The Influence of ACE Insertion/Deletion Gene Polymorphism on the Risk of IgA Nephropathy: A Debatable Topic

The frequency of the ACE I/D polymorphism in South America: a systematic review and meta-analysis

Angiotensin-converting enzyme (ACE) is a key component of the renin-angiotensin system and plays an important role in homeostasis and maintenance of blood pressure. However, little is known about allele and genotypic frequencies, as well as phenotypic characteristics associated with ACE polymorphism genotypes in South American populations. This study aimed to verify the allelic predominance and genotype frequency of ACE I/D polymorphism in South America and its association with the main diseases and related conditions. We conducted a systematic review considering studies published in the last 25 years available in PubMed, Scielo, LILACS, LIPECS, Coleciona SUS, CUMED, BINACIS, IBECS, and MEDLINE databases, resulting in the inclusion of 121 studies. Quality of the studies was assessed according to the Strengthening the Reporting of Genetic Association (STREGA) guidelines. We mapped the frequency of the ACE I/D polymorphism in South American populations. 8,856 (32.1%) subjects were DD, 13,050 were ID (47.4%), and 5,644 were II (20.5%) carriers. The main associated conditions included systemic arterial hypertension and other cardiovascular conditions, cardiorespiratory or respiratory characteristics, physical activity level, kidney conditions, aging-related diseases, as well as different types of cancers and metabolic conditions. 61.1% of the studies found no significant association between the respective conditions investigated and the ACE I/D polymorphism. Considering DD genotype or D allele, 21.5% of the studies observed negative and 4.9% positive outcomes. Regarding ID genotype, 4.1% of the studies identified negative and 0.8% positive outcomes, and for II genotype or I allele, 4.1% of the results had negative and 10.7% positive associations.

Association of ACE*(Insertion/Deletion) Variant with the Elevated Risk of Preeclampsia Among Gestational Women

The renin-angiotensin-aldosterone system has an indispensable function in the uteroplacental circulation, placental growth, and blood pressure optimization. The angiotensin I converting enzyme (ACE) gene is a critical integrator for electrolyte balance, and water retention, along with inhibiting preeclampsia. The main goal of this pertaining study is to assess the contribution of ACE*(Ins/Del) variant with the susceptibility for preeclampsia with focus on the severity of the disease among gestational hypertensive women. This retrospective study included 225 participants [125 PE gestational women, and 100 normotensive healthy controls] matching with age, and geographical region. PE women classified into 82 early-onset PE women, accompanied with 43 late-onset PE women. Additionally, PE women categorized into 59 mild PE women, together with 66 severe PE women. The genotyping and characterization of ACE*(Ins/Del) variant were applied using the PCR technique. Our findings indicated higher frequency of the ACE*(Del/Del) genotype and ACE*(D allele) with elevated risk of preeclampsia compared to normotensive controls under recessive (OR = 2.09, and p-value = 0.007), and allelic (OR = 1.75, and p-value = 0.012) models. In addition, testing logistic regression revealed that the levels of endothelin-1 and malondialdehyde exposed significant difference for the ACE*(Del/Del) genotype among early-onset and late-onset PE women (p-value = 0.024, and 0.23, respectively). Furthermore, carriers of the ACE*(Del/Del) genotype observed statistically significant with lower sodium concentrations among severe PE women (p-value = 0.034). The ACE*(Del/Del) genotype and ACE*(D allele) were associated with increased risk preeclampsia among gestational women. Furthermore, early-onset PE and late-onset PE were correlated with endothelin-1 and malondialdehyde concentrations among Egyptian women.

Blood and urine biomarkers of disease progression in IgA nephropathy

The prognosis of patients with IgA nephropathy (IgAN) is variable but overall not good. Almost all patients with IgAN are at risk of developing end-stage renal disease within their expected lifetime. The models presently available for prediction of the risk of progression of IgAN, including the International IgA Nephropathy Prediction Tool, consist of traditional clinical, pathological, and therapeutic indicators. Finding biomarkers to improve the existing risk prediction models or replace pathological indicators is important for clinical practice. Many studies have attempted to identify biomarkers for prediction of progression of IgAN, such as galactose-deficient IgA1, complement, a spectrum of protein biomarkers, non-coding RNA, and shedding cells. This article reviews the biomarkers of progression of IgAN identified in recent years, with a focus on those with clinical value, in particular the combination of multiple biomarkers into a biomarker spectrum. Future research should focus on establishing a model based primarily on biomarkers that can predict progression of IgAN and testing it in various patient cohorts.