The Kaleidoscope of Polyautoimmunity: An Odyssey of Diagnostic Dilemmas.

Diagnostic accuracy is of the utmost importance, both in the clinical setting and for research purposes. Mixed connective tissue disease (MCTD), rheumatoid arthritis (RA), Sjogren's syndrome (SS), and overlap syndrome (OS) frequently exhibit symptoms that mimic those of other conditions. Unfortunately, there is no singular definitive test for diagnosing these connective tissue diseases (CTDs), necessitating the reliance on expert opinions. Further complicating the matter, these diseases have overlapping clinical and serological features, and some individuals with one autoimmune disease may develop additional autoimmune disorders, either concurrently or at a later stage of their ailment. Autoimmune diseases (ADs) may manifest as a single AD or, concurrently with other ADs, a condition named polyautoimmunity (polyA). Polyautoimmunity refers to the presence of numerous autoimmune disorders in a single patient. Multiple autoimmune syndrome (MAS) is a condition that occurs when three or more autoimmune illnesses coexist. Moreover, the coexistence of two or more ADs with classification criteria is named "overt polyA," whereas the presence of autoantibodies not related to the index AD, without criteria fulfillment, is termed "latent polyA." Furthermore, both conditions can exist simultaneously within an individual patient. This case report's findings underscore that patients exhibiting both latent and overt polyautoimmunity tend to group, exhibiting distinct clinical and immunological characteristics. Additionally, CTDs not only have overlapping features amongst their various subclasses but also tend to mimic other conditions due to an underlying chronic inflammatory state. This case study also attempts to highlight the diagnostic dilemmas faced in such situations.

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.

To Test or Not to Test: A Case Report on Hereditary Hemorrhagic Telangiectasia.

A 50-year-old female patient presenting with joint pains, Raynaud's phenomenon, epistaxis, and telangiectasias was posed with a diagnostic conundrum, i.e., whether to accept the diagnosis of mixed connective tissue disease (MCTD), for which she fulfilled all the criteria, or test for another probable disease, namely hereditary hemorrhagic telangiectasia (HHT), even though only some clinical features were present and all diagnostic criteria were not satisfied. Taking the patient's onset of epistaxis as an important clue, the patient was counseled for genetic testing for HHT, which was positive. Treatment for both MCTD and HHT is underway, and appropriate surveillance is planned for the patient.

Evolution of diagnostic criteria and new insights into clinical testing in mixed connective tissue disease; anti-survival motor neuron complex antibody as a novel marker of severity of the disease.

Mixed connective tissue disease (MCTD) is an autoimmune disorder characterized by a combination of clinical features from systemic lupus erythematosus, systemic sclerosis, and inflammatory muscle disease, along with the presence of positive anti-U1-ribonucleoprotein (U1-RNP) antibodies. The exact etiology of the disease remains unclear, but it is believed to involve vascular damage within the context of heightened autoimmune responses. Consequently, Raynaud's phenomenon and pulmonary arterial hypertension are observed in patients with MCTD. While specific biomarkers for MCTD have not yet been identified, the recent study of the utility of anti-survival motor neuron complex (SMN) antibodies in MCTD suggests a promising avenue for further research and the accumulation of additional evidence.

Macitentan in Pulmonary Arterial Hypertension Associated with Connective Tissue Disease (CTD-PAH): Real-World Evidence from the Combined OPUS/OrPHeUS Dataset.

INTRODUCTION: Data on real-world clinical practice and outcomes of patients with pulmonary arterial hypertension associated with connective tissue disease (CTD-PAH) are scarce. The OPUS/OrPHeUS studies enrolled patients newly initiating macitentan, including those with CTD-PAH. This analysis describes patient characteristics, treatment patterns, outcomes, and safety profiles of patients with CTD-PAH newly initiating macitentan in the US using the OPUS/OrPHeUS combined dataset. METHODS: OPUS was a prospective, US, multicenter, long-term, observational drug registry (April 2014-June 2020). OrPHeUS was a retrospective, US, multicenter medical chart review (October 2013-March 2017). The characteristics, treatment patterns, safety, and outcomes during macitentan treatment of patients with CTD-PAH and its subgroups systemic sclerosis (SSc-PAH), systemic lupus erythematosus (SLE-PAH), and mixed CTD (MCTD-PAH) were descriptively compared to patients with idiopathic/heritable PAH (I/HPAH). RESULTS: The combined OPUS/OrPHeUS population included 2498 patients with I/HPAH and 1192 patients with CTD-PAH (708 SSc-PAH; 159 SLE-PAH; 124 MCTD-PAH, and 201 other CTD-PAH etiologies). At macitentan initiation for patients with I/HPAH and CTD-PAH, respectively: 61.2 and 69.3% were in World Health Organization functional class (WHO FC) III/IV; median 6-min walk distance was 289 and 279 m; and 58.1 and 65.2% received macitentan as combination therapy. During follow-up, for patients with I/HPAH and CTD-PAH, respectively: median duration of macitentan exposure observed was 14.0 and 15.8 months; 79.0 and 83.0% experienced an adverse event; Kaplan-Meier estimates (95% confidence limits [CL]) of patients free from all-cause hospitalization at 1 year were 60.3% (58.1, 62.4) and 59.3% (56.1, 62.3); and Kaplan-Meier estimates (95% CL) of survival at 1 year were 90.5% (89.1, 91.7) and 90.6% (88.6, 92.3). CONCLUSIONS: Macitentan was used in clinical practice in patients with CTD-PAH and its subgroups, including as combination therapy. The safety and tolerability profile of macitentan in patients with CTD-PAH was comparable to that of patients with I/HPAH. TRIAL REGISTRATION: OPsumit® Users Registry (OPUS): NCT02126943; Opsumit® Historical Users cohort (OrPHeUS): NCT03197688; www. CLINICALTRIALS: gov Graphical abstract available for this article.

Machine learning-driven immunophenotypic stratification of mixed connective tissue disease corroborating the clinical heterogeneity.

OBJECTIVES: To stratify patients with mixed connective tissue disease (MCTD) based on their immunophenotype. METHODS: We analyzed the immunophenotype and transcriptome of 24 immune cell subsets from patients with MCTD, systemic lupus erythematosus (SLE), idiopathic inflammatory myopathy (IIM), and systemic sclerosis (SSc) from our functional genome database, ImmuNexUT (https://www.immunexut.org/). MCTD patients were stratified by employing machine learning models including Random Forest, trained by immunophenotyping data from SLE, IIM, and SSc patients. Transcriptomes were analyzed with gene set variation analysis (GSVA) and clinical features of MCTD subgroups were compared. RESULTS: This study included 215 patients, including 22 patients with MCTD. Machine learning models, constructed to classify SLE, IIM, and SSc patients based on immunophenotyping, were applied to MCTD patients, resulting in 16 classified as SLE-immunophenotype and 6 as non-SLE-immunophenotype. Among MCTD patients, patients with the SLE-immunophenotype had higher proportions of Th1 cells [2.85% (interquartile range (IQR) 1.54-3.91) vs 1.33% (IQR 0.99-1.74) p= 0.027] and plasmablasts [6.35% (IQR 4.17-17.49) vs 2.00% (IQR 1.20-2.80) p= 0.010]. Notably, the number of SLE-related symptoms was higher in patients with the SLE-immunophenotype [2.0 (IQR 1.0-2.0) vs 1.0 (IQR1.0-1.0) p= 0.038]. Moreover, GSVA scores of interferon-α and -γ responses were significantly higher in patients with the SLE-immunophenotype in central memory CD8+ T cells, while hedgehog signalling was higher in non-SLE-immunophenotype patients in 5 cell subsets. CONCLUSION: This study describes the stratification of MCTD patients based on immunophenotyping, suggesting the presence of distinct immunological processes behind the clinical subtypes of MCTD.

Mixed Connective Tissue Disease: The Two Cases Report Representing the Range of this Illness.

INTRODUCTION: Mixed connective tissue disease (MCTD) is defined as a systemic rheumatic disease characterized by the presence of high titer anti-U1 ribonucleoprotein (U1 RNP) antibodies in combination with clinical features commonly seen in systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA) and polymyositis (PM). CASE PRESENTATION: The annual incidence of MCTD is 1.9 per 100,000 adults. Any organ system can be involved in MCTD however four clinical features that suggest the presence of MCTD rather than another systemic rheumatic disease are Raynaud phenomenon with swollen hands or puffy fingers, absence of severe kidney disease and central nervous system (CNS) disease at first presentation generally, insidious onset of pulmonary hypertension and presence of autoantibodies anti-U1 ribonucleoprotein (U1 RNP), especially antibodies to the 68 kD protein. MCTD, although initially thought to be a disease with a benign course is not considered a valid argument at present. This connective tissue disorder can present with life-threating organ involvement with rapid progression of disease. CONCLUSION: We report two cases of MCTD, one with mild disease and another with life-threatening illness, describing the range of severity at presentation of this disorder.

Childhood mixed connective tissue disease at disease onset: Evidence from a systematic review.

OBJECTIVE: Childhood Mixed Connective Tissue Disease (cMCTD) is the rarest pediatric connective tissue disease that includes features of systemic lupus erythematosus, polymyositis/dermatomyositis, juvenile idiopathic arthritis, and systemic sclerosis, identified by Sharp in 1972 and whose diagnosis remains challenging. This systematic review aims to identify clinical features at the onset of cMCTD and manifestations not currently included into the available diagnostic criteria. METHODS: A systematic literature review was performed in accordance with PRISMA guidelines 2020 using bibliographic databases: MEDLINE via PubMed and EMBASE. ELIGIBILITY CRITERIA: patients diagnosed with MCTD with onset before 18 years. STUDIES INCLUDED: registries, retrospective and prospective cohort studies, case series and reports with analysis of data on signs and symptoms of presentation. RESULTS: 39 articles were included (215 subjects, 82.5% female), mean age of 141 months (± 41 months DS, range 2.5-204). The most used criteria for the diagnosis of MCTD were the Kasukawa criteria (54.5%). The clinical manifestations described at onset were Raynaud's phenomenon (69.7%), arthritis (60.9%), muscular involvement (53.5%), dermatological signs (39.5%), swollen fingers or hands (29.3%), arthralgias (25.6%), fever (22.3%), lung involvement (14.4%), sclerodactily (13.5%), lymphadenopathy (10.7%) serositis (10.2%), esophageal involvement (6.9%), nervous system involvement (6.9%), xeroftalmia (3.7%), xerostomia (3.7%), hepatosplenomegaly (2.8%), cardiac involvement (2.8%), hepatitis (2.3%), parotiditis (2.3%), Hashimoto's thyroiditis (0.9%), ocular involvement (0.9%). CONCLUSIONS: The data from this systematic review suggest great heterogeneity of the clinical presentation of cMCTD for which there are no validated diagnostic criteria that may suggest a new diagnostic approach to allow earlier or more accurate diagnosis in the future.

Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies.

INTRODUCTION: Overlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood. METHODS: Retrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa's criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM). RESULTS: Sixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4-17) with median follow up of 7.9 years (2.1-19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1-7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure. CONCLUSION: This is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

Mixed connective tissue and ovarian cancer: a case report.

Background: Mixed connective tissue disease (MCTD) is characterized by high titres of distinct antibodies: U1 ribonucleoprotein with variable clinical features seen in rheumatoid arthritis, systemic lupus erythematosus, scleroderma, polymyositis, and dermatomyositis. Limited case reports revealed the association between MCTD and cancer, like lymphoma, lung cancers, and others. Case presentation: A 22-year-old female presented with enlargement of the abdomen and oedema of the lower extremities, gradually started 25 days The patient had been diagnosed to have rheumatoid arthritis. She was treated with 7.5 mg/week MTX for 6 months. Physical examination revealed: pallor, lower limb oedema, with synovitis and deformities of hands. The laboratory tests showed anaemia, elevated levels of creatine phosphokinase ESR, positivity of antinuclear antibody, anti-ds DNA, and antinuclear ribonucleoprotein. Urinary protein excretion was 1625 mg/24 h. Chest X-ray showed bilateral pleural effusion. Echocardiography revealed pericardial effusion Thoracic-abdominal and pelvic tomography showed a heterogeneous mass with a diameter of 5 × 6 cm at the expense of the right ovary. The mass was removed surgically, and a biopsy was taken, and was compatible with ovarian high-grade serous adenocarcinoma. A course of solumedrol 1 g/IV/3 days was applied, and then continue with 60 mg/day oral predlone. Later on discharge, she was taken 25 mg/day predlone, and methotrexate 10 mg. Conclusions: Our case showed that the patient had no risk factors for developing ovary cancer. On the contrary, our patient was a young, non-smoker, without any previous treatment before the RA diagnosis was taken, and finally, she had 3 children with full-term pregnancy, and well health. This case highlights the importance of maintaining a high index of suspicion for malignancy in MCTD patients. However, further investigation on the role of the immune system in the development of ovarian cancer in women with autoimmune diseases including MCTD remains necessary.

Pulmonary hypertension in connective tissue diseases: What every CTD specialist should know - but is afraid to ask!

Pulmonary hypertension (PH) is a possible complication of connective tissue diseases (CTDs), especially systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). It is defined by an elevation of the mean pulmonary arterial pressure above 20mmHg documented during a right heart catheterization (RHC). Due to their multiorgan involvement, CTDs can induce PH by several mechanisms, that are sometimes intricated: pulmonary vasculopathy (group 1) affecting arterioles (pulmonary arterial hypertension, PAH) and possibly venules (pulmonary veno-occlusive-like disease), left-heart disease (group 2), chronic lung disease (group 3) and/or chronic thromboembolic PH (group 4). PH suspicion is often raised by clinical manifestations (dyspnea, fatigue), echocardiographic data (increased peak tricuspid regurgitation velocity), isolated decrease in DLCO in pulmonary function tests, and/or unexplained elevation of BNP/NT-proBNP. Its formal diagnosis always requires a hemodynamic confirmation by RHC. Strategies for PH screening and RHC referral have been extensively investigated for SSc-PAH but data are lacking in other CTDs. Therapeutic management of PH depends of the underlying mechanism(s): PAH-approved therapies in group 1 PH (with possible use of immunosuppressants, especially in case of SLE or MCTD); management of an underlying left-heart disease in group 2 PH; management of an underlying chronic lung disease in group 3 PH; anticoagulation, pulmonary endartectomy, PAH-approved therapies and/or balloon pulmonary angioplasty in group 4 PH. Regular follow-up is mandatory in all CTD-PH patients.

Anti-survival motor neuron complex antibodies as a novel biomarker for pulmonary arterial hypertension and interstitial lung disease in mixed connective tissue disease.

OBJECTIVE: The presence of anti-U1 RNP antibodies (Abs) is critical for diagnosing MCTD. The aim of this study is to evaluate the clinical relevance of anti-survival motor neuron (SMN) complex Abs, which often coexist with anti-U1 RNP Abs. METHODS: A total of 158 newly diagnosed consecutive cases of SLE, SSc or MCTD with anti-U1 RNP Abs were enrolled in this multicentre observational study between April 2014 and August 2022. Serum anti-SMN complex Abs were screened by immunoprecipitation of 35S-methionine-labelled cell extracts, and associations between anti-SMN complex Abs positivity and clinical characteristics were analysed. RESULTS: Anti-SMN complex Abs were detected in 36% of MCTD patients, which was significantly higher than that in SLE (8%) or SSc (12%). Among MCTD patients classified based on the combination of the clinical features of SLE, SSc and idiopathic inflammatory myopathies, anti-SMN complex Abs showed the highest prevalence in a subset with clinical features of all three components. Anti-SMN complex Abs-positive MCTD had a higher prevalence of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), which are related to poor prognosis, than negative patients. Moreover, all three cases of death within 1 year of the treatment were positive for anti-SMN complex Abs. CONCLUSIONS: Anti-SMN complex Abs is the first biomarker of a typical subset of MCTD which bears organ damages such as PAH and ILD.

Clinical presentation, course, and prognosis of patients with mixed connective tissue disease: A multicenter retrospective cohort.

OBJECTIVES: The objective of this study is to better characterize the features and outcomes of a large population of patients with mixed connective tissue disease (MCTD). METHODS: We performed an observational retrospective multicenter cohort study in France. Patients who fulfilled at least one diagnostic criterion set for MCTD and none of the criteria for other differentiated CTD (dCTD) were included. RESULTS: Three hundred and thirty patients (88% females, median [interquartile range] age of 35 years [26-45]) were included. The diagnostic criteria of Sharp or Kasukawa were met by 97.3% and 93.3% of patients, respectively. None met other classification criteria without fulfilling Sharp or Kasukawa criteria. After a median follow-up of 8 (3-14) years, 149 (45.2%) patients achieved remission, 92 (27.9%) had interstitial lung disease, 25 (7.6%) had pulmonary hypertension, and 18 (5.6%) died. Eighty-five (25.8%) patients progressed to a dCTD, mainly systemic sclerosis (15.8%) or systemic lupus erythematosus (10.6%). Median duration between diagnosis and progression to a dCTD was 5 (2-11) years. The presence at MCTD diagnosis of an abnormal pattern on nailfold capillaroscopy (odds ratio [OR] = 2.44, 95% confidence interval [95%CI] [1.11-5.58]) and parotid swelling (OR = 3.86, 95%CI [1.31-11.4]) were statistically associated with progression to a dCTD. Patients who did not progress to a dCTD were more likely to achieve remission at the last follow-up (51.8% vs. 25.9%). CONCLUSIONS: This study shows that MCTD is a distinct entity that can be classified using either Kasukawa or Sharp criteria, and that only 25.8% of patients progress to a dCTD during follow-up.

Mixed connective tissue disease-myositis overlap syndrome presenting as an allergic disease process to the emergency department: A case report.

BACKGROUND: The "allergy epidemic" of the Western World, has led to an overwhelming number of emergency department presentations with allergic rhinitis, allergic conjunctivitis, atopic eczema, and asthma. Careful consideration should be given to screening for the typical signs and symptoms of Mixed connective tissue disease (MCTD) in patients presenting to the ED with what appears to be a simple allergic process. MCTD is a rare systemic rheumatic disease characterized by high levels of anti-U1RNP antibodies and various clinical signs and symptoms. The pathophysiology of MCTD is poorly understood. An association between allergen-mediated processes and MCTD has been reported in recent literature. Our case report involves a 40 year old African American female with initial outpatient presentation suggestive of atopic disease, with progressive worsening of symptoms while receiving allergen immunotherapy. The patient presented to the emergency department with bilateral leg cramping. The patient was found to have a CPK of 7000 unresponsive to fluids. The patient was evaluated by the Allergy and Rheumatology services. The patient was ultimately diagnosed with MCTD-Myositis Overlap Syndrome and started on steroids and IVIG with improvement in symptoms. While MCTD is not a diagnosis readily made in the ED, early identification and treatment of the disease is critical for prevention of long term complications.

Predictors of Interstitial Lung Disease in Mixed Connective Tissue Disease.

Interstitial lung disease (ILD) frequently complicates mixed connective tissue disease (MCTD) and contributes to increased mortality. We aimed to identify predictors of ILD in MCTD patients. This is a nationwide, multicentre, retrospective study including patients with an adult-onset MCTD clinical diagnosis who met Sharp's, Kasukawa, Alarcón-Segovia, or Kahn's diagnostic criteria and had available chest high-resolution computed tomography (HRCT) data. Univariate and multivariate analyses were conducted. We included 57 MCTD patients, with 27 (47.4%) having ILD. Among ILD patients, 48.1% were asymptomatic, 80.0% exhibited a restrictive pattern on pulmonary function tests, and 81.5% had nonspecific interstitial pneumonia on chest HRCT. Gastroesophageal involvement (40.7% vs. 16.7%, p = 0.043) and lymphadenopathy at disease onset (22.2% vs. 3.3%, p = 0.045) were associated with ILD. Binary logistic regression identified lymphadenopathy at disease onset (OR 19.65, 95% CI: 1.91-201.75, p = 0.012) and older age at diagnosis (OR 1.06/year, 95% CI: 1.00-1.12, p = 0.046) as independent ILD predictors, regardless of gender and gastroesophageal involvement. This study is the first to assess a Portuguese MCTD cohort. As previously reported, it confirmed the link between gastroesophageal involvement and ILD in MCTD patients. Additionally, it established that lymphadenopathy at disease onset and older age at diagnosis independently predict ILD in MCTD patients.

A very rare cause of blue finger: A case-based review.

Introduction: Cryofibrinogen is an abnormal, cold-insoluble protein composed of a combination of fibrinogen, fibrin, and fibronectin. Cryofibrinogenemia can be essential (e.g. primary) or secondary to various conditions. While low levels of cryofibrinogen can be seen in asymptomatic healthy individuals without evidence of clinical features typical of cryofibrinogenemia, cryofibrinogenemia associated with clinical features is considered very rare. The clinical features of cryofibrinogenemia ranges from skin manifestations, including Raynaud's phenomenon and livedo reticularis, to more severe organ-threatening manifestations such as tissue ischemia and gangrene. Case description: We report a case of a 48-year-old male who presented with blue finger and palpable purpura on his distal extremities. Laboratory workup was positive for anti-nuclear antibodies, anti-double-stranded DNA, anti-ribonucleoprotein, and rheumatoid factor, while antineutrophil cytoplasmic antibodies and cryoglobulins were negative. Testing for hypercoagulable states and infectious etiologies was unrevealing. Later, angiographic computed tomography showed multiple pulmonary embolisms and disruption of blood flow to the left fifth digit. As the aforementioned workup could not explain the presence of the thrombus by a thromboembolic cause, a search for an in situ cause other than antiphospholipid syndrome was initiated and concentrated mainly on cryofibrinogenemia. Blood samples collected using prewarmed anticoagulant containing tubes were sent to central lab familiar with performing the test. Two weeks later, a positive result for the presence of cryofibrinogen confirmed the diagnosis of cryofibrinogenemia. Due to the presence of multiple signs compatible with mixed connective tissue disease, he was diagnosed with cryofibrinogenemia secondary to mixed connective tissue disease, and treatment with prednisone, low-molecular-weight heparin, prostacyclin and hydroxychloroquine was initiaed with favorable outcome. Conclusion: Cryofibrinogenemia is a rare and underdiagnosed condition. Clinicians should be aware of this cryopathy especially in the cases of Raynaud's phenomenon and ischemic ulcers not explained by other causes. Precautions must be taken during the diagnostic process, and therapy should be given as soon as possible.

The phenotype of mixed connective tissue disease patients having associated interstitial lung disease.

OBJECTIVE: We aimed to compare two matched populations of patients with MTCD with and without associated ILD and to identify predictive factors for ILD progression and severity. METHODS: This international multicenter retrospective study (14 tertiary hospitals), included MCTD patients who fulfilled at least one historical MCTD classification criteria. ILD was defined by the presence of typical chest high-resolution computed tomography (HRCT) abnormalities. Factors associated with ILD were assessed at baseline. Long-term progressive ILD was assessed in MCTD-ILD patients with multiple forced vital capacity (FVC) measurements. RESULTS: 300 patients with MCTD were included. Mean age at diagnosis was 39.7 ± 15.4 years and 191 (63.7%) were women. Mean follow-up was 7.8 ± 5.5 years. At baseline, we identified several factors associated with ILD presence: older age (p = 0.01), skin thickening (p = 0.03), upper gastro-intestinal (GI) symptoms (p<0.001), FVC <80% (p<0.0001), diffusing capacity for carbon monoxide <80% (p<0.0001), anti-topoisomerase antibodies (p = 0.01), SSA/Ro antibodies (p = 0.02), cryoglobulinemia (p = 0.04) and elevated C-reactive protein (p<0.001). Patients with MTCD-ILD were more likely to be treated with synthetic immunosuppressant agents (p<0.001) in particular mycophenolate mofetil (p = 0.03). Digital ulcers (DU) were identified as a risk factor for FVC decline >10%. During follow-up mortality was higher in the MTCD-ILD group (p<0.001). CONCLUSION: In this large international cohort of patients with MTCD, we identified different factors associated with ILD. Our findings also provide evidence that MCTD-ILD patients have increased mortality and that DU are associated with progressive lung disease.

An unusual cardiac involvement in mixed connective tissue disease / Una afección cardíaca poco común en la enfermedad mixta del tejido conjuntivo

Mixed connective tissue disease is an autoimmune disorder with overlapping features of systemic lupus erythematosus, systemic sclerosis and polymyositis. Cardiac involvement is common, being pericarditis the most frequent manifestation, as also pulmonary hypertension. The authors present a case of a woman with one year of symptoms of polyarthritis and myalgia with gradual muscle weakness and weight loss, with severe impaired mobility in the last months. The initial evaluation showed an inflammatory systemic condition with an infiltrative pattern in echocardiogram, with pulmonary hypertension, that was confirmed by cardiac magnetic resonance. After an extensive study, where infiltrative cardiomyopathies were a differential diagnosis, the patient meet criteria to mixed connective disease with signs of pulmonary hypertension and an atypical cardiac involvement. Immunosuppressive treatment and rehabilitation were initiated and one year after the patient remains asymptomatic without any limitations. (AU)

La enfermedad mixta del tejido conectivo es un trastorno autoinmune con características superpuestas de lupus eritematoso sistémico, esclerosis sistémica y polimiositis. La afectación cardiaca es común, siendo la pericarditis la manifestación más frecuente, al igual que la hipertensión pulmonar. Los autores presentan el caso de una mujer con un año de síntomas de poliartritis y mialgia con debilidad muscular gradual y pérdida de peso, con grave deterioro de la movilidad en los últimos meses. La evaluación inicial mostró un cuadro inflamatorio sistémico con patrón infiltrativo en ecocardiograma, con hipertensión pulmonar, que se confirmó por resonancia magnética cardiaca. Tras un amplio estudio, en el que las miocardiopatías infiltrativas constituyeron un diagnóstico diferencial, la paciente cumplía criterios de conectivopatía mixta con signos de hipertensión pulmonar y una afectación cardiaca atípica. Se inició tratamiento inmunosupresor y rehabilitación y un año después la paciente permanece asintomática sin limitaciones. (AU)

Towards Early Diagnosis of Mixed Connective Tissue Disease: Updated Perspectives.

Mixed Connective Tissue Disease (MCTD) is an autoimmune disease first described by Sharp et al in 1972, characterized by the presence of anti-Ribonucleoprotein antibodies directed against the U1 complex (anti-U1RNP). The condition shares clinical characteristics with Systemic Lupus Erythematosus, Rheumatoid Arthritis, and Systemic Sclerosis. Diagnosis is quite difficult due to its rarity, the lack of validated classification criteria, and its heterogeneous clinical presentation. While in the early stages its nuanced clinical features might lead to it being incorrectly classified as other Connective Tissue Diseases (CTDs) or even not recognized, in cases of longstanding disease its classification as a CTD is clear but challenging to discriminate from overlap syndromes. MCTD should be considered a distinct entity due to the presence of a specific genetic substrate and the presence of the high titer of a specific autoantibody, anti-U1RNP, present in all the commercial kits for Extractable Nuclear Antigens, and almost always associated with Antinuclear Antibody positivity with a coarse speckled pattern. Except for anti-U1RNP, no specific biomarkers are available to guide clinicians to a correct classification of MCTD, which is arrived at by the association of clinical, serological and instrumental evaluation. In the first stages, the disease is mainly characterized by Raynaud's phenomenon, inflammatory arthritis, puffy fingers, myalgia and/or myositis, and rarely, trigeminal neuropathy. Longstanding disease is generally associated with the development of Pulmonary Hypertension and Interstitial Lung Disease, which are the two main causes of mortality in MCTD. The aim of this review is to summarize current knowledge on the early recognition of MCTD.