During a 4-year multicenter cooperative study of acquired factor VIII inhibitors in persons with hemophilia A, new inhibitors were detected in 31 of 1,306 patients who entered the study without an inhibitor or the history of an inhibitor. The incidence of new inhibitors was eight per 1,000 patient-years of observation. The factor VIII:C level before inhibitor development was less than or equal to 0.03 U/mL in 29 individuals and 0.06 U/mL and 0.07 U/mL in the remaining two. Factor VIII:Ag levels were measured in 27 individuals and were less than 0.03 U/mL in 23 and 0.05 to 0.11 U/mL in the remaining four. Maximum inhibitor levels ranged from 1.0 to 9,044 Bethesda U/mL. In seven patients under the age of 20, relatively weak inhibitors (none higher than 4.3 Bethesda U/mL) were detected on only a single occasion despite continued factor VIII challenge. In the other 24 patients with inhibitors detected on multiple occasions, 50% had appeared by age 20 and 71% by age 30. Seventeen of the 31 inhibitors, including 12 of 15 with maximum values greater than 10 Bethesda U/mL, developed within 75 exposure days to factor VIII.

A patient congenitally deficient in factors II, VII, IX, and X has been further investigated after a follow-up of 15 yr. At birth, these factors, when determined by clotting assays, were undetectable. Following therapy with vitamin K1, the clotting activity of these factors rose but never exceeded 18% of normal. Immunologic assays revealed much higher levels of these factors than did clotting assays, thus suggesting that the vitamin-K-dependent factors were present in abnormal forms. Two-dimensional crossed immunoelectrophoresis showed that at least two forms of prothrombin were present in the patient's plasma. One form was similar to normal prothrombin; the other had the same mobility as acarboxyprothrombin. In addition, the majority of this fast-migrating peak was not adsorbable onto insoluble barium salts. These observations suggested that some molecules of the patient's prothrombin lacked the normal complement of gamma-carboxyglutamic acid residues. This observation was confirmed by a specific assay for gamma- carboxyglutamate. Since malabsorption of vitamin K, warfarin intoxication, and hepatic dysfunction were excluded as causes of this patient's syndrome, this rare congenital abnormality could represent either a defective gamma-carboxylation mechanism within the hepatocyte or faulty vitamin K transport.

Replacement therapy for hemophilia B (factor IX deficiency) using prothrombin complex concentrate (PCC) has been associated with serious complications of thromboembolic events and transmission of viral infections. Monoclonal antibody-purified factor IX (Mononine) provides a highly purified factor IX concentrate, while eliminating other vitamin K-dependent factors (II, VII, and X). Mononine was evaluated for in vivo recovery, half-life, and for its safety and efficacy in 10 patients with hemophilia B. The in vivo recovery of factor IX with Mononine was a 0.67 +/- 0.14 U/dL (mean +/- SD) increase per 1U/kg of infused factor IX, and the biologic half-life (t1/2), determined using the terminal phase of elimination, was 22.6 +/- 8.1 hours. Comparison of in vivo recovery of other vitamin K-dependent factors following a single infusion of either Mononine or PCC showed that, whereas Mononine infusion caused no changes in other vitamin K-dependent factors or in prothrombin activation fragment (F1+2), PCC infusion was associated with significant increases of factors II (2.7 U/dL per 1 U/dL of IX increase) and X (2.2 U/dL for 1 U/dL for 1 U/dL of IX). Patients who used Mononine as their sole therapeutic material during the 12-month period showed an excellent response in hemostasis for their bleeding episodes. Their experience with long-term use of Mononine was at least equivalent to their previous experience with PCC in the frequency and amount of factor usage. No patients developed antibody against mouse IgG or an increase in IX inhibitor during the 12-month period. These results indicate that monoclonal antibody-purified factor IX concentrate provides hemostatically effective factor IX replacement while avoiding extraneous thrombogenic substances.

Immunologic abnormalities resembling those seen in patients with the acquired immunodeficiency syndrome (AIDS) are frequently observed in multitransfused but otherwise healthy individuals with hemophilia. To determine whether there was clinical or laboratory evidence to suggest an abnormality of immunoregulation in persons with hemophilia before the recognition of AIDS, we examined data collected by the Hemophilia Study Group from 1975 to 1979 on 1,551 patients with factor VIII deficiency. The prevalence of lymphocytopenia and thrombocytopenia in patients over 5 years of age on entry was found to be 9.3% (94/1,013) and 5.0% (26/518), respectively. These rates were significantly different from a normal population (P less than .00001 and less than .0003). No cases meeting the definition of AIDS were noted during the study. However, on follow-up in 1984 of a cohort of 79 patients with thrombocytopenia or lymphocytopenia on two or more occasions during the study, eight patients (10%) with AIDS-related abnormalities, including idiopathic thrombocytopenic purpura, non-Hodgkin's lymphoma, generalized lymphadenopathy, and oral moniliasis without obvious cause were identified. Of the 79 patients, liver disease accounted for five of the ten deaths (12.6% mortality) observed during a minimum follow-up of five years after detection of cytopenia. Only one death was attributed to bleeding in the absence of liver disease. We conclude that (a) the frequency of lymphocytopenia and thrombocytopenia was increased in multitransfused factor VIII-deficient hemophiliacs before the advent of AIDS, and (b) persistent lymphocytopenia and thrombocytopenia appear to be strongly associated with liver disease, which was the leading cause of death in a cohort of hemophiliacs followed five or more years.

During a 4-year multicenter cooperative study of acquired factor VIII inhibitors in persons with hemophilia A, new inhibitors were detected in 31 of 1,306 patients who entered the study without an inhibitor or the history of an inhibitor. The incidence of new inhibitors was eight per 1,000 patient-years of observation. The factor VIII:C level before inhibitor development was less than or equal to 0.03 U/mL in 29 individuals and 0.06 U/mL and 0.07 U/mL in the remaining two. Factor VIII:Ag levels were measured in 27 individuals and were less than 0.03 U/mL in 23 and 0.05 to 0.11 U/mL in the remaining four. Maximum inhibitor levels ranged from 1.0 to 9,044 Bethesda U/mL. In seven patients under the age of 20, relatively weak inhibitors (none higher than 4.3 Bethesda U/mL) were detected on only a single occasion despite continued factor VIII challenge. In the other 24 patients with inhibitors detected on multiple occasions, 50% had appeared by age 20 and 71% by age 30. Seventeen of the 31 inhibitors, including 12 of 15 with maximum values greater than 10 Bethesda U/mL, developed within 75 exposure days to factor VIII.

The case history of a child with acute promyelocytic leukemia (APL) is reported to illustrate both an unusual presentation of APL as a pelvic mass and to review the pathophysiology and treatment of the disease. Therapy of APL consists of chemotherapy, namely adriamycin/daunomycin for remission induction, and of control of disseminated intravascular coagulation. A chloroma, if present, may require local irradiation in addition to chemotherapy. With aggressive management, the number of prolonged remissions may be greater for APL than for any other form of acute myelogenous leukemia (AML), with significant numbers of patients achieving five-year survival.

Immunologic abnormalities resembling those seen in patients with the acquired immunodeficiency syndrome (AIDS) are frequently observed in multitransfused but otherwise healthy individuals with hemophilia. To determine whether there was clinical or laboratory evidence to suggest an abnormality of immunoregulation in persons with hemophilia before the recognition of AIDS, we examined data collected by the Hemophilia Study Group from 1975 to 1979 on 1,551 patients with factor VIII deficiency. The prevalence of lymphocytopenia and thrombocytopenia in patients over 5 years of age on entry was found to be 9.3% (94/1,013) and 5.0% (26/518), respectively. These rates were significantly different from a normal population (P less than .00001 and less than .0003). No cases meeting the definition of AIDS were noted during the study. However, on follow-up in 1984 of a cohort of 79 patients with thrombocytopenia or lymphocytopenia on two or more occasions during the study, eight patients (10%) with AIDS-related abnormalities, including idiopathic thrombocytopenic purpura, non-Hodgkin's lymphoma, generalized lymphadenopathy, and oral moniliasis without obvious cause were identified. Of the 79 patients, liver disease accounted for five of the ten deaths (12.6% mortality) observed during a minimum follow-up of five years after detection of cytopenia. Only one death was attributed to bleeding in the absence of liver disease. We conclude that (a) the frequency of lymphocytopenia and thrombocytopenia was increased in multitransfused factor VIII-deficient hemophiliacs before the advent of AIDS, and (b) persistent lymphocytopenia and thrombocytopenia appear to be strongly associated with liver disease, which was the leading cause of death in a cohort of hemophiliacs followed five or more years.

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.