Venous thrombosis after caesarean section in a young woman with homozygous APC resistance and type I protein S deficiency

Plasminogen deficiency

Plasminogen (plg) deficiency has been classified as (i) hypoplasminogenemia or 'true' type I plg deficiency, and (ii) dysplasminogenemia, also called type II plg deficiency. Both forms, severe hypoplasminogenemia and dysplasminogenemia, are not causally linked to venous thrombosis. Dysplasminogenemia does not lead to a specific clinical manifestation and probably represents only a polymorphic variation in the general population, mainly in Asian countries. Severe hypoplasminogenemia is associated with compromised extracellular fibrin clearance during wound healing, leading to pseudomembraneous (ligneous) lesions on affected mucous membranes (eye, middle ear, mouth, pharynx, duodenum, upper and lower respiratory tract and female genital tract). Ligneous conjunctivitis is by far the most common clinical manifestation. More than 12% of patients with severe hypoplasminogenemia exhibit congenital occlusive hydrocephalus. In milder cases of ligneous conjunctivitis, topical application of plg-containing eye drops, fresh frozen plasma, heparin, corticosteroids or certain immunosuppressive agents (such as azathioprine) may be more or less effective. Oral treatment with sex hormones was successful in two female patients with ligneous conjunctivitis. In severe cases with possibly life-threatening multi-organ involvement, true therapeutic options are not available at present. The plg-knockout mouse is a useful tool to study the many different properties of plg in a variety of settings, such as wound healing, tissue repair and tissue remodeling, virulence and invasiveness of certain bacteria in the human host, tumor growth and dissemination, as well as arteriosclerosis.

Obstetric implications of activated protein C resistance and factor V Leiden mutation

An increasing number of reports have focused on activated protein C resistance (APCR) as it has been shown not only to be the most common genetic factor predisposing patients to thromboembolic disease but the most common identifiable cause overall. More than 90 percent of the cases of APCR are caused by the factor V Leiden mutation, in which a guanine to adenine substitution in the factor V gene at nucleotide position 1691 results in a glutamine to arginine switch at position 506. Recent studies have also pointed to evidence of an association between APCR/factor V Leiden mutation and hypertensive disorders of pregnancy, first and second trimester miscarriage, placental infarction, and placental abruption.

Inherited protein C deficiency, protein S deficiency and hyperhomocysteinaemia in a patient with hereditary spherocytosis

We report a family with hereditary spherocytosis in whom there is, in addition, a cluster of genetic predispositions to thrombosis. Although inherited prothrombotic abnormalities are prevalent in the general population, the likelihood of this combination of abnormalities being found in a single family is extremely low. The management of such high risk individuals is discussed.