[Pulmonary-renal syndrome]

Cutting edge issues in Goodpasture's disease

Goodpasture's disease, or anti-glomerular basement membrane (anti-GBM) disease, is a systemic autoimmune disorder defined by anti-GBM antibody-mediated damage (mainly immunoglobulin G-1) resulting in progressive crescentic glomerulonephritis and, frequently, diffuse pulmonary alveolar hemorrhage. It may be regarded as a "conformeropathy" where the quaternary structure of the α345NC1 hexamer that constitutes GBM undergoes a conformational change, exposing pathogenic epitopes on the α3 and α5 chains, eliciting a pathogenic autoantibody anti-GBM response. Goodpasture's disease accounts for 20% of all patients presenting with a pulmonary-renal syndrome and may be associated with detectable perinuclear antineutrophil cytoplasmic autoantibody positivity in up to a third of patients. Associated triggers may include tobacco smoking, hydrocarbon solvent exposure, and cocaine abuse. Cough, hemoptysis, and dyspnea with fatigue are the commonest presenting features. It is critical to rapidly distinguish Goodpasture's disease from other causes of pulmonary-renal syndromes such as Wegener's granulomatosis. Early and intensive treatment with plasmapheresis and immunosuppression with systemic corticosteroids pending results of diagnostic testing, and later cyclophosphamide, is often beneficial, with 90% of patients surviving the acute presentation of Goodpasture's disease. The need for hemodialysis on initial presentation, a serum creatinine >5 mg/dL, and 50% to 100% crescents on renal biopsy, portend the necessity of long-term hemodialysis. Further elucidation of the molecular pathobiology of Goodpasture's disease, particularly the regulation of involved antigen-specific T cells, may improve early diagnosis, treatment, and outcomes in this rare but potentially lethal autoimmune disorder.

IgA nephropathy presenting with renal failure and pulmonary hemorrhage

Pulmonary renal syndromes are unusual, but frequently life-threatening manifestations of a distinct group of disorders in the pediatric age group. Although IgA nephropathy is a common cause of hematuria, it is an extremely rare cause of pulmonary renal syndrome, causing high mortality, and has mostly been reported in adult patients. We describe the youngest patient with this presentation reported to date, a 14-year-old male, who presented with end stage renal disease and pulmonary hemorrhage and was found to have IgA nephropathy by renal biopsy and pulmonary capillaritis by open lung biopsy. His lung disease was successfully treated with immunosuppressive medications. Despite this being a rare manifestation of IgA nephropathy, clinicians need to be aware of this presentation as it is potentially fatal, but amenable to aggressive immunosuppression.

Vasculitis and the intensive care

Most frequent reasons for intensive care unit (ICU) admission in vasculitis patients are severe respiratory insufficiency due to diffuse alveolar haemorrhage, sepsis and/or pneumonia and an acute abdomen due to bowel infarction. Other reasons are massive gastrointestinal bleeding, thromboembolism and/or scissures. In a patient, not previously diagnosed as having vasculitis, diagnosis can be difficult and must be made as soon as possible, since immunosuppressive therapy should be instituted immediately. Immunosuppressive therapy in severe cases consists of high-dose corticosteroids and cyclophosphamide. In addition, in many cases plasma exchange has to be instituted as well. Prognosis is related to disease activity scores of vasculitis and of severity of illness as measured by the APACHE III scoring system and/or the SOFA score. Septic shock is still the leading cause of death in patients with vasculitis. Nowadays, death due to active untreated vasculitis is rare in experienced clinics.