Year : 1997 | Volume
: 8 | Issue : 3 | Page : 224--226
The Special Issue on Pediatric Nephrology: A Trailer
Saudi Center for Organ Transplantation, Riyadh, Saudi Arabia
K S Ramprasad
Consultant Nephrologist, Saudi Center for Organ Transplantation, P.O. Box 27049, Riyadh 11417, Riyadh
|How to cite this article:|
Ramprasad K S. The Special Issue on Pediatric Nephrology: A Trailer.Saudi J Kidney Dis Transpl 1997;8:224-226
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Ramprasad K S. The Special Issue on Pediatric Nephrology: A Trailer. Saudi J Kidney Dis Transpl [serial online] 1997 [cited 2020 Nov 28 ];8:224-226
Available from: https://www.sjkdt.org/text.asp?1997/8/3/224/39348
Pediatric nephrology has emerged as a sub-speciality of immense importance in recent years. Its significance becomes evident when one realizes that, at least in the developing countries, children and adolescents below 18 years of age comprise about half the population. In addition, there are certain renal disorders that are peculiar to children, e.g., congenital nephrotic syndrome. Some other disorders like reflux nephropathy may be present from childhood and if unrecognized, may result in chronic renal failure (CRF) in adult life. Another important facet, which has received a great deal of attention recently is growth in children with renal disease. All these special features underscore the importance of pediatric nephrology and prompted the editorial board of the Saudi Journal of Kidney Diseases and Transplantation to devote a special issue to this very vital subspeciality.
Hereditary renal diseases are very diverse in nature and are excellently reviewed by Dr. Grunfeld. These disorders can be broadly classified into: a) cystic diseases of the kidney, b) Alport's syndrome and related diseases, c) inherited metabolic and non-metabolic disorders with kidney involvement and d) inherited renal tubular disorders. It is emphasized that most hereditary renal diseases often manifest for the first time in adult life and thus all physicians, and not just pediatricians, should be aware of these disorders. Progress in molecular genetics has contributed greatly to our understanding of the general mechanisms of these diseases.
Renal tubular acidosis (RTA) is a clinical syndrome that all physicians should be familiar with, and correct management will help ameliorate nephrocalcinosis, rickets and growth failure. In their review, Dr. Saborio, et al have given a detailed description of the types of RTA including pathogenesis, diagnosis and management of each. The authors summarize that treatment of RTA is orientated towards correcting mineral and acid-base disturbances and prevention of nephrocalcinosis. If treatment is started early enough, it is possible to achieve improvement in growth velocity and adequate pubertal development.
In his article, Dr. Sanjad has given a detailed account of the various renal tubular disorders and has included his own experience in Riyadh. The renal tubular disorders present as specific transport defects of one or multiple solutes with little or no glomerular involvement. Since most of these disorders are hereditary in nature, their frequency is expected to be high in places like Saudi Arabia, where consanguineous marriages are common. Dr. Sanjad has classified these disorders into proximal tubular disorders which are due to: a) absent or defective sodium-solute co-transport system as seen in cystinuria, vitamin D resistant rickets and proximal tubular acidosis, b) altered genes affecting more than one transport system, e.g., Fanconi syndrome and c) mutant genes resulting in endogenous tubulotoxic pathways, e.g., cystinosis, galactosuria etc.
The distal tubulopathies fall under three main categories: a) impaired urinary acidification and hydrogen ion secretion as in RTA, b) impaired urinary concentration e.g., nephrogenic diabetes insipidus and c) disorders of impaired cation absorption or secretion. The author states that glycogen storage diseases followed by cystinosis and tyrosinemia were the most common tubulopathies seen in Riyadh while Bartter's syndrome, renal tubular acidosis and familial hypomagnesemia hypercalciuria were the most commonly observed distal tubulopathies. The acquired tubulopathies were primarily associated with underlying tubulointerstitial or obstructive nephropathy or associated with drugs such as aminoglycosides, amphotericin B etc.
Dr. Chevalier, in his outstanding paper mentions how acute renal failure (ARF) in the neonate differs from that in older children and adults and that many cases of neonatal ARF are the consequence of intra-uterine or perinatal events. He classifies the causes of ARF in the neonate into: a) asphyxia/circulating disorders including pre-renal and parenchymal disorders, b) congenital malformation/cystic disorders and c) toxic nephropathies. If renal failure is prolonged, peritoneal dialysis is the preferred renal replacement therapy preferably with a neonatal single cuff Tenckhoff silastic catheter which is placed surgically. Dwell times should never exceed one hour because of the higher permeability of the neonatal peritoneal membrane. Continuous venovenous hemofiltration is also useful in infants with ARF. Mortality still exceeds 50% and death generally results from non-renal causes. The article of Dr. Rahman, et al presents the medical management of CRF in children in a nutshell. The authors state that proper management should focus on the following aspects: a) promoting linear growth, b) preventing osteodystrophy, c) correcting anemia, d) preventing metabolic acidosis, e) maintaining fluid and electrolyte balance and f) controlling hypertension.
Dr. Abdurrahman outlines the importance of achieving optimal growth in children with chronic renal diseases. The factors that contribute to growth failure in these children include age at onset and natural history of the renal disease, calorie and protein malnutrition, anemia, biochemical derange-ments, renal osteodystrophy, hormonal disturbances and psychosocial problems. Management is complex and involves physicians, nurses, dieticians and social workers.
Recent knowledge showing the efficacy of recombinant human growth hormone has been stressed. However, the optimal dose of this drug as well as duration of therapy have not been fully established. Also, concern has been expressed regarding its side effects including pseudotumor cerebri and renal allograft rejection. However, the ultimate goal should be early renal transplantation and improvement in growth following transplantation is most likely to occur in children under seven years of age.
Dr. Balfe has given a very clear picture of the use of continuous peritoneal dialysis (CPD) in children. We learn that currently, CPD is the predominant mode of renal replacement therapy (RRT) in children. The various events in a child on CPD including growth and nutrition, renal osteodystrophy, anemia and training to be imparted have all been dealt with in detail. The complications that continue to pose problems are peritonitis, hernias and stress. The author emphasizes that there is ample scope for improvement in areas such as techniques to assess dialysis adequacy, composition of dialysis solutions including pH, osmolality and different osmotic agents, additives to the dialysis fluid such as hormones and growth factors, catheters and cycles and lastly, strategies to reduce peritonitis rates. Reference is also made to possible genetic engineering of the peritoneal mesothelial cell to produce erythropoietin, vitamin D and growth hormone.
Dr. Al-Sabban has presented the spectrum of glomerular disease among children in Saudi Arabia albeit from one city. The commonest glomerulopathy encountered was focal and segmental glomerulosclerosis. The data presented are indeed useful in the absence of a renal disease registry in Saudi Arabia. The author speculates that the high prevalence of focal and segmental glomerulosclerosis could be related to the fact that the patient group was a highly selective one.
The paper of Dr. Al Menawy, et al stresses the safety of percutaneous renal biopsy in children and adolescents. The noteworthy findings are a 100% success rate in obtaining adequate tissue and about 10% incidence of minor complications. Emphasis is laid on the experience of the person performing the biopsy as well as the use of ultrasound guidance to achieve such good results. Another important message is that renal biopsy can be performed even as a daycare procedure without compromising on safety.
Dr. Al-Harbi has presented some useful data on CRF in children in the Asir region of Saudi Arabia. The reported incidence for CRF and end-stage renal disease (ESRD) in children below 12 years of age were respectively 15.6 and 9.2 per million children. Urinary system anomalies constituted the leading cause followed by glomerulopathies. The authors stress on the importance of early diagnosis and perhaps curative treatment of these anomalies in order to decrease the incidence of CRF in the pediatric population.
Dr. Al-Salloum, et al have described their experience with CAPD in children. In their study involving 43 children, reflux nephropathy constituted the commonest cause of ESRD. The total period of CAPD was 579 patientmonths. The overall incidence of peritonitis was high with gram positive organisms being the commonest pathogens. The authors conclude that CAPD is a viable form of RRT in children in Saudi Arabia and greater efforts are needed to make it more popular.
Dr. Souqiyyeh, et al has presented some very interesting and encouraging data on pediatric renal transplantation in Saudi Arabia. They have analyzed 124 renal transplant recipients from four major renal transplant centers in Saudi Arabia. The results are indeed gratifying with a five-year graft survival of 92.2% in living donor transplants and 82.7% in the cadaver donor group. A noteworthy finding was that recipients below the age of five years had better graft survival when compared with older age-groups. It is indeed heartening to learn that pediatric renal transplantation has been performing well in Saudi Arabia.
We learn from Abu-Chaaban, et al that nephrotic syndrome is the commonest pediatric renal problem seen in Dubai followed by urinary tract infection and congenital renal anomalies. The highlight of the paper is the relative high prevalence of cystinosis particularly among patients of Palestinian origin, all of whom had consanguineous parents.
Dr. Hazza, et al reports that nephrotic syndrome is the commonest pediatric renal disease in Jordan. Also, the commonest cause of CRF was reflux nephropathy followed by here dofamilial causes. The authors report a high mortality among their patients with ESRD and implicate inadequate facilities, delay in commencement of dialysis and/or poor patient compliance for this high mortality. These factors may be common to all developing countries.
Dr. Kamoun from Tunisia has presented data on CRF in children from his country. He reports an incidence for ESRD of seven cases per million children per year. Again, hereditary nephropathies were the leading cause followed by glomerulonephritis and malformative uropathies.
In conclusion, the commonest renal diseases seen in the pediatric age-group are congenital renal anomalies and glomerulopathies. It is important to diagnose the former group early because many lesions are potentially correctable. In those patients who develop ESRD, CPD seems to be a viable form of dialysis although the ultimate goal should be early renal transplantation the results of which are encouraging. Future trends should focus on intra-uterine diagnosis of congenital renal anomalies, genetic studies and counseling, improvement in growth promotion as well as technical improvements in renal replacement therapy including dialysis and transplantation.