Renal manifestations of paediatric systemic lupus erythematosus

Bibliometric analysis of childhood-onset systemic lupus erythematosus from 2000 to 2022

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disorder. When SLE occurs in individuals under the age of 18, it is referred to as childhood-onset SLE (cSLE). Currently, there is a dearth of bibliometric research pertaining to cSLE.

METHOD

Relevant studies in the field of cSLE from 2000 to 2022 were screened from the Web of Science Core Collection (WoSCC). CiteSpace and VOSviewer software were used to visualize the annual publications, countries, institutions, authors, journals, keywords, and references, after which the authors conducted the scientific analysis.

RESULTS

A total of 2857 articles were included in this study, and the number of articles published in the past 20 years showed an overall upwards trend. The most prolific countries are the United States, China, and Brazil; however, the United States, Canada, and the United Kingdom are clearly superior in terms of literary influence, and there is more cooperation between them and their institutions. LUPUS (n = 389) contributed the most to the variance. Brunner, HI's contribution in the field of cSLE is outstanding. The words related to 'lupus nephritis' and 'antibodies' are important words reflected in the keyword network diagram. The keywords included 'evidence-based recommendation', 'validation', 'diagnosis' and 'adult' from 2019, and 'continuous bursts' to the present.

CONCLUSION

This study examined the research status of cSLE patients, discussed and analysed the research hotspots and trends in this field, and provided a reference for further research in this field to promote the development of cSLE research.

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.

Overlapping drug-induced vasculitis, ANCA-associated vasculitis, and lupus nephritis caused by low-dose hydralazine

INTRODUCTION

We present a case of drug-induced vasculitis secondary to low-dose hydralazine with overlapping features of antineutrophil cytoplasmic antibody-associated vasculitis and drug-induced lupus nephritis.

CASE PRESENTATION

A 52-year-old Hispanic woman with a medical history of resistant hypertension treated with hydralazine 10 mg twice daily for 1 year presented with generalized weakness, dizziness, nausea, vomiting, and gross hematuria. There was fever, tachycardia, leukocytosis, lactic acidosis, hyperkalemia, renal failure, and anemia. Chest computed tomography and bronchoscopy revealed a left lower lobe infiltrate and diffuse alveolar hemorrhage. Serologic testing was positive for anti-double-stranded DNA, anti-Smith, lupus anticoagulant, anti-histone, anti-cardiolipin IgM antibodies, and antineutrophil cytoplasmic antibodies (myeloperoxidase and proteinase 3). A kidney biopsy revealed crescentic glomerulonephritis with an overlapping finding of membranous nephropathy. Broad-spectrum antibiotics, immunosuppressants, corticosteroids, and plasmapheresis were initiated. The patient survived but required continuous hemodialysis.

CONCLUSIONS

Although a few cases of simultaneous antibody-associated vasculitis and drug-induced lupus nephritis secondary to hydralazine use have been reported, this case is singular. Similar findings were previously reported with doses of 50-100 mg two to three times daily over 1-5 years. In our patient, a dose of only 10 mg twice daily for a year caused a severe disease presentation. This brings to light the combination of different vasculitides that can coexist and the potentially life-threatening adverse effects of low-dose hydralazine that should be kept in mind.

Systemic Lupus Erythematosus in Children

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, that mainly affects skin, joints and kidneys but can affect any organ in the body. It is characterized by presence of multiple autoantibodies like ANA, antibodies to dsDNA and RNA associated proteins. The major mechanism leading to tissue damage includes immune complex mediated complement activation, interferon alpha release by plasmacytoid dendritic cells, NETosis by neutrophils as well as defects in monocytes leading to poor clearance of cellular debris and direct cellular dysfunction mediated by antibodies. A child can present with pyrexia of unknown origin, immune mediated cytopenias, malar rash, oral ulcers, serositis, glomerulonephritis or nervous system dysfunction. As renal disease has a bearing on the long term impact, all children should have urine exam and blood pressure measurement done to rule out renal disease. The treatment varies depending on the severity and organs involved. In life or organ threatening situations, pulse methylprednisolone is used. Hydroxychloroquine, Mycophenolate mofetil, Azathioprine and Cyclophosphamide are the commonly used drugs in SLE. Over the years the prognosis of SLE has improved probably due to early diagnosis and better use of immunosuppressive treatment, regular follow up and treatment of co-morbidities. The 10-year survival now approaches 90% and with advent of new and targeted therapy it is hoped that the morbidity and organ damage can also be minimized.

Does kidney biopsy in pediatric lupus patients "complement" the management and outcomes of silent lupus nephritis? Lessons learned from a pediatric cohort

BACKGROUND

Silent lupus nephritis (SLN) is systemic lupus erythematosus (SLE) without clinical and laboratory features of kidney involvement but with biopsy-proven nephritis. This study aims to describe and compare the baseline characteristics and outcomes of pediatric SLN with overt LN (OLN) and to identify associated risk factors and biochemical markers.

METHODS

In this retrospective, observational study, multivariate logistic regression and receiver operating characteristic (ROC) analyses studied age, sex, race, serum complements, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis.

RESULTS

In our cohort of 69 patients, 47 were OLN, and 22 were SLN. OLN (OR = 4.9, p = 0.03) and non-African Americans (AA) (OR = 13.0, p < 0.01) had higher odds, and increasing C3 and C4 were associated with lower odds of proliferative nephritis (OR 0.95 and 0.65 per one unit increase in C3 and C4, respectively, p < 0.01). They demonstrated a good discriminative ability to detect proliferative nephritis as assessed by the area under the ROC curve (C3 = 0.78, C4 = 0.78). C3 and C4 in proliferative SLN and OLN were comparable and significantly lower than their non-proliferative counterparts. No association was observed between age, sex, anti-double-stranded-DNA antibody, anti-Smith antibody, eGFR, and proliferative nephritis. Proliferative SLN and OLN patients received similar treatments. Adverse events were identified in the proliferative OLN only.

CONCLUSIONS

Lower complement levels are associated with proliferative lesions in pediatric LN-both SLN and OLN. The non-AA population had higher odds of having proliferative nephritis than the AA. Prospective, randomized, long-term follow-up of proliferative SLN patients is needed to ascertain the beneficial effect of early diagnosis and treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.