Cytokine Milieu in Undifferentiated Connective Tissue Disease: a Comprehensive Review

Jak Inhibitors for Treatment of Autoimmune Diseases: Lessons from Systemic Sclerosis and Systemic Lupus Erythematosus

Systemic sclerosis and systemic lupus erythematosus represent two distinct autoimmune diseases belonging to the group of connective tissue disorders. Despite the great progress in the basic science, this progress has not been translated to the development of novel therapeutic approaches that can radically change the face of these diseases. The discovery of JAK kinases, which are tyrosine kinases coupled with cytokine receptors, may open a new chapter in the treatment of so far untreatable diseases. Small synthetic compounds that can block Janus kinases and interact directly with cytokine signalling may provide therapeutic potential in these diseases. In this review, we discuss the therapeutic potential of Jak kinases in light of the cytokine network that JAK kinases are able to interact with. We also provide the theoretical background for the rationale of blocking cytokines with specific JAK inhibitors.

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.

Comparing pregnancy outcomes in patients with criteria and non-criteria autoimmune disease: A systematic review

BACKGROUND

Not all patients fulfil criteria for specific autoimmune rheumatic diseases (ARDs) and are then defined as having non-criteria (nc)ARD. It is uncertain whether well-recognised associations with adverse pregnancy outcomes in patients with criteria ARD also exist in patients with ncARD or undifferentiated connective tissue disease (UCTD). Therefore, we undertook a systematic review of the prevalence of adverse pregnancy outcomes in various ncARD and UCTD compared with criteria ARD to identify whether there are increased risks and to examine for any benefits of treatment.

METHODS

This study was conducted in accordance with the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard. A systematic literature review was performed using online databases including Medline and PubMed from inception to the beginning of April 2021 using appropriate keywords for various ARD and pregnancy outcomes.

RESULTS

After screening 665 articles, 36 articles were chosen for full text review and 15 selected for final analysis. There were eight studies of nc antiphospholipid syndrome (APS) of more than 7000 pregnancies and seven studies of UCTD of more than 1000 pregnancies. No studies of any other ncARD in pregnancy were identified. We found that patients with either ncAPS or UCTD seem to have an increased burden of poor pregnancy outcomes compared with the general population. Despite the heterogeneity and poor quality of the studies, we also noted that ncAPS and criteria APS patients may have similar rates of obstetric complications with standard and/or non-standard APS treatment regimens.

CONCLUSION

Our findings of increased risks of poor pregnancy outcomes in patients with ncAPS or UCTD will be helpful for pre-pregnancy counselling and management of these patients in pregnancy and support their referral to specialist obstetric-rheumatology and obstetric-haematology clinics.

An elevated polyclonal free light chain level reflects a strong interferon signature in patients with systemic autoimmune diseases

High amount of polyclonal free light chains (FLC) are reported in systemic autoimmune diseases (SAD) and we took advantage of the PRECISESADS study to better characterize them. Serum FLC levels were explored in 1979 patients with SAD (RA, SLE, SjS, Scl, APS, UCTD, MCTD) and 614 healthy controls. Information regarding clinical parameters, disease activity, medications, autoantibodies (Ab) and the interferon α and/or γ scores were recorded. Among SAD patients, 28.4% had raised total FLC (from 12% in RA to 30% in SLE and APS) with a normal kappa/lambda ratio. Total FLC levels were significantly higher in SAD with inflammation, active disease in SLE and SjS, and an impaired pulmonary functional capacity in SSc, while independent from kidney impairment, infection, cancer and treatment. Total FLC concentrations were positively correlated among the 10/17 (58.8%) autoantibodies (Ab) tested with anti-RNA binding protein Ab (SSB, SSA-52/60 kDa, Sm, U1-RNP), anti-dsDNA/nucleosome Ab, rheumatoid factor and negatively correlated with complement fractions C3/C4. Finally, examination of interferon (IFN) expression as a potential driver of FLC overexpression was tested showing an elevated level of total FLC among patients with a high IFNα and IFNγ Kirou's score, a strong IFN modular score, and the detection in the sera of B-cell IFN dependent factors, such as TNF-R1/TNFRSF1A and CXCL10/IP10. In conclusion, an elevated level of FLC, in association with a strong IFN signature, defines a subgroup of SAD patients, including those without renal affectation, characterized by increased disease activity, autoreactivity, and complement reduction.

Increased expression of caspase 1 during active phase of connective tissue disease

Key factors of pyroptosis play an important role in the inflammatory response to connective tissue disease (CTD). However, information on active and stable stages of CTD is scarce. To distinguish the differences of concentrations of C-reactive protein (CRP), caspase 1, caspase 4, caspase 5 and sCD14 in plasma between the patients with active and stable stages of CTD. A cohort study was conducted to recruit patients diagnosed with CTD of active phase and stable phase as well as health control. These data included the analysis of the concentration of sCD14, caspase 1, caspase 4 and caspase 5 in peripheral plasma by ELISA. The Wilcoxon rank-sum test was used to compare the two groups. The sex ratio and ages of the three groups were not different statistically. The concentrations of sCD14, caspase4 and caspase5 of plasma in the CTD of active phase and the stable phase as well as the health control. The concentration of caspase 1 in active phase of CTD (470.19 [422.33–513.14] pmol/L) was significantly higher than that in stable group (203.95 [160.94–236.12] pmol/L) and healthy control (201.65 [191.11–240.35] pmol/L] pmol/L) (p < 0.001, both), but there was no significant difference between stable group and healthy control (p = 0.2312). Similarly, the concentration of CRP in the active phase of CTD (8.96 [3.06–20.28] mg/L) was significantly higher than that in the stable group (3.00 [1.30–11.40] mg/L) and the healthy control (3.70 [2.30–4.73] mg/L) (p = 0.0013, p = 0.0006, respectively), but there was no significant difference between the stable group and the healthy control (p = 0.3205). However, there were no significant differences in the concentration of sCD14, caspase 4 and caspase 5 in the active phase of CTD and the stable group as well as the health group. Consequently, the patients of the active phase of CTD showed increased expression of caspase 1.

Clinical and Serologic Features in Patients With Incomplete Lupus Classification Versus Systemic Lupus Erythematosus Patients and Controls

OBJECTIVE

Incomplete lupus erythematosus (ILE) involves clinical and/or serologic manifestations consistent with but insufficient for systemic lupus erythematosus (SLE) classification. Because the nature of ILE is poorly understood and no treatment recommendations exist, we examined the clinical manifestations, medication history, and immunologic features in a diverse collection of ILE and SLE patients.

METHODS

Medical records of subjects enrolled in the Lupus Family Registry and Repository were reviewed for medication history and American College of Rheumatology (ACR) classification criteria to identify ILE patients (3 ACR criteria; n = 440) and SLE patients (≥4 ACR criteria; n = 3,397). Participants completed the Connective Tissue Disease Screening Questionnaire. Anticardiolipin and plasma B lymphocyte stimulator (BLyS) were measured by enzyme-linked immunosorbent assay, antinuclear antibodies (ANAs) by indirect immunofluorescence, and 13 autoantibodies by bead-based assays.

RESULTS

On average, ILE patients were older than SLE patients (46.2 years versus 42.0 years; P < 0.0001), and fewer ILE patients were African American (23.9% versus 32.2%; P < 0.001). ILE patients exhibited fewer autoantibody specificities than SLE patients (1.3 versus 2.6; P < 0.0001) and were less likely to have ANA titers ≥1:1,080 (10.5% versus 19.5%; P < 0.0001). BLyS levels were intermediate in ILE patients (controls < ILE; P = 0.016; ILE < SLE; P = 0.008). Pericarditis, renal, or neurologic manifestations occurred in 12.5% of ILE patients and were associated with non-European American race/ethnicity (P = 0.012). Hydroxychloroquine use increased over time, but was less frequent in ILE than SLE patients (65.2% versus 83.1%; P < 0.0001).

CONCLUSION

Although usually characterized by milder symptoms, ILE manifestations may require immunomodulatory treatments. Longitudinal studies are necessary to understand how ILE affects organ damage and future SLE risk, and to delineate molecular pathways unique to ILE.

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.

Pachydermodactyly - a report of two cases

Pachydermodactyly (PDD) is a rare and benign form of digital soft tissues fibromatosis, which affects the skin of the fingers. The disorder is characterized by asymptomatic, symmetric, progressive soft tissue swelling of the proximal interphalangeal (PIP) joints of the fingers. The etiology of disease remains unknown. It is usually acquired, even though there are some publications that document family cases. It affects mainly adolescent men.

We report two boys with the bilateral swelling of the of the PIP joints of the fingers and skin and subcutaneous tissue thickening. Based on clinical manifestations, radiological study and histopathological examination, pachydermodactyly was diagnosed.

PDD is a rare and benign disorder, although it is important to consider other diseases, especially rheumatic conditions, in the differential diagnosis in order to avoid unnecessary additional tests and treatments.

U1-RNP and TLR receptors in the pathogenesis of mixed connective tissue diseasePart I. The U1-RNP complex and its biological significance in the pathogenesis of mixed connective tissue disease

Mixed connective tissue disease (MCTD) is a rare autoimmune syndrome, signified by complex interactions between disease-related phenomena, including inflammation, proliferative vascular arteriopathy, thrombotic events and humoral autoimmune processes. It is still controversial whether MCTD is a distinct clinical entity among systemic connective tissue diseases, although several authors consider that it is distinct and underline characteristic, distinct clinical, serological and immunogenetic features. The putative target of autoimmunity in MCTD is U1-RNP, which is a complex of U1-RNA and small nuclear RNP. Both the U1-RNA component and the specific proteins, particularly U1-70K, engage immune cells and their receptors in a complex network of interactions that ultimately lead to autoimmunity, inflammation, and tissue injury. U1-RNA is capable of inducing manifestations consistent with TLR activation. Stimulation of innate immunity by native RNA molecules with a double-stranded secondary structure may help explain the high prevalence of autoimmunity to RNA binding proteins.