Myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis with headache and kidney involvement at presentation and with arthralgia at relapse: A case report.

BACKGROUND: Patients with proteinase 3-antineutrophil cytoplasmic antibody associated vasculitis (AAV) experience different manifestations at the initial onset and relapse. However, such cases of different initial and relapse manifestations have not been reported in myeloperoxidase (MPO)-AAV patients. CASE SUMMARY: A 52-year-old woman was admitted to our hospital because of headache. Laboratory findings indicated nephrotic range proteinuria and microscopic hematuria, serum creatinine of 243 µmol/L, anti-MPO antibody titer of > 400 RU/mL, and positive perinuclearantineutrophil cytoplasmic antibody. Renal biopsy showed pauci-immune crescentic glomerulonephritis. The cerebrospinal fluid examination and brain magnetic resonance imaging did not show any abnormality. Therefore, MPO-AAV was diagnosed. Corticosteroids, plasmapheresis, and cyclophosphamide as induction therapy and mycophenolate mofetil (MMF) as maintenance therapy were administered. The patient's headache disappeared; serum creatinine returned to normal; complete remission of microscopic hematuria and proteinuria was observed. Anti-MPO antibody titer reached normal limits after immunosuppressive treatment. Twenty-five months after stopping the immunosuppressive treatment, the patient relapsed with arthralgia, without neurological or renal involvement. The patient's arthralgia improved after treatment with prednisone and MMF. CONCLUSION: We have reported a rare case of MPO-AAV who initially presented with headache and kidney involvement. However, relapse presented with only arthralgia, which was completely different from the initial manifestations. This case suggests that AAV relapse should be highly suspected in MPO-AAV patients after remission, when clinical manifestations at relapse are different from those at onset. Prednisone and MMF may provide a good choice for refractory arthralgia during relapse in MPO-AAV patients.

Blocking core fucosylation of epidermal growth factor (EGF) receptor prevents peritoneal fibrosis progression.

OBJECTIVE: Peritoneal fibrosis (PF) ultimately causes ultrafiltration failure and peritoneal dialysis (PD) termination, but there are few effective therapies for it. Core fucosylation, which is catalyzed by α1,6-fucosyltransferase (Fut8) in mammals, may play a crucial role in PF development. This study aims to assess the effects of inhibiting core fucosylation of epidermal growth factor (EGF) receptor on PF rats. METHODS: PF rats (established by 4.25% glucose dialysate) were treated with either an adenovirus-Fut8 short hairpin RNA (Fut8shRNA) or adenovirus-control. Masson's staining and net ultrafiltration were performed at week six. Fut8 level and core fucosylation of EGF receptor and collagen I in the peritoneal membrane were assessed, and EGF signaling was detected, including signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NF-κB) and their phosphorylation. Monocyte chemoattractant protein-1 (MCP-1) in peritoneal effluent was examined. RESULTS: Fut8 was upregulated in PF rats but decreased after Fut8shRNA treatment. EGF and EGF receptor expression was upregulated in PF rats, while core fucosylation of EGF receptor decreased after Fut8shRNA treatment. Masson's staining results showed an increase in peritoneal thickness in PF rats but a decrease after Fut8shRNA treatment. Fut8shRNA treatment increased net ultrafiltration, reduced the expression of collagen I and MCP-1 compared to PF rats. Fut8shRNA treatment suppressed phosphorylation of STAT3 and NF-κB in the peritoneal membrane of PF rats. CONCLUSIONS: Fut8shRNA treatment ameliorated the fibrotic changes in PF rats. A potential mechanism may be that Fut8shRNA treatment inactivated EGF signaling pathway by suppressing the phosphorylation of STAT3 and NF-κB.

Tubulointerstitial lesions converted into lupus nephritis.

A young woman was diagnosed with SLE and Sjögren's syndrome with tubulointerstitial lesions and remained stable after prednisone treatment. However, repeat renal biopsy after prednisone withdrawal revealed it was converted into glomerular lesions.

Blocking Posttranslational Core Fucosylation Ameliorates Rat Peritoneal Mesothelial Cell Epithelial-Mesenchymal Transition.

BACKGROUND:: Core fucosylation (CF), catalyzed by α-1,6 fucosyltransferase (Fut8) in mammals, plays an important role in pathological processes through posttranslational modification of key signaling receptor proteins, including transforming growth factor (TGF)-ß receptors and platelet-derived growth factor (PDGF) receptors. However, its effect on peritoneal fibrosis is unknown. Here, we investigated its influence on epithelial-mesenchymal transition (EMT) of rat peritoneal mesothelial cells (PMCs) in vitro induced by a high-glucose (HG) culture solution. METHODS:: Rat PMCs were first cultured in a HG (2.5%) culture solution to observe the CF expression level (fluorescein isothiocyanate-lens culinaris agglutinin), we next established a knockdown model of rat PMCs in vitro with Fut8 small interfering RNA (siRNA) to observe whether inhibiting CF decreases the messenger RNA (mRNA) expression and protein expression of Fut8 and reverses EMT status. Rat PMCs were randomly divided into control group, mock group (transfected with scrambled siRNA), Fut8 siRNA group, HG group, HG + mock group, and HG + Fut8 siRNA group. Finally, we examined the activation of TGF-ß/Smad2/3 signaling and PDGF/extracellular signal-regulated kinase (ERK) signaling to observe the influence of CF on them. RESULTS:: CF, Fut8 mRNA, and protein expression were all significantly upregulated in HG- induced EMT model than those in the control rat PMCs (P < 0.05). Fut8 siRNA successfully blocked CF of TGF-ß receptors and PDGF receptors and attenuated the EMT status (E-cadherin and α-SMA and phenotypic changes) in HG-induced rat PMCs. In TGF-ß/Smad2/3 signaling, Fut8 siRNA did not suppress the protein expression of TGF-ß receptors and Smad2/3; however, it significantly suppressed the phosphorylation of Smad2/3 (relative expression folds of HG + Fut8 group vs. HG group: 7.6 ± 0.4 vs. 15.1 ± 0.6, respectively, P < 0.05). In PDGF/ERK signaling, Fut8 siRNA did not suppress the protein expression of PDGF receptors and ERK, but it significantly suppressed the phosphorylation of ERK (relative expression folds of HG + Fut8 group vs. HG group: 8.7 ± 0.9 vs. 15.6 ± 1.2, respectively, P < 0.05). Blocking CF inactivated the activities of TGF-ß and PDGF signaling pathways, and subsequently blocked EMT. CONCLUSIONS:: These results demonstrate that CF contributes to rat PMC EMT, and that blocking it attenuates EMT. CF regulation is a potential therapeutic target of peritoneal fibrosis.