Two Cases of Inherited Triple Deficiency in a Large Kindred with Thrombotic Diathesis and Deficiencies of Antithrombin III, Heparin Cofactor II, Protein C and Protein S

Heparin cofactor II deficiency

OBJECTIVES

To review of the state of the art relating to congenital heparin cofactor II deficiency as a potential risk factor for thrombosis, as reflected by the medical literature and the consensus opinion of recognized experts in the field, and to make recommendations for the use of laboratory assays for assessing this thrombotic risk in individual patients.

DATA SOURCES

Review of the medical literature, primarily from the last 10 years.

DATA EXTRACTION AND SYNTHESIS

After an initial assessment of the literature, including review of clinical study design and laboratory methods, a draft manuscript was prepared and circulated to participants in the College of American Pathologists Conference XXXVI: Diagnostic Issues in Thrombophilia. Recommendations were accepted if a consensus of experts attending the conference was reached. The results of the discussion were used to revise the manuscript into its final form.

CONCLUSIONS

Consensus was reached that there is insufficient evidence to recommend testing for heparin cofactor II deficiency in patients with thromboembolic disease.

Portal vein thrombosis caused by protein C and protein S deficiency associated with cytomegalovirus infection

A 4-month-old girl who was examined because of splenomegaly had portal vein thrombosis, which apparently resulted from a combination of cytomegalovirus infection and deficiency of both protein S and protein C. The cytomegalovirus infection, by damaging endothelial cells, may have triggered a cascade of events that was ultimately expressed as portal vein thrombosis resulting from deficiency of proteins S and C.

Increased thrombosis incidence in a family with an inherited protein S deficiency and a high oxygen affinity hemoglobin variant

Inherited protein S deficiency and the presence of a rare high oxygen affinity hemoglobin variant: Hb Rainier [beta 145 (HC2) Tyr-->Cys] were found in a family. Among 16 studied members, nine were found as carriers of protein S deficiency (type I with decrease of total, free, and activity levels). Six subjects carried the high-affinity hemoglobin variant, which displayed an increase of blood viscosity. Four members combined both abnormalities. Three had thrombotic accidents before the age of 30. We suggest the combination of protein S deficiency and the presence of this hemoglobin variant can lead to a severe primary hypercoagulable state with pathological consequences compared to each genetic defect alone.

Combined inherited protein S and heparin co-factor II deficiency in a patient with upper limb thrombosis: a family study

A 42-year-old Italian woman presenting with spontaneous deep vein thrombosis of the right arm, was found to have inherited a deficiency of both protein S (PS) and heparin co-factor II (HC II). The two defects seemed to segregate independently, since her son exhibited only a HC II deficiency while one of her sisters manifested only the PS defect. All affected patients appeared heterozygous for one or other or both deficiency states. The proposita and her sister exhibited a congenital PS deficiency consisting of normal or near normal levels of total PS antigen and C4b-binding protein (C4b-BP) but a moderate reduction both of free PS antigen and of PS functional activity. In addition, the proposita and her son had half normal levels of HC II antigen and activity. Except for the proposita, all were asymptomatic. Inherited deficiencies either of PS or of HC II have been associated with thrombotic manifestations. Since the proposita had an inherited combined defect of the two proteins, severe thrombotic events might be expected. However, this was not found to be the case. The role of HC II deficiency in the pathogenesis of thrombosis whether alone or combined remains to be fully investigated.