Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously ...estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the
Kidney and Pregnancy Study Group of the Italian Society of Nephrology
is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.
The number of pregnancies in women with pregestational diabetes has been steadily increasing worldwide. These pregnancies are associated with an increased risk of a variety of complications, ...including miscarriages, congenital malformations, macrosomia, fetal growth restriction, preeclampsia, preterm delivery and stillbirth. In pregnant women with diabetic nephropathy it is important to evaluate both the effect of pregnancy on kidney function and the effect of kidney disease on pregnancy outcomes. Pregnant women with normal renal function and microalbuminuria have a low risk of loss of kidney function during pregnancy, while women with GFR < 60 ml/min and/or proteinuria ≥ 3 g/24 h at the beginning of pregnancy are at risk of permanent kidney damage. The risk of fetal and maternal complications is associated with the severity of chronic kidney disease and glycemic control. Advances in prenatal care have improved fetal and maternal outcomes and preconception counseling has become key for a successful pregnancy in all women with diabetes and especially in those with diabetes and chronic kidney disease.
Autosomal dominant polycystic kidney disease (ADPKD) is a genetic kidney disease characterized by gradual kidney enlargement and progressive renal function loss. Pregnancy is a significant risk ...factor for adverse maternal and fetal outcomes in chronic kidney disease (CKD), regardless of the nephropathy. Women with ADPKD often face concerns about worsening their renal condition and passing the disease on to their offspring. Recent studies show better outcomes due to improved pregnancy surveillance and prior counseling. Risk factors for poor fetal and maternal outcomes include advanced maternal age, pre-existing hypertension, urinary infections, proteinuria, and renal failure.
Collaboration between nephrologists and gynecologists is essential for addressing clinically significant concerns in pregnant women with ADPKD. Nephrologists should play an active role in assisting and supporting pregnant ADPKD patients as part of a multidisciplinary team.
Comparison of mortality in ESRD patients on convective and diffusive extracorporeal treatments.
The aim of this study was to evaluate the effect of convective hemodiafiltration (HDF) or ...hemofiltration (HF) versus diffusive treatments hemodialysis (HD) on end-stage renal disease (ESRD) patient mortality and dialysis-related amyloidosis (DRA) using data from the Lombardy Registry.
For this purpose, 6,444 patients (aged 56.4 ± 15.6 years, females 39.5%, diabetics 10.6%) who started renal replacement therapy (RRT) on HD, HDF, or HF between 1983 and 1995 were considered. A total of 1,082 patients were treated with HDF or HF (first choice in the case of 188), with a median follow-up of 29.7 months. The median follow-up of the 6,298 patients on HD (first choice in the case of 6256) was 22.4 months. The time of survival on dialysis to carpal tunnel syndrome (CTS) surgery was evaluated as a hard marker of DRA morbidity. Survival was compared by means of the Cox proportional regression hazards model, using CTS surgery and all deaths as events for morbidity and mortality, respectively. Explanatory covariates were age, gender, and comorbidities; dialysis modality was tested as a time-dependent covariate.
The relative risk (RR) for CTS surgery was significantly higher in older patients RR = 1.04 per year of age on admission to RRT, 95% confidence interval (CI) 1.02 to 1.06; P = 0.0001, in diabetics (RR = 2.63, 95% CI 1.30 to 5.31; P = 0.0007), and in patients with heart disease (RR = 5.36, 95% CI 2.27 to 12.68 P = 0.0001). Adjusting for age and diabetic status, the RR for CTS surgery was 42% lower in the patients treated with HDF or HF (RR = 0.58, 95% CI 0.35 to 0.95, P = 0.03). The RR for mortality, adjusted for age, gender, and comorbidities, was 10% lower in patients treated with HDF or HF (RR = 0.90, 95% CI 0.76 to 1.06; P = NS).
These results support the hypothesis that convective treatments are associated with a nonsignificant trend toward better survival and significantly delay the need for CTS surgery. An older age and the presence of diabetes and heart disease are other important risk factors for CTS surgery. These results could have an important clinical impact given the relevance of DRA in dialysis patient morbidity.
Single nucleotide polymorphisms (SNPs) of the calcium-sensing receptor (CASR) gene at the regulatory region were associated with idiopathic calcium nephrolithiasis. To confirm their association with ...nephrolithiasis, we tested patients with primary hyperparathyroidism (PHPT).
A genotype-phenotype association study.
In all, 332 PHPT patients and 453 healthy controls were genotyped for the rs7652589 (G>A) and rs1501899 (G>A) SNPs sited in the noncoding regulatory region of the CASR gene. Allele, haplotype, and diplotype distribution were compared between PHPT patients and controls, and in stone forming and stone-free PHPT patients.
The allele frequency at rs7652589 and rs1501899 SNPs was similar in PHPT patients and controls. The A minor alleles at these two SNPs were more frequent in stone forming (n=157) than in stone-free (n=175) PHPT patients (rs7652589: 36.9 vs 27.1%, P=0.007; rs1501899: 37.1 vs 26.4%, P=0.003). Accordingly, homozygous or heterozygous PHPT patients for the AA haplotype (n=174, AA/AA or AA/GG diplotype) had an increased stone risk (odds ratio 1.83, 95% confidence interval 1.2-2.9, P=0.008). Furthermore, these PHPT patients had higher serum concentrations of ionized calcium and parathyroid hormone (1.50 ± 0.015 mmol/l and 183 ± 12.2 pg/ml) than patients with the GG/GG diplotype (n=145, 1.47 ± 0.011 mmol/l (P=0.04) and 150 ± 11.4 pg/ml (P=0.049)). Using a logistic regression model, the increase in stone risk in PHPT patients was predicted by AA/AA or AA/GG diplotype, the highest tertile of serum ionized calcium values and the lowest tertile of age.
Polymorphisms located in the regulatory region of the CASR gene may increase susceptibility of the PHPT patients to kidney stone production.
Membranous Nephropathy (MN) is a rare autoimmune cause of kidney failure. Here we report a genome-wide association study (GWAS) for primary MN in 3,782 cases and 9,038 controls of East Asian and ...European ancestries. We discover two previously unreported loci, NFKB1 (rs230540, OR = 1.25, P = 3.4 × 10
) and IRF4 (rs9405192, OR = 1.29, P = 1.4 × 10
), fine-map the PLA2R1 locus (rs17831251, OR = 2.25, P = 4.7 × 10
) and report ancestry-specific effects of three classical HLA alleles: DRB1*1501 in East Asians (OR = 3.81, P = 2.0 × 10
), DQA1*0501 in Europeans (OR = 2.88, P = 5.7 × 10
), and DRB1*0301 in both ethnicities (OR = 3.50, P = 9.2 × 10
and OR = 3.39, P = 5.2 × 10
, respectively). GWAS loci explain 32% of disease risk in East Asians and 25% in Europeans, and correctly re-classify 20-37% of the cases in validation cohorts that are antibody-negative by the serum anti-PLA2R ELISA diagnostic test. Our findings highlight an unusual genetic architecture of MN, with four loci and their interactions accounting for nearly one-third of the disease risk.
Kidney transplantation (KT) is often considered to be the method best able to restore fertility in a woman with chronic kidney disease (CKD). However, pregnancies in KT are not devoid of risks (in ...particular prematurity, small for gestational age babies, and the hypertensive disorders of pregnancy). An ideal profile of the potential KT mother includes “normal” or “good” kidney function (usually defined as glomerular filtration rate, GFR ≥ 60 ml/min), scant or no proteinuria (usually defined as below 500 mg/dl), normal or well controlled blood pressure (one drug only and no sign of end-organ damage), no recent acute rejection, good compliance and low-dose immunosuppression, without the use of potentially teratogen drugs (mycophenolic acid and m-Tor inhibitors) and an interval of at least 1–2 years after transplantation. In this setting, there is little if any risk of worsening of the kidney function. Less is known about how to manage “non-ideal” situations, such as a pregnancy a short time after KT, or one in the context of hypertension or a failing kidney. The aim of this position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology is to review the literature and discuss what is known about the clinical management of CKD after KT, with particular attention to women who start a pregnancy in non-ideal conditions. While the experience in such cases is limited, the risks of worsening the renal function are probably higher in cases with markedly reduced kidney function, and in the presence of proteinuria. Well-controlled hypertension alone seems less relevant for outcomes, even if its effect is probably multiplicative if combined with low GFR and proteinuria. As in other settings of kidney disease, superimposed preeclampsia (PE) is differently defined and this impairs calculating its real incidence. No specific difference between non-teratogen immunosuppressive drugs has been shown, but calcineurin inhibitors have been associated with foetal growth restriction and low birth weight. The clinical choices in cases at high risk for malformations or kidney function impairment (pregnancies under mycophenolic acid or with severe kidney-function impairment) require merging clinical and ethical approaches in which, beside the mother and child dyad, the grafted kidney is a crucial “third element”.
Claudin-16 and -19 are proteins forming pores for the paracellular reabsorption of divalent cations in the ascending limb of Henle loop; conversely, claudin-14 decreases ion permeability of these ...pores. Single-nucleotide polymorphisms in gene coding for
were associated with kidney stones and calcium excretion. This study aimed to explore the association of
,
, and
single-nucleotide polymorphisms with calcium excretion.
We performed a retrospective observational study of 393 patients with hypertension who were naïve to antihypertensive drugs, in whom we measured 24-hour urine calcium excretion; history of kidney stones was ascertained by interview; 370 of these patients underwent an intravenous 0.9% sodium chloride infusion (2 L in 2 hours) to evaluate the response of calcium excretion in three different 2-hour urine samples collected before, during, and after saline infusion. Genotypes of
,
, and
were obtained from data of a previous genome-wide association study in the same patients.
Thirty-one single-nucleotide polymorphisms of the 3' region of the
gene were significantly associated with 24-hour calcium excretion and calcium excretion after saline infusion. The most significant associated single-nucleotide polymorphism was rs219755 (24-hour calcium excretion in GG, 225±124 mg/24 hours; 24-hour calcium excretion in GA, 194±100 mg/24 hours; 24-hour calcium excretion in AA, 124±73 mg/24 hours;
<0.001; calcium excretion during saline infusion in GG, 30±21 mg/2 hours; calcium excretion during saline infusion in GA, 29±18 mg/2 hours; calcium excretion during saline infusion in AA, 17±11 mg/2 hours;
=0.03). No significant associations were found among
and
single-nucleotide polymorphisms and calcium excretion and between
,
, and
single-nucleotide polymorphisms and stones. Bioinformatic analysis showed that one single-nucleotide polymorphism at
among those associated with calcium excretion may potentially influence splicing of transcript.
genotype at the 3' region is associated with calcium excretion in 24-hour urine and after the calciuretic stimulus of saline infusion.
T regulatory type 1 (Tr1) cell-mediated induction of tolerance in preclinical models of transplantation is remarkably effective. The clinical application of such a therapy in patients on dialysis ...undergoing kidney transplantation should take into account the possible alterations of the immune system observed in these patients. Herein, we aimed at testing the ability to generate donor-specific Tr1 cell-enriched lymphocytes from patients on dialysis on the waiting list for kidney transplantation.
The Tr1 cell-enriched lymphocytes were generated by coculturing interleukin-10-producing dendritic cells obtained from healthy donors with peripheral blood mononuclear cells (PBMCs) of patients on dialysis, following the same protocol used in a previous cell therapy clinical trial to prevent graft-versus-host disease. Alternatively, purified CD4(+) T cells were used instead of total PBMCs. The ability to generate clinical-grade Tr1 cell-enriched products was defined by testing the reduced response to restimulation with mature dendritic cells generated from the original donor (i.e., anergy assay).
The Tr1 cell-enriched medicinal products generated from PBMCs of patients on dialysis showed a low anergic phenotype, incompatible with their eventual clinical application. This was irrespective of HLA matching with the donor or the intrinsically reduced ability to proliferate in response to alloantigens. On the contrary, the use of purified CD4(+) T cells isolated from patients on dialysis led to the generation of a highly anergic donor-specific medicinal product containing an average of 10% Tr1 cells.
The Tr1 cell-enriched medicinal products can be efficiently generated from patients on dialysis by carefully tailoring the protocol on the patients' immunological characteristics.
Even though fertility is reduced, conception and delivery are possible in all stages of CKD. While successful planned pregnancies are increasing, an unwanted pregnancy may have long-lasting ...deleterious effects, hence the importance of birth control, an issue often disregarded in clinical practice. The evidence summarized in this position statement is mainly derived from the overall population, or other patient categories, in the lack of guidelines specifically addressed to CKD. Oestroprogestagents can be used in early, non-proteinuric CKD, excluding SLE and immunologic disorders, at high risk of thromboembolism and hypertension. Conversely, progestin only is generally safe and its main side effect is intramestrual spotting. Non-medicated intrauterine devices are a good alternative; their use needs to be carefully evaluated in patients at a high risk of pelvic infection, even though the degree of risk remains controversial. Barrier methods, relatively efficacious when correctly used, have few risks, and condoms are the only contraceptives that protect against sexually transmitted diseases. Surgical sterilization is rarely used also because of the risks surgery involves; it is not definitely contraindicated, and may be considered in selected cases. Emergency contraception with high-dose progestins or intrauterine devices is not contraindicated but should be avoided whenever possible, even if far preferable to abortion. Surgical abortion is invasive, but experience with medical abortion in CKD is still limited, especially in the late stages of the disease. In summary, personalized contraception is feasible, safe and should be offered to all CKD women of childbearing age who do not want to get pregnant.
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