specific oligonucleotide probe methods, and HLA class I by the microlymphocytotoxicity test, in 13 Italian anti-Ro-positive mothers of children with CCHB and 41 anti-Ro-positive mothers with healthy children (20 mothers with systemic lupus erythematosus [SLE] and 21 with Sjögrens syndrome [SS]). Anti-Ro antibodies were studied by immunoblot. RESULTS HLA-DRB1*03011 and DRB1*03011; DQA1*0501;DQB1*0201 were more frequent in mothers of infants with CCHB than in mothers who had SLE, but not in mothers who had SS and whose children were healthy. Mothers of infants with CCHB were either HLA-B5/35, B17, or B44 positive and had a higher prevalence of B44;DRB11;DQA1*0501;DQB1*0301 and isolated anti-52-kd antibodies, which were absent in SS and SLE controls. CONCLUSION Mothers of infants with CCHB presented a strong genetic similarity to mothers who had SS, except for HLA class I phenotype. HLA-DRB1*03011;DQA1*0501;DQB1*0201 seemed not to be primary CCHB-associated genes, but were involved in an SS-like anti-Ro/La response. The combined presence of HLA-DRB1*03011 and anti-52-kd SSA/Ro antibodies conveyed the highest risk of giving birth to an affected child.

Rare autoantibodies to cellular antigens in systemic lupus erythematosus.

Objective A high number of antinuclear antibody specificities can be detected in systemic lupus erythematosus (SLE). Some of them are related to a distinct clinical subset of disease, independently of their frequency. The aim of our study was to investigate, in a cohort of SLE patients, the prevalence and the clinical relevance of autoantibodies to cellular antigens less frequently found in SLE. Methods Antinuclear antibodies were detected by indirect immunofluorescence on HEp-2 cells while counterimmunoelectrophoresis was used to detect anti-ENA antibodies in 540 patients with SLE, classified according to ACR and SLICC criteria. Clinical and serological features were collected from clinical charts. Results A total of 319 (58.9%) out of 540 sera were positive for anti-ENA antibodies. Anti-Ro/SSA was found in 235 sera, 50 of which also contained anti-La/SSB. Anti-U1RNP were detected in 67, anti-Sm in 46 and anti-ribosomal P protein in 13 sera. In a multivariate analysis anti-Sm was associated with discoid lupus (p = 0.045) and photosensitivity (p = 0.037), anti-U1RNP with malar rash and Raynaud’s phenomenon (p = 0.01 and p = 0.0004, respectively) and anti-Ro/SSA with malar rash, oral ulcers, xerostomia, xerophthalmia and rheumatoid factor (p = 0.029, p = 0.01, p = 0.031, p = 0.002 and p = 0.028, respectively). Other anti-ENA antibodies were found in 50 positive sera (15.6%). Anti-Ki antibodies were detected in 31, anti-Ku in 8, anti-centromere in 5, isolated anti-La/SSB, anti-PCNA and anti-Topo I in 3 each and anti-Jo-1 in 2 sera. About half of these antibodies (27 out of 50) were detected as the single anti-ENA specificity in serum. At multivariate analysis anti-Ki was significantly associated with male gender while anti-Ku with African ethnicity (p = 0.017 and p < 0.0001, respectively). No sign of muscular or pulmonary involvement was found in anti-Jo-1-positive patients whilst features of systemic sclerosis were detectable in two out of three anti-Topo I. Conclusions Our study shows that antibodies to cellular antigens more rarely found in SLE are detectable in more than 15% of patients with anti-ENA antibodies. Most of them are found as single anti-ENA specificity. Anti-Ki and anti-Ku are found in a subset of disease, characterized by male gender and African origin, respectively. Clinical features of scleroderma were found only in patients with anti-Topo I.

Clinical and serological features of 35 patients with anti-Ki autoantibodies.

The objective of this study was to analyse clinical and serological associations of anti-Ki antibodies. Thirty-five patients with anti-Ki antibodies, detected by CIE, selected from laboratory routine, were studied. All patients were affected by autoimmune diseases: SLE and pSS were the most frequent diagnoses. The cohort was constituted by 27 female and eight males. Main clinical features were skin involvement (60%), xerophtalmia (48.6%), Raynaud’s phenomenon (43%), photosensitivity (34%), xerostomia (31.4%). CNS involvement was present in four (11.4%) and renal disease in seven cases (20%). ANA, anti-dsDNA and RF were detected in 100%, 60% and 34.5%. In SLE, anti-Ki was detected in 6% of cases, more frequently in males compared to other SLE patients without anti-Ki (P < 0.004). Nineteen anti-Ki positive patients affected by SLE showed more frequently malar rash and multiple autoantibody specificities compared to 16 anti-Ki positive patients with other diseases (P = 0.044 and P = 0.0003, respectively). Our study confirms a preferential occurrence of anti-Ki antibodies in patients with sicca and skin involvement. Malar rash and multiple ANA specificities were significantly associated with SLE compared to other diseases in our study. Anti-Ki were detected in 6% of patients with SLE with a significant prevalence in males.

Chilblain lupus erythematosus is associated with antibodies to SSA/Ro

Chillblain Lupus Erythematosus (CL) of Hutchinson is a subtype of Lupus Erythematosus characterized by erythematous lesions symmetrically distributed on the face, nose, fingers and toes, knees and heels. The lesions are induced by cold, damp climates. A number of patients affected by CL eventually develop features of Systemic Lupus Erythematosus (SLE). We report here 7 patients, all but one affected by SLE, with chilblain cutaneous lesions on their hands, feet and face. The onset of CL preceded the diagnosis of SLE, from 1 to 10 years in 3 cases, it was concurrent in one case and was subsequent in the other 2 cases. Six out of the seven patients referred typical Raynauds phenomenon and one had acrocyanosis. CL lesions developed and were aggravated by the cold during autumn and winter, they improved during summer. Skin biopsy performed in 5 patients from the lesions showed, on histology, a typical pattern of alterations with granular deposits at the dermo-epidermal junction on direct immunofluorescence. Laboratory findings showed: ANA and anti-SSA/Ro were detected in all the patients, anti-SSA/Ro were isolated in 4 patients and associated with anti-Sm in one case, anti-U1 RNP in one case and with anti-Sm and anti-RNP in a third case. Complement consumption was observed in 5 patients, anti-dsDNA in the six patients with SLE, hypergammaglobulinemia in 4 and rheumatoid factor in one. The fine specificity of anti-SSA/Ro as determined by immunoblotting using a human spleen extract as a substrate, showed: anti-60kD and anti-52 kD in two sera, anti-60kD isolated in 2 sera, anti-52kD isolated in one serum (from the patient without SLE) while 2 sera did not blotted. In conclusion, our study confirms the previous report of anti-SSA/Ro antibodies in association with CL. This clinical and serologic association widens the spectrum of cutaneous disease that is associated with antibodies to SSA/Ro to include conditions such as to SCLE, hypergammaglobulinemic purpura and neonatal lupus.