Diffuse alveolar haemorrhage in children: an international multicentre study.

Background: Paediatric diffuse alveolar haemorrhage (DAH) is a rare heterogeneous condition with limited knowledge on clinical presentation, treatment and outcome. Methods: A retrospective, descriptive multicentre follow-up study initiated from the European network for translational research in children's and adult interstitial lung disease (Cost Action CA16125) and chILD-EU CRC (the European Research Collaboration for Children's Interstitial Lung Disease). Inclusion criteria were DAH of any cause diagnosed before the age of 18 years. Results: Data of 124 patients from 26 centres (15 counties) were submitted, of whom 117 patients fulfilled the inclusion criteria. Diagnoses were idiopathic pulmonary haemosiderosis (n=35), DAH associated with autoimmune features (n=20), systemic and collagen disorders (n=18), immuno-allergic conditions (n=10), other childhood interstitial lung diseases (chILD) (n=5), autoinflammatory diseases (n=3), DAH secondary to other conditions (n=21) and nonspecified DAH (n=5). Median (IQR) age at onset was 5 (2.0-12.9) years. Most frequent clinical presentations were anaemia (87%), haemoptysis (42%), dyspnoea (35%) and cough (32%). Respiratory symptoms were absent in 23%. The most frequent medical treatment was systemic corticosteroids (93%), hydroxychloroquine (35%) and azathioprine (27%). Overall mortality was 13%. Long-term data demonstrated persistent abnormal radiology and a limited improvement in lung function. Conclusions: Paediatric DAH is highly heterogeneous regarding underlying causes and clinical presentation. The high mortality rate and number of patients with ongoing treatment years after onset of disease underline that DAH is a severe and often chronic condition. This large international study paves the way for further prospective clinical trials that will in the long term allow evidence-based treatment and follow-up recommendations to be determined.

Antineutrophil Cytoplasmic Autoantibody-Associated Glomerulonephritis as a Complication of Home Parenteral Nutrition.

Patients on long-term home parenteral nutrition (HPN) occasionally develop glomerulonephritis due to chronic central venous catheter (CVC)-related infection. Most previously reported cases were membranoproliferative glomerulonephritis (MPGN). This is a case report of a 16-year-old girl receiving HPN for short bowel syndrome. After 11 years on HPN, she developed acute kidney injury with macroscopic hematuria, nephrotic-range proteinuria, and a reduced glomerular filtration rate (GFR). Initially, MPGN associated with chronic bacteremia was suspected with the assumption that the condition would be treated with antibiotics and CVC replacement. However, her kidney biopsy revealed antineutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis (AAG). This was consistent with the fact that the patient tested positive for proteinase 3-ANCA. Immunosuppressive therapy with methylprednisolone pulses (followed by oral prednisone) and rituximab led to remission. Her GFR and protein excretion returned to normal. Chronic bacteremia as a complication of long-term HPN may cause various types of glomerulonephritis including, rarely, AAG requiring immunosuppressive therapy.