Interleukin-8 and neutrophil extracellular traps in children with lupus nephritis and vitamin C deficiency.

BACKGROUND: Vitamin C is a potent scavenger of reactive oxygen species, which induce neutrophil extracellular trap (NET) formation. NETs are a major source of autoantigens and are involved in systemic lupus erythematosus (SLE) pathogenesis. We determined vitamin C status and evaluated NET formation and inflammatory cytokines in children with lupus nephritis. METHODS: Serum vitamin C was measured in 46 patients (82.6% females, mean age 14.5 ± 0.3 years). Vitamin C levels < 0.3 mg/dL indicated vitamin C deficiency. Patients were divided into two groups according to serum vitamin C levels: normal and low (< 0.3 mg/dL). We compared NET formation and levels of SLE-related cytokines, including interleukin (IL)-8, IL-10, and tumor necrosis factor-α (TNF-α), between groups. NET formation was determined through measurement of serum citrullinated histone 3 levels and mRNA expression of peptidyl arginine deiminase-4 and assessment of the percentage of neutrophils with NETs by immunofluorescence. RESULTS: Nine patients (19.6%) had vitamin C deficiency. Kidney pathology assessment at disease onset revealed that histological activity index and number of kidney biopsies containing crescentic glomeruli were higher in vitamin C-deficient patients, but chronicity index was not. NET formation and serum IL-8 were more prominent in vitamin C-deficient patients. Serum IL-8 levels were 12.9 ± 5.2 pg/mL in low vitamin C group and 5.2 ± 0.9 pg/mL in normal vitamin C group (p = 0.03). Serum IL-10 and TNF-α were similar between groups. CONCLUSIONS: Our study demonstrated correlation among vitamin C deficiency, increased NET formation, and IL-8 upregulation in children with lupus nephritis. A prospective study is required to evaluate cause‒effect relationships of vitamin C status, NET formation and IL-8 expression.

Growth and nutritional status of pediatric patients treated with the ketogenic diet.

BACKGROUND AND OBJECTIVES: Ketogenic diet (KD), a well-known nonpharmacologic treatment of intractable epilepsy, could adversely affect growth and nutritional status; however, such data are limited in Thailand. This study aimed to assess growth and nutritional status of Thai children treated with KD together with dietary adherence and its related factors. METHODS AND STUDY DESIGN: The records of children treated with KD for more than 1 month between January 2009 to September 2020 were reviewed. Weight, height, and biochemical indices were retrieved at baseline, 1, 3, 6, 12, 18, and 24 months. Type of KDs, compliance and adverse effects were extracted. RESULTS: Forty-eight patients (21 male) were enrolled. Median age was 3.5 years (IQR 0.9, 10.1). There was no significant decrease in weight-for-age z-score (WAZ) despite a trend toward minimal reduction in WAZ at 3 months. Median follow-up time was 13 months (IQR 7, 29.5). Height-for-age z-score (HAZ) significantly decreased at 12 months [median -1.55 (IQR -3.35, -0.43) vs baseline median -0.6 (IQR -2.07, 0.29)]. Adherence of KD in tube feeding patients was better than oral feeding. Thirty seven percent (18/48) of the patients continued the diet beyond 2 years. Early discontinuation before 6 months was mostly due to poor compliance from patients and families (6/11, 55%). Common adverse effects were GI problems (77%), dyslipidemia (64%) and hypercalciuria (29%). CONCLUSIONS: Under close monitoring, KD can be administered in Thai children with minimal adverse effects on growth and nutritional status. Adherence depends on route of feeding, clinical response, and cooperation of the families.

Extracellular traps in peripheral blood mononuclear cell fraction in childhood-onset systemic lupus erythematosus.

Although the role of low-density granulocytes (LDGs), neutrophils in the peripheral blood mononuclear cell (PBMC) fraction, and neutrophil extracellular traps (NETs) in assessing lupus disease severity is acknowledged, data specific to childhood-onset lupus remains scarce. This study analyzed 46 patients with childhood-onset systemic lupus erythematosus (82.6% females, mean age 14.5 ± 0.3 years), including 26 cases with normal complement levels and 20 with low complement levels, along with 20 healthy adult volunteers. Key parameters that distinguished healthy volunteers from lupus patients and differentiated between lupus patients with low and normal complement were serum interferon (IFN)-α, serum citrullinated histone 3 (CitH3), and extracellular traps (ETs) in LDGs. However, NETs (assessed by nuclear staining morphology), LDG abundance, and other parameters (such as endotoxemia, cytokines, and double-stranded (ds) DNA) did not show such differentiation. When lipopolysaccharide (LPS) was administered to LDGs in the PBMC fraction, it induced ETs in both low and normal complement groups, indicating the inducible nature of ETs. In adult healthy volunteers, activation by recombinant IFN-α or dsDNA in isolated neutrophils induced LDGs and NETs (identified using immunofluorescent staining for CitH3, myeloperoxidase, and neutrophil elastase) at 45 min and 3 h post-stimulation, respectively. Additionally, approximately half of the LDGs underwent late apoptosis at 3 h post-stimulation, as determined by flow cytometry analysis. Activation by IFN-α or dsDNA in LDGs also led to a more pronounced expression of CD66b, an adhesion molecule, compared to regular-density neutrophils, suggesting higher activity in LDGs. In conclusion, IFN-α and/or dsDNA in serum may transform regular-density neutrophils into LDGs before progressing to NETosis and apoptosis, potentially exacerbating lupus severity through cell death-induced self-antigens. Therefore, LDGs and ETs in LDGs could provide deeper insights into the pathophysiology of childhood-onset lupus.