The serum levels of some of the common genotypes are:

PiMM: 100% (normal)
PiMS: 80% of normal serum level of A1AT
PiSS: 60% of normal serum level of A1AT
PiMZ: 60% of normal serum level of A1AT
PiSZ: 40% of normal serum level of A1AT
PiZZ: 10-15% (severe alpha-1 antitrypsin deficiency)
PiZ is caused by a glutamate to lysine mutation at position 342 (366 in pre-processed form)
PiS is caused by a glutamate to valine mutation at position 264 (288 in pre-processed form)Other rarer forms have been described; in all, there are over 80 variants. Medical uses
Alpha-1 antitrypsin concentrates are prepared from the blood plasma of blood donors. The US Food and Drug Administration (FDA) has approved the use of four alpha-1 antitrypsin products derived from a human plasma: Prolastin, Zemaira, Glassia, and Aralast. These products for intravenous augmentation A1AT therapy can cost up to $100,000 per year per patient. They are administered intravenously at a dose of 60 mg/kg once a week; higher doses do not provided additional benefit although they can be used in anticipation of an interruption of weekly administration, such as for a vacation.Alpha1-proteinase inhibitor (Respreeza) was approved for medical use in the European Union in August 2015. It is indicated for maintenance treatment, to slow the progression of emphysema in adults with documented severe alpha1-proteinase inhibitor deficiency (e.g., genotypes PiZZ, PiZ (null), Pi (null, null), PiSZ). People are to be under optimal pharmacologic and non-pharmacologic treatment and show evidence of progressive lung disease (e.g.
Maribavir, sold under the brand name Livtencity, is an antiviral medication that is used to treat post-transplant cytomegalovirus (CMV).The most common side effects include taste disturbance, nausea, diarrhea, vomiting and fatigue.Maribavir is a cytomegalovirus pUL97 kinase inhibitor that works by preventing the activity of human cytomegalovirus enzyme pUL97, thus blocking virus replication.Maribavir was approved for medical use in the United States in November 2021. Medical uses
Maribavir is indicated to treat people twelve years of age and older and weighing at least 35 kilograms (77 lb) with post-transplant cytomegalovirus infection/disease that does not respond (with or without genetic mutations that cause resistance) to available antiviral treatment for cytomegalovirus. Adverse effects
Adverse effects of maribavir include taste disturbances, nausea, and vomiting. Contraindications
Maribavir may reduce the antiviral activity of ganciclovir and valganciclovir, so coadministration with these medications is not recommended. History
Maribavir is licensed by ViroPharma from GlaxoSmithKline in 2003, for the prevention and treatment of human cytomegalovirus (HCMV) disease in hematopoietic stem cell/bone marrow transplant patients. The mechanism by which maribavir  inhibits HCMV replication is by inhibition of an HCMV encoded protein kinase enzyme called UL97 or pUL97. Maribavir showed promise in Phase II clinical trials and was granted fast track status, but failed to meet study goals in a Phase III trial.