Clinical significance of soluble-endoglin levels in systemic lupus erythematosus: possible association with anti-phospholipid syndrome

Changes of platelet count throughout pregnancy in women with antiphospholipid syndrome

OBJECTIVE

Antiphospholipid antibodies (aPL) activate several cell types, such as endothelial cells, monocytes, neutrophils, fibroblasts, trophoblasts and platelets, thus leading to thrombosis and obstetric complications in patients with antiphospholipid syndrome (APS). The aim of the present study was the longitudinal investigation of platelet count in women with APS. Additionally, platelet count in women with APS who developed preeclampsia during pregnancy were compared to women with APS and uncomplicated pregnancy for potential early detection of preeclampsia.

MATERIAL AND METHODS

This longitudinal study included 65 women with APS, 38 women with preeclampsia and 84 women with normal pregnancies, where platelet count was determined every four weeks, starting in early pregnancy.

RESULTS

Platelet count was significantly lower in women with APS compared to women who developed preeclampsia and normal pregnancies starting at 12 weeks of gestation. The areas under the curve (AUC) for platelet count were 0.765 at 12 weeks of gestation (95% of CI of 0.634-0.896), 0.747 at 20 weeks (95% of CI of 0.600-0.894), 0.719 at 24 weeks (95% of CI of 0.555-0.882), respectively. The cut off points for platelets were 216 at 12-14 weeks of gestation, 226.5 at 20 weeks of gestation, and 163.5 at 24 weeks of gestation, respectively.

DISCUSSION

We demonstrated a significant lower platelet count in women with APS throughout gestation. Additionally, platelet count is significantly decreased in women with APS who developed preeclampsia. According to our results, platelet count seems to have a predictive value for the development of preeclampsia in these women.

Anti-double Stranded DNA Antibodies: Origin, Pathogenicity, and Targeted Therapies

Systemic lupus erythematosus (SLE) is characterized by high-titer serological autoantibodies, including antibodies that bind to double-stranded DNA (dsDNA). The origin, specificity, and pathogenicity of anti-dsDNA antibodies have been studied from a wider perspective. These autoantibodies have been suggested to contribute to multiple end-organ injuries, especially to lupus nephritis, in patients with SLE. Moreover, serum levels of anti-DNA antibodies fluctuate with disease activity in patients with SLE. By directly binding to self-antigens or indirectly forming immune complexes, anti-dsDNA antibodies can accumulate in the glomerular and tubular basement membrane. These autoantibodies can also trigger the complement cascade, penetrate into living cells, modulate gene expression, and even induce profibrotic phenotypes of renal cells. In addition, the expression of suppressor of cytokine signaling 1 is reduced by anti-DNA antibodies simultaneously with upregulation of profibrotic genes. Anti-dsDNA antibodies may even participate in the pathogenesis of SLE by catalyzing hydrolysis of certain DNA molecules or peptides in cells. Recently, anti-dsDNA antibodies have been explored in greater depth as a therapeutic target in the management of SLE. A substantial amount of data indicates that blockade of pathogenic anti-dsDNA antibodies can prevent or even reverse organ damage in murine models of SLE. This review focuses on the recent research advances regarding the origin, specificity, classification, and pathogenicity of anti-dsDNA antibodies and highlights the emerging therapies associated with them.

Angiogenic factors in pregnancies of women with antiphospholipid syndrome and systemic lupus erythematosus

OBJECTIVES

An imbalance of angiogenic placental factors such as endoglin, soluble fms-like tyrosine kinase 1(sFlt-1) and placental growth factor (PlGF) has been implicated in the pathophysiology of preeclampsia. This study aimed to evaluate serum levels of sFlt-1, PlGF and endoglin in women with primary and secondary antiphospholipid Syndrome (APS) and systemic lupus erythematosus (SLE) longitudinally through pregnancy.

MATERIAL AND METHODS

Serum levels of sFlt-1, PlGF and endoglin were measured prospectively at 4-week intervals (from gestational weeks 12-36) in 17 women with primary APS (PAPS), 18 women with secondary APS (SAPS), and 23 women with SLE.

RESULTS

6/17 (35%) of women with PAPS, 3/18 (17%) of women with SAPS, and 2/23 (9%) of women with SLE developed early-onset preeclampsia. Women who developed preeclampsia had significantly higher mean sFlt-1 and endoglin levels, higher sFlt-1/PlGF ratios, and lower mean PlGF-levels than women who did not. These changes became statistically significant at 12 weeks for sFlt-1, PlGF and endoglin.

DISCUSSION

Endoglin, sFlt-1 and PlGF are potential early screening parameters for the development of preeclampsia in pregnant women with autoimmune diseases like APS and SLE.

Endoglin in liver fibrogenesis: Bridging basic science and clinical practice

Endoglin, also known as cluster of differentiation CD105, was originally identified 25 years ago as a novel marker of endothelial cells. Later it was shown that endoglin is also expressed in pro-fibrogenic cells including mesangial cells, cardiac and scleroderma fibroblasts, and hepatic stellate cells. It is an integral membrane-bound disulfide-linked 180 kDa homodimeric receptor that acts as a transforming growth factor-β (TGF-β) auxiliary co-receptor. In humans, several hundreds of mutations of the endoglin gene are known that give rise to an autosomal dominant bleeding disorder that is characterized by localized angiodysplasia and arteriovenous malformation. This disease is termed hereditary hemorrhagic telangiectasia type I and induces various vascular lesions, mainly on the face, lips, hands and gastrointestinal mucosa. Two variants of endoglin (i.e., S- and L-endoglin) are formed by alternative splicing that distinguishes from each other in the length of their cytoplasmic tails. Moreover, a soluble form of endoglin, i.e., sol-Eng, is shedded by the matrix metalloprotease-14 that cleaves within the extracellular juxtamembrane region. Endoglin interacts with the TGF-β signaling receptors and influences Smad-dependent and -independent effects. Recent work has demonstrated that endoglin is a crucial mediator during liver fibrogenesis that critically controls the activity of the different Smad branches. In the present review, we summarize the present knowledge of endoglin expression and function, its involvement in fibrogenic Smad signaling, current models to investigate endoglin function, and the diagnostic value of endoglin in liver disease.