Undifferentiated connective tissue disease: a seven-center cross-sectional study of 184 patients

Hydroxychloroquine improves pregnancy outcomes in patients undergoing frozen embryo transfer with positive serum autoantibodies

PROBLEM

Does hydroxychloroquine (HCQ) improve pregnancy outcomes after frozen embryo transfer (FET) cycles in patients who are positive for autoantibodies？ METHOD OF STUDY: This was a retrospective clinical study involving 128 patients who were positive for autoantibodies undergoing FET cycles between October 2017 and December 2022. Subjects were divided into two groups: a study group of 65 cycles with HCQ (HCQ was administered orally over 2 months before transplantation and continued during the first trimester) and a control group consisting of 63 cycles without HCQ (no HCQ was used throughout the FET cycle). Each patient was enrolled in the cohort only once. Then, we analyzed the clinical pregnancy outcomes between the two groups.

RESULTS

Analysis showed that HCQ was a factor that independently associated with clinical pregnancy rate (CPR) OR (Odds Ratio): 3.106; 95% confidence interval (CI): 1.458-6.616; p = .003. Furthermore, the implantation rate (IR), CPR and ongoing pregnancy rate (OPR) of the treatment group were significantly higher than those in the control group. The biochemical pregnancy rate (BPR) and early miscarriage rate (EMR) were significantly lower than that in the control group (p = .029, p < .001).

CONCLUSION

We found that HCQ improved clinical pregnancy outcomes and reduced the rate of first-trimester abortion in patients who were positive for autoantibodies during FET cycles.

Predicting progression from undifferentiated connective tissue disease to definite connective tissue disease: A systematic review and meta-analysis

PURPOSE

Undifferentiated connective tissue disease (UCTD) encapsulates a broad range of conditions including incomplete forms of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), some of whom progress to a formal clinical diagnosis over time. This systematic review (SR) and meta-analysis aimed to identify clinical and laboratory features and biomarkers that can predict progression of UCTD.

METHODS

A systematic literature search was carried out on MEDLINE, EMBASE and the Cochrane Central Register of Randomized Controlled Trials. Abstracts and full-text manuscripts were screened by two reviewers. Publications were included if they included at least 20 UCTD patients, a minimum of six months of follow up, and provided data on at least one risk factor for developing a defined CTD. The QUIPS tool was used to assess risk of bias (RoB) and GRADE for grading the quality of the evidence. The study is registered with PROSPERO (ID: CRD42021237725).

RESULTS

Fifty-nine studies were included in the SR, and forty-one in the meta-analysis. The predictors for progression to SLE with the highest certainty of evidence included those with younger age (MD -5.96 [-11.05-0.87 years]), serositis (RR 2.69 [1.61-4.51]), or the presence of anti-dsDNA antibodies (RR 4.27 [1.92-9.51]). For SSc, the highest certainty of evidence included puffy fingers (RR [3.09 [1.48-6.43]), abnormal nailfold changes (NFC) (avascular areas [RR 5.71 (3.03-10.8)] or active or late SSc pattern [RR 2.24 (1.25-4.01)] and anti-topoisomerase-I (RR 1.83 [1.45-2.30]). No novel biomarkers were included in the meta-analysis; however HLA molecules, regulatory T cell shift, pro-inflammatory cytokines and complement activation products were identified as potential predictors for evolution of disease.

CONCLUSIONS

Clinical and immunological parameters may predict which patients with UCTD progress to definitive disease; however, the heterogeneous nature and RoB in most studies limits the ability to apply these results in routine clinical practice. Limited data suggest that some novel biomarkers may provide additional predictive value but these will need larger well designed studies to fully delineate their clinical utility.

Undifferentiated Connective Tissue Disease in Pregnancy: A Topic Yet to be Explored

Undifferentiated connective tissue disease (UCTD) is characterized by signs and symptoms suggestive of a connective tissue disease (CTD), but not fulfilling criteria for a specific CTD. Although UCTD is probably the most common rheumatic disease diagnosed in pregnant women, data about disease course during pregnancy and perinatal outcomes are very limited. Compared to other CTDs, UCTD seems to have milder clinical manifestations in pregnancy. Its natural history is related to disease activity at conception. In fact, if the disease is in a state of remission or minimal activity at conception, pregnancy outcomes are generally good. On the contrary, patients who become pregnant in a moment of high disease activity and/or who have multiple antibodies positivity show an increased risk of disease flares, evolution to a definite CTD and obstetric complications, such as fetal growth restriction, preeclampsia and preterm birth. Therefore, a preconception assessment is essential in women with UCTD to evaluate maternal and fetal risks, to initiate interventions to optimize disease activity, and to adjust medications to those that are least harmful to the fetus. The aim of the present study was to review the available literature about pregnancy course, maternal and fetal outcomes and therapeutic approaches of pregnant women with UCTD.

Differentiating between UCTD and early-stage SLE: from definitions to clinical approach

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous clinical manifestations that can potentially affect every organ and system. SLE is usually identified on the basis of clinical or serological manifestations; however, some individuals can present with signs and symptoms that are consistent with SLE but are not sufficient for a definite diagnosis. Disease in these individuals can either progress over time to definite SLE or remain stable, in which case their disease is often described as intermediate, possible or probable SLE. Alternatively, such individuals might have undifferentiated connective tissue disease (UCTD). Being able to differentiate between those with stable UCTD and those with SLE at an early stage is important to avoid irreversible target-organ damage from occurring. This Review provides insight into existing and evolving perceptions of the early stages of SLE, including clinical and mechanistic considerations, as well as potential paths towards early identification and intervention. Further research into the earliest phases of SLE will be important for the development of targeted diagnostic approaches and biomarkers for the identification of individuals with early disease who are likely to progress to definite SLE.

Interstitial Lung Disease Associated with Connective Tissue Diseases

Pulmonary manifestations of connective tissue diseases (CTD) carry high morbidity and potential mortality, and the most serious pulmonary type is interstitial lung disease (ILD). Identifying and promptly intervening CTD-ILD with immune suppressor therapy will change the natural course of the disease resulting in survival improvement. Compared to idiopathic pulmonary fibrosis, the most common presentation of idiopathic interstitial pneumonia (IIP), CTD-ILD carries a better prognosis due to the response to immune suppressor therapy. Nonspecific interstitial pneumonia (NSIP) is the most common type of CTD-ILD that is different from the fibrotic classical presentation of IPF, known as usual interstitial pneumonia (UIP). An exception is rheumatoid arthritis that presents more frequently with UIP type. Occasionally, IPF may not have typical radiographic features of UIP, and a full assessment to differentiate IPF from CTD-ILD is necessary, including the intervention of a multidisciplinary team and the histopathology. Interstitial pneumonia with autoimmune features (IPAF) shows promising advantages to identify patients with ILD who have some features of a CTD without a defined autoimmune disease and who may benefit from immune suppressors. A composition of clinical, serological, and morphologic features in patients presenting with ILD will fulfill criteria for IPAF. In summary, the early recognition and treatment of CTD-ILD, differentiation from IPF-UIP, and identification of patients with IPAF fulfill the assessment by the clinician for an optimal care.

A three-arm, multicenter, open-label randomized controlled trial of hydroxychloroquine and low-dose prednisone to treat recurrent pregnancy loss in women with undifferentiated connective tissue diseases: protocol for the Immunosuppressant regimens for LIving FEtuses (ILIFE) trial

Background

Undifferentiated connective tissue disease (UCTD) is known to induce adverse pregnancy outcomes and even recurrent spontaneous abortion (RSA) by placental vascular damage and inflammation activation. Anticoagulation can prevent pregnancy morbidities. However, it is unknown whether the addition of immune suppressants to anticoagulation can prevent spontaneous pregnancy loss in UCTD patients. The purpose of this study is to evaluate the efficacy of hydroxychloroquine (HCQ) and low-dose prednisone on recurrent pregnancy loss for women with UCTD.

Methods

The Immunosuppressant for Living Fetuses (ILIFE) Trial is a three-arm, multicenter, open-label randomized controlled trial with the primary objective of comparing hydroxychloroquine combined with low-dose prednisone and anticoagulation with anticoagulation alone in treating UCTD women with recurrent spontaneous abortion. The third arm of using hydroxychloroquine combined with anticoagulant for secondary comparison. A total of 426 eligible patients will be randomly assigned to each of the three arms with a 1:1:1 allocation ratio. The primary outcome is the rate of live births. Secondary outcomes include adverse pregnancy outcomes and progression of UCTD.

Discussion

This is the first multi-center, open-label, randomized controlled trial which evaluates the efficacy of immunosuppressant regimens on pregnancy outcomes and UCTD progression. It will provide evidence on whether the immunosuppressant ameliorates the pregnancy prognosis in UCTD patients with RSA and the progression into defined connective tissue disease.

Trial registration

ClinicalTrials.gov NCT03671174. Registered on 14 September 2018.

"Mixed connective tissue disease": a condition in search of an identity

Mixed connective tissue disease was first described as a new autoimmune rheumatic disease in 1972 based on the claim of a distinct clinical picture associated with anti-RNP antibody positivity. Subsequently, this new entity has divided opinions in the rheumatology community. We have reviewed recent cohort studies with more than 100 patients, comparing the clinical and immunological features, treatment, prognosis and evolution to well-defined autoimmune rheumatic diseases. We also reviewed clinical features of undifferentiated autoimmune rheumatic diseases based on the most recent studies. After gathering and reviewing these data, we discuss whether the designation “mixed connective tissue disease” should be maintained.

Acquired renal glucosuria in an undifferentiated connective tissue disease patient with a SLC5A2 heterozygous mutation: A case report

INTRODUCTION

Renal glucosuria is a renal tubular disorder caused by genetic conditions, drugs, and poisons. Mutations in the SLC5A2 gene are recently found to be responsible for the inherited renal glucosuria, while undifferentiated connective tissue disease (UCTD) was not considered pathogenic for renal glucosuria. Here, we present a case of acquired renal glucosuria in a UCTD patient.

PATIENT CONCERNS

A 30-year-old woman was seen in the outpatient clinic for complaints of frequent urination and dysuria. Laboratory tests showed a urinary tract infection (UTI) and persistent renal glucosuria. After antibiotic treatment, the UTI symptoms were relieved, but the renal glucosuria remained.

DIAGNOSIS

Laboratory tests ruled out renal tubular acidosis and diabetes mellitus. Genetic analysis showed a heterozygous mutations in the SLC5A2 gene. Meanwhile, immunological tests showed a high antinuclear antibody titer (1:160) and an elevated anti-Rho/SSA antibody level. Schirmer test, tear breakup time, and lip biopsy results were all negative. The patient did not meet the criteria for any known connective diseases. Therefore, she was diagnosed with UCTD.

INTERVENTIONS

The patient was started with the treatment of Hydroxychloroquine.

OUTCOMES

Hydroxychloroquine treatment resolved the renal glucosuria. The patient's follow- up urinalysis showed no glucosuria at all.

LESSONS

This is the first case report to demonstrate that UCTD may induce renal glucosuria in a patient with a heterozygous mutation in SLC5A2. This case suggests that during the process of diagnosing renal glucosuria, in addition to familial renal glucosuria (FRG), autoimmune diseases, though rare, should also be taken into consideration.

Undifferentiated connective tissue diseases and adverse pregnancy outcomes. An undervalued association?

Undifferentiated connective tissue diseases (UCTDs) are a heterogeneous group of disorders characterized by symptoms and signs suggestive of systemic autoimmune rheumatic disease (ARD), but which do not fulfill all the established criteria for definite diagnosis of a condition. Although a third of UCTDs can progress to a definite ARD within months or years, most UCTDs can remain stable for years with minimal disease activity. The annual incidence of UCTD in the general population ranges from 14 to 140 per 100 000 people. UCTDs are associated with the persistence of several circulating autoantibodies including antinuclear, antiphospholipid or antithyroid antibodies. Immunological evaluation of subjects with UCTDs suggests a proinflammatory state and dysregulation of the Th1/Th2 balance. Autoantibodies have well-known deleterious effects on placentation and have been associated with an increased risk of prematurity, fetal growth restriction (FGR), preeclampsia, and congenital atrioventricular heart block. Although epidemiological and biological data suggest a potential negative impact on reproductive outcomes, the relationship between UCTD and pregnancy outcomes has not been adequately studied. While awaiting definitive data from large studies, obstetricians should be aware that rheumatic disorders in their early, incomplete, or undifferentiated phases can adversely affect pregnancy outcomes, increasing the likelihood of pregnancy loss, FGR, preeclampsia, and prematurity.

Interstitial Pneumonia with Autoimmune Features: Overview of proposed criteria and recent cohort characterization

The accurate diagnosis of interstitial lung disease (ILD) is essential for optimal prognostication and management. While connective tissue disease (CTD) is among the most common causes of ILD, some patients have features suggestive of autoimmunity without meeting criteria for a specific CTD. To help define and study this disease entity more uniformly, a 2015 research statement proposed consensus-based criteria and coined the term "interstitial pneumonia with autoimmune features" (IPAF). In this review, we summarize and compare previously proposed criteria to characterize these patients, provide an overview of the IPAF criteria and highlight recent investigations aimed at characterizing IPAF cohorts. We then call attention to questions that have arisen with the application of the IPAF criteria and discuss future areas of study.

Longitudinal analysis of quality of life in patients with undifferentiated connective tissue diseases

INTRODUCTION/OBJECTIVES

To prospectively assess the quality of life (QoL) of patients affected by undifferentiated connective tissue diseases (UCTDs) and to identify factors associated with changes over time.

PATIENTS AND METHODS

A total of 46 consecutive UCTD patients completed the Short-Form 36 (SF-36) questionnaire at presentation and then yearly. At each 6-month visit, all patients underwent a detailed history taking and a laboratory and physical assessment, in order to follow the evolution of the disease over time and to assess the the co-existence of fibromyalgia.

RESULTS

At presentation, scores lower than the average of the general population were detected in 34 (74%) and 41 (89%) patients in the physical and mental domains, respectively. No difference between patients with and without Raynaud's phenomenon was detected. Fibromyalgia was the only independent variable associated with an impaired physical component summary score (p = 0.0009). No patient feature was found to be associated with the basal mental component summary score. During 24 months of follow-up, a significant improvement (ie, a change ≥5 from baseline) in physical component summary and mental component summary scores was observed in 14 (33.3%) and 20 (43.4%) patients, respectively. Patients who significantly improved in the physical domain more frequently had a history of glucocorticoids intake (p<0.001), while those who improved in the mental component more frequently had a history of either glucocorticoids (p = 0.043) or immunosuppressors (p = 0.037) intake during follow-up.

CONCLUSION

UCTD patients perceive a worse QoL, regardless of Raynaud's phenomenon Fibromyalgia is one of the major contributors of physical QoL, whereas no factor influencing mental component has been identified. An improvement in QoL can be observed in less than half of patients over a 2-year follow-up. Larger studies are needed to identify factors influencing QoL and to define the role of pharmacological treatments.

Cytokine Milieu in Undifferentiated Connective Tissue Disease: a Comprehensive Review

Undifferentiated connective tissue disease (UCTD) is a unique clinical entity, a potential forerunner of well-established systemic autoimmune/rheumatic diseases. UCTD is characterized by the presence of various clinical symptoms, as well as a diverse repertoire of autoantibodies, resembling systemic autoimmune diseases. Since approximately one third of these patients consequently transform into a full-blown systemic autoimmune/rheumatic disease, it is of major importance to assess pathogenic factors leading to this progression. In view of the fact that the serological and clinical picture of UCTD and systemic autoimmune diseases are very similar, it is assumed that analogous pathogenic factors perpetuate both disease entities. In systemic autoimmune conditions, a quantitative and qualitative impairment of regulatory T cells has been shown previously, and in parallel, a relative dominance of pro-inflammatory Th17 cells has been introduced. Moreover, the imbalance between regulatory and Th17 cells plays a pivotal role in the initiation and propagation of UCTD. Additionally, we depict a cytokine imbalance, which give raise to a biased T cell homeostasis from the UCTD phase throughout the fully developed systemic autoimmune disease stage. The levels of interleukin (IL)-6, IL-12, IL-17, IL-23, and interferon (IFN)-γ were pathologically increased with a parallel reduction of IL-10. We believe that the assessment of Th17/Treg cell ratio, as well as the simultaneous quantitation of cytokines may give a useful diagnostic tool at the early UCTD stage to identify patients with a higher chance of consecutive disease progression toward serious systemic autoimmune diseases. Moreover, the early targeted immunomodulating therapy in these patients may decelerate, or even stop this progression, before the development of serious autoimmune conditions with organ damage.

Connective tissue diseases, multimorbidity and the ageing lung

Connective tissue diseases encompass a wide range of heterogeneous disorders characterised by immune-mediated chronic inflammation often leading to tissue damage, collagen deposition and possible loss of function of the target organ. Lung involvement is a common complication of connective tissue diseases. Depending on the underlying disease, various thoracic compartments can be involved but interstitial lung disease is a major contributor to morbidity and mortality. Interstitial lung disease, pulmonary hypertension or both are found most commonly in systemic sclerosis. In the elderly, the prevalence of connective tissue diseases continues to rise due to both longer life expectancy and more effective and better-tolerated treatments. In the geriatric population, connective tissue diseases are almost invariably accompanied by age-related comorbidities, and disease- and treatment-related complications, which contribute to the significant morbidity and mortality associated with these conditions, and complicate treatment decision-making. Connective tissue diseases in the elderly represent a growing concern for healthcare providers and an increasing burden of global health resources worldwide. A better understanding of the mechanisms involved in the regulation of the immune functions in the elderly and evidence-based guidelines specifically designed for this patient population are instrumental to improving the management of connective tissue diseases in elderly patients.

Systemic lupus erythematosus: An update for ophthalmologists

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.

Ischemic colitis due to a mesenteric arteriovenous malformation in a patient with a connective tissue disorder

Ischemic colitis is a rare, life-threatening, consequence of mesenteric arteriovenous malformations. Ischemia ensues from a steal phenomenon through shunting, and may be compounded by the resulting portal hypertension. Computed tomographic angiography is the most common first-line test because it is quick, non-invasive, and allows for accurate anatomic characterization. Also, high-resolution three-dimensional images can be created for treatment planning. Magnetic resonance angiography is similarly sensitive for vascular mapping. Conventional angiography remains the gold standard for diagnosis and also allows for therapeutic endovascular embolization. Our patient underwent testing using all three of these modalities. We present the first reported case of this entity in a patient with a vascular connective tissue disorder.

Interpretation of autoantibody positivity in interstitial lung disease and lung-dominant connective tissue disease

The initial evaluation of patients with interstitial lung disease (ILD) primarily involves a comprehensive, active search for the cause. Autoantibody assays, which can suggest the presence of a rheumatic disease, are routinely performed at various referral centers. When interstitial lung involvement is the condition that allows the definitive diagnosis of connective tissue disease and the classical criteria are met, there is little debate. However, there is still debate regarding the significance, relevance, specificity, and pathophysiological role of autoimmunity in patients with predominant pulmonary involvement and only mild symptoms or formes frustes of connective tissue disease. The purpose of this article was to review the current knowledge of autoantibody positivity and to discuss its possible interpretations in patients with ILD and without clear etiologic associations, as well as to enhance the understanding of the natural history of an allegedly new disease and to describe the possible prognostic implications. We also discuss the proposition of a new term to be used in the classification of ILDs: lung-dominant connective tissue disease.

Preclinical systemic lupus erythematosus

Preclinical lupus encompasses a spectrum from enhanced SLE risk without clinical symptoms to individuals with autoantibodies and some SLE clinical features without meeting ACR classification. Studies have identified antibody and serological biomarkers years before disease onset. Incomplete lupus and undifferentiated connective tissue disease may occur during preclinical disease periods, but only 10-20% of these individuals transition to SLE and many have a mild disease course. Further studies are warranted to characterize biomarkers of early disease, identify individuals in need of close monitoring or preventive interventions, and elucidate mechanisms of disease pathogenesis without confounding factors of immunosuppressive medications or organ damage.

The diagnosis and classification of undifferentiated connective tissue diseases

The term undifferentiated connective tissue disease (UCTD) refers to unclassifiable systemic autoimmune diseases which share clinical and serological manifestations with definite connective tissue diseases (CTDs) but not fulfilling any of the existing classification criteria. In this review we will go through the more recent evidence on UCTD and we will discuss in what extent the availability of new criteria for the CTDs could interfere with the "UCTD concept". The development of criteria able to identify early phases of defined CTD, may help in the differentiation of stable UCTD form their early stages and may offer a valuable guide to the treating physician to set up appropriate follow up schedules as well as therapeutic protocols. This simplified subset of CTD could offer a model to study clinic pathological correlations as well as the role of possible environmental factors in the development of autoimmunity.

Raynaud's phenomenon: from molecular pathogenesis to therapy

Raynaud's phenomenon (RP) is a well defined clinical syndrome characterized by recurrent episodes of digital vasospasm triggered by exposure to physical/chemical or emotional stress. RP has been classified as primary or secondary, depending on whether it occurs as an isolated condition (pRP) or is associated to an underlying disease, mainly a connective tissue disease (CTD-RP). In both cases, it manifests with unique "triple" (pallor, cyanosis and erythema), or "double" color changes. pRP is usually a benign condition, while sRP can evolve and be complicated by acral digital ulcers and gangrene, which may require surgical treatment. The pathogenesis of RP has not yet been entirely clarified, nor is it known whether autoantibodies have a role in RP. Even so, recent advances in our understanding of the pathophysiology have highlighted novel potential therapeutic targets. The aim of this review is to discuss the etiology, epidemiology, risk factors, clinical manifestations, recently disclosed pathogenic mechanisms underlying RP and their correlation with the available therapeutic options, focusing primarily on pRP and CTD-RP.

Comparison of characteristics of connective tissue disease-associated interstitial lung diseases, undifferentiated connective tissue disease-associated interstitial lung diseases, and idiopathic pulmonary fibrosis in Chinese Han population: a retrospective study

Our study compared the prevalence and characteristics of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD), undifferentiated connective tissue disease-associated interstitial lung disease (UCTD-ILD), or idiopathic pulmonary fibrosis (IPF) between January 2009 and December 2012 in West China Hospital, western China. Patients who met the criteria for ILD were included and were assigned to CTD-ILD, UCTD-ILD, or IPF group when they met the criteria for CTD, UCTD, or IPF, respectively. Clinical characteristics, laboratory tests, and high-resolution CT images were analyzed and compared among three groups. 203 patients were included, and all were Han nationality. CTD-ILD was identified in 31%, UCTD-ILD in 32%, and IPF in 37%. Gender and age differed among groups. Pulmonary symptoms were more common in IPF, while extrapulmonary symptoms were more common in CTD-ILD and UCTD-ILD group. Patients with CTD-ILD had more abnormal antibody tests than those of UCTD-ILD and IPF. Little significance was seen in HRCT images among three groups. A systematic evaluation of symptoms and serologic tests in patients with ILD can identify CTD-ILD, UCTD-ILD, and IPF.

Diagnosis and treatment of connective tissue disease-associated interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious pulmonary complications associated with connective tissue diseases (CTDs), resulting in significant morbidity and mortality. Although the various CTDs associated with ILD often are considered together because of their shared autoimmune nature, there are substantial differences in the clinical presentations and management of ILD in each specific CTD. This heterogeneity and the cross-disciplinary nature of care have complicated the conduct of prospective multicenter treatment trials and hindered our understanding of the development of ILD in patients with CTD. In this update, we present new information regarding the diagnosis and treatment of patients with ILD secondary to systemic sclerosis, rheumatoid arthritis, dermatomyositis and polymyositis, and Sjögren syndrome. We review information on risk factors for the development of ILD in the setting of CTD. Diagnostic criteria for CTD are presented as well as elements of the clinical evaluation that increase suspicion for CTD-ILD. We review the use of medications in the treatment of CTD-ILD. Although a large, randomized study has examined the impact of immunosuppressive therapy for ILD secondary to systemic sclerosis, additional studies are needed to determine optimal treatment strategies for each distinct form of CTD-ILD. Finally, we review new information regarding the subgroup of patients with ILD who meet some, but not all, diagnostic criteria for a CTD. A careful and systematic approach to diagnosis in patients with ILD may reveal an unrecognized CTD or evidence of autoimmunity in those previously believed to have idiopathic ILD.

Undifferentiated CTD: a wide spectrum of autoimmune diseases

The existence of systemic autoimmune diseases not fulfilling classification criteria for defined connective tissue diseases (CTDs) is a common clinical experience. These conditions have been variably defined as incomplete lupus erythematosus, early undifferentiated connective tissue diseases and undifferentiated connective tissue diseases (UCTDs). However, the definition of UCTD includes a wide spectrum of diseases ranging from 'organ-dominant' conditions (e.g., idhiopatic non-specific interstitial pneumonia) to simplified conditions (stable UCTD), to early CTDs or mild forms of CTDs. In the present article, the literature data on undifferentiated diseases and their clinical spectrum as well as the importance of the definition of new classificative criteria are discussed.

Blimp-1 siRNA inhibits B cell differentiation and prevents the development of lupus in mice

Cumulative evidence suggest that B-lymphocytes play a role in the development of systemic lupus erythematosus (SLE). Thus, the therapeutic approach targeting specific B cells provides a promising way to treat SLE. Blimp-1 (B lymphocyte induced maturation protein), a transcriptional factor, controls the terminal differentiation of mature B cells to plasma cells. To explore the potential of Blimp-1 in the SLE development, we constructed the adenovirus encoding Blimp-1 siRNA, and injected it into BWF1 lupus mice. The results demonstrated that Blimp-1 siRNA decreased the Blimp-1 expression of B cells by regulating XBP-1 (X Box binding protein-1), BCMA (B-cell maturation antigen) expression through c-myc pathway. In addition, Blimp-1 siRNA eliminated anti-dsDNA antibody-producing plsma cells, reduced serum anti-dsDNA antibody levels and impeded the development of lupus. Therefore, our data provide the insight into the mechanism of Blimp-1 in SLE development and might represent a promising therapeutic strategy for autoantibody-mediated diseases.

Undifferentiated connective tissue disease in a rheumatology center in Cali, Colombia: clinical features of 94 patients followed for a year

The aim of the study is to evaluate the clinical and serological features of patients with undifferentiated connective tissue disease (UCTD) of a rheumatology referral center in Cali, Colombia, who were followed for a year. A retrospective analysis of a cohort of patients with an initial diagnosis of UCTD and monitoring for at least 12 months was carried out. A total of 94 patients with UCTD (97.9% women) were evaluated, with an average follow-up of 51 ± 35.7 months. Only 13 patients (13.8%) evolved into a defined connective tissue disease (CTD), of which 8.5% (n:8) developed systemic lupus erythematosus (SLE), 4.2% (n:4) Sjögren syndrome (SS) and 1.1% (n:1) rheumatoid arthritis (RA). A mean period of 35.8 ± 29.2 months between UCTD diagnosis and definite develop of a CTD was found. Arthritis, Raynaud's phenomenon and photosensitivity were statistically significant (<0.001) for development of CTD. After a mean follow-up of 4.25 years, most of the patients with UCTD showed a favorable evolution. Arthritis, Raynaud's phenomenon and the presence of photosensitivity were predictors for the development of CTD. It requires a consensus to establish criteria for the classification of UCTD.

Undifferentiated connective tissue disease presenting with prevalent interstitial lung disease: case report and review of literature

Undifferentiated connective tissue diseases (UCTDs) are clinical entities characterised by signs and symptoms suggestive of a systemic autoimmune disease, which do not fulfil the diagnostic criteria for a defined connective tissue disease. Lung involvement can complicate the course and management of the disease, often determining a worse outcome. Respiratory dysfunction as the first clinical manifestation has seldom been reported.We describe a case of a female patient who developed significant respiratory dysfunction as the principal clinical sign. Video-assisted thoracoscopy was performed and a histological pattern of nonspecific interstitial pneumonia (NSIP) was found. A pathological diagnosis suggested careful follow-up with extensive immunological screening which then detected Raynaud's phenomenon and positivity of antinuclear antibodies. After a multidisciplinary discussion (pneumologist, radiologist, pathologist and rheumatologist) a final diagnosis of NSIP associated with UCTD was made. The diagnosis of UCTD should be considered when NSIP is diagnosed even in cases with evident first clinical manifestations of severe respiratory dysfunction. A multidisciplinary approach in the field of interstitial lung disease with NSIP, also including rheumatologic expertise, is fundamental to achieve a prompt and correct diagnosis.

Autoimmune-featured interstitial lung disease: a distinct entity

BACKGROUND

Patients with interstitial lung disease (ILD) may have features of an autoimmune disorder that do not meet the diagnostic criteria for connective tissue diseases. We determined the prevalence and characteristics of autoimmune-featured ILD (AIF-ILD) and compared these with those of idiopathic pulmonary fibrosis (IPF) and known connective tissue disease-related ILD (CTD-ILD).

METHODS

Patients with ILD who did not meet the criteria for a connective tissue disease were defined as having AIF-ILD if they had a sign or symptom suggestive of a connective tissue disease and a serologic test reflective of an autoimmune process. Clinical characteristics, high-resolution CT images, and lung biopsy specimens were analyzed and compared with those of patients with IPF and CTD-ILD. Survival was evaluated using a Kaplan-Meier curve.

RESULTS

Two hundred subjects completed the questionnaire and serologic testing. AIF-ILD was identified in 32%, IPF in 29%, and CTD-ILD in 19%. Gender, age, and race differed among groups (P < .01). Sixty-two percent of patients with AIF-ILD had a typical usual interstitial pneumonia (UIP) pattern on CT images. In 31 patients with AIF-ILD, lung biopsy specimens showed UIP in 81% and nonspecific interstitial pneumonia in 6%. Patients with AIF-ILD and IPF had similar survival, worse than those with CTD-ILD (P < .01). Antinuclear antibody (ANA) titers ≥ 1:1280 were associated with improved survival in patients with AIF-ILD (P = .02).

CONCLUSIONS

Systematic evaluation of symptoms and serologic tests in ILD can identify AIF-ILD. A UIP pattern on CT images and histopathology is common in AIF-ILD. Although survival for patients with AIF-ILD is poor, ANA titers ≥ 1:1280 are associated with improved survival.

Frequent coexistence of anti-topoisomerase I and anti-U1RNP autoantibodies in African American patients associated with mild skin involvement: a retrospective clinical study

Introduction

The presence of anti-topoisomerase I (topo I) antibodies is a classic scleroderma (SSc) marker presumably associated with a unique clinical subset. Here the clinical association of anti-topo I was reevaluated in unselected patients seen in a rheumatology clinic setting.

Methods

Sera from the initial visit in a cohort of unselected rheumatology clinic patients (n = 1,966, including 434 systemic lupus erythematosus (SLE), 119 SSc, 85 polymyositis/dermatomyositis (PM/DM)) were screened by radioimmunoprecipitation. Anti-topo I-positive sera were also tested with immunofluorescence and RNA immunoprecipitation.

Results

Twenty-five (15 Caucasian, eight African American, two Latin) anti-topo I positive patients were identified, and all except one met the ACR SSc criteria. Coexistence of other SSc autoantibodies was not observed, except for anti-U1RNP in six cases. When anti-topo I alone versus anti-topo I + U1RNP groups were compared, African American (21% vs. 67%), overlap with SLE (0 vs. 50%; P = 0.009) or PM/DM (0 vs. 33%; P = 0.05) or elevated creatine phosphokinase (CPK) (P = 0.07) were more common in the latter group. In comparison of anti-topo I-positive Caucasians versus African Americans, the latter more frequently had anti-U1RNP (13% vs. 50%), mild/no skin changes (14% vs. 63%; P = 0.03) and overlap with SLE (0 vs. 38%; P = 0.03) and PM/DM (0 vs. 25%; P = 0.05).

Conclusions

Anti-topo I detected by immunoprecipitation in unselected rheumatology patients is highly specific for SSc. Anti-topo I coexisting with anti-U1RNP in African American patients is associated with a subset of SLE overlapping with SSc and PM/DM but without apparent sclerodermatous changes.

Sm peptides in differentiation of autoimmune diseases

Systemic lupus erythematosus (SLE) and related diseases are characterized by circulating autoantibodies to defined intracellular targets. Among the earliest identified autoantibodies were those directed to components of U2-U6 small nuclear ribonucleoproteins (snRNPs) known as Smith (Sm) antigen, which are highly specific for SLE. The Sm-antigen is composed of at least nine different polypeptides with molecular weights ranging from 9 to 29.5 kDa (B (B1, 28 kDa), B' (B2, 29 kDa), N (B3, 29.5 kDa), D1 (16 kDa), D2 (16.5 kDa), D3 (18 kDa), E (12 kDa), F (11 kDa), and G (9 kDa)). All of the nine core proteins, but most frequently the B and D polypeptides, are targets of the anti-Sm autoimmune response. However, since SmBB' and U1 specific RNPs share the cross-reactive epitope motif PPPGMRPP, SmD is regarded as the most SLE specific Sm-antigen. It has been shown that the polypeptides D1, D3, and BB' contain symmetrical dimethylarginine, constituting a major autoepitope within the C-terminus of SmD1 and SmD3. Several synthetic peptides have been used for the detection of anti-Sm antibodies and thus for the diagnosis of SLE. Anti-Sm antibodies have been reported to occur later than other SLE associated autoantibodies and, on average, around 1 year before the clinical onset of SLE. The present review provides a comprehensive summary on the history of anti-Sm antibodies and their use as biochemical tools to study cellular processes and as biomarker in the diagnosis of SLE. Additionally, a meta-analysis focused on recent data analyzes the prevalence of anti-Sm antibodies in SLE.

Connective tissue disease-associated interstitial lung disease: a call for clarification

This commentary highlights the present dilemmas surrounding the classification of a patient with interstitial pneumonia who has clinical features suggesting an associated connective tissue disease but the features fall short of a clear diagnosis of connective tissue disease-associated interstitial lung disease under the current rheumatologic classification systems. This commentary illustrates what we perceive to be the limitations in the present approach to the classification of this group of patients and discusses problems with redefining the diagnosis of undifferentiated connective tissue disease to encompass patients with interstitial pneumonia. Finally, we advocate not only for a multidisciplinary approach to evaluation, but also disease classification and offer a proposal to define them as a distinct phenotype--lung-dominant CTD--for which prognostic, therapeutic, and pathobiologic implications can be tested in future, hopefully multiinstitutional, studies.