Ana González Hernández

Sex hormones and autoimmunity.

Autoimmune diseases occur more in women than in men, and this may be attributable to the role of estrogens. Androgens promote autoimmune diseases with a profile of type 1 cytokines, such as rheumatoid arthritis, whereas estrogens promote autoimmune diseases with a type 2 cytokine profile, like systemic lupus erythematosus. Both androgens and estrogens regulate the Th1/Th2 balance. Type 1 autoimmune diseases are improved when decrease type 1 cytokines (i.e. during fasting), or when there is a rise in type 2 cytokines (increased estrogens, as in pregnancy). Type 2 autoimmune diseases improve when type 2 cytokines are diminished (decreased estrogen, as in post-partum period) or when type 1 response is stimulated.

Inverse Association Between Obesity and Antinuclear Antibodies in Women

To the Editor: More than 70% of all autoimmune illnesses occur in women, a figure that has been attributed to stimulation of the Th2 response by estrogens. However, a little-explored relationship is that which may exist between obesity and autoimmune disorders in women. Since the discovery of leptin1 it has been known that the cytokine-producing capacity of adipose tissue is high. Serum concentration of leptin is 3- to 4-fold higher in women than in men. However, little is known about the reasons for this difference. To date no studies have investigated the relationship between leptin and autoimmune disease in the…

Efficiency of different strategies to detect autoantibodies to extractable nuclear antigens.

Autoantibodies to extractable nuclear antigens (anti-ENA) are identified mainly in samples positive for antinuclear antibodies (ANA). Although the method of choice for ANA screening is indirect immunofluorescence (IIF), several techniques are available to detect anti-ENA. The aim of this study was to compare the efficiency of five different strategies to determine anti-ENA. During a 2-year period we screened ANA in 30375 samples with IIF, and the 4475 samples ANA positive were tested for anti-ENA by double immune diffusion screening or fluoroenzymeimmunoassay (Screening FI); anti-ENA specificities were then determined by line immunoassay (LIA) or fluoroenzymeimmunoassay (FI). We compared five strategies that involved FI or LIA identification of anti-ENA with or without prior screening, or an algorithm that combined fluorescence pattern, number of anti-ENA specificities requested by the clinician and ANA dilution titer. One cost unit (CU) was defined as the cost of 1 test of ANA determination. We detected 553 anti-ENA positive samples. The most efficient strategy was the algorithm, at a cost of 3.3 CU per sample processed, the second most efficient strategy was screening plus FI identification (cost=3.8 CU), and the third most efficient strategy was screening plus LIA identification (cost=3.9 CU). The fourth most efficient strategy was FI identification without prior screening (13.3 CU per sample) and the least efficient was LIA identification without prior screening (13.6 CU per sample). In conclusion, an algorithm that combined techniques for detection, ANA titer, fluorescence pattern and number of specificities requested was the most efficient strategy for determining anti-ENA.

Factores asociados al conocimiento y el control de la hipertensión arterial en Canarias

INTRODUCTION AND OBJECTIVES To analyze the factors associated with knowledge and control of hypertension in the adult population of the Canary Islands (18-75 years). METHODS We recruited a random sample of the general population aged ≥18 years. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mmHg or known hypertension (self-declared, or controlled hypertension <140/90 mmHg). The bivariate association of known and controlled hypertension with age, sex, anthropometry, serum lipids, medication, and lifestyle was corroborated by adjusting a multivariate logistic model. RESULTS We included 6675 participants. The prevalence of hypertension was higher in men (40% vs 31%, P<.001), who also had a lower frequency of treated and controlled hypertension. Female sex (P<.001), age ≥55 years (P<.001), obesity (P<.001), and diabetes (P<.001) were associated with known hypertension. The modifiable factors that, in spite of treatment, increased the risk of poor control of hypertension were alcohol consumption (>30 g/day, odds ratio [OR]=2.4, P<.001; >15-≤30 g/day, OR=2, P=.009; >5-≤15, g/day, OR=1.83, P=.004), obesity (body mass index ≥30, OR=2, P=.003; >24.9-<30, OR=1.7, P=.024), serum cholesterol >250 mg/dL (OR=1.6, P=.006) and elevated heart rate (>80 bpm, OR=1.45, P=.045; >70-≤80 bpm, OR=1.36, P=.038). CONCLUSIONS The awareness of hypertension increases with frequent use of the health system and with factors associated with known hypertension: female sex, age, underlying health problems. The modifiable factors associated with poor control of known hypertension are alcohol consumption, obesity, elevated heart rate, and hypercholesterolemia.

Factors associated with parietal cell autoantibodies in the general population

The presence in serum of parietal cell autoantibodies (PCA) is a characteristic of autoimmune gastritis. We determined the prevalence of PCA in the general population and investigate their association with type 2 diabetes, insulin resistance and lifestyle factors related with autoimmune gastritis. A cross-sectional study was performed, involving 429 individuals enrolled in a cohort study of the general population of the Canary Islands. All participants underwent physical examination, provided a blood sample and responded to a questionnaire regarding health and lifestyle factors. Serum concentrations of PCA, soluble CD40 ligand (sCD40L), C-peptide and glucose (to determine insulin resistance) were measured. The association of PCA with the other factors was determined with bivariate analysis, and logistic regression models were used to adjust the associations for age and sex. The prevalence of PCA was 7.8% (95% CI=10.3-5.3). The factors associated with PCA were female sex (p=0.032), insulin resistance (p=0.016), menopause (p=0.029) and sCD40L (p=0.019). Alcohol consumption (p=0.006) and smoking (p=0.005) were associated with low prevalences of PCA. After adjustment for age and sex, the association with PCA was confirmed for smoking (OR=0.1 [0.0-0.9]), alcohol consumption (OR=0.3 [0.1-0.9]), insulin resistance (OR=2.4 [1.1-4.9]), female sex (OR=2.4 [1.1-5.3]), sCD40L (OR=3.7 [1.2-11.4]) and menopause (OR=5.3 [1.2-23.3]). In conclusion, smoking and alcohol consumption acted as protective factors against the appearance of PCA in the general population, whereas female sex, menopause, insulin resistance and elevated serum sCD40L were risk markers for PCA. In patients who smoke or drink alcohol, clinicians should be cautious when using PCA to rule out autoimmune gastritis.

Autoantibody detection with indirect immunofluorescence on HEp-2 cells: Starting serum dilutions for systemic rheumatic diseases

Antinuclear antibodies (ANA) are determined, among other reasons, to identify samples which need a second test to detect the associated specificities. Our aim was to evaluate the clinical and economic impact generated by using an initial dilution for ANA of 1:160. We analyzed all samples for which ANA, anti-ENA and anti-dsDNA were requested over a 1-year period. ANA were detected by indirect immunofluorescence. Anti-ENA were analyzed with a combination of techniques. Anti-dsDNA were detected by radioimmunoassay. Cost analysis was performed by calculating the difference between two cut-offs (ANA 1:40 and 1:160). A total of 13,233 samples were processed for ANA, of which 59.9% were positive with the 1:40 cut-off and 39.2% with the 1:160 cut-off. At ANA titer 1:40, 0.2% of the samples were anti-ENA-positive and 2.2% were anti-dsDNA positive. Only ANA dilutions of 1:160 and higher showed significantly increased positive predictive value for anti-ENA (1.5 versus 0.2, p=0.029) and anti-dsDNA (8.3 versus 2.2, p<0.001) compared to the 1:40 titer. With the 1:160 cut-off, 16.6% fewer ANA tests, 41.8% fewer anti-ENA determinations and 36.4% fewer anti-dsDNA tests would have been needed. The average saving was 0.87 cost-units per sample (1 unit=2.06euro). We conclude that setting the starting dilution for ANA at 1:160 avoids unnecessary studies, increases the positive predictive values of ANA for anti-ENA and anti-dsDNA, and generates clinical and economic benefits.

TYMS, MTHFR, p53 and MDR1 gene polymorphisms in breast cancer patients treated with adjuvant therapy

PURPOSE The distribution of TSER (TYMS), C677T (MTHFR), Arg72Pro (p53) and C3435T (MDR1) gene polymorphisms was investigated in 80 consecutive breast cancer patients treated with adjuvant chemotherapy. RESULTS Observed allelic frequencies were: TSER, (2) 0.55 and (3) 0.45; MTHFR C677T, (C) 0.65 and (T) 0.35; p53 Arg72Pro, (Arg) 0.76 and (Pro) 0.24; MDR1 C3435T, (C) 0.51 and (T) 0.49. MTHFR C677T was found to be a strong predictor of the presence of multifocal tumour (odds ratio, 4.1; 95% CI, 1.1-15.7; P=0.035). CONCLUSION Our data indicate that breast cancer patients with the C/C variant may present multifocal tumour most frequently.