Slow development of massive splenomegaly, portal and pulmonary hypertension in systematic lupus erythematosus: can nodular regenerative hyperplasia of the liver explain all these findings?

SMURF1 inhibits the Th17 and Th17.1 polarization and improves the Treg/Th17 imbalance in systemic lupus erythematosus through the ubiquitination of RORγt

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease. This study aimed to investigate the role of SMAD specific E3 ubiquitin protein ligase 1 (SMURF1) in the Th17 and Th17.1 differentiation and Treg/Th17 imbalance, which are major factors contributing to the pathogenesis of SLE. SLE patients and healthy individuals were recruited to detect the SMURF1 levels in naïve CD4⁺ cells from peripheral blood. Purified and expanded naïve CD4⁺ T cells were employed to evaluate the effects of SMURF1 on Th17 and Th17.1 polarization in vitro. MRL/lpr lupus model was employed to explore the disease phenotype as well as Treg/Th17 balance in vivo. The results showed that SMURF1 was down-regulated in naïve CD4⁺ T cells in peripheral blood of patients with SLE and in spleen of MRL/lpr mice. SMURF1 overexpression suppressed the polarization of naïve CD4⁺ T cells toward Th17 and Th17.1 phenotype and down-regulated the expression of retinoid-related orphan receptor-gammat (RORγt). Subsequently, SMURF1 down-regulation aggravated the disease phenotype, inflammation, and the Treg/Th17 imbalance in MRL/lpr mice. Furthermore, we found that SMURF overexpression promoted the ubiquitination and decreases the stability of RORγt. In conclusion, SMURF1 inhibited the polarization of Th17 and Th17.1 cells and improved the Treg/Th17 imbalance in SLE, which was mediated as least partly by the ubiquitination of RORγt.

A case of systemic lupus erythematosus associated auto-splenectomy presenting as invasive pneumococcal sepsis

A 21-year-old female with a history of systemic lupus erythematosus (SLE) presented to the emergency department with septic shock. She had been maintained on 5 mg prednisolone daily and hydroxychloroquine 400 mg once daily and been investigated three years prior for recurrent left upper quadrant chest pain. Her previous SLE complications included pericardial effusion and high-risk pregnancy. Intensive care support was required due to septic shock, and a diagnosis of primary invasive Streptococcus pneumoniae bacteraemia was made following positive blood cultures. Computer tomography imaging of the abdomen demonstrated asplenia, with a diagnosis of auto-splenectomy thought most likely. Retrospective analysis of blood films from the two years prior was consistent with hyposplenism, including Howell-Jolly Bodies. The patient recovered from her sepsis and is maintained on amoxicillin prophylaxis. She was vaccinated according to post splenectomy guidelines and registered to the spleen registry. We report a case of auto-splenectomy and subsequent invasive pneumococcal disease in a SLE patient.

Predominant Role of Immunoglobulin G in the Pathogenesis of Splenomegaly in Murine Lupus

Systemic lupus erythematosus (SLE) is characterized by high levels of autoantibodies and multiorgan tissue damage. The pathogenesis of splenomegaly in SLE remains unknown. In this study, the role of immunoglobulin G (IgG) generation and deposition in the inflammation of the spleen and associated dysfunction in SLE was investigated. In the lupus mice, we observed the development of spontaneous splenomegaly, and we found that lupus serum IgG is an important pathological factor involved in the initiation of inflammation and further germinal center (GC) and plasma cell formation. We discovered that macrophages of the splenic marginal zone are dispensable for the GC response induced by lupus IgG, but red pulp macrophages are important for GC responses. Furthermore, we found that pathogenic lupus IgG promotes inflammation and GC formation through the macrophage-mediated secretion of TNF-α. Syk inhibitor treatment suppressed the changes in the histopathology of the spleen induced by lupus IgG. This study will contribute to the understanding of the pathogenesis of splenomegaly in lupus and promote the development of an effective therapeutic strategy for SLE.

Systemic lupus erythematosus complicated by noncirrhotic portal hypertension: A case report and review of literature

A 48 year-old Chinese woman suffering from polyarthritis, irregular fever and trichomadesis was admitted to the hospital. A diagnosis of systemic lupus erythematosus (SLE) was made based on polyarthritis, pancytopenia, reduced complement 3, multiple positive autoantibodies, a positive Coomb’s test and protein in her urine. In addition, splenomegaly was detected during physical examination and confirmed by abdominal ultrasonography and magnetic resonance imaging, indicating that the patient had SLE and portal hypertension. Further negative investigations ruled out the possibility of cirrhosis. The patient was diagnosed with active SLE complicated by noncirrhotic portal hypertension (NCPH) without liver histopathology, due to the patient’s refusal for liver biopsy. Portal vein diameter and splenomegaly decreased following treatment with methylprednisolone, hydroxychloroquine and metoprolol tartrate. To date, SLE complicated by NCPH has rarely been reported, as it is under-recognized clinically as well as pathologically. Here we describe a case of SLE complicated by NCPH and review the literature for its characteristics, which may contribute to improving the recognition of NCPH and reducing missed and delayed diagnosis of this disorder.

Cyclic GMP catabolism up-regulation in MRL/lpr lupus-prone mice is associated with organ remodeling

Production of high titer of antibodies against nuclear components is a hallmark of systemic lupus erythematosus, an autoimmune disease characterized by the progressive chronic inflammation of multiple joints and organs. Organ damage and dysfunction such as renal failure are typical clinical features in lupus. Cell hypermetabolism and hypertrophy can accelerate organ dysfunction. In this study we focus on a specific murine model of lupus, the MRL/lpr strain, and investigated the role of cyclic guanosine monophosphate (cGMP) catabolism in organ remodeling of main target tissues (kidney, spleen and liver) in comparison with age-matched control mice. In MRL/lpr-prone mice, the cGMP-phosphodiesterase (PDE) activities were significantly increased in the kidney (3-fold, P<0.001), spleen (2-fold, P<0.001) and liver (1.6-fold, P<0.05). These raised activity levels were paralleled by both an increased activity of PDE1 in the kidney (associated with nephromegaly) and in the liver, and PDE2 in the spleen of lupus-prone mice. The up-regulation of PDE1 and PDE2 activities were associated with a decrease in intracellular cGMP levels. This underlines an alteration of cGMP-PDE signaling in the kidney, spleen and liver targeting different PDEs according to organs. In good agreement with these findings, a single intravenous administration to MRL/lpr mice of nimodipine (PDE1 inhibitor) but not of EHNA (PDE2 inhibitor) was able to significantly lower peripheral hypercellularity (P=0.0401), a characteristic feature of this strain of lupus-prone mice. Collectively, our findings are important for generating personalized strategies to prevent certain forms of the lupus disease as well as for understanding the role of PDEs and cGMP in the pathophysiology of lupus.

Clinical analysis of 15 cases of liver nodular regenerative hyperplasia. Cell Biochem Biophys. 2012;64:115-121. [PMID: 22707296 DOI: 10.1007/s12013-012-9379-5]

Nodular regenerative hyperplasia (NRH) of liver may be one of the leading causes of non-cirrhotic intrahepatic portal hypertension (NCIPH), although the exact relationship is currently unknown. Diagnosis of NRH is relatively difficult and involves surgical pathology, and thus it is necessary to improve the preoperative recognition of NRH. Here, we analyze 15 cases of NRH to better understand this disease. All the liver specimens were microscopically examined by hematoxylin-eosin staining and reticulin and Masson trichrome staining. Diagnoses of NRH were confirmed by pathological examination. Clinically, NRH presents as diffused liver lesions with mildly increased liver enzymes. Portal hypertension is the most common clinical manifestation presenting prominently as splenomegaly, hypersplenism, and esophageal varices bleeding. NRH is often associated with autoimmune or collagen vascular diseases, and such patients often present with a variety of positive autoantibodies and increased erythrocyte sedimentation rate (ESR), Ig and γ %. Pathological examination of the liver showed diffuse small regenerative nodules without fibrous septa and obstructive portal venopathy. For those patients with portal hypertension of unknown cause and preserved liver function, especially, those combined with autoimmune diseases, NRH should be considered.

Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH.