Rapidly progressive antineutrophil cytoplasm antibodies associated with pulmonary-renal syndrome in a 10-year-old girl

Immunoadsorption in Anti-GBM Glomerulonephritis: Case Report in a Child and Literature Review

Antiglomerular basement membrane glomerulonephritis (anti-GBM GN) is a rare autoimmune disease that is characterized by rapidly progressive glomerulonephritis that may be associated with pulmonary hemorrhage. Anti-GBM GN is caused by autoantibodies (classically type G immunoglobulin) directed against the α3 subunit of type IV collagen. Without any appropriate treatment, the disease is generally fulminant, and patient and kidney survival is poor. The current guidelines recommend the use of plasma exchanges and immunosuppressive drugs. Immunoadsorption (IA) can remove pathogenic IgGs from the circulation and do not require plasma infusions, contrary to plasma exchanges. IA has seldom been used in adult patients with good tolerance and efficiency. We report herein the first pediatric case successfully treated with IA combined with immunosuppressive drugs in a 7-year-old girl who presented acute kidney injury (estimated glomerular filtration rate 38 mL/minute/1.73 m²). A kidney biopsy revealed numerous >80% glomerular crescents and linear IgG deposits along the glomerular basement membrane. Ten IA sessions led to rapid and sustained clearance of autoantibodies and improvement of kidney function until 21 months after onset (glomerular filtration rate 87 mL/minute/1.73 m²). No adverse effect was noted. This report adds to the growing body of evidence suggesting IA as a therapeutic alternative to plasma exchanges in anti-GBM GN. The other 27 published pediatric cases of anti-GBM GN are reviewed.

Microscopic polyangiitis causing diffuse alveolar hemorrhage and rapidly progressive glomerulonephritis

Diffuse alveolar hemorrhage complicating small vessel vasculitis is a life-threatening emergency and should be considered in the differential diagnosis of patients who develop rapidly progressive dyspnea with alveolar opacities on chest imaging. In these patients, the coexistence of pulmonary and renal involvement suggests a multisystem disease. We present a case of a man who presented to our hospital with diffuse alveolar hemorrhage, severe anemia, and rapidly progressive glomerulonephritis.

Microscopic polyangiitis in an adolescent presenting as severe anemia and syncope

Microscopic polyangiitis (MPA) is an autoimmune systemic vasculitis of small vessels. The condition has been best characterized in older adults and little is known of the natural history of this disease in children and adolescents. In this report, a case of an adolescent presenting with symptomatic anemia and syncopal episodes is described. An extensive evaluation ultimately led to the diagnosis of MPA. The unique findings in this case and review of the literature are presented, outlining the variable clinical presentations and challenge of diagnosing this condition in pediatric patients.

Acquired Nonneoplastic Neonatal and Pediatric Diseases

The lung biopsy is an established procedure to procure a pathologic diagnosis in a child with a suspected pneumonic process of undetermined etiology. Improvements in pediatric anesthesia and surgery have reduced the operative complications to a minimum. A biopsy can usually be taken through a small intercostal incision when localization is not especially important in a patient with diffuse changes (see Chapter 1). The alternative method for tissue sampling is the endoscopic transbronchial biopsy. There is less risk to the patient, but the specimen is smaller and crush artifacts from the instrument are more common.

Childhood microscopic polyangiitis associated with MPO-ANCA

We reviewed the clinical, histological and serological parameters of microscopic polyangiitis (MPA) associated with antineutrophil cytoplasmic antibodies (ANCA) specific to myeloperoxidase (MPO). Six girls and one boy aged 12.0+/-2.6 years (7-15 years) met the following inclusion criteria: (1) clinical manifestations of systemic small vessel involvement; (2) histological demonstration of pauci-immune necrotizing glomerulonephritis; and (3) serological findings of increased concentration of MPO-ANCA by ELISA test. The main clinical manifestations were: influenza-like symptoms (100%), hematuria/proteinuria (100%), purpura (100%), pulmonary-renal syndrome (57%), acute renal failure (ARF) (29%), ischemic cerebral insults (29%), and necrotizing vasculitis of the skin (29%). All patients underwent renal biopsy examined by immunohistochemistry with expression of alpha-smooth muscle actin (alpha SMA) in glomerular and interstitial spaces. Patients were followed from 6 months to 5.5 years (35.4+/- 23.2 months). None of the patients died. Two of seven children who had ARF progressed to end stage renal disease; one developed chronic renal failure, and four normalized renal function. ARF and central nervous system involvement at presentation were parameters of poor renal outcome. A high score of fibro-cellular glomerular crescents was associated with worse prognosis. Early treatment enables a favorable prognosis of MPO-ANCA-associated MPA in children.

Pulmonary-renal vasculitic disorders: differential diagnosis and management

Pulmonary-renal syndrome (PRS) is a combination of diffuse pulmonary hemorrhage and glomerulonephritis. Pulmonary-renal syndrome is not a single entity and is caused by a variety of conditions, including Goodpasturés syndrome associated with autoantibodies to the glomerular and alveolar basement membranes, various forms of primary systemic vasculitis associated with serum positivity for antineutrophil cytoplasmic antibodies (ANCA), cryoglobulinemia, systemic lupus erythematosus, systemic sclerosis, antiphospholipid syndrome, environmental factors, and drugs. The majority of cases of PRS are associated with ANCAs. The antigen target in Goodpasturés syndrome is the alpha-3 chain of type IV collagen. The antigen target in PRS associated with systemic vasculitis is proteinase-3 and myeloperoxidase. Pulmonary-renal syndrome has been observed from the first to the ninth decade of life. The widespread adoption of serologic testing performed in an appropriate clinical context hopefully will limit diagnostic delay. The goals of treatment in PRS are to remove the circulating antibodies, to stop further production of autoantibodies, and to remove any antigen that stimulates antibody production. Treatment is based on plasmapheresis, steroids, and cyclophosphamide; however, infections are frequent contributors to death, and less toxic alternatives may improve outcome and prognosis resulting in a long-term survival. The degree of renal function and the percent of crescents on renal biopsy are better predictors of outcome. Renal transplantation can be safely carried out in PRS.