In patients with plasminogen deficiency, blood levels of plasminogen activity are reduced (ref 1). Diagnosis therefore depends on the development of symptoms followed by blood testing to confirm a deficiency of plasminogen (performed by plasminogen activity and antigen assays). The availability of these tests is not consistent in the United States or around the world. Plasminogen activity levels below the normal range likely confirms the diagnosis; a specific plasminogen activity cut off level (for example, a plasminogen activity of less than 50%) has not yet been defined that establishes the diagnosis. Some medical researchers and practitioners recommend using a level of <40% plasminogen activity; however, it has been documented that individuals with confirmed PLGD have had levels that are above this cutoff (for example about 50%), and therefore this is currently under investigation. Genetic testing can also help establish the diagnosis despite the absence of symptoms.
The diagnosis of PLGD is challenging, for a variety of reasons. Affected individuals may present to different types of physicians including their general medical doctor, their dentist, or specialists such as an ophthalmologist, ear-nose-and throat doctor, lung doctor, etc. As PLGD is a very rare condition, it is unlikely that these physicians have personally seen someone with PLGD, or learned about this rare deficiency during their training. This often delays diagnosis and prolongs the time that affected individuals endure their symptoms. Once the cause of the symptoms has been identified, the ability of physicians to identify specialists who can help treat and guide therapy may be difficult.
- Tefs et al. Molecular and clinical spectrum of type I plasminogen deficiency: a series of 50 patients. Blood. 2006;108(9):3021-3026.