Paving the way in PLGD treatment and research
The IHTC has been a pioneer in the development of treatment and clinical studies for patients with plasminogen deficiency (PLGD). Our center is known internationally as an expert in the diagnosis and management of this disorder.
In conjunction with the University of Milan, the IHTC is conducting an international study to improve our understanding of plasminogen deficiency and to develop the data required for optimal management as treatment becomes available.
Plasminogen is synthesized in the liver and is present in most tissues. Plasminogen, with the help of enzymes such as tissue-plasminogen activator (tPA) and urokinase-plasminogen activator, is converted to the enzyme plasmin. The main role of plasmin is to break down fibrin (the main component of a clot). Defective clot breakdown has been associated with an increased risk of blood clots.
Plasminogen levels do not reach the healthy adult range until late adolescence, and newborns have levels approximately one-half that of healthy adults. Higher levels of plasminogen are found in women during the third trimester of pregnancy.
TYPES OF PLASMINOGEN DEFICIENCY
There are two types of plasminogen deficiency:
Type I: an equal decrease in both the level and activity of plasminogen in the blood
Type II (dysplasminogenemia): the level of plasminogen is normal, but its activity is decreased
The most common clinical symptom of plasminogen deficiency is ligneous (“wood-like”) conjunctivitis. The conjunctiva (the membrane that lines the eyelids and covers the front of the eye) becomes irritated because of a build-up of white, yellow-white, or red thick masses with a wood-like consistency that may replace normal tissue. The build-up occurs mostly on the eyelids and may be triggered by injury or infection. The build-up often recurs after it has been removed.
The wood-like lesions have been reported to occur in other mucous membranes, such as the mouth, nose, throat, windpipe, and female genital tract. Some affected children may experience congenital occlusive hydrocephalus (increased fluid around the brain). Removal of the lesions does not cure the condition and may promote the return of the lesions. The lesions are responsive to IV plasminogen replacement, and to direct application to the eyes.
PLASMINOGEN DEFICIENCY INCIDENCE
The incidence of plasminogen deficiency is not well known and may be underestimated because ophthalmologists, dentists, obstetricians, gynecologists, and ENT physicians may treat these patients and either not refer them to the appropriate specialist, or not recognize the symptoms as being related to plasminogen deficiency.
Plasminogen deficiency that runs in families appears to be an uncommon but recognized cause of an inherited clotting disease. The clotting complications of this deficiency mostly involve the veins and include thrombophlebitis (red inflamed veins), pulmonary embolism (clot in the lungs), and stroke.
It is interesting to note that in affected individuals, blood clots haven’t been reported to be associated with pregnancy or oral contraceptive use. Even more intriguing is the report that plasminogen levels become normal in a deficient patient during pregnancy or with use of oral hormonal therapy.
This finding indicates that in heterozygote patients the correctly functioning gene may be able to produce more plasminogen. Because homozygous patients rarely develop clots, the possibility of heterozygous plasminogen deficiency as a cause for a clotting event may be dismissed or overlooked by many clinicians.
READ ABOUT PLG REPLACEMENT THERAPY IN BLOOD
Learn more about plasminogen deficiency