Idiopathic pulmonary hemosiderosis (IPH) is a lung disease of unknown cause that is characterized by alveolar capillary bleeding and accumulation of haemosiderin in the lungs.
It is rare, with an incidence between 0.24and 1.23 cases per million people.
It is thought to be an immune-mediated disease, with lung bleeding causing accumulation of iron, which in itself causes additional lung damage.
Idiopathic pulmonary hemomosiderosis can occur either as a primary lung disorder or as the sequela to other pulmonary, cardiovascular or immune system disorder.
PH1 involves PH with circulating anti-GBM antibodies.
PH2 involves PH with immune complex disease such as systemic lupus erythematosus, SLE.
PH3 involves no demonstrable immune system involvement.
A distinct subset of patients with pulmonary hemosiderosis have the Heiner syndrome with hypersensitivity to cow’s milk: associated with formation of IgG antibodies against basement membrane.
Its mechanism of hemorrhage is similar to that observed in Goodpasture syndrome.
The deposition of iron in the lungs, occurring in the form of haemosiderin, is the defining characteristic of this illness.
Other conditions may occur separately or together with haemosiderosis:
Pulmonary fibrosis
Adult respiratory distress syndrome (ARDS)
Immune complex disease
intra-alveolar bleeding
Diagnosis:
Manifests as a triad of hemoptysis, diffuse parenchymal infiltrates on chest radiographs, and iron deficiency anemia.
It is diagnosed at an average age of 4.5 plus or minus 3.5 years,
and it is twice as common in females.
Its clinical course is highly variable, and most of the patients continue to have episodes of pulmonary haemorrhage despite therapy.
Death may occur suddenly from acute pulmonary haemorrhage or after progressive pulmonary insufficiency resulting in chronic respiratory failure.
Treatment:
Corticosteroids are the mainstay of treatment of IPH, though they are controversial and lack clear evidence in their benefit.
Corticosteroids are thought to decrease the frequency of hemorrhage.
No agent has emerged as a clear standard of care.
Other possible agents includes: immune modulators such as hydroxychloroquine, azathioprine, 6-mercaptopurine, cyclophosphamide, and anti-oxidant N-acetylcysteine.
Patients today have an 86% survival beyond five years.