Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis.

OBJECTIVES: To clarify the impact of anti-U1RNP antibodies on the clinical features and prognosis of patients with SSc. METHODS: We conducted a monocentric case-control, retrospective, longitudinal study. For each patient with SSc and anti-U1RNP antibodies (SSc-RNP+), one patient with mixed connective tissue disease (MCTD) and 2 SSc patients without anti-U1RNP antibodies (SSc-RNP-) were matched for age, sex, and date of inclusion. RESULTS: Sixty-four SSc-RNP+ patients were compared to 128 SSc-RNP- and 64 MCTD patients. Compared to SSc-RNP-, SSc-RNP+ patients were more often of Afro-Caribbean origin (31.3% vs. 11%, p < 0.01), and more often had an overlap syndrome than SSc-RNP- patients (53.1 % vs. 22.7%, p < 0.0001), overlapping with Sjögren's syndrome (n = 23, 35.9%) and/or systemic lupus erythematosus (n = 19, 29.7%). SSc-RNP+ patients were distinctly different from MCTD patients but less often had joint involvement (p < 0.01). SSc-RNP+ patients more frequently developed interstitial lung disease (ILD) (73.4% vs. 55.5% vs. 31.3%, p < 0.05), pulmonary fibrosis (PF) (60.9% vs. 37.5% vs. 10.9%, p < 0.0001), SSc associated myopathy (29.7% vs. 6.3% vs. 7.8%, p < 0.0001), and kidney involvement (10.9% vs. 2.3% vs. 1.6%, p < 0.05). Over a 200-month follow-up period, SSc-RNP+ patients had worse overall survival (p < 0.05), worse survival without PF occurrence (p < 0.01), ILD or PF progression (p < 0.01 and p < 0.0001). CONCLUSIONS: In SSc patients, anti-U1RNP antibodies are associated with a higher incidence of overlap syndrome, a distinct clinical phenotype, and poorer survival compared to SSc-RNP- and MCTD patients. Our study suggests that SSc-RNP+ patients should be separated from MCTD patients and may constitute an enriched population for progressive lung disease.

Exploring clinical features and therapeutic outcomes in Indian children with mixed connective tissue disease: A multicenter study.

INTRODUCTION: Mixed connective tissue disease (MCTD) is a rare entity in children. There is a paucity of studies on juvenile-onset MCTD (jMCTD) worldwide especially from Southeast Asia. OBJECTIVES: To describe clinical and laboratory features of jMCTD diagnosed at pediatric rheumatology centers across India. METHODS: A predesigned detailed case proforma in an excel format was prepared and was sent to all the Pediatric Rheumatology centers in India. Eleven centers provided the clinical and laboratory data of their jMCTD patients, which was then compiled and analyzed in detail. RESULTS: Thirty-one jMCTD patients from 11 centers were included in the study. Our cohort had 27 females and four male patients over 12 months (August 2021 to July 2022). The median age at presentation was 12 years (range 5-18 years) and the median duration of symptoms was 24 months at diagnosis (range 2-96 months). The common features included arthritis (90%), malar rash (70.9%), and Raynaud's phenomenon (70.9%). At a mean follow-up of 43 months (range 1-168 months), 45% of them were in remission. There were two deaths reported, due to macrophage activation syndrome and sepsis respectively. CONCLUSION: We present the largest multicenter experience on jMCTD from the Indian subcontinent. The study's findings serve as a crucial stepping stone toward unraveling the complexities of jMCTD and improving patient care and management strategies.

Antibodies in Aseptic Meningitis of Connective Tissue Disorder: A Case Report.

Mixed connective tissue disorder (MCTD) is the first overlap syndrome described with features of overlapping manifestations of at least two other autoimmune rheumatic conditions. It is an autoimmune disease of rarity and is strongly associated with specific antibodies to U1 small nuclear ribonucleoprotein (anti-U1-RNP). This disorder affects almost all organs of the body, and it has varied clinical presentations as it has an autoimmune and inflammatory background, causing heightened immune cell activation. They present more commonly with less fatal symptoms like joint pain, stiffness, and mucocutaneous changes. The majority present initially with Raynaud's phenomenon followed by muscular skeletal involvement and around half of them present with swallowing problems due to esophageal dysmotility. Rarely do they also present with more morbid symptoms of pulmonary hypertension and central nervous system involvement. MCTD on follow-up had a 10 percent association with neurological manifestations as reported by the National Organization for Rare Diseases (NORD), and the most reported diseases were trigeminal neuralgia and aseptic meningitis. Patients presenting with such symptoms and, when treated only with guideline-based antibiotics therapy, would delay the treatment, leading to a poorer prognosis. The following is an interesting case of a young female presenting with a headache, which was masquerading as an underlying undiagnosed connective tissue disorder. Headache is a predominant presentation that has several etiologies in autoimmune disease and meticulous differential diagnosis workup is a must. This case highlights the fact that any persistent atypical, unusual symptom needs to be always considered for further evaluation to arrive at a diagnosis and for a favorable outcome.

A case presentation of renal involvement in MCTD / 대한내과학회지

MCTD (Mixed Connective Tissue Disease) is a rare disease characterized by clinical characteristics of patients with overlapping features of SLE (systemic lupus erythematosus), SS (systemic sclerosis), and PM (polymyositis), and serologically characterized by high titers of Anti U1 RNP Ab. At early stage, finger swelling or Raynaud's phenomenon with high titers of Anti U1 RNP Ab are only apparent. Proteinuria and membranous nephropathy are characteristic renal manifestation of MCTD. Recently we had the opportunity to observe patient with Raynaud's phenomenon, finger swelling, high titers of Anti U1 RNP Ab, and asymptomatic proteinuria who underwent a renal biopsy. The patient was diagnosed as early MCTD and renal histology revealed membranous nephropathy. Our purpose is to report this patient and to review the literature.

Neonatal Lupus Erythematosus / 대한피부과학회지

Neonatal lupus erythematosus(NLE) is a rare syndrome occuring in neonates with transplacentally acquired maternal autoantibodies, in particular anti-Ro, anti-La or anti-U1RNP. We report a case of NLE in a 50-day-old male neonate born to a systemic lupus erythematosus-mother with anti-U1RNP autoantibodies; on a review, there have been 8 cases of NLE reported in Korean literature.