Mycophenolic acid MPA) is produced by Penicillium brevicompactum and roqueforti.  P. brevicompactum is a common contaminant present in damp indoor spaces.  However, no information regarding its identification in damp indoor spaces has been located in the scientific literature.  MPA is a common contaminant of silage, particularly corn and foods.

    MPA is obtained via a fermentation  process using either P brevicompactum or roqueforti.  MPA in the prescription form, Mycophenolate mofetil (MMF) is given to kidney transplant patients for immune suppression.  MMF is rapidly metabolizes to MPA and appears in the blood shortly after oral dosing.  Interestingly, MMF and MPA bind to plasma album at 97 and 82 %.  From this observation antibodies to album bound MMF and MPA should also be present in  blood samples of patients.
     The immunosuppressive effects of results from an inhibition of the enzyme, inosine monophosphate dehydrogenase (IMPDH) interfering with the de novo synthesis pathway of guanosine nucleotides.  T and B cells require this pathway to incorporate purines into DNA,  Originally it was believed that only T and B cells were affected, however the toxic effects seen in  kidney transplant patients suggest other wise.

    The side effects of MMF are as follows:  G.I. Tract bleeding, neutropenia, potential to develop lymphoma and other malignancies, diarrhea, leukopenia, sepsis, vomiting, higher rate of infections (bacterial and viral), abdominal, back and chest pain, fever, headache, anemia, thrombocytopenia, among others.

     Little information is available in the literature on the toxicology of MPA in animals.  Mice and monkeys following acute oral exposure at does up to 4000 mg/kg body weight resulting in no deaths.  One study  female rats showed that 4.5 mg/kg a day resulting malformations of the head and eyes.  In addition, studies on rats and rabbits at a dose of 6 and 90 mg/kg/day found fetal resorptions and malformations. One must keep in  thought that acute oral toxic doses are not equivalent to chronic oral doses taken by transplant patients.  In addition, they are not equivalent to chronic inhalation that may occur in WDB.

For more information see:  search engine:  http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB