Congenital dysfibrinogenemia caused by γAla327Val mutation: structural abnormality of D region.

BACKGROUND: : Congenital dysfibrinogenemia (CD) is a coagulation disorder caused by mutations in the fibrinogen genes, which result in abnormal fibrinogen function. However, the precise pathogenesis underlying it remains unclear. METHODS: : In this study, we identified a novel heterozygous mutation in an asymptomatic patient with CD caused by γ Ala327Val mutation. Aimed to investigate the pathogenesis, functional studies of fibrinogen isolated from the proband and her family members were performed, such as coagulation function, fibrinogen aggregation test, and fibrin clot lysis test. Coagulation was monitored using a thromboelastometer, and the fibrin clot network structure was observed by scanning electron microscopy. The effect of the mutation on fibrinogen structure and function was predicted by molecular modeling. RESULTS: : The fibrinogen activity concentration in patients with CD was significantly lower than that in healthy individuals, indicating that fibrinogen activity was low. Proband's fibrinogen activity concentration was 0.75 g/L(Clauss method) and antigen concentration (immune turbidimetry method) was 1.59 g/L(normal reference range for both parameters: 2.0-4.0 g/L). Thromboelastography showed that the K value of patients with CD was higher than that of healthy individuals and Angle values were decreased, indicating that mutation impaired fibrinogen function. Compared to fibrinogen from healthy individuals, fiber network structure of the proband was loose, pore size was increased, and fiber branch nodes were increased. CONCLUSIONS: : Ala327Val heterozygous missense mutation leads to changes in the structure of fibrinogen D region and impairs the aggregation function of fibrinogen. This mutation is reported here for the first time.

Correlation between hypocalcemia and acute exacerbation of chronic obstructive pulmonary disease in the elderly.

Introduction: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an important disease of hospitalized elderly patients, who often have electrolyte imbalances. This study was performed to analyze total serum calcium levels in elderly patients with AECOPD and identify the correlation between hypocalcemia and AECOPD. Methods: 153 elderly patients with AECOPD served as the observation group, and 115 healthy elderly people undergoing physical examinations served as the control group. Differences in the corrected serum calcium, albumin (ALB), and neutrophil/lymphocyte ratio (NLR) were analyzed between the observation and control groups before and after treatment. The incidence of hypocalcemia was compared among patients at different ages and with different pulmonary function classifications before treatment. The relationship between hypocalcemia and respiratory infection was analyzed. Differences in the pretreatment NLR, ALB, logarithm of the serum C-reactive protein level (LogCRP), and hospital stay were compared between patients with and without hypocalcemia. Results: The corrected serum calcium level (P < 0.001), NLR (P = 0.001) and albumin level (P < 0.001) were significantly different among the pretreatment group, post-treatment group, and control group. The serum calcium level, LogCRP, and NLR were significantly lower after than before treatment (P < 0.05). Significant differences in the incidence of hypocalcemia were found among patients of different ages (P = 0.002). The respiratory infection rate (P < 0.001), hospital stay (P < 0.001), NLR (P = 0.007), and LogCRP (P < 0.001) was higher in patients with than without hypocalcemia. However, the albumin level was lower in patients with than without hypocalcemia (P < 0.001). Conclusions: In elderly patients with AECOPD, hypocalcemia may be related to the disease progression, respiratory infection rate, and hospital stay of patients with AECOPD.

A novel fibrinogen gamma-chain mutation, p.Cys165Arg, causes disruption of the γ165Cys-Bß227Cys disulfide bond and ultimately leads to hypofibrinogenemia.

BACKGROUND: Congenital hypofibrinogenemia is a type of hereditary disease characterized by impaired fibrinogen synthesis and/or secretion induced by mutations in the fibrinogen gene. OBJECTIVES: We investigated the phenotypes, genotypes, and pathogenesis of congenital hypofibrinogenemia in an affected family. PATIENTS/METHODS: The proband had a risk of bleeding; therefore, conventional coagulation screening was performed for the proband and her family members. Mutation sites in all exons and flanking sequences of FGA, FGB, and FGG were identified, with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) performed to indicate the expression of abnormal chains. The effect of the mutation sites on fibrinogen structure and function was predicted by molecular modeling, and purified plasma fibrinogen from the proband was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and scanning electron microscopy. Thromboelastography was applied to assess the risk of bleeding and clotting in the proband. RESULTS: Fibrinogen levels in the proband were 1.21 g/L, 1.31 g/L, and 1.38 g/L according to Clauss assay, the prothrombin time method, and enzyme-linked immunosorbent assay, respectively. A novel heterozygous mutation (γCys165Arg), a heterozygous mutation (AαIle6Val), and two genetic polymorphisms (AαThr331Ala and BßArg478Lys) in fibrinogen were found in the proband, and MALDI-TOF MS indicated absence of the mutated chain in patient plasma. Additionally, the heterozygous mutation (γCys165Arg) displayed substitution of a nonpolar γ165Cys (low mass) with a positively charged Arg (high mass) along with a small fiber diameter and loose network structure. CONCLUSIONS: Fibrinogen γCys165Arg mutations cause damage to the interchain disulfide bonds of fibrinogen and hinder fibrinogen secretion, possibly explaining the pathological mechanism associated with congenital hypofibrinogenemia.

Application of albumin/globulin ratio in elderly patients with acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has become an important disease of hospitalized elderly patients, which lack simple and inexpensive indicators for evaluating the condition and prognosis. This study was performed to investigate the clinical significance of the serum albumin/globulin ratio (AGR) in elderly patients with AECOPD. METHODS: The data of 252 hospitalized elderly patients with AECOPD, 89 stable COPD patients and 115 elderly healthy individuals were analyzed and compared. The differences in the AGR, logarithm of the serum C-reactive protein (LogCRP) level, prealbumin (PA) level, and immunoglobulin G (IgG) level were compared. AECOPD patients were grouped using the optimal cutoff values of each index to compare the difference in the combined infection rate. The correlation between hospital stays and AGR was analyzed. RESULTS: The AGR, LogCRP, PA level, and IgG level were different among the AECOPD group, stable COPD group and healthy control groups (P<0.05). The AGR, LogCRP, and PA level were different (P<0.05) among the Global Initiative for Chronic Obstructive Lung Disease (GOLD) I, II, II, and IV groups. Age, AGR, LogCRP, and PA level were different (P<0.05) between the infection and non-infection groups. After grouping according to the optimal cutoff values, the combined infection rate was different (P<0.05). The AGR was negatively correlated with the hospital stay (r=-0.583, P<0.001). The hospital stay was longer in patients with an AGR of <1.37 than ≥1.37 (P<0.001). CONCLUSIONS: The AGR can be regarded as a reference index for evaluating the condition of elderly patients with AECOPD, determining the presence of combined infection, and predicting the prognosis.

Abnormal fibrinogen with an Aα 16Arg → Cys substitution is associated with multiple cerebral infarctions.

We found a heterozygous dysfibrinogenemia caused by a substitution of AαArg16Cys. The proband suffered multiple cerebral infarctions. Routine coagulation tests revealed a prolonged thrombin time. The fibrinogen levels in the functional assays were considerably lower than the levels in the immunological assays. The polymerization of the purified fibrinogen was strongly impaired in the presence of calcium. As previously observed in other heterozygous Aα R16C variants, the release rate and amount of fibrinopeptide A (FPA) were lower in the proband than those in normal controls. Additionally, the release of fibrinopeptide B (FpB) was delayed. The immunoblotting analysis using antibodies against human serum albumin indicated that albumin is bound to Aα R16C. The mass spectrometry analysis showed that the Aα R16C fibrinogen chains appeared in the patient's circulation. The clot structure analysis using scanning electron microscopy (SEM) revealed that the fibrin network was dense and consisted of thin and highly branched fibres. Using overlaid fibrinolytic enzymes in a clot lysis experiment, clot degradation was observed to be delayed. These results indicated that the thrombotic tendency may be ascribed to a fibrinolytic resistance caused by an abnormal clot structure with thin fibres and fibrinogen-albumin complexes.

Novel compound heterozygous SPTA1 mutations in a patient with hereditary elliptocytosis.

Hereditaryelliptocytosis (HE) is a hereditary hemolytic disease, characterized by the presence of many elliptical erythrocytes in the peripheral blood that is caused by abnormal cytoskeletal proteins in the erythrocyte membrane. In the present study, a novel, causal HE mutation was reported. Routine blood examinations were performed on the proband and their family, and the fluorescence intensity of eosin­5­maleimide (EMA)­labeled erythrocytes was determined via flow cytometry. Subsequently, DNA was extracted from the peripheral blood of the proband and their family members, and amplified by quantitative polymerase chain reaction. The Sanger sequencing approach was used to determine and identify gene mutations, which were verified by matrix­assisted laser desorption­ionization time of flight (MALDI­TOF) mass spectrometry. To exclude genetic polymorphisms, newly identified mutations were subjected to large­scale gene screening using high­resolution melt analysis. Protein expression levels in the erythrocyte membrane of the proband were determined via SDS­PAGE, which demonstrated that, compared with healthy controls, the proband exhibited a reduction in EMA­labeled erythrocytes. In addition, DNA analysis demonstrated that the proband carried three mutations in the spectrin α chain erythrocytic 1 (SPTA1) gene: c.161A>C, c.5572C>G and 6531­12C>T. The corresponding mutant polypeptides were also analyzed by MALDI­TOF mass spectroscopy. SDS­PAGE analysis indicated that the proband exhibited normal levels of erythrocyte membrane proteins. In the present study, a novel HE case with a His54Pro mutation in the SPTA1 gene was reported. The results suggested that the His54Pro mutation influenced the role of erythrocyte membrane proteins without reducing its level of expression.

Rare LPL gene missense mutation in an infant with hypertriglyceridemia.

BACKGROUND: Severe hypertriglyceridemia usually results from a combination of genetic and environmental factors and is most often attributable to mutations in the lipoprotein lipase (LPL) gene. OBJECTIVES: The aim of this study was to identify rare mutations in the LPL gene causing severe hypertriglyceridemia. METHODS: A Chinese infant who presented classical features of severe hypertriglyceridemia recruited for DNA sequencing of the LPL gene. The pathogenicity grade of the variants was defined based on the prediction of pathogenicity using in silico prediction tools. Review some studies to understand the molecular mechanisms underlying the severe hypertriglyceridemia. RESULTS: We identified a rare mutation in the LPL gene causing severe hypertriglyceridemia: a nucleotide substitution (c.836T>G) resulting in a leucine to arginine substitution at position 279 of the protein (p.Leu279Arg).The pathogenicity of the variant was predicted by in silico analysis using PolyPhen2 and SIFT prediction programs, which indicated that mutation p.Leu279Arg is probably harmful. We have also reviewed published studies concerning the molecular mechanisms underlying severe hypertriglyceridemia. A missense mutation in the 6 exon of the LPL gene is reportedly associated with LPL deficiency. CONCLUSIONS: We have here identified a rare pathogenic mutation in the LPL gene in a Chinese infant with severe hypertriglyceridemia.

Prevalence of hyperhomocysteinemia during routine physical examination in Guangxi Province, China and related risk factors.

BACKGROUND: Studies on homocysteine (Hcy) have mainly focused on the correlation between the homocysteine concentration and disease development. Few epidemiological investigations have been performed. This study was conducted to investigate the prevalence of hyperhomocysteinemia (HHcy) during routine physical examination in Guangxi Province, China and the correlation of serum Hcy with gender, age, serum uric acid (UA), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and blood glucose (GLU) to provide evidence for preventing and treating HHcy. METHODS: Data of 8043 patients who underwent physical examinations at the First Affiliated Hospital of Guangxi Medical University, China from 2015 to 2016 were collected. These data included gender, age, and the serum Hcy, UA, GLU, TC, TG, HDL-C, and LDL-C concentrations. RESULTS: The overall prevalence of HHcy was 50.8% (52.3% in males, 48.1% in females). Age, UA, TC, TG, and LDL-C were significantly higher and HDL-C was significantly lower in patients with than without HHcy, regardless of gender (all P<.05). The Hcy level was positively correlated with UA, TC, TG, and LDL-C but negatively correlated with HDL-C. Gender, age, UA, TC, and TG were independent risk factors for HHcy. CONCLUSION: The prevalence of HHcy was very high during routine physical examination in Guangxi Province, China. HHcy was related to gender, age, high concentrations of UA, TC, TG, and LDL-C; and low concentrations of HDL-C. Strengthening early intervention of HHcy can reduce the risk of cardiovascular disease.