Renal deposits of complement factors as predictors of end-stage renal disease and death in patients with lupus nephritis.

OBJECTIVE: Lupus nephritis (LN) increases the risks of end-stage renal disease (ESRD) and death, but these risks are difficult to estimate. Since complement factors play an essential role in the pathogenesis and are deposited in the kidneys as C1q and C3, we studied whether these deposits predict ESRD and death in patients with LN. METHODS: We collected demographic, clinical and pathological data from 183 adult patients with LN classes II-V diagnosed with a first native kidney biopsy. Pathological data included the localization and intensity of immunofluorescence staining of C1q and C3. We obtained dates of incident ESRD and death from the United States Renal Data System and National Death Index, respectively, and evaluated survival curves and hazard ratios for ESRD and death as a composite outcome and as separate outcomes. RESULTS: The presence and intensity of deposits of C1q and C3 in glomeruli, tubular walls and vascular walls differed between classes and were associated with known unfavourable prognostic factors, such as hypertension, hypoalbuminemia and hypocomplementemia. However, over a median follow-up of 7.5 years, their presence and intensity were associated with neither survival free of ESRD and death nor hazard ratios for ESRD and death. CONCLUSION: Renal deposits of complement factors did not predict ESRD and death in patients with LN.

Deposition of the Membrane Attack Complex in Healthy and Diseased Human Kidneys.

The membrane attack complex-also known as C5b-9-is the end-product of the classical, lectin, and alternative complement pathways. It is thought to play an important role in the pathogenesis of various kidney diseases by causing cellular injury and tissue inflammation, resulting in sclerosis and fibrosis. These deleterious effects are, consequently, targeted in the development of novel therapies that inhibit the formation of C5b-9, such as eculizumab. To clarify how C5b-9 contributes to kidney disease and to predict which patients benefit from such therapy, knowledge on deposition of C5b-9 in the kidney is essential. Because immunohistochemical staining of C5b-9 has not been routinely conducted and never been compared across studies, we provide a review of studies on deposition of C5b-9 in healthy and diseased human kidneys. We describe techniques to stain deposits and compare the occurrence of deposits in healthy kidneys and in a wide spectrum of kidney diseases, including hypertensive nephropathy, diabetic nephropathy, membranous nephropathy, IgA nephropathy, lupus nephritis, C3 glomerulopathy, and thrombotic microangiopathies such as the atypical hemolytic uremic syndrome, vasculitis, interstitial nephritis, acute tubular necrosis, kidney tumors, and rejection of kidney transplants. We summarize how these deposits are related with other histological lesions and clinical characteristics. We evaluate the prognostic relevance of these deposits in the light of possible treatment with complement inhibitors.

Optimizing the Use of Geriatric Livers for Transplantation in the Eurotransplant Region.

Acceptance criteria for liver allografts are ever more expanding because of a persisting wait-list mortality. Older livers are therefore offered and used more frequently for transplantation. This study aims to analyze the use and longterm outcome of these transplantations. Data were included on 17,811 first liver transplantations (LTs) and information on livers that were reported for allocation but not transplanted from 2000 to 2015 in the Eurotransplant (ET) region. Graft survival was defined as the period between transplantation and date of retransplantation or date of recipient death. In the study period, 2394 (13%) transplantations were performed with livers ≥70 years old. Graft survival was 74%, 57%, and 41% at 1-, 5-, and 10-year follow-up, respectively. A history of diabetes mellitus in the donor (hazard ratio [HR], 1.3; P = 0.01) and positive hepatitis C virus antibody in the recipient (HR, 1.5; P < 0.001) are specific risk factors for transplantations with livers ≥70 years old. Although donor age is associated with a linearly increasing risk of graft loss between 25 and 80 years old, no difference in graft survival could be observed when "preferred" recipients were transplanted with a liver <70 or ≥70 years old (HR 1.1; CI 0.92-1.23, P = 0.40) or with a donor <40 or ≥70 years old (HR 1.2; CI 0.96-1.37, P = 0.13). Utilization of reported livers ≥70 years old increased from 42% in 2000-2003 to 76% in 2013-2015 without a decrease in graft survival (P = 0.45). In conclusion, an important proportion of LTs in the ET region are performed with livers ≥70 years old. The risk of donor age on graft loss increases linearly between 25 and 80 years old. Livers ≥70 years old can, however, be transplanted safely in preferred patients and are to be used more frequently to further reduce wait-list mortality.

Effect of APOE ε4 allele on survival and fertility in an adverse environment.

BACKGROUND: The apolipoprotein-ε4 allele (APOE-ε4) is strongly associated with detrimental outcomes in affluent populations including atherosclerotic disease, Alzheimer's disease, and reduced lifespan. Despite these detrimental outcomes, population frequencies of APOE-ε4 are high. We hypothesize that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility. METHODS AND FINDINGS: This rural Ghanaian population (n = 4311) has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years) and fertility after stratifying by exposure to high or low pathogen levels. Households drawing water from open wells and rivers were classified as exposed to high pathogen levels while low pathogen exposure was classified as those drawing water from borehole wells. We found a non-significant, but positive survival benefit, i.e. the hazard ratio per APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05), adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842), APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed to high pathogen levels. Compared with women not carrying an APOE-ε4 allele, those carrying one APOE-ε4 allele had on average one more child and those carrying two APOE-ε4 alleles had 3.5 more children (p = 0.018). CONCLUSIONS: Contrary to affluent modern-day populations, APOE-ε4 did not carry a survival disadvantage in this rural Ghanaian population. Moreover, APOE-ε4 promotes fertility in highly infectious environments. Our findings suggest that APOE-ε4 may be considered as evolutionarily adaptive. Its adverse associations in affluent modern populations with later onset diseases of aging further characterize APOE-ε4 as an example of antagonistic pleiotropy.

Measuring senescence rates of patients with end-stage renal disease while accounting for population heterogeneity: an analysis of data from the ERA-EDTA Registry.

PURPOSE: Although a population's senescence rate is classically measured as the increase in mortality rate with age on a logarithmic scale, it may be more accurately measured as the increase on a linear scale. Patients on dialysis, who suffer from accelerated senescence, exhibit a smaller increase in their mortality rate on a logarithmic scale, but a larger increase on a linear scale than patients with a functioning kidney transplant. However, this comparison may be biased by population heterogeneity. METHODS: Follow-up data on 323,308 patients on dialysis and 91,679 patients with a functioning kidney transplant were derived from the ERA-EDTA Registry. We measured the increases in their mortality rates using Gompertz frailty models that allow individual variation in this increase. RESULTS: According to these models, the senescence rate measured as the increase in mortality rate on a logarithmic scale was smaller in patients on dialysis, while the senescence rate measured as the increase on a linear scale was larger in patients on dialysis than patients with a functioning kidney transplant. CONCLUSIONS: Also when accounting for population heterogeneity, a population's senescence rate is more accurately measured as the increase in mortality rate on a linear scale than a logarithmic scale.

Genetic variants determining survival and fertility in an adverse African environment: a population-based large-scale candidate gene association study.

Human survival probability and fertility decline strongly with age. These life history traits have been shaped by evolution. However, research has failed to uncover a consistent genetic determination of variation in survival and fertility. As an explanation, such genetic determinants have been selected in adverse environments, in which humans have lived during most of their history, but are almost exclusively studied in populations in modern affluent environments. Here, we present a large-scale candidate gene association study in a rural African population living in an adverse environment. In 4387 individuals, we studied 4052 SNPs in 148 genes that have previously been identified as possible determinants of survival or fertility in animals or humans. We studied their associations with survival comparing newborns, middle-age adults, and old individuals. In women, we assessed their associations with reported and observed numbers of children. We found no statistically significant associations of these SNPs with survival between the three age groups nor with women's reported and observed fertility. Population stratification was unlikely to explain these results. Apart from a lack of power, we hypothesise that genetic heterogeneity of complex phenotypes and gene-environment interactions prevent the identification of genetic variants explaining variation in survival and fertility in humans.

Measuring aging rates of mice subjected to caloric restriction and genetic disruption of growth hormone signaling.

Caloric restriction and genetic disruption of growth hormone signaling have been shown to counteract aging in mice. The effects of these interventions on aging are examined through age-dependent survival or through the increase in age-dependent mortality rates on a logarithmic scale fitted to the Gompertz model. However, these methods have limitations that impede a fully comprehensive disclosure of these effects. Here we examine the effects of these interventions on murine aging through the increase in age-dependent mortality rates on a linear scale without fitting them to a model like the Gompertz model. Whereas these interventions negligibly and non-consistently affected the aging rates when examined through the age-dependent mortality rates on a logarithmic scale, they caused the aging rates to increase at higher ages and to higher levels when examined through the age-dependent mortality rates on a linear scale. These results add to the debate whether these interventions postpone or slow aging and to the understanding of the mechanisms by which they affect aging. Since different methods yield different results, it is worthwhile to compare their results in future research to obtain further insights into the effects of dietary, genetic, and other interventions on the aging of mice and other species.

Disentangling rectangularization and life span extension with the moving rectangle method.

PURPOSE: The moving rectangle method is used to disentangle the contributions of rectangularization and life span extension to the increase in life expectancy. It requires the choice of an endpoint of the survival curve that approaches the maximum age at death. We examined the effect of choosing different end points on the outcomes of this method. METHODS: For five developed countries, survival curves from age 50 years were constructed per calendar year from 1922 onward. Survival values of 0.1, 0.01, and 0.001 were chosen as end points of the survival curve, and the contributions of rectangularization and life span extension to the increase in life expectancy were calculated using the moving rectangle method. RESULTS: The choice of different survival values as end points profoundly influenced the estimated contributions of rectangularization and life span extension to the increase in life expectancy. When choosing 0.001, rectangularization contributed most years, whereas when choosing 0.1, life span extension contributed most years. CONCLUSIONS: When the moving rectangle method is used to estimate the contributions of rectangularization and life span extension to the increase in life expectancy, its outcomes depend on the choice of the endpoint of the survival curve.

An Emerging Epidemic of Noncommunicable Diseases in Developing Populations Due to a Triple Evolutionary Mismatch.

With their transition from adverse to affluent environments, developing populations experience a rapid increase in the number of individuals with noncommunicable diseases. Here, we emphasize that developing populations are more susceptible than western populations to acquire these chronic diseases, because their genetic, cultural, and epigenetic characteristics do not match with the eagerly awaited affluent environments. In regard to this, there is an urgent need for public health organizations to reorganize current environments in developing populations so as to fit their inherited characteristics. Unfortunately, this need is neglected as an essential part of the Sustainable Development Goals that form the core of the United Nations' Post-2015 Development Agenda. Only through global collaborative efforts can the environments in developing populations be reorganized and, thereby, the emerging epidemic of noncommunicable diseases be stalled.