Hypoprothrombinemialupus anticoagulant syndrome secondary to Sjogrens syndrome: A case report

Hypoprothrombinemia-lupus anticoagulant syndrome (HLAS) is a rare disease in which patients present with varying degrees of bleeding and positive lupus anticoagulant with reduced prothrombin on laboratory tests. This article reports a case of HLAS in a middle-aged woman with recurrent gingival bleeding and epistaxis as the first presentation. After admission, tests revealed prolonged prothrombin time (PT), activated partial thromboplastin time (APTT), and reduced coagulation factor II activity, and positive lupus anticoagulant (LA). Meanwhile, the patient had symptoms of dry mouth and dry eyes for a long time, and the examination of autoantibodies, tear secretion test and salivary gland emission computed tomography (ECT) were consistent with the diagnosis of Sjogren's syndrome. The final diagnosis was HLAS secondary to Sjogren's syndrome. After treatment with methylprednisolone and cyclophosphamide, the coagulation disorder gradually improved, and no recurrent bleeding occurred. HLAS is a rare clinical case, which reminds medical staff to be alert to the possibility of HLAS when encountering patients with unexplained prolonged APTT and PT and positive lupus anticoagulant.

Lupus anticoagulant-hypoprothrombinemia syndrome in children: Three case reports and systematic review of the literature

OBJECTIVE

Children with lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) are characterized by prolonged activated partial thromboplastin time (APTT) and prothrombin time (PT), lupus anticoagulant positivity and low prothrombin (factor II, FII) levels. Bleeding or thrombosis tendencies related to LAHPS in children can occur due to the development of anti-prothrombin antibodies that are usually linked to autoimmune or infectious diseases.

METHODS

We report three pediatric cases of LAHPS and describe details on their clinical symptoms, laboratory characteristics, treatment. PubMed, Medline, and Web of Science searches were conducted on LAHPS in children between 1960 and 2023; articles in English were included.

RESULTS

The coagulation profile revealed prolonged PT and APTT, with low prothrombin levels (19.4%, 21.0% and 12.9%, respectively) and positive lupus anticoagulant in 3 pediatric cases. Fifty-nine relevant articles reported 93 pediatric LAHPS cases (mean age: 9 years (0.8-17 years)); 63 females and 30 males, 87 patients presented with minor to severe bleeding diathesis, and 3 patients presented with thrombosis events. Among 48 patients ≥9 years old, 36 had SLE; among 45 patients <9 years, 29 had viral infection. When all patients were divided into two groups based on age, associated disease, and factor II level, Pearson's χ2 tests were performed, p =.00, and there was clinical significance between autoimmune and infectious disease in patients ≥9 years old and <9 years old, and in patients FII level ≤10% and >10%. LAHPS patients with autoimmune disease had a protracted course and needed prolonged treatment with immune-modulating therapy, while those patients with infectious disease resolved spontaneously or needed short-term immune-modulating therapy.

CONCLUSION

LAHPS caused by autoimmune disease are common in patients ≥9 years old, especially SLE, and FII level ≤10% is often reported in patients caused by autoimmune disease, suggesting that children ≥9 years old diagnosed with LAHPS-related autoimmune disease should pay special attention to the FII level. While LAHPS caused by infectious disease is more frequently observed in patients <9 years, especially viral infection. Early diagnostic investigations are critical to differentiating LAHPS caused by autoimmune or infectious disease, as the prognosis, treatment and outcome are distinct.

[Recurrent epistaxis with coagulation disorders in a boy aged 2 years]

A boy, aged 2 years and 5 months, had recurrent epistaxis, and the coagulation function examination showed that activated partial thromboplastin time (APTT) was significantly prolonged. Further laboratory examinations showed that the prolonged APTT was not immediately corrected in the APTT correction test, with positive lupus anticoagulant and low prothrombin activity. The boy was diagnosed with hypoprothrombinemia-lupus anticoagulant syndrome. The condition was improved after treatment with glucocorticoid, immunoglobulin, and vitamin K₁. The boy has been followed up for 6 months, and no epistaxis was observed. Prothrombin activity returned to normal, and lupus anticoagulant remained positive. This is a relatively rare disease, and for patients with bleeding symptoms and coagulation disorders, it is recommended to perform the tests such as APTT correction test, lupus anticoagulant testing, and coagulation factor dilution test, which can improve the detection rate of this disease, so as to achieve early diagnosis, provide rational treatment in the early stage, and improve the prognosis.

Lupus anticoagulant-hypoprothrombinemia syndrome presenting with co-existing cerebral venous thrombosis and subdural hemorrhage

The lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS) - the association of acquired factor II deficiency and lupus anticoagulant - is a rare disease that may cause a predisposition not only to thrombosis but also to severe bleeding. We are reporting on a 36-year-old female patient presenting with co-existing cerebral venous thrombosis and subdural hemorrhage. The coagulation screening showed a prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), and a normal fibrinogen level and platelet count. Evaluation of the clotting factors revealed decreased levels of factors II (37%). Factors V, VIII, IX and XI were normal. Lupus anticoagulant (LA) was demonstrated by the Dilute Russell's Viper Venom Test (DRVVT). Immunological work-up was positive for IgG type anticardiolipines antibodies (aCL). Successful management consisted first of oral prednisone (60mg/d). Thus, anticoagulation was introduced once factor II had stabilized.

Prozone Effect in the Diagnosis of Lupus Anticoagulant for the Lupus Anticoagulant-Hypoprothrombinemia Syndrome

OBJECTIVES

The main clinical sequela of a lupus anticoagulant is increased thrombosis risk. However, bleeding due to lupus anticoagulant-hypoprothrombinemia syndrome is a rare but well-described manifestation of antiphospholipid syndrome. The association of acute acquired hypoprothrombinemia is caused by a lupus anticoagulant's specificity to prothrombin, which results in clearance of prothrombin and bleeding due to hypoprothrombinemia (usually <10% of normal). Severe life-threatening bleeding is most frequently reported in children with systemic lupus erythematosus or in healthy children after viral infection. In such cases, steroid therapy is usually effective in controlling the bleeding problems and improving prothrombin levels.

METHODS

We report one pediatric patient with a lupus anticoagulant who had acute hemorrhagic diathesis.

RESULTS

The diagnosis in this case was complicated by the presence of a prozone effect in lupus anticoagulant testing. The prozone effect (also known as hook effect) refers to situations where very high concentrations of antibody mask detection, typically in antigen-antibody reactions, which depend on visualization of agglutination. Decreasing the antibody/antigen ratio results in detectable antigen-antibody complexes.

CONCLUSIONS

We report for the first time a variation on this theme in a patient with a lupus anticoagulant-type antiphospholipid antibody and hypoprothrombinemia, which corrected with immunosuppression and restoration of normal prothrombin levels.

[A Case of Lupus Anticoagulant-Hypoprothrombinemia Syndrome with Phosphatidylserine-Dependent Anti-Prothrombin Antibody]

Lupus anticoagulant-hypothrombinemia syndrome (LAHS) is a rare disease involving hemorrhagic diathe- sis due to hypothrombinemia with lupus anticoagulant. We report a 28-week-pregnant woman at twenty years of age, who had been hospitalized with jaundice. In laboratory data, AST, ALT, and bilirubin were elevated and the prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged. Although the liver failure was improved after she delivered a baby by Caesarean section, postoperative intraperitoneal bleeding persisted. The diagnosis by liver biopsy was autoimmune hepatitis. Although the bleeding was stopped on the seventh postoperative day, the prolongation of PT and APTT remained. LA was positive in the diluted Russell's viper venom time. Anti-cardiolipin and anti-beta-2-glycoprotein anti- bodies were also positive. The prothrombin activity was reduced. A high titer of phosphatidylserine- dependent antiprothrombin antibody (aPS/PT), which causes bleeding, was observed. Based on these data, she was diagnosed with LAHS. The liver dysfunction and prolongation of PT and APTT were normalized following the administration of corticosteroids. In this case, aPS/PT may have contributed to the pathological physiology of LAHS. [Case Report].

[Pathogenesis and Laboratory Findings in Antiphospholipid Syndrome, Especially Associated with Lupus Anticoagulant]

Antiphospholipid syndrome (APS), an acquired thrombotic condition, is a complex clinical state characterized by the presence of circulating antiphospholipid antibodies in patients with thrombosis or pregnancy morbidity. Revised APS classification criteria are used for diagnosis, which include at least one clinical criterion (thrombosis or pregnancy loss) and at least one of the laboratory criteria [anticardiolipin antibodies, anti-β2GPI antibodies, lupus anticoagulant (LA)]. LA is also an independent risk factor for developing thrombosis, though some LA-positive cases have been reported to have a bleeding symptom. Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare disorder characterized by a bleeding tendency due to low prothrombin activity in patients with LA, and has recently been reported not only in children but also in adults We have encountered LA cases with bleeding and low coagulation factor activities except for prothrombin. Based on our findings, we propose that LA-positive cases with a bleeding symptom and characterized by low coagulation factor activity including prothrombin be termed lupus anticoagulant-associated coagulopathy (LAAC). Furthermore, coagulation factor autoantibodies are often detected in LAAC patients; thus, correct measurement of LA is important to distinguish LAAC patients from those possessing an inhibitor to coagulation factors such as acquired hemophilia A as well as to select the optimal therapeutic strategy.

Role of prophylactic vitamin K in preventing antibiotic induced hypoprothrombinemia

OBJECTIVE

To determine prophylactic role of single dose of vitamin K in prevention of antibiotic induced hypoprothrombinemia.

METHODS

This prospective comparative study included critically ill children in age group 2 mo to 12 y, admitted to a tertiary care hospital in India, likely to receive prolonged antibiotic therapy. One hundred twenty children, 60 in each group (A & B) were enrolled in the study. Patient allocation was done on alternate basis. Group A children received prophylactic vitamin K while group B did not. Baseline coagulation studies and other investigations were done in all children. Coagulation studies were repeated on day 10 and day 14 of antibiotic therapy and in between if required clinically. Children who developed deranged INR were given therapeutic vitamin K. If deranged INR returns to normal at 12 h of vitamin K administration then it indirectly confirms vitamin K deficiency. Analysis was done by fisher's t test and chi square test.

RESULTS

In children on prolonged antibiotic therapy, vitamin K deficiency was a common problem (15%). It was common in male sex, severe grade of protein energy malnutrition (PEM), N-methylthiotetrazole (NMTT) group containing antibiotics use and duration of antibiotic more than 10 d. It was same in children whether they received or did not receive prophylactic vitamin K on day 1 of antibiotic therapy (95% CI; p value 0.79).

CONCLUSIONS

Vitamin K deficiency is common problem in patients on prolonged antibiotic therapy. There is no role of single dose of prophylactic vitamin K in preventing antibiotic induced hypoprothrombinemia.

Lupus anticoagulant-hypoprothrombinemia syndrome: report of 8 cases and review of the literature

The lupus anticoagulant-hypoprothrombinemia syndrome (LAHS)--the association of acquired factor II deficiency and lupus anticoagulant--is a rare disease drastically different from antiphospholipid syndrome in that it may cause predisposition not only to thrombosis but also to severe bleeding. We performed a retrospective study of 8 patients with LAHS referred to 6 French tertiary care centers between January 2003 and February 2011, and a literature review retrieving all related articles published between 1960 and April 2011. Including our 8 new cases, LAHS has been reported in 74 cases. The disease mostly occurs in young adults, with a female to male sex ratio of 1.4. Associated conditions mostly include autoimmune diseases such as systemic lupus erythematosus and infectious diseases. Bleeding is a frequent feature (89% of cases), while arterial and/or venous thrombosis is less common (13%). Factor II level is severely decreased at diagnosis (median value, 11%; range, 1%-40%). LAHS associated with autoimmune diseases is more persistent than LAHS associated with infection, and hemorrhagic complications are more common. Corticosteroids should be considered the first-line treatment, but the thrombotic risk strongly increases during treatment because of the improvement of factor II level. Despite the fact that 50% of patients develop severe bleeding, the mortality rate is <5%, after a median follow-up of 13 months (range, 0.5-252 mo). LAHS associated with autoimmune diseases should be diagnosed and managed carefully because the disease is persistent and severe hemorrhagic complications are common.

[Lupus anticoagulant-hypoprothrombinemia syndrome with a false-positive test for coagulation factor inhibitors]

We report a case of a 1-year-old boy diagnosed with lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS), which is a rare disorder. His initial presentation of sinusitis was accompanied by hemorrhagic episodes including ecchymoses and epistaxis 6 months after antibiotic therapy. Laboratory results revealed prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT) that did not correct with mixing studies. Factors II, VIII, IX, X, XI, and XII activities were 20%, 44%, 42.5%, 59%, 4%, and 10%, respectively. The Bethesda inhibitor assay showed inhibitors against multiple coagulation factor. APTT, mixing studies, diluted Russell's viper venom time, and the Bethesda inhibitor assay detected LA. LA-HPS with a suspected false-positive test for coagulation factor inhibitors was diagnosed. Bleeding stopped and results of coagulation studies returned to normal without therapy 2 months after onset of the disease.

Congenital combined deficiency of coagulation factors VII and II in a young adult

We present herein a case of a young female with congenital combined coagulation factor VII (FVII) and factor II (FII) deficiencies. She was completely asymptomatic and found to have a prolonged prothrombin time during a routine preoperative evaluation. Low levels of plasma FVII and FII in the absence of an inhibitor confirmed the diagnosis in our patient. Congenital combined FVII and FIX deficiency as well as combined FVII and FX deficiency have been previously reported. The congenital combined deficiency of FVII and FII in our patient is exceptional and represents the first such instance in the English literature. Furthermore, we hypothesize that she had not shown any bleeding manifestations because of possible compensation for the missing factors II and VII by enhanced activity of some intrinsic coagulation pathway components or depression of fibrinolysis.

The clinical significance of the lack of arterial or venous thrombosis in patients with congenital prothrombin or FX deficiency

Several reports have dealt with the occurrence of both arterial and venous thrombosis in patients with haemophilia A, haemophilia B, and von Willebrand disease. Similar thrombotic events have been occasionally reported also in rare congenital coagulation disorders, particularly in fibrinogen or FVII deficiencies. On the contrary no sure venous or arterial thrombotic event has ever been reported in congenital prothrombin or Factor X deficiency. The significance of this observation is discussed. This discrepancy cannot be explained on the basis of the rarity of the two conditions, since in similarly rare congenital bleeding disorders such as FV or FXIII deficiency a few patients with thrombosis have been described. It appears that only these two defects are able to allow a sure protection from thrombosis. These observations may indirectly support the rationale for the use of direct thrombin or Factor X inhibitors in the prophylaxis and/or therapy of thrombotic manifestations.

The laboratory approach to inherited and acquired coagulation factor deficiencies

Besides the long-recognized hemophilias, there are many other factor deficiencies. Some also are inherited, but others are acquired because of both immune and nonimmune etiologies. Understanding the optimal laboratory approach to evaluating factor deficiency will aid physicians and laboratory scientists in obtaining a prompt diagnosis and in avoiding pitfalls in coagulation testing.

Hereditary prothrombin deficiency

Hereditary prothrombin deficiency is one of the rare congenital coagulation defects. We report a case of 4 months old child who initially presented at 11/2 month of age with high-grade fever, generalized convulsions and brownish aspirate through nasogastric tube, diagnosed and managed as meningitis and sepsis. He was readmitted at 4 months of age with bruises over legs. Coagulation profile was suggestive of common pathway defect. Further evaluation revealed absent prothrombin level while other factors were within normal limits.

Lupus anticoagulant-hypoprothrombinemia in healthy adult

The presence of lupus anticoagulant is associated with an elevated risk of venous and arterial thrombosis, and recurrent miscarriages as well. For some cases, this disease can present with bleeding as a consequence of lupus anticoagulant hypoprothrombinemia (LAHPS). LAHPS is a rare disease and it is reported to be most frequent in young females with/without systemic lupus erythematosus or in healthy children who are suffering with a viral infection. In such cases, steroid therapy is usually effective in normalizing the biological abnormalities and controlling the bleeding problems. A 34-year-old previously healthy man was admitted to our department because of his prolonged coagulation times; these abnormalities were discovered before performing orthopedic surgery. The prothrombin time (PT) was 15.2 sec, and the activated partial thromboplastin time (APTT) was 37.7 sec. A 1:1 dilution of patient plasma with normal plasma nearly corrected the PT, but this failed to correct the APTT. Evaluation of the clotting factors revealed decreased levels of factors II, V, VIII, IX and XI. The presence of LA was demonstrated by the dRVVT test, and the patient was diagnosed with LAHPS. He was successfully treated with corticosteroid before performing the orthopedic surgery.

Thromboembolism complicating the treatment of lupus anticoagulant hypoprothrombinemia syndrome

Lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) is a rare disorder characterized by a bleeding tendency due to factor II deficiency associated with the presence of lupus anticoagulant (LAC) autoantibodies. We describe a patient with systemic lupus erythematosus and LAHPS in whom successful treatment of central nervous system bleeding due to severe factor II deficiency was followed by a major thromboembolic complication. Literature review revealed 2 other patients with LAHPS who developed thrombosis resulting from the treatment of factor II deficiency. We suggest that factor II deficiency counterbalances the prothrombotic effect of LAC in LAHPS, and correcting this deficiency may promote thromboembolism.

Prothrombin Suresnes: a case of homozygous F299V mutation responsible for hypodysprothrombinemia

A patient with a severe prothrombin deficiency and a hemorrhagic diathesis was found to have positive cross-reactive material in plasma and a homozygous F299V mutation (F7V in the A chain). This mutation reinforces the previous conclusion that the A chain affects the geometry of the catalytic triad. Marked prolongation of the Taipan venom and Russell venom clotting times also demonstrated a defective activation mechanism and a defective interaction with factor Xa.

Severe INR Elevation in a Patient??with??Choledocholithiasis Receiving Cefoperazone

Cefoperazone is a third-generation cefalosporin that contains the N-methyl- thio-tetrazole (NMTT) side chain, which inhibits vitamin K-dependent carboxylation. Administration of NMTT-containing cefalosporins can cause alterations in the hepatic glutathione redox state, resulting in a dose-related increase in oxidised glutathione, which is responsible for the inhibition of microsomal reduction of vitamin K epoxide. In addition, cefoperazone is not metabolised and is excreted predominantly through the bile. In patients with hepatic impairment, the clearance of cefoperazone has been shown to be significantly reduced and the half-life prolonged. We report a case of choledocholithiasis related to a prolonged prothrombin time and INR secondary to cefoperazone therapy.

Perinatal stroke--risk factors and management

Stroke is an uncommon but increasingly recognised cause of mortality and long-term neurological morbidity in children. A significant number of these events appear to be caused by thromboembolic disease and, as with other childhood thrombotic problems, the incidence of central nervous system events appears highest during the neonatal period. In contrast to peripheral arterial and venous thrombotic problems, it is likely that a proportion of cerebral thromboembolic events occur either in utero or perinatally and reflect different risk factors from those occurring in older infants and children. The pathophysiology of perinatal stroke is complex and in many cases is likely to be multifactorial. It is now recognised that risk factors may relate to both maternal and placental problems as well as fetal and neonatal disorders. Large prospective studies of perinatal stroke are currently lacking and efforts to define the relative contribution from each of these areas are at an early stage. The complex nature of these disorders requires collaboration between a number of different disciplines including obstetrics, fetal medicine, pathology, neonatology and neurology. Of particular interest to haematologists is the possible impact of prothrombotic abnormalities in the pathophysiology of these events and also the potential for the use of antithrombotic agents in both management and prevention.

[Pulmonary hemorrhage and anti-phospholipid syndrome]

The presence of anti-phospholipid antibodies (anticardiolipin antibodies and lupus anticoagulant) associated to venous and/or arterial thrombotic phenomena and fetal losses define the anti-phospholipid syndrome. On rare occasions severe hypoprothrombinemia associated with this disease as a cause of hemorrhagic manifestations has been described. In addition very few cases of alveolar hemorrhage in anti-phospolipid syndrome (APS) have been described, being this complication usually related to microthrombosis and/or capillaritis of pulmonary vessels. We describe two patients without previous clinical manifestations of anti-phospholipid syndrome that showed pulmonary hemorrhage with anticardiolipin antibodies positivity. The first of them, a 33-year-old male, began his disease with low prothrombin time and the presence of antiprothrombin antibodies. In the biopsy by thoracoscopy the presence of pulmonary hemorrhage without capillaritis nor thrombotic phenomena was demonstrated, becoming evident certain clinical improvement and normalization of the prothrombin time after receiving immunosuppressive treatment but with persistence of the pulmonary hemorrhage 5 years later. The second case, a 89-year-old male, began his condition with bilateral lung infiltrates and hemoptysis, anticardiolipin antibodies positivity, and thrombopenia, with recurrence of the condition 1 year later. After other etiological possibilities were ruled out, and despite hemorrhagic trait in both patients, we consider that they should be in the clinical context of the anti-phospholipid syndrome, although at this time they did not meet the criteria recognized in order to diagnose this disease. Within the ampliable clinical spectrum of the anti-phospholipid syndrome we should take into account the pulmonary hemorrhage.

The rare coagulation disorders - review with guidelines for management from the United Kingdom Haemophilia Centre Doctors' Organisation

The rare coagulation disorders are heritable abnormalities of haemostasis that may present significant difficulties in diagnosis and management. This review summarizes the current literature for disorders of fibrinogen, and deficiencies of prothrombin, factor V, FV + VIII, FVII, FX, the combined vitamin K-dependent factors, FXI and FXIII. Based on both collective clinical experience and the literature, guidelines for management of bleeding complications are suggested with specific advice for surgery, spontaneous bleeding, management of pregnancy and the neonate. We have chosen to include a section on Ehlers-Danlos Syndrome because haematologists may be consulted about bleeding manifestations in such patients.

Acquired bleeding disorder in a patient with malignant lymphoma: antibody-mediated prothrombin deficiency

BACKGROUND

Bleeding manifestations secondary to acquired hemostatic abnormalities in cancer patients have been well described. Bleeding due to the development of hemostatic inhibitors is observed less frequently. In this report, the authors describe a patient with a low grade lymphoma who presented with an acquired bleeding disorder and abnormal hemostatic screening tests.

METHODS

Patient plasma samples were collected initially and during the course of treatment. Mixing studies and specific coagulation factor assays were performed to detect and confirm any deficiencies. Patient immunoglobulin G was isolated from plasma, and binding to prothrombin was demonstrated by immunoblot method and enzyme-linked immunosorbent assay (ELISA) techniques.

RESULTS

Initial prolongations in the prothombin time and the activated partial thromboplastin time suggested a factor deficiency in the common pathway of coagulation. Factor assays confirmed that the coagulation abnormality in this patient was the result of an acquired prothrombin (factor II) deficiency. This was confirmed by an immunoassay for prothrombin antigen. Further studies demonstrated the presence of a noninhibitory antibody to prothrombin that interacted with a calcium dependent epitope.

CONCLUSIONS

Successful treatment of the lymphoma resulted in clearance of the antibody and complete correction of all hemostatic abnormalities and manifestations. An acquired prothrombin deficiency has not been reported previously in association with a malignancy, and this patient represents the first such documented case.

Prothrombotic disorders and ischemic stroke in children

Childhood ischemic stroke, including arterial ischemic stroke (AIS) and sinovenous thrombosis (SVT), is relatively rare in children but can result in devastating morbidity and mortality. An understanding of the etiology of childhood stroke is important because strategies for primary and secondary prevention can be devised. Prothrombotic disorders may contribute to the etiology of childhood stroke, and include deficiencies of antithrombin, protein C, protein S, plasminogen, and presence of Factor V Leiden, Prothrombin gene G20210A, dysfibrinogenemia, antiphospholipid antibodies, hyperhomocysteinemia, and elevated lipoprotein (a). The overall incidence of prothrombotic disorders in childhood AIS is estimated to be 20% to 50% in most studies and, in childhood SVT, to be 33% to 99%. In addition, hyperlipidemia, polycythemia, iron deficiency anemia, and platelet disorders may result in a prothrombotic state associated with ischemic stroke. The etiologic contribution of these prothrombotic disorders to initial and recurrent stroke has not been clearly defined; however, additional risk factors are usually present in affected children. Given the prevalence of prothrombotic disorders in childhood stroke, and their likely causative role, children with stroke should be screened for prothrombotic disorders. Future prospective and multicenter studies will elucidate the contribution of specific prothrombotic disorders to initial and recurrent stroke, and optimal therapy.

Hereditary prothrombin deficiency presenting as intracranial haematoma in infancy

Hereditary deficiency of prothrombin is a rare autosomal recessive bleeding disorder, with severe bleeding diathesis in homozygotes, but rarely resulting in intracranial haematoma. We describe two infants of consanguineous parents, presenting with acute subdural haematoma. Because such haematomas in infancy are highly indicative of trauma caused by child battering and because the socio-economic status of the family was unstable, there was a suspicion of child battering. However, further investigations revealed a bleeding diathesis due to a prothrombin deficiency. DNA analysis of the prothrombin gene showed homozygosity for a novel mutation, substituting Lys for Glu at codon 7 and resulting in decreased specific clotting activity. We discuss the probability of bleeding diathesis versus child battering in the aetiology of intracranial haematoma.

[Use of hypoprothrombinemia provocation test for early diagnosis of liver disease caused by harmful environmental agents]

The aim of this work has been to assess the feasibility of using Prothrombin Time (PT) Assay before and after administration of Pelentan (Hypoprothrombinemia Provocation (HPP) Test) for early detection of subclinical toxic hepatic injuries. The proposed modification of PT Assay is based on the observation that people with slight hepatic injury receiving small doses of Pelentan (diethylcoumarol) display remarkably longer PT than healthy people receiving similar doses of the chemical. The test group comprised 37 people occupationally exposed to hepatotoxic agents, 85 males permanently abusing alcohol, while 24 clinically healthy people, not exposed occupationally to the toxic agents served as the control. In addition, 26 hepatitis B and/or C virus carriers were also examined. The results show that: 1. HPP test enables assessment of hepatic function in patients with suspected hepatic injury and in people permanently abusing alcohol; 2. low value of serum prothrombin index 24 h and 48 h after the administration of Pelentan is indicative of the positive result of the test; 3. HPP test provides more information on the functional condition of liver than single PT determination by the Quick assay.

Optimization of prothrombin time measurements in canine plasma

OBJECTIVE

To optimize a prothrombin time (PT) method designed for human plasma for use with canine plasma.

SAMPLE POPULATION

100 plasma samples from healthy dogs and 50 plasma samples with reduced activity of the single factors II, V, VII or X.

PROCEDURE

Canine plasma samples with various coagulation activity values (100, 75, 50, 25 and 10%: prepared by dilution from a plasma pool [n = 100]) were assayed at various sample dilutions and dilutions of the thromboplastin component of 3 commercial calcium thromboplastin reagents. The sc-named optimized PT test was compared with the standard test with respect to its sensitivity and correlation with the sum of the activity decreases of single factors II, V, VII, and X in relation to the respective reference range.

RESULTS

The time intervals between various coagulation activity values, which were small by use of the standard test, could be increased by diluting the sample and substituting fibrinogen, but not by diluting the tissue thromboplastin component of PT reagent. On the basis of 50 abnormal plasma samples, the optimized test had high sensitivity (0.90 to 1.00, dependent on reagent and sample dilution) in contrast to the standard test, which had low sensitivity (0.24 to 0.58, dependent on reagent). Also, correlation with the sum of the activity decreases was closer by use of the optimized (0.90 to 0.93) than the standard (0.58 to 0.84) test.

CONCLUSIONS

In contrast to the standard test, an optimized test is suitable as a sensitive screening test of the extrinsic coagulation system in dogs.

CLINICAL RELEVANCE

The optimized PT method is easy to perform and, therefore, should be in general use for assay of canine plasma.

Low antithrombin III levels in neonates with idiopathic respiratory distress syndrome: poor prognosis

Automated microanalytic chromogenic coagulation assays allow serial monitoring of critically ill newborn infants. In this study 84 premature infants [26 healthy prematures and 58 neonates with idiopathic respiratory distress syndrome (IRDS)] were studied daily during the first week of life, to investigate the possible significance of hemostatic abnormalities in IRDS. In neonates with IRDS, coagulation factors II and X, antithrombin III (AT-III), plasminogen, and alpha 2-antiplasmin were significantly lower than control values. Recovery of the initially low AT-III levels was delayed relative to the other coagulation parameters measured. An AT-III less than or equal to 0.15 U/ml was present within the first 6 h of life in eight patients who developed IRDS, seven of whom died within 48 h. Autopsy of these neonates showed widespread fibrin deposition and hemorrhage in vital organs consistent with intravascular coagulation. These findings indicate that very low levels of AT-III are associated with disseminated intravascular coagulation in neonates with IRDS and suggest that a deficiency of AT-III is predictive of a poor outcome.

Chromogenic substrate (S-2238) prothrombin assay in prothrombin deficiencies and abnormalities. Lack of identity with clotting assays in congenital dysprothrombinemias

Prothrombin was assayed using chromogenic substrate of S-2238 for patients who were being treated with coumarin, for patients who had liver disease, and for patients who had congenital hypoprothrombinemias and dysprothrombinemias. In coumarin therapy and in patients with liver disease the levels found correlated well with the one-stage clotting methods. The same was true for heterozygous and homozygous "true" prothrombin deficiency. In the case of congenital dysprothrombinemias the levels observed with the chromogenic substrate were higher than the clotting counterparts, particularly so in the case of prothrombin Padua. In the latter case the levels observed were always about 100% of normal, as compared with the levels of about 50% of normal found with clotting methods. These data indicate that chromogenic substrates are not always equivalent to "clotting" substrates, namely, that amidolytic activity is not always equivalent to clotting activity. Therefore the two methods cannot be used interchangeably, lest some defects escape detection.