Gaston Zilleruelo

Highlights of Major Differences Between Children and Adults with HIV-Associated Nephropathy

Major differences between human immunodeficiency virus (HIV) associated nephropathy (HIVN) in children and HIVN in adults include the following: HIVN occurs in both HIV-1 + and AIDS adults, but apparently only in AIDS children. In HIVN patients, the virus has been transmitted to adult males mostly by intravenous drug use, and to adult females mostly by intercourse with infected males, but the virus has been transmitted to male and female infants and children by the mother. Renal histology changes in HIVN adults are mostly of the focal and segmental sclerosis (FSS) type, but FSS type changes are found in only one-third-one-half of HIVN children. The onset of chronic renal failure in adults heralds a rapid (few weeks) course to death, but in children the course is much slower (several months). Acute renal failure is rarely diagnosed in HIVN children while it is commonly diagnosed in HIVN adults.

Progression of Chronic Renal Disease in Children: The University of Miami Experience

Various reports have emphasized the multiplicity of causes leading to chronic renal failure (CRF) in children and the wide variety of clinical presentations of chronic renal disease in this age group (1–3). However, the definition of CRF has varied and the rate of progression of chronic renal disease to end stage renal disease (ESRD) seems to be quite variable (4, 5). Here, we shall review our experience with the different causes of CRF and the outcome of afflicted patients over a period of ten years. A total of 101 patients with CRF followed by the Division of Pediatric Nephrology at the University of Miami/Jackson Memorial Medical Center between 1972 and 1982 were included in this study. Chronic renal failure was defined as a persistent (over two months duration) and progressive decline In renal function to values 2 SD from the mean for age and sex (6). End stage renal disease was defined by a glomerular filtration rate 8 mg/dl.

Nutritional Aspects of Growth in Children with Congenital Renal Anomalies

The problem of the uremic dwarf is of primary concern to the pediatric nephrologist. The ultimate rehabilitation of the pediatric patient with progressive renal failure will depend on our ability to solve this dilemma. It is undoubtedly a multifaceted problem, since growth, normal and abnormal, is influenced by genetic, humoral, and nutritional factors.

Abnormal Lipid Metabolism in Primary Nephrotic Syndrome

The idiopathic nephrotic syndrome (NS) in children is usually defined by the presence of heavy proteinuria, hypoalbuminemia, edema and moderate to severe hyperlipidemia (1). Hyperlipidemia Type 2B with increase in serum cholesterol and triglycerides is the most common and recognized metabolic complication in patients with NS. However, the precise mechanisms involved in its pathogenesis, the associated clinical complications of hyperlipidemia and the best approach for its management are not well established.

Discussion: Renal Replacement Therapy Progression of Renal Disease and Transplantation

The Einstein Group in the 1960’s had an abstract showing that the rate of increase of GFR in infants after birth was influenced by the level of protein intake. What the study did not do was look at the parallel effect of increases of sodium and other nutrients that go along with the protein. In the human studies, have people controlled sodium intake, mineral content intake, and so on?

Mineral Metabolism in Patients on Continuous Ambulatory Peritoneal Dialysis

Since the pioneering reports describing continuous ambulatory peritoneal dialysis (CAPD) as a novel dialytic therapy (1, 2), it has become an accepted therapeutic modality for patients with end stage renal disease (ESRD). Because of its relative technical simplicity and compatibility with home dialysis, CAPD rapidly has become a suitable therapy for children, particularly small infants (3). Aspects pertaining to mineral metabolism and renal osteodystrophy (ROD) are of particular interest in the pediatric population, and require careful scrutiny in order to fully assess the potential benefits of CAPD.

Discussion: Primary Nephrotic Syndrome

Related to the problem of recurrence in transplants, we talked about recurrence of disease in FSS versus membranous proliferative. The recurrences in focal sclerosing are very complicated recurrences; they look a bit like chronic rejection. It is very difficult to tell whether one has late chronic rejection or true recurrence of focal sclerosis, unless one has the type of situation where proteinuria appears within a day or two. In two of our patients we have even seen actual proteinuria on the operating table at the time of the transplant, proteinuria in the first urine that comes out of the new kidney. In type II membrano-proliferative, where there is said to be a lot of recurrences, the recurrences consist of the presence of intra-membranous ribbon-like material within the basement membrane (tubular and glomerular). However, the clinical implication of this is not so severe; many of these patients do not have evidence of progressive renal disease, and in fact, do quite well. We have had the opportunity to do repeat biopsies in two patients who have recurrent type II MPGN; they have not had any decline in renal function. That is an important distinction. The fact that we get these intra-membranous deposits is an interesting observation but they may not mean that much in terms of the actual clinical course of the patient, at least over the four or five years of follow-up that we and other people have documented.

Discussion: Renal Replacement Therapy Dialysis

Plasma level of 1,25 Vitamin D in these children who were undergoing CAPD was 58, which is very reasonable, in fact, a perfectly normal level. What Vitamin D metabolite were they on? If they had been given anything other than 1,25 initially, one could interpret this in a different way.

Lipid Changes in Children on Dialysis

Hyperlipidemia (mainly with elevated triglyceride levels) is a frequent finding in uremic patients on dialysis. The reported incidence of hypertriglyceridemia in adults with end stage renal disease (ESRD), as well as in those patients undergoing chronic hemodialysis, varies from 30 to 70 percent (1). The predominant pattern of this hyperlipidemia is Type IV, consistent with an increase in total triglycerides (TG) and very low density lipoproteins (VLDL) with near normal total cholesterol (TC). Prospective epidemiologic studies in patients with and without renal disease indicate that the Type IV pattern is associated with an increased incidence of ischemic heart disease (2–3). The hyperlipidemia associated with uremia may begin in adults when creatinine clearance falls under 50 ml/min (4). It has been reported that hyperlipidemia in children also occur early in the course of chronic renal failure (CRF) when creatinine clearance falls below 40 ml/mln/1.73m2 (5). As renal function deteriorates serum triglyceride levels become significantly elevated and HDL levels markedly decrease, while serum total cholesterol, phospholipids and LDL remain essentially unchanged. These lipid abnormalities worsen further with the onset of hemodialysis (5).

Mineral Metabolism in Nephrotic Syndrome

Although hypocalcemia has been recognized for decades in patients with nephrotic syndrome (NS), it was initially simply related to the reduction in the protein-bound calcium fraction as a result of the heavy proteinuria (1, 2). Thus, true hypocalcemia (low ionized calcium) was assumed to be absent in NS and the observed low serum total calcium concentration was not considered as having clinical significance. However, with the advent of calcium specific electrodes, direct measurements of serum ionized calcium became available in patients with NS.