Síndrome de anticoagulante lúpico-hipoprotrombinemia: una extraña asociación en el lupus eritematoso sistémico / Lupus anticoagulant-hypoprothrombinemia syndrome: A rare association in systemic lupus erythematosus

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Renal failure due to renal vein thrombosis in a fetus with growth restriction and thrombophilia.

We report a case of renal vein thrombosis diagnosed at 27 weeks of gestation in a dichorionic twin pregnancy. The left kidney of one fetus was hyperechoic and enlarged with echoic streaks following the direction of interlobular veins and the loss of corticomedullary differentiation. In the following weeks, left kidney became smaller and echoic, and Doppler examination showed no flow in both artery and vein. The right kidney had totally normal appearance in the beginning, but it became enlarged and hyperechoic, and progressed into a small echoic kidney with no flow in artery and vein. In the postnatal ultrasound examination, both kidneys appeared hyperechoic with no vascularization in the hilum region. There was thrombosis in arteries and veins of both kidneys, as well as in the inferior vena cava. The investigation for thrombophilia resulted with the combined presence of heterozygote mutation in factor V Leiden and prothrombin 20210 genes.

A severe neonatal presentation of factor II deficiency.

Prothrombin deficiency is an autosomal recessive disorder associated with moderate or severe bleeding tendency. In this study, a three-month-old boy with non-consanguineous parents was referred for convulsions because of intracerebral hemorrhage. Standard coagulation tests revealed that the patient's plasma prothrombin activity was 12%, while his father's and mother's levels were 55% and 70%, respectively. Analysis of the prothrombin gene revealed that this patient is a compound heterozygote for two missense mutations: one maternally inherited point mutation in the propeptide (p.Arg4Gln) and one paternally inherited mutation in the kringle-2 (p.Arg220Pro) domain. Structural analysis was performed and confirmed that the resulting mutations were inferred to respectively affect the cleavage of the propeptide from the Gla domain, and the stability of the kringle-2 domain, both resulting in a severe hypoprothrombinemia. In unusually bleeding newborn of non-consanguineous parents, rare severe homozygous bleeding disorders need to be considered to facilitate early diagnosis and treatment.

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.

Abnormalities of prothrombin: a review of the pathophysiology, diagnosis, and treatment.

Prothrombin (factor II) deficiency is a rare autosomal recessive coagulation disorder that occurs in approximately 1 in 1-2 million people. Prothrombin is activated to thrombin, which in turn proteolytically cleaves fibrinogen to fibrin and contributes to forming a stable fibrin clot. The haemostatic level of prothrombin is thought to be between 20 and 40%, and the half-life is approximately 3 days. There are more than 40 known mutations in prothrombin. Both hypoprothrombinemia and dysprothrombinemia have been described. Low prothrombin activity typically prolongs both the activated partial thromboplastin time and prothrombin time. Clinical manifestations are predominantly mucosal or surgical- or trauma-associated bleeding, but joint bleeding and intracranial haemorrhages have been reported. No purified prothrombin products are available for replacement therapy. Both fresh frozen plasma and prothrombin complex concentrates contain prothrombin and may be used for treatment.

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.

Prospective surveillance of antibiotic-associated coagulopathy in 970 patients.

N-methyl-thio-tetrazole (NMTT) has been proposed as a causative factor in antibiotic-associated coagulopathy. To evaluate this hypothesis, a nationwide surveillance program was initiated to determine the relative frequency of antibiotic-associated coagulopathy and the importance of specific risk factors. A total of 970 patients were studied, with 491 being treated for infections and 479 receiving antimicrobial surgical prophylaxis. The NMTT-containing antibiotic cefotetan was compared with non-NMTT-containing antibiotics, for example, cefoxitin and cefazolin (prophylaxis only), and an aminoglycoside-antianaerobic (AG + AA) combination. Prothrombin time (PT) and partial thromboplastin time (PTT) were measured for each patient prior to the start of antibiotics and within 24-96 hours after the conclusion of drug administration. The patient population was relatively young [mean (SD) age 51.0 (20) yrs] with good nutritional status. The overall frequency of hypoprothrombinemia (4.5%) and bleeding (1.7%) was very low, and was highest with the use of AG + AA (p less than 0.05). No statistical differences were observed for the remaining antibiotic regimens in either the prophylaxis or treatment group. Logistic regression analysis identified treatment with the AG + AA combination, presence of liver disease, and renal dysfunction as factors associated with an increased risk of hypoprothrombinemia. In conclusion, this study suggests that the frequency of antibiotic-associated coagulopathy is low, regardless of antibiotic, in patients who are not critically ill and not malnourished.

Hypoprothrombinemia in the compensated form of hepatosplenic schistosomiasis: further studies

Alteraçöes na coagulaçäo säo frequentemente observadas em portadores da esquistossomose, mas sua fisiopatologia aidna näo foi estabelecida. Medimos, por imunodifusäo, a concentraçäo da protrombina-antígeno em 56 indivíduos: 19 com a forma compensada da esquistossomose hepatoesplênica 17 com cirrose e 20 sadios. Foram também determinadas transaminases, albumina, transtiretina, tempo de protrombina, antitrombina III, fator VII e fibrinogênio. As médias de todos os parâmetros estavam alteradas no grupo cirrótico mas apenas as de albumina, protrombina e antitrombina III no grupo esquistossomótico. Noventa por cento dos portadores de cirrose e 60% dos portadores de esquistossomose tinham níveis plasmáticos diminuídos de albumina, transtiretina, protrombina e/ou antitrombina III; síntese hepática diminuída pode explicar estes resultados. Por outro lado, em 40% dos portadores de esquistossomose com concentraçöes plasmáticas de albumina e transtiretina normais as concentraçöes médias de protrombina e antitrombina III estavam diminuídas. Estes resultados sugerem que a protrombina e antitrombina III säo marcadores mais sensíveis de síntese hepática do que o conjunto albumina/transtiretina ou que um consumo crônico das proteínas da coagulaçäo ocorra. Considerando esta última possibilidade é possível supor-se que a trombina formada seja inibida pela antitrombina III e o complexo trombina-antitrombina III depurado pelo fígado. Consequentemente os níveis plasmáticos de protrombina e antitrombina III diminuem mas o do fibrinogênio é preservado

Factor X Roma: a congenital factor X variant defective at different degrees in the intrinsic and the extrinsic activation.

A factor X molecular variant was identified in a 13-year-old girl affected by a bleeding tendency. Factor X antigen levels and activation by Russel's viper venom (tested both by clotting and amidolytic assays) were normal. Factor X crossed immunoelectrophoresis was found to be identical to that of the control plasma. Factor X functional activity was low (3% of the normal) if tested by PTT-derived assays, whereas it was found at intermediate levels (about 30-50% of the normal) if measured by prothrombin time-derived assays. The defect in the extrinsic activation was more clearly disclosed using as activating agent thromboplastin from ox brain. The factor X of the patient was completely adsorbed by aluminum hydroxide. The parents of the propositus (first degree cousins) showed factor X functional levels compatible with a condition of heterozygosity for the abnormality. This factor X molecular variant appears different from the other ones so far described and was named 'Factor X Roma'.

Mechanism of thioamide antithyroid drug associated hypoprothrombinemia.

The thioamide class of antithyroid drugs has been associated with the development of hypoprothrombinemia. Two drugs in this class, propylthiouracil and methimazole, resemble the methyltetrazole-thiol leaving group of certain cephalosporin antibiotics. Both were found in vitro to inhibit the vitamin K dependent step in clotting factor synthesis, the gamma-carboxylation of glutamic acid with 50 per cent inhibitory concentrations of 2 mM for propylthiouracil and 0.1 mM for methimazole. Methimazole was also found to inhibit vitamin K epoxide reductase, an enzyme related to the carboxylation reaction, with a 50 per cent inhibitory concentration of 25 uM. In vivo methimazole, administered twice at a dose of 500 mg/kg to rats on a vitamin K deficient diet produced hypoprothrombinemia. These results suggest that the mechanism of hypoprothrombinemia associated with thioamide antithyroid drugs may be similar to the mechanism of hypoprothrombinemia associated with cephalosporins which contain the methyltetrazole-thiol leaving group.

Coagulopoietin activity in rat plasma: influence of degree of hypoprothrombinemia and reproducibility of the response.

Injection of plasma from a vitamin K-deficient hypoprothrombinemic rat into a normal rat causes an increase in plasma prothrombin activity in the recipient rat. Maximum concentrations of the factor responsible for this response (coagulopoietin) are present in the plasma of rats fed a vitamin K-deficient diet for 7 days and do not increase as the period of deficiency is increased. The coagulopoietin activity of plasma from individual rats is variable, but similar activity was observed when multiple recipient rats received the same donor plasma.

Inherited factor X deficiency: presentation of a case with etiologic and treatment considerations.

The first documented case of inherited factor X deficiency in the dental literature is presented. Its ascertainment as a result of postoperative surgical complications illustrates the clinician's need to be familiar with the hereditary bleeding diatheses, as treatment is dependent on the underlying etiology of the specific disorder. In the present case treatment included administration of the antifibrinolytic agent epsilon-aminocaproic acid (EACA) and fresh frozen plasma. On the basis of our findings, a minimal therapeutic level of circulating factor X is estimated to be 15 percent of the normal level. Genetic heterogeneity within the factor X deficiency phenotype is discussed and, on the basis of laboratory findings, a CRM-positive autosomal recessive structural or regulator gene defect is proposed as the etiologic factor in the current case. Forty-nine cases in the literature are reviewed to delineate the pattern of bleeding in hereditary factor X deficiency.

Induction of hepatic enzymes by methaqualone and effect on warfarin-induced hypoprothrombinemia.

The effect of methaqualone on the induction of hepatic enzymes was evaluated in rats and compared with that of phenobarbital by measuring effects on hexobarbital and methaqualone hypnosis, plasma and tissue levels of methaqualone, hepatic aniline hydroxylase and aminopyrine demethylase activity and warfarin-induced hypoprothrombinemia. Maximal reductions in hexobarbital hypnosis occurred 3 days after daily administration of 60 mg of methaqualone per kg per day. At this time, the activities of aniline hydroxylase and aminopyrine demethylase were increased 60 and 139%, respectively, and hepatic microsomal proteins increased 15% above controls in methaqualone-pretreated animals. Methaqualone altered its own metabolism as demonstrated by a 48% reduction in methaqualone hypnosis in pretreated animals. The extent and duration of induction by phenobarbital was considerably greater than methaqualone in all experiments. Methaqualone pretreatment did not affect warfarin-induced hypoprothrombinemia, whereas phenobarbital-pretreated animals showed a 32 to 64% reduction in response to the anticoagulant. These studies indicate that methaqualone is a relatively weak inducer of hepatic drug-metabolizing enzymes and has no effect on the anticoagulant acitivty of warfarin.