The treatment of glomerulonephritis in children

Predicting the exposure of mycophenolic acid in children with autoimmune diseases using a limited sampling strategy: A retrospective study

Mycophenolic acid (MPA) is commonly used to treat autoimmune diseases in children, and therapeutic drug monitoring is recommended to ensure adequate drug exposure. However, multiple blood sampling is required to calculate the area under the plasma concentration-time curve (AUC), causing patient discomfort and waste of human and financial resources. This study aims to use machine learning and deep learning algorithms to develop a prediction model of MPA exposure for pediatric autoimmune diseases with optimizing sampling frequency. Pediatric autoimmune patients' data were collected at Nanfang Hospital between June 2018 and June 2023. Univariate analysis was applied for feature selection. Ten algorithms, including Random Forest, XGBoost, LightGBM, Gradient Boosting Decision Tree, CatBoost, Artificial Neural Network, Grandient Boosting Machine, Transformer, Wide&Deep, and TabNet, were employed for modeling based on two, three, or four concentrations of MPA. A total of 614 MPA AUC0-12h samples from 209 patients were enrolled. Among the 10 models evaluated, the Wide&Deep model exhibited the best predictive performance. The predictive performance of the Wide&Deep model using four and three blood concentration points was similar (R 2 ≈ 1 for four points; R 2 = 0.95 for three points). No significant difference in accuracy within ±30% was observed between models utilizing three and four blood concentration points (p = 0.06). This study demonstrates that in the Wide&Deep model, MPA exposure can be accurately estimated with three sampling points in children with autoimmune diseases. This model could help reduce discomfort in pediatric patients without reducing the accuracy of MPA exposure estimates in clinical practice.

[Henoch-Shönlein purpura]

Henoch-Shönlein purpura (HSP) is an immunoglobulin A (IgA) vasculitis that affects the small vessels. It is a multi-organ system disease that may include cutaneous purpura, arthralgia, acute enteritis and nephritis. Nephritis is characterized by mesangial proliferation with IgA deposits. Neurological, pulmonary, cardiac or genitourinary complications occur rarely. The acute stage progresses by successive flare-ups of limited duration. Although the cause is unknown, it is clear that IgA plays a central role in the immunopathogenesis of HSP. The syndrome usually affects children in which evolution is generally favourable. In adults the disease is rare and seems different from children with much more severe manifestations and prognosis. Short-term outcome, in children as in adults, depends on the severity of gastrointestinal manifestations. Long-term outcome depends on renal involvement. In studies with enough observation time, as much as one third of the patients will progress to end stage renal failure. The benign manifestations of the disease are managed by appropriate symptomatic measures. In case of severe involvement, including severe gastrointestinal complications or proliferative glomerulonephritis, immunosuppressive drugs may be required including steroids. These specific treatments are still controversial and their efficacy has to be evaluated.

Crescentic glomerulonephritis in a child with infective endocarditis

Renal manifestations associated with infective endocarditis (IE) may present with different clinical patterns, and the most common renal histopathological finding is diffuse proliferative and exudative type of glomerulonephritis, leading to hematuria and/or proteinuria. Renal failure due to crescentic glomerulonephritis (CGN) in children with IE is a very rare condition. We report here a 6-year-old boy, who had a history of cardiac surgery for pulmonary atresia and ventricular septal defect, presenting with the clinical findings of IE and hematuria associated with renal failure due to CGN. He was treated with a combination of intravenous (IV) methylprednisolone pulses and appropriate antibiotics, but also received one dose of IV cyclophosphamide. Complete serological, biochemical, and clinical improvement was achieved after 2 months of follow-up. Antibiotic therapy is the essential part of the treatment of IE-associated glomerulonephritis; however, this case also highlights the importance of aggressive immunosuppressive therapy to suppress the immunological process related with infection in this life-threatening condition leading to renal failure.

Plasmapheresis as the sole therapy for rapidly progressive Henoch-Schönlein purpura nephritis in children

To clarify the therapeutic role of plasmapheresis (PP) for patients with Henoch-Schönlein purpura (HSP) nephritis, the clinical courses of nine children with a rapidly progressive type of HSP nephritis, who were treated with PP as the sole therapy, were retrospectively evaluated. All patients had nephrotic-range proteinuria (4.9 +/- 2.5 g/m2/d, mean +/- SD) and decreased glomerular filtration rate (GFR) (46.5 +/- 9.5 mL/min/1.73 m2) at the time of the initiation of PP. Biopsy specimens taken before PP showed large crescents involving more than 50% of the glomerular circumference in 56.8 +/- 6.9% of the glomeruli examined. The mean interval between disease onset and initiation of PP was 39.1 +/- 22.1 days. The PP regimen consisted of thrice-weekly treatment for 2 weeks, then weekly treatment for 6 weeks. No patients received any steroids or cytotoxic drugs, except for the use of steroids to manage severe abdominal pain. All patients responded promptly to PP with improvement in renal function, reduction of proteinuria, and subsidence of purpuric rash and abdominal pain. Six of nine patients showed further improvements without any other treatments; four had complete recovery, and two had only microscopic hematuria at the latest observation (follow-up period, 9.6 +/- 4.3 years). The remaining three patients showed a rebound increase of proteinuria after completion of PP; two of whom progressed to end-stage renal failure at 14.1 years and 1.8 years after disease onset. Because all patients had the most severe forms of nephritis, reported to carry a grave prognosis, this study suggests that PP as the sole therapy is effective in improving the prognosis of patients with rapidly progressive HSP nephritis, particularly if instituted early in the course of the disease. The role of PP in treating HSP nephritis deserves to be assessed further in larger randomized controlled trials.

[Rheumatoid purpura in adults. Apropos of 40 cases]

Fourty cases of Henoch-Schönlein purpura in adults (21 females, 19 males--age 39 years) are reviewed [departments of nephrology (28 cases) and internal medicine (12 cases)]. Dermatological manifestations occur in 39 cases and are similar to those seen in children. Gastrointestinal involvement (23 cases) usually takes the form of abdominal pains or diarrhea; gastrointestinal haemorrhages are rare. These symptoms are less severe than in children in this review as in the literature. Joint manifestations (22 cases) disappear without sequelae. The outcome of the disease depends on the nephropathy, present in 33 patients (82.5%) (all of those of the department of nephrology (100%) and 42% of those of the department of internal medicine). In one third of cases, renal manifestation appears after the onset of the disease (until 24 months). As in the children, haematuria and proteinuria are quasi constant. The renal histopathology is a focal and segmental proliferative glomerulonephritis in 58%, with IgA deposition in the mesangium (16/21 cases). Treatment regimen includes steroïds (10 cases), combination of steroïds with immunosuppressive agents (8 cases), steroïds-immunosuppressive drugs-plasma exchange (2 cases), dapsone (1 case). Of the 26 patients followed for 27 months, 11 are in clinical remission, 7 have persistent proteinuria or hematuria, and 8 have chronic renal failure after 3 months to 13 years. In this review, renal insufficiency, hypertension and young age predict a poor outcome. This severe outcome is probably explained by the fact that most of our patients referred to renal units. Unlike in the children, in which the affection is usually an acute illness, Henoch-Schönlein purpura in the adults seems to be a chronic disease, with prognosis depending on the nephropathy.

Hemostatic complications in renal disorders of the young

This review focuses on the hemorrhagic and thrombotic complications sometimes associated with the most common renal disorders in children. A Medline search of the literature was conducted from 1966 to January 1995, using combinations of key words appropriate for each disorder. Additional references were located through the bibliographies of the publications and recent journals were searched independently. The most common renal disorders with hemostatic complications in children were: renal vein thrombosis (268 children in 80 publications), hemolytic uremic syndrome (473 children in 29 publications), nephrotic syndrome (4,158 children in 51 publications), renal transplantation (3,976 children in 14 publications), glomerulonephritis (20 publications), end-stage renal disease, and dialysis (22 publications). The age distribution, clinical presentation, etiology, diagnosis, treatment, and outcome of the affected children were analyzed for each disorder. Children with inherited pre-thrombotic disorders usually do not present during childhood unless there is a secondary risk factor. Similarly, most children with renal disease do not develop thromboembolic complications. Therefore, when a child with a renal disorder develops a thromboembolic event, evaluation for an inherited pre-thrombotic disorder should be seriously considered. Guidelines for the use of heparin and warfarin in these children (both therapeutically and prophylactically) are given. At this time, the risk/benefit of thrombolytic therapy in children is not known and a general recommendation for thrombolytic therapy cannot be made.

Chronic glomerulonephritis in childhood. Membranoproliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and IgA nephropathy

The chronic glomerulonephritides that lead to permanent loss of renal function may present with an acute nephritic syndrome, nephrotic syndrome, or asymptomatic hematuria and proteinuria. Membranoproliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and IgA nephropathy are common childhood glomerulonephritides that may lead to chronic renal failure. Their clinical manifestations, natural history, and long-term prognosis are distinct. This article reviews various presentations of these common childhood glomerulonephritides and an approach to management and potential therapy.

Crescentic glomerulonephritis in children

Data on patients with crescentic glomerulonephritis (greater than 50% glomeruli with crescents), referred to the Hospital for Sick Children during the past 13 years, were reviewed. Thirty patients (13 male, 17 female) aged 3.7-15.7 years (mean 9.5) were evaluated. Initial clinical features included: oedema (24/30), hypertension (19/30), gross haematuria (15/30), oliguria (15/30) and a decreased glomerular filtration rate (GFR less than 30 ml/min per 1.73 m2) (22/30). Henoch-Schönlein purpura was present in 9 patients, microscopic polyarteritis in 3, polyarteritis nodosa in 1, Wegener's granulomatosis in 1, systemic lupus erythematosus in 1, post-streptococcal glomerulonephritis in 2, mesangiocapillary glomerulonephritis in 7, anti-glomerular basement membrane glomerulonephritis in 2, and 4 were idiopathic. In 10 patients 50%-79% of glomeruli were affected by crescentic changes (group 1) and in the remaining 20, 80% or more (group 2). The crescents were cellular, fibrocellular or fibrous, and the degree of sclerosis was assessed. Patients in both groups were treated with plasma exchange, corticosteroids, anticoagulants, cyclophosphamide and azathioprine in different combinations. On follow-up, 3 patients were dead, 1 was lost to follow-up, 12 were on dialysis/transplant programmes, 4 had a GFR of less than 30 and 10 a GFR of more than 30 ml/min per 1.73 m2. In our experience, 50% progressed to end-stage renal failure. The interval between disease onset and start of treatment was a prognostic factor for outcome. Fibrous crescents were associated with a worse outcome than fibrocellular crescents (P less than 0.05). Outcome was not, however, related to the percentage of glomeruli affected (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Idiopathic membranoproliferative glomerulonephritis in childhood

Membranoproliferative glomerulonephritis (MPGN), recognized since 1965, is now known to have three forms, designated types I, II, and III. The types are similar in the frequency of hypocomplementemia and clinical course but are dissimilar in glomerular ultrastructure, pathogenesis, mechanisms of complement activation, predisposition to recur in the renal transplant, and, to some extent, in clinical presentation. Although glomerular proliferation is usually diffuse, it may be focal and segmental particularly in mild cases of MPGN I. Hypocomplementemia, present in about 80% of patients, is the result of hypercatabolism of C3 by three mechanisms as well as of diminished C3 synthesis. The hypocomplementemia is unrelated to clinical course or prognosis. Although MPGN I and III both have a high frequency of an extended haplotype on chromosome 6, which has known associations with autoimmune phenomena, and both have a high frequency of inherited complement defects, they are nevertheless dissimilar in glomerular ultrastructure, complement profile, and immunohistology in ways which suggest a wide difference in pathogenesis. Abnormalities in humoral immunity appear not to be involved in MPGN III. Treatment with anticoagulant, antiplatelet and cytotoxic drugs have, in controlled trials, been either ineffective or marginally effective. Long-term use of alternate-day prednisone in high dosage appears to be the most efficacious regimen in both controlled and uncontrolled studies.

Membranoproliferative glomerulonephritis: the Cincinnati experience--cumulative renal survival from 1957 to 1989

Seventy-six children with idiopathic MPGN have been followed at this medical center since 1957 (mean 10.6 years of disease). Seventy-one of the children have been treated with a regimen of prednisone (mean 7.7 years of treatment). Monotherapy with alternate-day prednisone was used in 50 of the children. Other immunosuppressive and cytotoxic drugs have not been used since 1981. In the 71 treated patients, the cumulative renal survival (creatinine less than 3.0 mg/dl (265.5 mumol/L)) was 82% in the tenth year and 56% in the twentieth year after disease onset. Cumulative renal survival, calculated from the date of initiation of the prednisone regimen, was 75% in the tenth year and 59% in the twentieth year. As our experience with this disease has increased, long-term cumulative renal survival has improved.

Excretion of epidermal growth factor-like material in acute Henoch-Schönlein purpura nephritis

In Henoch-Schönlein purpura nephritis (HSPN), glomeruli may develop cellular "crescents" composed of infiltrating monocytes and proliferating renal epithelia. In this study, we demonstrate that peripheral human monocytes can release an epidermal growth factor (EGF)-like substance detectable by a radioreceptor assay, which recognizes both EGF and transforming growth factor-alpha (TGF-alpha), but not with a radioimmunoassay, which recognizes only EGF. Furthermore, we report that urine from pediatric patients during the acute phase of HSPN contains a similar EGF-like species in addition to the endogenous EGF which is normally present. The EGF-like material was not present in urine from nine healthy children or from six children with acute post-streptococcal glomerulonephritis. The extent of crescent formation in our patients is uncertain, since renal biopsy was performed in only one case. However, we speculate that the urinary material resembling TGF-alpha which appears during the acute phase of HSPN may derive from monocytes infiltrating the kidney.