Age of red blood cells and outcome in acute kidney injury.

INTRODUCTION: Transfusion of red blood cells (RBCs) and, in particular, older RBCs has been associated with increased short-term mortality in critically ill patients. We evaluated the association between age of transfused RBCs and acute kidney injury (AKI), hospital, and 90-day mortality in critically ill patients. METHODS: We conducted a prospective, observational, predefined sub-study within the FINNish Acute Kidney Injury (FINNAKI) study. This study included all elective ICU admissions with expected ICU stay of more than 24 hours and all emergency admissions from September to November 2011. To study the age of RBCs, we classified transfused patients into quartiles according to the age of oldest transfused RBC unit in the ICU. AKI was defined according to KDIGO (Kidney Disease: Improving Global Outcomes) criteria. RESULTS: Out of 1798 patients, 652 received at least one RBC unit. The median [interquartile range] age of the oldest RBC unit transfused was 12 [11-13] days in the freshest quartile and 21 [17-27] days in the quartiles 2 to 4. On logistic regression, RBC age was not associated with the development of KDIGO stage 3 AKI. Patients in the quartile of freshest RBCs had lower crude hospital and 90-day mortality rates compared to those in the quartiles of older blood. After adjustments, older RBC age was associated with significantly increased risk for hospital mortality. Age, Simplified Acute Physiology Score II (SAPS II)-score without age points, maximum Sequental Organ Failure Assessment (SOFA) score and the total number of transfused RBC units were independently associated with 90-day mortality. CONCLUSIONS: The age of transfused RBC units was independently associated with hospital mortality but not with 90-day mortality or KDIGO stage 3 AKI. The number of transfused RBC units was an independent risk factor for 90-day mortality.

Female donors and transfusion-related acute lung injury: A case-referent study from the International TRALI Unisex Research Group.

BACKGROUND: Although quantitative evidence is lacking, it is generally believed that the majority of cases of transfusion-related acute lung injury (TRALI) are caused by female blood donors. We aimed to examine the relation between female donors and the occurrence of TRALI. STUDY DESIGN AND METHODS: We performed an international, multicenter case-referent study. TRALI patients who were diagnosed clinically, independent of serology or donor sex, and had received transfusions either only from male donors or only from female donors (unisex cases) were selected. The observed sex distribution among the donors of these TRALI patients was compared to the expected sex distribution, based on the relevant donor populations. RESULTS: Eighty-three clinical TRALI cases were included; 67 cases received only red blood cells (RBCs), 13 only plasma-rich products, and three both. Among RBC recipients the relative risk (RR) of TRALI after a transfusion from a female donor was 1.2 (95% confidence interval [CI], 0.69-2.1) and among plasma-rich product recipients the RR was 19 (95% CI, 1.9-191). The p value for the difference between RBCs and plasma was 0.023. CONCLUSION: Our data support the notion that plasma from female donors is associated with an increased risk of TRALI, while RBCs from female donors are not.

Factor V Leiden as risk factor for unexplained stillbirth--a population-based nested case-control study.

INTRODUCTION: Stillbirth is a relatively uncommon pregnancy complication in developed countries yet causing strong emotional burden. Thrombophilia has been associated with stillbirth but population-based studies are few. We assessed selected genetic and acquired parameters for the risk of unexplained stillbirth, including FV Leiden. MATERIALS AND METHODS: We performed a population-based nested case-control study of 100,000 consecutive pregnancies in Finland. Cases and controls were identified by combining national registers and accepted according to strict criteria after checking their medical records. Stillbirth was defined as intrauterine fetal death > or =22weeks of gestation. We excluded stillbirths due to lethal congenital developmental conditions, umbilical cord complications, and infections. We studied 44 cases of unexplained stillbirth and 766 controls. RESULTS: FV Leiden was associated with 3.8-fold (95% CI 1.2-11.6) risk for unexplained stillbirth, 3.9-fold (95% CI 1.1-13.9) risk for unexplained late stillbirth (> or =28weeks of gestation), and 10.8-fold (95% CI 2.1-55.3) risk for unexplained stillbirth with placental lesions. The same figures for singleton pregnancies were 3.1-fold (95% CI 0.9-10.9), 4.3-fold (95% CI 1.2-15.3), and 10.6-fold (95% CI 2.1-54.3). Slightly increased risk associated with blood group O was not statistically significant. We found a trend for increased risk in advanced maternal age and smoking during pregnancy. High pre-pregnancy BMI was not associated with increased risk, nor was low educational level or first pregnancy. CONCLUSIONS: Our population-based study from a country with comprehensive prenatal care confirms the association between FV Leiden and unexplained stillbirth.

Blood group AB and factor V Leiden as risk factors for pre-eclampsia: a population-based nested case-control study.

INTRODUCTION: Pre-eclampsia is an important cause of maternal morbidity and mortality. Its etiology is still unknown. Clinical symptoms correlate with activation of coagulation and inherited thrombophilia has been associated with pre-eclampsia. ABO blood group has been associated with thrombotic disorders and pre-eclampsia. We assessed ABO blood group, seven thrombophilia associated polymorphisms, and anti-beta2-glycoprotein I antibodies as risk factors for pre-eclampsia. MATERIALS AND METHODS: We performed a population-based nested case-control study of 100,000 consecutive pregnancies in Finland. Cases and controls were identified by combining national registers and medical records were reviewed. We studied 248 cases fulfilling strict criteria for pre-eclampsia and 679 controls. Severe pre-eclampsia, early pre-eclampsia, and pre-eclampsia with intra-uterine growth restriction (IUGR) were analyzed separately. RESULTS: Blood group AB increased the risk for pre-eclampsia as a whole (OR 2.1, 95% CI 1.3-3.5), and in the three subgroups (OR 2.3, 3.8, 3.4; 95% CI 1.3-3.9, 2.0-7.1, 1.6-7.1). FV Leiden increased the risk as a whole (OR 1.7, 95% CI 0.8-3.9), and in the three subgroups, although not statistically significantly. Anti-beta2-glycoprotein I antibodies were not associated with pre-eclampsia. High body mass index, diabetes, first pregnancy, and twin pregnancy increased the risk from 1.5-fold to 8.2-fold. CONCLUSIONS: Our results confirm and extend the prior observation of blood group AB being a risk factor for pre-eclampsia. ABO blood group is known from all pregnant women. The value of blood group as risk factor for pre-eclampsia should be further assessed in prospective studies. In this study, FV Leiden was not statistically significant risk factor.

An unfavorable combination of Factor V Leiden with age, weight, and blood group causes high risk of pregnancy-associated venous thrombosis: a population-based nested case-control study.

INTRODUCTION: Hereditary and acquired risk factors increase the risk for thrombosis among pregnant women. Few risk estimates are, however, well established. The aim of the present study was to assess risk for pregnancy-associated venous thrombosis of factor V Leiden (FVL), FII G20210A, FV A4070G, MTHFR C677T, TFPI C536T, PROC T38853G, FXIII V34L, blood group, age, and body mass index (BMI), and their interactions and public health impact. MATERIALS AND METHODS: Study design is a population-based nested case-control study of 100,000 consecutive pregnancies in Finland. Cases and controls were identified by combining national registers. Thirty four cases with objectively diagnosed venous thrombosis and 641 controls were studied. RESULTS: FVL (OR 11.6, 95% CI 3.6-33.6), age >35 vs. <25 (OR 6.3, 95% CI 1.7-23.1), and BMI >30 vs. <25 (OR 5.6, 95% CI 2.3-13.9) were associated with thrombosis. Overall absolute risk of a FVL carrier was 1 in 314. FVL interacted with age, BMI, and blood group. Population attributable risk proportion was 19% for FVL, 23% for age >35, 33% for BMI >25, and 35% for non-O blood group. Unexpectedly, the prevalence of FVL increased with age in controls. CONCLUSIONS: FVL appeared as a strong risk factor for pregnancy-associated venous thrombosis. Especially in elderly overweight mothers, FVL may cause a substantial thrombosis risk. Further studies are needed to confirm the increased prevalence of FVL in elderly mothers with normal pregnancies.

Population-based audit of fresh-frozen plasma transfusion practices.

BACKGROUND: In contrast to decreasing red blood cell (RBC) consumption in Finland, the use of fresh-frozen plasma (FFP) has been increasing since the 1990s, suggesting that FFP use may not always be optimal. To improve transfusion practices, knowledge of current FFP use and regional, national, and international comparison is necessary. STUDY DESIGN AND METHODS: Nine (of 21) Finnish hospital districts participated. Data concerning FFP-transfused patients in the years 2002 and 2003 were collected from existing computerized medical records into a yearly updated database as part of a Finnish benchmarking project on blood component use. RESULTS: Data included 11,590 FFP-transfused patients and 60,240 FFP units (71.2% of Finnish FFP use) delivered to Finnish hospitals during the study period. FFP was transfused most often to surgery patients (62.8% of FFP transfusion hospital visits) with blood circulatory system problems (32.3% of surgically treated and FFP-transfused patients). In only 65.9 percent of FFP-transfused patients were coagulation variables measured at any point in the hospital episode, and FFP was usually transfused in paired doses. Mean FFP use in Finland is comparable to other countries. CONCLUSION: Although overall FFP use in Finland is similar to that of international figures, it does not ensure best practice. Perioperative staff, being the largest FFP user, should be encouraged to dose FFP based on coagulation variables and body weight. Improvement efforts should be directed to patient groups transfused with large amounts of FFP.

Genetic background of type I protein C deficiency in Finland.

In contrast to other populations the usually rare type II form of protein C deficiency is as common in Finland as type I deficiency. We recently reported that a single mutation explained virtually all cases of type II protein C deficiency in Finland, indicating strong founder effect. We now investigated in the same population the genetic background of type I protein C deficiency. Thirty-eight apparently unrelated families were studied. They represent the vast majority of all families with type I deficiency in Finland. A genetic defect was identified in 23 (61%) families who carried 13 different mutations. Only three of the 13 mutations have been reported in other populations. Unlike in type II deficiency, considerable heterogeneity in mutations was found in type I deficiency. Our results indicate interesting differences in mutational histories of these two different forms of protein C deficiency in Finland.

Common variants of the beta and gamma subunits of the epithelial sodium channel and their relation to plasma renin and aldosterone levels in essential hypertension.

BACKGROUND: Rare mutations of the epithelial sodium channel (ENaC) result in the monogenic hypertension form of Liddle's syndrome. We decided to screen for common variants in the ENaC beta and gamma subunits in patients with essential hypertension and to relate their occurrence to the activity of circulating renin-angiotensin-aldosterone system. METHODS: Initially, DNA samples from 27 patients with low renin/low aldosterone hypertension were examined. The DNA variants were subsequently screened for in 347 patients with treatment-resistant hypertension, 175 male subjects with documented long-lasting normotension and 301 healthy Plasma renin and aldosterone levels were measured under baseline conditions and during postural and captopril challenge tests. RESULTS: Two commonly occurring betaENaC variants (G589S and a novel intronic i12-17CT substitution) and one novel gammaENaC variant (V546I) were detected. One of these variants occurred in a heterozygous form in 32 patients, a prevalence (9.2%) significantly higher than that in normotensive males (2.9%, p = 0.007) and blood donors (3.0%, p = 0.001). betaENaC i12-17CT was significantly more prevalent in the hypertension group than in the two control groups combined (4.6% vs. 1.1%, p = 0.001). When expressed in Xenopus oocytes, neither of the two ENaC amino acid-changing variants showed a significant difference in activity compared with ENaC wild-type. No direct evidence for a mRNA splicing defect could be obtained for the betaENaC intronic variant. The ratio of daily urinary potassium excretion to upright and mean (of supine and upright values) plasma renin activity was higher in variant allele carriers than in non-carriers (p = 0.034 and p = 0.048). CONCLUSIONS: At least 9% of Finnish patients with hypertension admitted to a specialized center carry genetic variants of beta and gammaENaC, a three times higher prevalence than in the normotensive individuals or in random healthy controls. Patients with the variant alleles showed an increased urinary potassium excretion rate in relation to their renin levels.