Secondary organizing pneumonia
Secondary organizing pneumonia (SOP) refers to organizing pneumonia that can be attributed to a specific cause, in contrast to cryptogenic organizing pneumonia (COP) in which no cause is present.
Pathology
Etiology
SOP can be attributed to the following causes :
Prior infection
- bacteria
- atypical pneumonia (e.g. Legionella, Mycoplasma etc.)
- Streptococcus pneumoniae
- Staphylococcus aureus
- Pseudomonas aeruginosa
- fungi
- Cryptococcus neoformans
- Pneumocystis jiroveci
- Penicillium janthinellum
- viruses
- adenovirus, herpes, CMV, influenza, HIV, RSV, COVID-19
- parasites
- Plasmodium vivax
- Dirofilaria immitis
Drugs
- antimicrobials
- amphotericin B, cephalosporins, nitrofurantoin, minocycline
- chemotherapeutics
- bleomycin, busulfan, chlorambucil, doxorubicin, trastuzumab
- interferons
- methotrexate
- amiodarone
- phenytoin
Miscellaneous
- inflammatory bowel disease
- leukaemias, Hodgkin disease
- lung transplantation
- radiotherapy - radiation-induced organizing pneumonia
- rheumatological disorders e.g. rheumatoid arthritis, SLE, Sjogren, etc.