Acquired Inhibitors of Factor V^[*]

Summary

The clinical and laboratory data on the 12 patients with an acquired inhibitor to factor V have been reviewed. The degree of clinical bleeding in these patients varied from none to severe, and in most patients the inhibitor was transient. The combination of a markedly prolonged partial thromboplastin time and Quick prothrombin time and failure of normal plasma to correct these tests, in the presence of a normal thrombin and prothrombin and proconvertin time, seems to be pathognomonic for a factor V inhibitor. The inhibitors have physicochemical properties of immunoglobulins and a few have been characterized as polyclonal IgG antibodies or a mixture of IgM and IgG antibodies. The etiology and pathophysiologic mechanism of their development is unknown, but there seems to be a close relationship to major surgery. When tested with inhibitor plasma, the plasmas from 9 patients with hereditary factor V deficiency from 7 unrelated families did not contain factor V antibody-neutralizing material.

^* Presented in part at a symposium on Immune Disorders of Hemostasis at the VIth Congress of the International Society on Thrombosis and Haemostasis, Philadelphia, Pennsylvania, U.S.A., June 26–July 2, 1977.

• References

• 1 Crowell EB. 1974; Observations on a factor V inhibitor. British Journal of Haematology 29: 397
• 2 Feinstein DI, Rapaport SI, Mcgehee WG, Patch MJ. 1970; Factor V anticoagulants. Clinical, biochemical, and immunological observations. Journal of Clinical Investigation 49: 1578
• 3 Feinstein DI, Rapaport SI, Chong MMY. 1973; Factor V inhibitor. Report of a case, with comments on a possible effect of streptomycin. Annals of Internal Medicine 78: 385
• 4 Feinstein DI, Rapaport SI. 1972; Acquired inhibitors of blood coagulations. Progress in Hemostasis and Thrombosis I: 75
• 5 Ferguson JH, Johnston Jr CL, Howell DA. 1958; A circulating inhibitor (anti-AcG) specific for the labile factor V of the blood doting mechanism. Blood 13: 382
• 6 Fratantoni JC, Hilgartner M, Nachman RL. 1972; Nature of the defect in congenital factor V deficiency; study in a patient with an acquired circulating anticoagulant. Blood 39: 751
• 7 Friedman IA, Quick AJ, Higgins F. 1961; Hereditary labile factor (factor V) deficiency. Journal of American Medical Association 175: 370
• 8 Giddings JC, Shearn SAM, Bloom AL. 1975; The immunological localization of factor V in human tissue. British Journal of Haematology 29: 57
• 9 Goodnight Jr SH, Feinstein DI, Østerud B, Rapaport SI. 1971; Factor VII antibodyneutralizing matrial in hereditary and acquired factor VII deficiency. Blood 38: 1
• 10 Handley DA, Duncan EM. 1969; A circulating anticoagulant specific for factor V. Pathology I: 265
• 11 Lane TA, Shapiro SS, Burba ER, Shapiro SS, Hulten M. 1975; Acquired inhibitors of blood coagulation factors. Seminars in Thrombosis and Hemostasis I: 336
• 12 Lopez VR, Pflugshaupt R, Butler R. 1968; A specific inhibitor of human clotting factor V. Acta Haematologica (Basel) 40: 275
• 13 Margolius Jr A, Jackson DP, Ratnoff OD. 1961; Circulating anticoagulants. a study of 40 cases and a review of the literature. Medicine 40: 145
• 14 Nilsson IM, Hedner V, Ekberg M, Denneberg T. 1974; Circulating anticoagulant against factor V. Acta medica Scandinavica 195: 73
• 15 Onoura CA, Lindenbaum J, Nossel HJ. 1973; Massive hemorrhage associated with circulating antibodies to factor V. American Journal of the Medical Sciencies 265: 407
• 16 Shapiro SS, Hulten M. 1975; Acquired inhibitors to the blood coagulation factors. Seminars in Thrombosis and Hemostasis I: 336
• 17 Stenbjerg S, Husted S, Mygend K. 1975; A circulating factor V inhibitor. Possible side effect of treatment with streptomycin. Scandinavian Journal of Haematology 14: 280