A pharmacokinetics-based approach to the monitoring of patient adherence to atorvastatin therapy.

The inadequate adherence of patients whose hyperlipidemia is treated with atorvastatin (ATR) to medical instructions presents a serious health risk. Our aim was to develop a flexible approach based on therapeutic drug monitoring (TDM), nonparametric population pharmacokinetic modeling, and Monte Carlo simulation to differentiate adherent patients from partially and nonadherent individuals in a nonrandomized, unicentric, observational study. Sixty-five subjects were enrolled. Nonparametric, mixed-effect population pharmacokinetic models of the sums of atorvastatin and atorvastatin lactone concentrations (ATR+ATRL) and of the concentrations of the acid and lactone forms of ATR and its 2- and 4-hydroxylated pharmacologically active metabolites (ATR+MET) were elaborated by including the TDM results obtained in 128 samples collected from thirty-nine subjects. Monte Carlo simulation was performed based on the elaborated models to establish the probabilities of attaining a specific ATR+ATRL or ATR+MET concentration in the range of 0.002-10 nmol (mg dose)-1 L-1 at 1-24 h postdose by adherent, partially adherent, and nonadherent patients. The results of the simulations were processed to allow the estimation of the adherence of further 26 subjects who were phlebotomized at sampling times of 2-20 h postdose by calculating the probabilities of attaining the ATR+ATRL and ATR+MET concentrations measured in these subjects in adherent, partially adherent, and nonadherent individuals. The best predictive values of the estimates of adherence could be obtained with sampling at early sampling times. 61.54% and 38.46% of subjects in the adherence testing set were estimated to be fully and partially adherent, respectively, while in all cases the probability of nonadherence was extremely low. The evaluation of patient adherence to ATR therapy based on pharmacokinetic modeling and Monte Carlo simulation has important advantages over the collection of trough samples and the use of therapeutic ranges.

[Analysis of the relationship between vitamin D3 level and disease severity in hereditary angioedema]. / A D3-vitamin-szint és a betegség súlyossága közötti kapcsolat vizsgálata herediter angioödémában.

Introduction: In recent years, many papers analyzed the relationship between serum vitamin D3 level and the frequency and activity of various diseases at least partially attributed to immune mechanisms. Aim: We looked for correlations among the number and location of edematous episodes occurring in patients with hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE) and the quantity of the C1-inhibitor used for supplementation as well as the vitamin D3 levels of patients. Method: We measured vitamin D3 levels in 118 of the 175 C1-INH-HAE patients of the National Angioedema Reference Center during the winter-spring (n = 111) and the summer-autumn periods (n = 105) in 2013-2014. Complement levels and clinical data were extracted from the National Angioedema Registry and from patient diaries. Results: The proportion of vitamin D3 deficient patients (serum level <20 ng/ml) was approximately 59.5% during winter-spring, 27.6% in summer-autumn, and 23.5% during both periods. There was a significant difference between vitamin D3 serum levels measured in the winter-spring or in the summer-autumn months (p<0.0001). The same applies to the number of the vials of C1-inhibitor concentrate administered as acute treatment for angioedema attacks (p = 0.01). In any season, vitamin D3 level did not correlate with the number of attacks experienced by the patients during the given period or of the vials of C1-inhibitor concentrate administered. Conclusions: We could not demonstrate a relationship between vitamin D3 level and the frequency or location of edematous episodes in HAE patients. The need for treatment (as reflected by the number of the vials administered) was higher in the winter-spring period. As vitamin D3 deficiency was more severe than expected in our patients, supplementation is clearly necessary. Orv Hetil. 2019; 160(25): 987-993.

Thyroid hormones and complement parameters in hereditary angioedema with C1-inhibitor deficiency.

BACKGROUND: Thyroid hormones control and up-regulate the synthesis of many plasma proteins. OBJECTIVE: To explore possible associations between thyroid hormone and complement levels in patients with hereditary angioedema resulting from the deficiency of the C1-inhibitor (C1-INH-HAE). METHODS: In this case-control study, serum thyrotropin, free triiodothyronine (FT3), and free thyroxine (FT4) levels, anti-thyroid peroxidase and antithyroglobulin antibody titers, and C1-INH concentrations were measured in 117 euthyroid patients with C1-INH-HAE and compared with their clinical properties. The control group comprised 150 healthy, age- and sex-matched, euthyroid individuals. RESULTS: The thyrotropin and antithyroglobulin levels were similar between the patients and the controls. Significantly lower FT3 (P < .001) and FT4 (P = .002) levels, as well as higher anti-thyroid peroxidase titers (P < .001), were seen in the patients with C1-INH-HAE. The proportion of patients with reduced C1-INH activity was greater among those with below-median FT4 levels than among those with above-median values (P = .02). Patients who experienced more edematous attacks per year had lower FT4 levels (within the normal range) than those afflicted by fewer episodes (P = .01). The FT3 and FT4 levels were significantly higher in patients undergoing long-term danazol therapy than in those who did not receive this drug (P = .01 and P = .02, respectively). The proportion of patients with FT4 levels in the below-median range was higher in the subset with increased d-dimer concentration (P = .009). CONCLUSION: Minor variations of the thyroid hormone levels (within the reference range) can influence the function of C1-INH in C1-INH-HAE. Our findings suggest a role for the endocrine system in the pathophysiology of C1-INH-HAE.

The effect of long-term danazol treatment on haematological parameters in hereditary angioedema.

BACKGROUND: The 17-alpha-alkylated derivatives of testosterone are often used for the prevention of oedematous episodes in hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE). However, these agents can have many adverse effects, including erythrocytosis and polyglobulia. Our aim was to investigate occurrence of erythrocytosis and polyglobulia after long-term danazol prophylaxis in C1-INH-HAE. METHODS: During the initial stage of our retrospective study, we explored whether C1-INH-HAE is associated with susceptibility to erythrocytosis and/or polyglobulia. In the second stage, we analyzed the haematological parameters of 39 C1-INH-HAE patients before, as well as after treatment with danazol for 1, 3, or 5 years. In the third stage, we studied the incidence of erythrocytosis and of polyglobulia after dosing with danazol for more than 5 years. RESULTS: We did not find any significant difference between C1-INH-HAE patients not receiving danazol and healthy controls as regards the occurrence of erythrocytosis or polyglobulia. The haematological parameters did not change after treatment with danazol for 1, 3, or 5 years. Platelet count was an exception-it decreased significantly (p = 0.0115) versus baseline, but within the reference range. Treatment-related polyglobulia did not occur. We observed erythrocytosis in a single female patient after 1-year-and in three female patients after more than 5-year long-treatment with danazol. Erythrocytosis did not require intervention or the discontinuation of danazol therapy. CONCLUSIONS: We conclude that neither erythrocytosis, nor polyglobulia occurs more often in C1-INH-HAE patients than in healthy individuals; it can be observed only sporadically even after treatment with danazol.

Neutrophil activation during attacks in patients with hereditary angioedema due to C1-inhibitor deficiency.

BACKGROUND: Earlier studies have shown that the absolute number of neutrophil granulocytes (NGs) may increase during attack of hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE). Whether NGs undergo activation during attack has not yet been investigated. However, as neutrophil elastase (NE) can cleave and inactivate C1-INH which may contribute to the dysregulation of the kallikrein-kinin system and hence, to edema formation. Our aim was to investigate the possible activation of NGs during attacks. METHODS: We studied blood samples obtained from 26 patients with C1-INH-HAE during symptom-free periods and during attacks, along with samples from 26 healthy volunteers. NG count (NGC), NE, myeloperoxidase (MPO), pentraxin 3 (PTX3), CRP, C5a, factor H, IL-8, and TNF-α levels were measured. RESULTS: NGC was higher during attacks than during symptom-free periods (p = 0.0132), and the same was observed for NE (p = 0.0026), MPO (p = 0.0008), and PTX3 levels (p = 0.0409). There was a strong positive correlation between NE and MPO levels during attacks (p < 0.0001, R = 0.709). Furthermore, IL-8 (p = 0.0061) and TNF-α (p = 0.0186) levels were also elevated during attacks, compared with symptom-free periods. By contrast, C5a and factor H levels were similar in samples obtained during attacks or in symptom-free periods. CONCLUSION: Increased NGC was associated with elevated NE and MPO levels - this suggests neutrophil activation during attacks. The strong positive correlation between NE and MPO levels, together with the elevated PTX3 concentration, may indicate the expression of neutrophil extracellular traps. All these processes may contribute to the activation of kallikrein-kinin system, which leads to the onset of an edematous episode.

Comprehensive study into the activation of the plasma enzyme systems during attacks of hereditary angioedema due to C1-inhibitor deficiency.

BACKGROUND: The activation of plasma enzyme systems contributes to hereditary angioedema attacks. We aimed to study the activation markers of the fibrinolytic, coagulation, and contact systems in a larger number of paired samples obtained from the same C1-INH-HAE patients in symptom-free periods and during attacks. METHODS: Eleven parameters (Factors XI, XII, and C1-inhibitor activity; the concentrations of the D-dimer, prothrombin fragments 1 + 2, plasminogen, plasminogen activator inhibitor-1 [PAI-1], thrombin-anti-thrombin III [TAT] complex, fibrinogen) were measured along with prothrombin time and activated partial thromboplastin time (aPTT), using commercial kits. We compared these markers in samples obtained from the same 39 patients during attack-free periods and during 62 edematous episodes. Forty healthy subjects of matching sex and age served as controls. RESULTS: Compared with the healthy controls, significantly higher FXI and FXII activity (p = 0.0007, p = 0.005), as well as D-dimer (p < 0.0001), prothrombin fragments 1 + 2 (p < 0.0001), and TAT (p = 0.0303) levels were ascertained in the patients during symptom-free periods. The evaluation of samples from symptom-free periods or obtained during attacks revealed the increase of FXII activity, as well as of the concentration of D-dimer, prothrombin fragments 1 + 2, and TAT during edematous episodes. PAI-1 level, prothrombin time, and aPTT decreased significantly during attacks, compared with symptom-free periods. D-dimer level was significantly higher during multiple- vs. single-site attacks. CONCLUSIONS: Comparing a large number of paired samples from symptom-free periods or from edematous episodes allowed accurate appraisal of the changes occurring during attacks. Moreover, our study pointed out that individual episodes may be characterized by different marker patterns.

Lipid, haemostatic and inflammatory variables in relation to the estrogen receptor alpha (ESR1) PvuII and XbaI gene polymorphisms.

BACKGROUND: Estrogen is known to affect lipoprotein metabolism, the haemostatic system and inflammatory markers. Our aim was to determine whether estrogen receptor alpha (ESR1) PvuII and XbaI gene polymorphisms can influence lipid, haemostatic and inflammatory variables in healthy Caucasian women and men of reproductive age. METHODS: 58 healthy women (aged between 18 and 45 years) and 55 healthy men (aged between 21 and 45 years) of reproductive age were enrolled in our study. FSH levels, lipid (total cholesterol, triglyceride, HDL cholesterol, lipoprotein(a), apo A-I, apo B), haemostatic (prothrombin time, activated partial thromboplastin time (aPTT), thrombin time, fibrinogen, factor V, VII, VIII, protein C, protein S, antithrombin III) and inflammatory (CRP) variables were measured on autoanalyzers using commercially available kits. Serum VLDL and LDL cholesterol concentrations were calculated with the equation of Friedewald. The ESR1 PvuII and XbaI genotypes were determined with PCR-RFLP method. RESULTS: In the total group, the ESR1 XbaI GG genotype carriers had significantly higher serum lipoprotein(a) concentrations than the AA or AG genotype carriers. Serum total cholesterol concentrations were significantly higher in healthy women with the PvuII CC genotype than in those with the TT or TC genotypes, whereas healthy women with the GG genotype of the ESR1 XbaI polymorphism had significantly higher serum total cholesterol and LDL cholesterol levels compared to those with the AA or AG genotypes. No other effects of the ESR1 PvuII and XbaI polymorphisms were found on the investigated lipid, haemostatic and inflammatory variables either in the total group or in women and men separately. CONCLUSIONS: The ESR1 PvuII and XbaI gene polymorphisms seem to affect lipoprotein metabolism in healthy subjects of peak reproductive age. However, further studies are needed to determine the molecular mechanisms by which the two polymorphisms could influence serum lipid levels.