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Abstract Objectives Systemic lupus erythematosus is an autoimmune disease that involves multiple organ systems. One of its major complications, lupus nephritis (LN), is associated with a high mortality rate, and children-onset LN have a more severe course and worse prognosis than adults. Oxidative stress and inflammatory responses are involved in LN development and pathogenesis. Thus, this study aimed to explore the role of signaling regulation of the Nrf2/HMGB1/TLR/NF-κB pathway in LN pathogenesis and unravel the expression of TLR4+CXCR4+ plasma cells subset (PCs) in LN. Methods C57BL/6 and MRL/lpr mice were divided into four groups: control, model, vector control, and Nrf2 overexpression groups. The vector control and Nrf2 overexpression groups were injected with adenoviral vectors into the kidney in situ. Pathological changes in kidney tissues were observed by hematoxylin–eosin staining. The expression of Nrf2, HMGB1, TLR4, NF-κB, and downstream inflammatory factors in kidney samples was analyzed by quantitative polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. The ratios of TLR4+CXCR4+ PC subsets in the blood and kidneys of mice were determined by flow cytometry. Results In MRL/lpr mice, Nrf2 was downregulated while HMGB1/TLR4/NF-κB pathway proteins were upregulated. Nrf2 overexpression decreased the expression of HMGB1, TLR4, NF-κB, and its downstream inflammatory cytokines (IL-1β and TNFα). These cytokines were negatively correlated with an increase in Nrf2 content. PC and TLR4 + CXCR4 + PCs in the blood and kidney samples were significantly increased in MRL/lpr mice; however, they were decreased upon Nrf2 overexpression. Conclusion This study showed severe kidney injury in an LN mouse model and an increased ratio of TLR4 + CXCR4 + PCs. Furthermore, we observed that Nrf2 regulates LN immune response through the Nrf2/HMGB1/TLR4/NF-κB pathway, which can be considered an important target for LN treatment. The clinical value of the findings of our study requires further investigation.

Abstract Background Antithrombin (AT) is the main physiological anticoagulant involved in hemostasis. Hereditary AT deficiency is a rare autosomal dominant thrombotic disease mainly caused by mutations in SERPINC1, which was usually manifested as venous thrombosis and pulmonary embolism. In this study, we analyzed the clinical characteristics and screened for mutant genes in two pedigrees with hereditary AT deficiency, and the functional effects of the pathogenic mutations were evaluated. Methods Candidate gene variants were analyzed by next-generation sequencing to screen pathogenic mutations in probands, followed by segregation analysis in families by Sanger sequencing. Mutant and wild-type plasmids were constructed and transfected into HEK293T cells to observe protein expression and cellular localization of SERPINC1. The structure and function of the mutations were analyzed by bioinformatic analyses. Results The proband of pedigree A with AT deficiency carried a heterozygous frameshift mutation c.1377delC (p.Asn460Thrfs*20) in SERPINC1 (NM000488.3), a 1377C base deletion in exon 7 resulting in a backward shift of the open reading frame, with termination after translation of 20 residues, and a different residue sequence translated after the frameshift. Bioinformatics analysis suggests that the missing amino acid sequence caused by the frameshift mutation might disrupt the disulfide bond between Cys279 and Cys462 and affect the structural function of the protein. This newly discovered variant is not currently included in the ClinVar and HGMD databases. p.Arg229* resulted in a premature stop codon in exon 4, and bioinformatics analysis suggests that the truncated protein structure lost its domain of interaction with factor IX (Ala414 site) after the deletion of nonsense mutations. However, considering the AT truncation protein resulting from the p.Arg229* variant loss a great proportion of the molecule, we speculate the variant may affect two functional domains HBS and RCL and lack of the corresponding function. The thrombophilia and decreased-AT-activity phenotypes of the two pedigrees were separated from their genetic variants. After lentiviral plasmid transfection into HEK293T cells, the expression level of AT protein decreased in the constructed c.1377delC mutant cells compared to that in the wild-type, which was not only reduced in c.685C > T mutant cells but also showed a significant band at 35 kDa, suggesting a truncated protein. Immunofluorescence localization showed no significant differences in protein localization before and after the mutation. Conclusions The p.Asn460Thrfs*20 and p.Arg229* variants of SERPINC1 were responsible for the two hereditary AT deficiency pedigrees, which led to AT deficiency by different mechanisms. The p.Asn460Thrfs*20 variant is reported for the first time.

BackgroundBehçet’s disease (BD) is a unique autoimmune chronic systemic vasculitis that affects veins and arteries of all sizes. BD can lead to recurrent vascular events, especially venous thrombosis, with an incidence rate of 40%, or pseudoaneurysms formed under long-term inflammatory reaction or iatrogenic stimulation. BD-related risk factors promote endothelial dysfunction, platelet activation and overactivation of tissue factors leading to mural inflammatory thrombi. Thrombosis may be the first clinical manifestation of BD.Case presentationA 32-year-old man complaining of progressive swelling and pain in the right lower extremity for 30 days was initially diagnosed with “venous thrombosis of the right lower extremity,” using color Doppler ultrasonography. Patient underwent inferior vena cava filter placement combined with deep vein angioplasty of the right lower extremity and catheter-directed urokinase thrombolysis. Postoperative oral anticoagulant therapy was administered. However, the patient was readmitted 20 days later for pulsatile pain in the right groin. Prior medical history included 4 years of repeated oral and perineal ulcers, and 2 months of blurred vision. Abdominal computed tomography angiography (CTA) revealed rupture of the right common iliac artery (CIA) and left internal iliac artery (IIA), complicated by a pseudoaneurysm. Based on the clinical manifestations and other auxiliary examination results, the patient was re-diagnosed with “BD combined with deep venous thrombosis of the right lower extremity and an iliac artery pseudoaneurysm.” Stent implantation was performed for iliac artery pseudoaneurysm after symptoms were controlled with timely immunosuppressive therapy. After endovascular treatment, the patient underwent continued immunosuppressive therapy and dynamic reexaminations of abdominal CTA, which revealed that a small amount of contrast agent at the stent in the right CIA continued to flow into the cavity of the pseudoaneurysm; in addition, the size of the pseudoaneurysm was gradually increasing. Therefore, the patient underwent a second stent implantation for iliac artery pseudoaneurysm, and the condition improved further.ConclusionThe importance of early diagnosis of BD should be recognized, and the choice of interventional and surgical procedures should be carefully evaluated, as this may trigger further damage to vascular access in BD patients with aneurysm.

BackgroundSpontaneous splenic rupture (SSR) is a rare, often life-threatening, acute abdominal injury that requires immediate diagnosis and early treatment. SSR is mainly treated surgically or conservatively. A few cases of interventional embolization for SSRs have been reported.Case PresentationA 30-year-old male patient complaining mainly of left upper abdominal pain underwent emergency abdominal computed tomography (CT) and showed enlargement of the spleen with a massive mixed-density shadow approximately 10.0 × 8.0 × 12.5 cm in size. The boundary was unclear and showed obvious progressive enhancement. Considering the intrasplenic tumor lesions with rupture and hemorrhage, the possibility of vascular tumors was high, with intraperitoneal blood and fluid accumulation. Digital subtraction angiography of the splenic arteriography and embolization of the ruptured splenic artery branches were performed. Postoperative hemoglobin progressively decreased, inflammatory indicators, such as white blood cell counts, procalcitonin (PCT), and C-reactive protein (CRP) were significantly increased, and 2 days after embolization, the patient developed severe hypoxemia, shock, pulmonary edema, and acute respiratory distress syndrome. CT re-examination 9 days after embolization showed reduced lesion absorption. After stabilization of the condition, splenectomy was performed, and postoperative platelet count increase, anticoagulant improvement, and discharge were observed. Postoperative pathological examination revealed extensive hemorrhage and necrosis, vascular tissue with abnormal hyperplasia in the surrounding area, vascular tissue in the bleeding area and outer wall (elastic fiber staining +), and local myofibroblast hyperplasia. Immunohistochemistry showed actin (SM +) and Ki67 (10% +).ConclusionSSR caused by splenic hemangioma is rare, and the choice between surgical treatment or splenic artery embolization remains dependent on the patient's hemodynamic stability and imaging findings.

Extraskeletal osteosarcoma is a rare malignant soft-tissue sarcoma that is difficult to diagnose. Surgery is a common treatment, although chemotherapy and radiotherapy are also used. Patients at risk of bleeding can undergo embolization combined with resection. The occurrence of primary splenic extraskeletal osteosarcoma in humans does not seem to have been reported in the literature. A 50-year-old woman who complained of pain in the left upper abdomen for 1 day was initially diagnosed with “splenic hemangioma with a high possibility of rupture and bleeding” and urgently underwent digital subtraction angiography, combined with splenic arteriography and embolization. Abdominal pain worsened 2 days postoperatively, with a hemoglobin level of 106.0 g/L. Consequently, emergency laparotomy combined with splenectomy was performed. The clinical and imaging features, pathological diagnosis, and embolization treatment of this case were analyzed retrospectively. CT of the upper abdomen revealed splenomegaly, an irregular low-density shadow in the spleen, and a flake-like calcification in the lateral margin of the left kidney. Nuclear MRI of the upper abdomen showed splenomegaly and a mass (approximately 8.4 cm × 5.7 cm × 6.3 cm) below the spleen with clear boundaries—this exhibited an uneven signal, which was slightly low in T1-weighted imaging (T1WI) and slightly high in T2-weighted imaging (T2WI). Several small cystic lesions or cystic cavities were observed in the mass, which exhibited a longer T2 signal. During the enhanced scan, the signal of the lesion showed progressive enhancement, and the enhancement range increased in the delayed phase scan, as well as a hematoma below the spleen capsule and calcification below the lesion (nodular T1WI/T2WI hypointense, approximately 3.3 cm × 3.6 cm). Postoperative biopsy pathology showed splenic soft tissue tumor: at low magnification, the multinucleated giant cells were scattered; at medium magnification, osteoclast-like multinucleated giant cells were observed; and at high magnification, lace- or grid-like tumor osteogenesis was detected. Immunohistochemistry showed that the expression of CD31, CD34, F8, s-100, desmin, SMA, and CD99 was negative, whereas the expression of β-catenin, BCL-2, SATB-2, and P16 was positive. CD68 and MDM-2 showed low expression, while 50% of the cells were positive for Ki-67 expression. No abnormal concentration of radioactivity was found on the bone scan with 99mTc-MDP after the operation, further ruling out the occurrence of other bone tumors. The patient was diagnosed with primary extraskeletal osteosarcoma. It is necessary for multidisciplinary teams to diagnose malignant extraskeletal osteosarcomas.