Indian women with higher serum concentrations of folate and vitamin B12 are significantly less likely to be infected with carcinogenic or high-risk (HR) types of human papillomaviruses (HPVs)

BACKGROUND: Studies conducted in the USA have demonstrated that micronutrients such as folate and vitamin B12 play a significant role in modifying the natural history of high-risk human papillomaviruses (HR-HPVs), the causative agent for developing invasive cervical cancer (CC) and its precursor lesions. OBJECTIVE: The purpose of the current study was to investigate whether these micronutrients have similar effects on HR-HPV infections in Indian women. METHODS: The associations between serum concentrations of folate and vitamin B12 and HR-HPV infections were evaluated in 724 women who participated in a CC screening study in the southern state of Andhra Pradesh, India. Serum folate and vitamin B12 concentrations were measured by using a competitive radio-binding assay. Digene hybrid capture 2 (HC2) assay results were used to categorize women into two groups, positive or negative for HR-HPVs. Unconditional logistic regression models specified a binary indicator of HC2 (positive/negative) as the dependent variable and serum folate concentrations combined with serum vitamin B12 concentrations as the independent predictor of primary interest. Models were fitted, adjusting for age, education, marital status, parity, type of fuel used for cooking and smoking status. RESULTS: Women with higher concentrations of serum folate (>6 ng/mL) and vitamin B12 (>356 pg/mL) were at lower risk of being positive for HR-HPVs compared to those with serum folate ≤6 ng/mL and serum vitamin B12 ≤ 356 pg/mL (odds ratio = 0.26; 95% confidence interval: 0.08-0.89; P = 0.03). CONCLUSIONS: These results demonstrated that improving folate and vitamin B12 status in Indian women may have a beneficial impact on the prevention of CC. Micronutrient based interventions for control of HR-HPV infections may represent feasible alternatives to vaccine based approaches to HPV disease prevention, which are currently unaffordable for use in resource limited areas in rural India

Altered DNA methylation of repetitive elements may explain the modified risk of cervical intraepithelial neoplasia (CIN) associated with genetic polymorphisms of the folate metabolic pathway in the US post folic acid fortification era

Despite the controversy regarding the adverse effects of exposure to higher folate concentrations on health outcomes particularly cancer, there has been paucity of research to understand the biological mechanisms affected by such exposures in relation to the risk of developing pre-cancer or cancer. We have recently addressed this concern by demonstrating that higher plasma folate concentrations were not associated with greater risk of being diagnosed with higher grades of cervical intraepithelial neoplasia (CIN 2+) especially in women with sufficient plasma vitamin B12 concentrations. Higher plasma folate was also associated with a pre-cancer protective level of peripheral blood mononuclear cells (PBMC) long interspersed nuclear elements-1 (LINE-1) methylation, a validated surrogate marker of global DNA methylation status. However, it is unknown whether these results could be reproduced using homocysteine (Hcy), a functional indicator of both folate and vitamin B12 status and whether genetic polymorphisms in the folate metabolic pathway (FMP) may have an effect on these associations in a population of women exposed to FA fortification program. The objectives of this research were to determine the (1) association between Hcy and risk of CIN 2+ (2) the association between MTHFR C677T, TS 3’UTR 6bp deletion and DHFR 19bp deletion polymorphisms and the risk of CIN 2+ (3) modifying effects of plasma folate and vitamin B12 on the association between the genetic polymorphisms and the risk of CIN 2+ (4) the association between the genetic polymorphisms and pre-cancer/cancer associated epigenetic biomarkers and DNA damage markers (5) modifying effects of plasma folate and vitamin B12 on the association between the genetic polymorphisms and these biomarkers. Higher Hcy was associated with increased risk of CIN 2+ and a lower degree of PBMC LINE-1 methylation. Women with MTHFR 677CT or TT genotype and lower plasma folate were at a reduced risk for CIN 2+ and had lower degree of PBMC LINE-1methylation compared to women with MTHFR 677 CT or TT genotype and higher plasma folate. In conclusion, even in the FA fortification era, not all women have adequate folate status to overcome the adverse effects of higher Hcy and MTHFR C677T. PBMC LINE-1 methylation is a useful marker to assess the risk of CIN 2+ in individuals having MTHFR C677T polymorphism. Keywords: folate, fortification, tHcy, genetic polymorphisms, CIN, PBMC LINE-methylatio

The accuracy of HPV genotyping in isolation and in combination with CD4 and HIV viral load for the identification of HIV‐infected women at risk for developing cervical cancer

Abstract Background Human papillomavirus (HPV) genotype testing has limited utility to identify human immunodeficiency virus‐infected (HIV+) women's risk for developing cervical cancer (CC) due to high positivity rate of high‐risk (HR) HPVs. We investigated the accuracy of HPV testing in isolation/in combination with CD4 and HIV viral load (VL) to identify HIV+ women at risk for developing CC. Methods Study consisted of 344 HIV+ women on combination antiretroviral therapy (cART), tested for cervical cytology/HPV using the Cobas test and had data on absolute CD4 count and VL measurements. We calculated the positive predictive value (PPV) and negative predictive value (NPV) of HPV testing, pre‐, post‐cART, and current CD4 and VL in isolation and in combinations to identify those with or free of higher than atypical squamous cells of unknown significance (ASCUS+) or low‐grade intraepithelial lesions (LSIL+). Results HPV test in combination with pre‐/post‐cART or current CD4 counts and VL had higher PPVs compared to HPV test alone for identifying ASCUS+ or LSIL+. PPV of HPV‐CD4 combinations yielded higher PPVs compared to HPV‐VL combinations. The NPVs with pre‐, post‐cART, or current CD4 count and VL in isolation or in combinations were comparable to that of HPV test alone. Conclusions Our results provide a more accurate tool for managing HIV+ women by combining Cobas HPV with CD4 and VL, especially those who had an undesirable pre‐cART CD4 and VL status. Our results also indicate the usefulness of CD4 and VL measurements to identify those at lower risk in the absence of HPV testing

A lower degree of PBMC L1 methylation in women with lower folate status may explain the MTHFR C677T polymorphism associated higher risk of CIN in the US post folic acid fortification era.

BackgroundStudies in populations unexposed to folic acid (FA) fortification have demonstrated that MTHFR C677T polymorphism is associated with increased risk of higher grades of cervical intraepithelial neoplasia (CIN 2+). However, it is unknown whether exposure to higher folate as a result of the FA fortification program has altered the association between MTHFR C677T and risk of CIN, or the mechanisms involved with such alterations. The current study investigated the following in a FA fortified population: 1) The association between MTHFR C677T polymorphism and risk of CIN 2+; 2) The modifying effects of plasma folate concentrations on this association; and 3) The modifying effects of plasma folate on the association between the polymorphism and degree of methylation of long interspersed nucleotide elements (L1s), in peripheral blood mononuclear cell (PBMC) DNA, a documented biomarker of CIN risk.MethodsThe study included 457 US women diagnosed with either CIN 2+ (cases) or ≤ CIN 1 (non-cases). Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors for CIN.ResultsThe 677CT/TT MTHFR genotypes were not associated with the risk of CIN 2+. Women with CT/TT genotype with lower folate, however, were more likely to be diagnosed with CIN 2+ compared to women with CT/TT genotype with higher folate (OR = 2.41, P = 0.030). Women with CT/TT genotype with lower folate were less likely to have a higher degree of PBMC L1 methylation compared to women with CT/TT genotype with higher folate (OR = 0.28, P = 0.017).ConclusionsThis study provides the first evidence that the MTHFR 677CT/TT genotype-associated lower degree of PBMC L1 methylation increases the risk of CIN 2+ in women in the US post-FA fortification era. Thus, even in the post-FA fortification era, not all women have adequate folate status to overcome MTHFR 677CT/TT genotype-associated lower degree of L1 methylation

A Lower Degree of PBMC L1 Methylation Is Associated with Excess Body Weight and Higher HOMA-IR in the Presence of Lower Concentrations of Plasma Folate

<div><h3>Background</h3><p>Identification of associations between global DNA methylation and excess body weight (EBW) and related diseases and their modifying factors are an unmet research need that may lead to decreasing DNA methylation-associated disease risks in humans. The purpose of the current study was to evaluate the following; 1) Association between the degree of peripheral blood mononuclear cell (PBMC) L1 methylation and folate, and indicators of EBW, 2) Association between the degree of PBMC L1 methylation and folate, and insulin resistance (IR) as indicated by a higher homeostasis model assessment (HOMA-IR).</p> <h3>Methods</h3><p>The study population consisted of 470 child-bearing age women diagnosed with abnormal pap. The degree of PBMC L1 methylation was assessed by pyrosequencing. Logistic regression models specified indicators of EBW (body mass index–BMI, body fat–BF and waist circumference–WC) or HOMA-IR as dependent variables and the degree of PBMC L1 methylation and circulating concentrations of folate as the independent predictor of primary interest.</p> <h3>Results</h3><p>Women with a lower degree of PBMC L1 methylation and lower plasma folate concentrations were significantly more likely to have higher BMI, % BF or WC (OR = 2.49, 95% CI:1.41–4.47, <em>P</em> = 0.002; OR = 2.49, 95% CI:1.40–4.51, <em>P</em> = 0.002 and OR = 1.98, 95%  = 1.14–3.48 <em>P</em> = 0.0145, respectively) and higher HOMA-IR (OR = 1.78, 95% CI:1.02–3.13, P = 0.041).</p> <h3>Conclusion</h3><p>Our results demonstrated that a lower degree of PBMC L1 methylation is associated with excess body weight and higher HOMA-IR, especially in the presence of lower concentrations of plasma folate.</p> </div

The demographic and life style factors of the study population based on indicators of EBW.

<p>EBW-excess body weight, BMI-body mass index , BF-body fat, WC-waist circumference</p>!<p>CDC recommendation for moderate physical activity is 150 min/week</p>*<p>P values for Pearson's chi-square test are shown for frequencies and median test for comparison of medians</p

The distribution of women by different combinations of plasma and RBC folate and the degree of PBMC L1 methylation by EBW indicators and HOMA-IR.

<p>PBMC L1-peripheral blood mononuclear cell long interspersed nucleotide element-1, EBW- excess body weight BMI-body mass index, BF-body fat, WC-waist circumference</p>*<p>Pearson's chi-square test</p

The association between the degree of PBMC L1 methylation and indicators of EBW after controlling for demographic and lifestyle factors.

<p>PBMC L1-peripheral blood mononuclear cell long interspersed nucleotide element-1, EBW- excess body weight BMI-body mass index, BF-body fat, WC-waist circumference</p>*<p>P < 0.05</p

Mean ± SD and median degree of PBMC L1 methylation by categories of EBW indicators and circulating concentrations of folate.

<p>PBMC L1-peripheral blood mononuclear cell long interspersed nucleotide element-1, EBW- excess body weight, BMI-body mass index, BF-body fat, WC-waist circumference</p>*<p>Wilcoxon rank sum test</p

Interaction of plasma folate and the degree of PBMC L1 methylation on indicators of EBW after adjusting for demographic and lifestyle factors.

<p>PBMC L1-peripheral blood mononuclear cell long interspersed nucleotide element-1, EBW- excess body weight BMI-body mass index, BF-body fat, WC-waist circumference</p>*<p>P < 0.05</p