Part 3 – Long-term side effects of hemolytic uremic syndrome (HUS)

This article is the third in a series of three that have been published at Food Poison Journal and Marlerblog, describing the process of HUS and the real long-term consequences.  See Parts 1 and 2.   

Adolescents and young adults with chronic kidney disease face a number of complications (Andreoli SP, Acute and Chronic Renal Failure in Children, 2009) including alterations in calcium and phosphate balance and renal osteodystrophy (softening of the bones, weak bones and bone pain), anemia (low blood count and lack of energy), hypertension (high blood pressure) as well as other complications.

Renal osteodystrophy (softening of the bones) is an important complication of chronic renal failure. Bone disease is nearly universal in patients with chronic renal failure; in some patients symptoms are minor to absent while others may develop bone pain, skeletal deformities and slipped epiphyses (abnormal shaped bones and abnormal hip bones) and have a propensity for fractures with minor trauma. Treatment of the bone disease associated with chronic renal failure includes control of serum phosphorus and calcium levels with restriction of phosphorus in the diet, supplementation of calcium, the need to take phosphorus binders and the need to take medications for bone disease.

Anemia (low blood cell count that leads to a lack of energy) is a very common complication of chronic renal failure. The kidneys make a hormone that tells the bone marrow to make red blood cells and this hormone is not produced in sufficient amounts in children with chronic renal failure. Thus, children with chronic renal failure gradually become anemic while their chronic renal failure is slowly progressing. The anemia of chronic renal failure is treated with human recombinant erythropoietin (a shot given under the skin one to three times a week or once every few weeks with a longer acting human recombinant erythropoietin).

Renal replacement therapy can be in the form of dialysis (peritoneal dialysis or hemodialysis) or renal transplantation. The average waiting time for a deceased donor kidney for children age 0-17 years is approximately 275-300 days while the average waiting time for patient’s age 18-44 years is approximately 700 days (United States Renal Data Systems, Table 7.8, 2005).

Following transplantation, a patient will need to take immunosuppressive medications for the remainder of his/her life to prevent rejection of the transplanted kidney. Medications used to prevent rejection have considerable side effects. Corticosteroids are commonly used following transplantation. The side effects of corticosteroids are Cushingnoid features (fat deposition around the cheeks and abdomen and back), weight gain, emotional liability, cataracts, decreased growth, osteomalacia and osteonecrosis (softening of the bones and bone pain), hypertension, acne and difficulty in controlling glucose levels.

Cyclosporine and/or tacrolimus are also commonly used as immunosuppressive medications following transplantation. Side effects of these drugs include hirsutism (increased hair growth), gum hypertrophy, interstitial fibrosis in the kidney (damage to the kidney), as well as other complications. Meclophenalate is also commonly used after transplantation (sometimes imuran is used); each of these drugs can cause a low white blood cell count and increased susceptibility to infection. Many other immunosuppressive medications and other medications (anti-hypertensive agents, anti-acids, etc.) are prescribed in the postoperative period.

Lifelong immunosuppression as used in patients with kidney transplants is associated with several complications including an increased susceptibility to infection, accelerated atherosclerosis (hardening of the arteries) and increased incidence of malignancy (cancer) and chronic rejection of the kidney.

A patient may need more than one kidney transplant during his/her life. United States Renal Data Systems (USRDS) report that the half-life (time at which 50% of the kidneys are still functioning and 50% have stopped functioning) is 10.5 years for a deceased transplant in children age 0-17 years and 15.5 years for a living related transplant in children 0-17 years. Similar data for a transplant at age 18 to 44 years is 10.1 years and 16.0 years for a deceased donor and a living related donor, respectively. Thus, depending upon age when the patient receives his/her first transplant he/she may need 1-2 transplants. The life expectancy of a person with a kidney transplant is significantly less than the general population and the life expectancy of person on dialysis a markedly less than the general population.

If and when a child needs a second kidney transplant after loss of his/her first transplant, he/she will need dialysis until a subsequent transplant can be performed. He/She can be on peritoneal dialysis or on hemodialysis. Peritoneal dialysis has been a major modality of therapy for chronic renal failure for several years. Continuous Ambulatory Peritoneal Dialysis (CAPD) and automated peritoneal dialysis also called Continuous Cycling Peritoneal Dialysis (CCPD) are the most common form of dialysis therapy used in children with chronic renal failure. In this form of dialysis, a catheter is placed in the peritoneal cavity (area around the stomach); dialysate (fluid to clean the blood) is placed into the abdomen and changed 4 to 6 times a day. Parents and adolescents are able to perform CAPD/CCPD at home. Peritonitis (infection of the fluid) is major complication of peritoneal dialysis.

E. coli O157:H7 and other shiga-toxin producing E. coli are very dangerous bacteria – especially to children. The acute phase – even for those who do not progress to hemolytic uremic syndrome (HUS) – can be a painful and frightening experience. For those who progress to HUS, the risk of death is real. And, even if the child survives, it may well be left with chronic health problems for the remainder of its life.