Serum ferritin levels in children with dengue infection.

The purpose of this study was to evaluate the levels of ferritin, an acute-phase reactant, in predicting the risk of dengue hemorrhagic fever (DHF) in patients with dengue infection. One hundred seventy-seven Thai children (100 males, 77 females) 4-16 years old (median age 11 years) with DF (n = 44) and DHF (n = 133) were enrolled in the study. All patients had serologic confirmation of dengue infection. Each had a venous blood sample drawn daily during hospitalization and at the outpatient clinic 2-4 weeks after discharge from the hospital, to determine serum ferritin levels. The median serum ferritin levels (ng/ml) in children with DHF (Day 2, 974; Day 3, 624; Day 4, 1,136; Day 5, 1,912; Day 6, 2, 105; Day 7, 1,840; Day 8, 1,478 and Day 9, 1,144 of illness) were higher than those with DF (Day 2, 25.4; Day 3, 45.6; Day 4, 655; Day 5, 1,050; Day 6, 1,075; Day 7, 615; Day 8, 764 and Day 9, 600 of illness) with p-values of 0.013, 0.001 and 0.013 on Days 5, 6 and 7 of illness, respectively. A cutoff level of serum ferritin of 1,200 ng/ml was used to calculate sensitivity and specificity for DHF. The results reveal the sensitivities on Days 5, 6 and 7 of illness were 81.5, 84.4 and 89.9%, respectively, and the specificities were 42.4, 39.0 and 36.4%, respectively. High serum ferritin levels > or = 1,200 ng/ml may be a predictor of dengue hemorrhagic fever.

Fisiopatología y tratamiento de la Fiebre Hemorrágica del Dengue / Pathophysiology and management of dengue hemorrhagic fever

La infección por dengue es causada por uno de los cuatro serotipos del virus. Las manifestaciones clínicas varían de infección asintomática a fiebre no diferenciada, fiebre del dengue y fiebre hemorrágica del dengue (FHD). La FHD se caracteriza por la presencia de fiebre elevada constante durante dos a siete días; diátesis hemorrágica, como prueba de torniquete positiva, petequias, epistaxis y hematemesis; trombocitopenia con recuento de plaquetas =< 100 x 10 9/L; y pérdida de plasma debido al aumento de la permeabilidad vascular que se evidencia por hemoconcentración. derrame pleural y ascitis. La diátesis hemorrágica se debe a vasculopatía, trombocitopenia. disfunción plaquetaria y coagulopatía. Las tres etapas de la presentación clínica se denominan febril, tóxica y de convalecencia. La etapa tóxica, que dura entre 24 y 48 horas, es el período más crítico en el que se produce una rápida pérdida de plasma, que ocasiona trastornos circulatorios. La gravedad de la FHD varía de manifestaciones leves (grados I y II, según la Organización Mundial de la Salud OMS), con cambios mínimos y temporarios de los signos vitales, a episodios graves (grados III y IV, según la OMS), con choque inminente (por ejemplo, con presión sanguínea de 100/90 mmHg) o choque profundo. No existe ningún tratamiento específico para la FHD. Los tratamientos complementarios intensivos son el aspecto más importante para el control de la infección. Es fundamental detectar la enfermedad en una primera instancia y controlar atentamente los trastornos circulatorios. El tratamiento óptimo con fluido para mantener la función de los órganos vitales durante el período crítico y el control eficaz de los episodios hemorrágicos permiten obtener resultados favorables. Se recomienda el suministro de factor VII recombinante activado en los casos en que la hemorragia masiva no pueda controlarse mediante la restitución de hemocomponentes.

Characterization of atypical lymphocytes and immunophenotypes of lymphocytes in patients with dengue virus infection.

To characterize the immunophenotypes of lymphocytes in patients with dengue infection, we performed flow cytometric analysis of peripheral blood mononuclear cells collected from 49 dengue hemorrhagic fever (DHF), 25 dengue fever (DF), and 26 dengue-like syndrome (DLS) cases. The mean total atypical lymphocytes in DHF (916.1 +/- 685.6 cells/microl) and DF (876.2 +/- 801.9 cells/microl) were higher than those of DLS (310.5 +/- 181.4 cells/microl). An atypical lymphocyte count of 10% or higher was a good indicator of dengue infection (sensitivity 50% and specificity 86%). Flow cytometric studies showed that the percentages of atypical lymphocytes correlated with those of CD19+ B lymphocytes and inversely correlated with the percentages of CD69+ lymphocytes. The mean absolute counts of atypical lymphocytes and CD19+ cells on the discharge day were significantly higher than those on the admission day. Low percentages of TdT+ cells were found in all groups of patients. We concluded that atypical lymphocyte and CD19+ cell counts may be a useful diagnostic tool for dengue infection and the recovery from the disease could be judged when numbers of both cell types are significantly elevated.

Absence of factor V Arg306--Thr and low factor V Arg306->Gly mutation prevalence in Thai blood donors.

Thrombosis among the Thai population is much lower than in western countries. The Thai population is protected to some extent against familial thrombophilia as by the very low prevalence of factor V Leiden, G20210A prothrombin and C677T methylenetetrahydrofolate reductase mutations. The present study reports the prevalence of two mutations of the factor V gene involving the codon for Arg 306 among 500 healthy adult voluntary blood donors (males 285, females 215) and 30 children (boys 20, girls 10) experiencing a total of 36 thrombotic episodes. The blood donors' ages ranged from 18 to 60 years while the children's ages ranged from 9 months to 15 years. The allelic frequencies of the factor V gene mutation of G1091C and A1090G among blood donors were 0% and 0.4%, respectively. Additionally, both mutations were not present in any of the 30 children with thrombosis. The low prevalence of factor V gene mutations in the codon Arg 306 may be relevant to the low rate of thrombosis among the Thai population.

National survey of patients with hemophilia and other congenital bleeding disorders in Thailand.

A national survey of patients with hemophilia and other congenital bleeding disorders in Thailand was conducted in the years 2000 to 2002. Questionnaires were sent to physicians working at hospitals throughout the country. Although the overall response rate to the questionnaires was 19%, the two highest rates of 80% and 73.7% were found at university and regional hospitals, respectively, where most of the patients received their diagnosis and treatment. A total of 1,450 patients comprised of hemophilia 1,325 cases, von Willebrand disease, 69 cases, congenital factor VII deficiency, 15 cases, hereditary platelet dysfunction, 22 cases, and undefined causes of congenital bleeding disorders, 19 cases. Most were pediatric patients <15 years of age. Treatment was mainly given on demand for a bleeding episode, while only 8.6% received additional home treatment for early bleeding episodes. Replacement therapy primarily relied on fresh frozen plasma, cryoprecipitate and cryo-removed plasma. Factor concentrate was seldom used because of the high price. As a result, hemophilia care services in Thailand should be strengthened by providing comprehensive education for medical personnel, making available simple laboratory kits to determine hemophilia A and B, ensuring an adequate supply of blood components and affordable factor concentrate, and establishing home care treatment.

Cost-effectiveness in establishing hemophilia carrier detection and prenatal diagnosis services in a developing country with limited health resources.

The cost-effectiveness of carrier detection and prenatal diagnosis for hemophilia at the International Hemophilia Training Center, Bangkok, Thailand was studied. From 1991 to 2002, 209 females from 124 families with hemophilia A and B were included. There were 180 hemophilia A carriers and 29 hemophilia B carriers which could be classified into 78 obligate and 131 possible carriers. The phenotypic analysis for possible carriers involved the determination of levels of factor VIII or IX clotting activity (FVIII:C, FIX:C) and the ratio of FVIII:C and von Willebrand factor antigen. The result revealed that 49 females (37.4%) were diagnosed as carriers, 65 females (49.6%) were normal and 17 females (13%) were undetermined. Additional genotypic analysis was provided to 46 families with 74 females with obligate, proven or undetermined carriers within the reproductive life. The polymorphisms associated with factor VIII and IX genes were used including Bcl I for the factor VIII gene and combined use of Mse I, Sal I, Nru I, Hha I and Dde I for the factor IX gene. The informative rate was 59.4% (44/74). Consequently, 12 prenatal diagnoses for fetus at risk were performed. Sex determination was initially determined and followed by the diagnosis of hemophilia through informative gene tracking and/or the measurement of fetal levels of FVIII:C or FIX:C. The result revealed that 3 male fetuses were affected. The total cost of carrier detection and prenatal diagnosis that the families had to pay in the government hospital was 238,600 Baht (US dollars 5,965). It was compared to the estimated cost of minimal replacement therapy using lyophilized cryoprecipitate for the survival time of 30 years in one patient with hemophilia of 1,012,500 Baht (US dollars 25,312.5). The cost of prevention was much less than the replacement therapy. In conclusion, it is cost-effective to establish the service for carrier detection and prenatal diagnosis for hemophilia especially in developing countries with limited health resources.

Rapid screening of PNH red cell populations using the gel test.

Paroxysmal nocturnal hemoglobinuria (PNH), an acquired clonal hematopoietic stem cell defect is underdiagnosed because of its atypical symptoms in some patients and because available methods, which are time consuming and complicated, are not widely used. The purpose of this study is to compare the results of the detection of PNH red cell populations using the PNH gel test and the Ham test. Fifty-eight blood samples obtained from 35 patients and 23 healthy blood donors were tested for PNH by the PNH gel test and the Ham test. It was found that 7 (20%) of the patients were positive for PNH by both tests. Twenty-three blood samples from healthy donors were all negative for PNH by both tests. The overall sensitivity and specificity of the gel test were 100%. This study showed that the PNH gel test was simple and could replace the Ham test as a screening test for PNH. This test would be especially easy to introduce in laboratories that are already using this system for blood grouping and antibody detection.

Antineutrophilic cytoplasmic antibody-positive systemic vasculitis associated with propylthiouracil therapy: report of 2 children with Graves' disease.

Systemic vasculitis is a rare complication of therapy with antithyroid medication. Antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis has been described in patients treated with propylthiouracil (PTU) and methimazole (MMI). The majority of cases have underlying Graves' disease. The authors report 2 children who developed ANCA-associated systemic vasculitis during PTU therapy of Graves' disease. One patient, after PTU treatment for 3 years, developed severe systemic vasculitis. After 3 weeks of arthritis, she abruptly presented with hematuria, proteinuria and edema concomitant with anemia. Her serum creatinine was elevated, to 6 mg/dl. Renal biopsy revealed crescentic glomerulonephritis. After admission, she developed intracerebral hemorrhage and pulmonary hemorrhage. She had positive perinuclear-ANCA (p-ANCA) with a titer of 1:160. Despite intensive therapy with immunosuppressive agents and plasmapheresis, as well as discontinuation of PTU, she died of the complications of severe systemic vasculitis. The other patient developed fever, arthralgia and leukocytoclastic vasculitis of the skin during treatment with PTU for about 2 years. Her symptoms and skin lesions disappeared after discontinuation of PTU. However, she has had a persistently high titer of p-ANCA 1:320 through 17 months follow-up time. Thus, patients who are treated with PTU can develop ANCA-positive vasculitis in a mild or severe form. Therefore, they should be carefully followed and monitored, not only for their thyroid status but also the serious complications of PTU.

Outcome of intracranial hemorrhage in infants with congenital factor VII deficiency.

The outcome of 8 episodes of intracranial hemorrhage in 7 patients (4 males, 3 females) with congenital factor VII deficiency was evaluated. Their levels of factor VII clotting activity (FVII:C) were less than 1 per cent (n = 3) and ranged from 1.7 to 2.3 per cent (n = 4). The onset varied from the first week (n = 2), first month (n = 3), and at the ages of 6, 11 and 12 months (n = 3). The replacement therapy of 10 ml/kg of fresh frozen plasma (FFP) every 6-12 hours for 5-7 days was given to 6 patients. Only one craniotomy for the removal of hematoma was performed. The seventh patient experienced two episodes of bleeding. First, she received 20 microg/kg of recombinant factor VIIa (rFVIIa) every 6 hours for 4 days (1,200 microg) followed by FFP in one episode. Second, a craniotomy for the removal of a 7 cm diameter hematoma was performed by giving 20 microg/kg of rFVIIa every 6 hours for 12 days (9,600 microg) followed by FFP in another episode. As a result of these treatments, 2 died and 5 survived with sequelae, except for one who received rFVIIa. The sequelae included seizure disorder (n = 1) and hydrocephalus (n = 3). Subsequently, the surviving patients received 15 ml/kg of lyophilized fresh plasma every 3-5 days as prophylactic treatment. In conclusion, rFVIIa in the dose of 20 microg/kg every 6 hours has been shown to be effective in controlling intracranial hemorrhage in patients with congenital factor VII deficiency.

Iron status of one-year-old infants in a well baby clinic.

Seventy-two healthy infants (37 males, 35 females) attending a private well baby clinic were enrolled in the study. Their mean birthweights and body weights at one year of age were 3,079 grams and 10 kilograms, respectively. Blood samples were drawn approximately on their first birthday for evaluating the iron status. Complete blood count, hemoglobin (Hb) typing and DNA analysis for common carrier status of thalassemia and hemoglobinopathis were also determined. According to the infants of serum ferritin, the patients were classified into 4 groups: group 1, iron deficiency anemia (Hb <11 g/dl and ferritin <12 ng/L) in 1 infants (1.4%); group 2, iron deficiency without anemia (Hb >11 g/dl and ferritin <12 ng/L) in 5 infants (6.9%); group 3, borderline iron depletion (ferritin 12-30 ng/L) in 39 infants (54.2%); group 4, iron sufficiency (ferritin >30 ng/L) in 27 infants (37.5%). The iron deficiency state emerged as 8.3 per cent (6/72). There was no significant difference of levels of Hb and mean corpuscular volume (MCV) among the infants with iron deficiency without anemia, borderline iron depletion and iron sufficiency. The results also revealed that 25 out of 72 (34.7%) infants were carriers of thalassemia and hemoglobinopathies. The carrier infants had significant lower Hb and MCV than those of the non-carrier infants with the p-values of 0.004 and 0.000, respectively; while their serum ferritin levels were not significantly different. Additionally, the association of carrier and iron deficiency state was further evaluated. The Hb and MCV among carrier infants with and without iron deficiency were not significantly different. Six infants with carrier state were found to have slightly decreased levels of Hb ranging from 10.3 to 10.9 g/dl with the ferritin ranging from 18.7 to 382.9 ng/L while the remainders had Hb of >11 g/dl. Therefore, 7 out of 72 (9.2%) infants had anemia (Hb <11 g/dl) which was caused by the carrier state of thalassemia and hemoglobinopathies (n=6) and iron deficiency anemia (n=1). The risk factors of iron deficiency status were associated with feeding regimen including continuation of breast feeding until one year of age without adequate haem iron supplement, exclusive formula feeding, inadequacy of solid food supplement with only one meal per day and excluding haem iron from animal liver without substitution. The infants with risk factors had significantly lower levels of serum ferritin (mean 14.1 +/- 1.7 ng/L) than those without risk factors (mean 31.9 +/- 1.9 ng/L) with a p-value of 0.000. In conclusion, adequate haem iron supplement in 3 meals of solid food is essential for the prevention of iron deficiency status in one-year-old infants.

The limitation of factor IX coagulant activity determination in the diagnosis of hemophilia B carriers.

A preliminary study of factor IX coagulant activity (FIX:C) for determining hemophilia B carriers was conducted at the Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital in Bangkok. Twenty-eight females (8 obligate, 20 potential carriers) from 17 hemophilia B families were enrolled in the study. Additionally, 25 normal females were included. They were not pregnant and not using oral contraceptives. Then, three cut-off levels of FIX:C including 50 per cent which was the commonly used level; 57 per cent which was the mean-2 SD of normal females and 75 per cent which was the level reported by Knobe and Ljung in 1999 were used for the diagnosis of hemophilia B carriers. The sensitivities of these three cut-off levels were 12.5 per cent (1/8) for 50 per cent, 37.5 per cent (3/8) for 57 per cent and 50 per cent (4/8) for 75 per cent. Also, the specificities were 100 per cent (25/25) for both 50 and 57 per cent, and 96 per cent (24/25) for 75 per cent. Although the low cut-off levels of 50 per cent and 57 per cent had low sensitivities, they yielded a high specificity (100%) compared to the higher level of 75 per cent. In the present study, the sensitivity of the cut-off level at 75 per cent was much lower than that of the study by Knobe and Ljung (93%) since the presented sample size of obligate carriers was rather small. So, enrollment of more subjects should be further carried out. In conclusion, FIX:C determination alone showed a limitation in the diagnosis of hemophilia B carriers. The addition of genetic analysis of linkage analysis or mutation detection is required for a definite diagnosis.