Iatrogenic hyperuricemia in children with cystic fibrosis

Symptoms, burden, and unmet needs of patients living with exocrine pancreatic insufficiency: a narrative review of the patient experience

Exocrine pancreatic insufficiency (EPI) stems from a deficiency of functional pancreatic enzymes with consequent maldigestion and malnutrition. EPI shares clinical symptoms and manifestations with other disorders and is a considerable burden to individuals affected. In this narrative review, we analyzed the literature to identify relevant publications on living with EPI with the scope of individuating evidence gaps, including those related to symptoms, health-related quality of life (HRQoL), emotional functioning, disease burden, presence of comorbidities, and the use of pancreatic enzyme replacement therapy (PERT). Abdominal pain emerged as one of the most prominent symptoms. HRQoL was affected in EPI, but no articles examined emotional functioning. Comorbidities reported involved other pancreatic disorders, diabetes, gastrointestinal disorders, sarcopenia and osteopenia, cardiovascular disorders, bacterial overgrowth, and nutritional deficiencies. PERT was found to be effective in improving EPI symptoms and was well tolerated by most individuals. Our review revealed a dearth of literature evidence on patients' experience with EPI, such as emotional functioning and disease burden. We also revealed that studies on long-term effects of PERT are missing, as are studies that would help advance the understanding of the disease and its progression, risk/mitigating factors, and comorbidities. Future studies should address these identified gaps.

Pancrelipase: an evidence-based review of its use for treating pancreatic exocrine insufficiency

Pancreatic exocrine insufficiency (PEI) is often observed in patients with pancreatic diseases, including chronic pancreatitis, cystic fibrosis, and tumors, or after surgical resection. PEI often results in malnutrition, weight loss and steatorrhea, which together increase the risk of morbidity and mortality. Therefore, nutritional interventions, such as low-fat diets and pancreatic enzyme replacement therapy (PERT), are needed to improve the clinical symptoms, and to address the pathophysiology of pancreatic exocrine insufficiency. PERT with delayed-release pancrelipase is now becoming a standard therapy for pancreatic exocrine insufficiency because it significantly improves the coefficients of fat and nitrogen absorption as well as clinical symptoms, without serious treatment-emergent adverse events. The major adverse events were tolerable gastrointestinal tract symptoms, such as stomach pain, nausea, and bloating. Fibrosing colonopathy, a serious complication, is associated with high doses of enzymes. Several pancrelipase products have been approved by the US Food and Drug Administration in recent years. Although many double-blind, placebo-controlled trials of pancrelipase products have been conducted in recent years, these studies have enrolled relatively few patients and have often been less than a few weeks in duration. Moreover, few studies have addressed the issue of pancreatic diabetes, a type of diabetes that is characterized by frequent hypoglycemia, which is difficult to manage. In addition, it is unclear whether PERT improves morbidity and mortality in such settings. Therefore, large, long-term prospective studies are needed to identify the optimal treatment for pancreatic exocrine insufficiency. The studies should also examine the extent to which PERT using pancrelipase improves mortality and morbidity. The etiology and severity of pancreatic exocrine insufficiency often differ among patients with gastrointestinal diseases or diabetes (type 1 and type 2), and among elderly subjects. Finally, although there is currently limited clinical evidence, numerous extrapancreatic diseases and conditions that are highly prevalent in the general population may also be considered potential targets for PERT and related treatments.

Gout and hyperuricaemia in adults with cystic fibrosis

Gout has not been described previously as a complication in cystic fibrosis (CF). Here we present data on nine CF patients who have presented with symptoms of acute gout. This gives an estimated prevalence of gout of around 2.5% in our adult CF population, compared to a previously described prevalence in the non-CF population of just over 1%. Serum urate is measured routinely at the annual review in our unit. Mean (SD) serum urate was 0.40 (0.09) mmol/L in male CF patients (n = 108) and 0.31 (0.08) mmol/L in female patients (n = 74). This was significantly greater than in historical controls. Thirty-seven percent of male CF patients and 36% of female patients had serum urate levels above the upper limit of normal.

A comparison of the efficacy and tolerance of pancrelipase and placebo in the treatment of steatorrhea in cystic fibrosis patients with clinical exocrine pancreatic insufficiency

OBJECTIVE

The safety and efficacy of Minimicrospheres, which are enteric-coated, delayed-release pancrelipase capsules, on fat absorption in pediatric/adolescent and adult cystic fibrosis (CF) patients was assessed. Exocrine pancreatic insufficiency, common in CF patients, causes steatorrhea due to insufficient release of pancreatic enzymes.

METHODS

In the open-label phase, 97 CF patients with pancreatic insufficiency and steatorrhea were stabilized on a high-fat diet and administered pancrelipase. Seventy-four patients with >80% coefficient of fat absorption received placebo or pancrelipase in the double-blind phase. Fat intake and excretion, stool frequency and consistency, and clinical global improvement were recorded.

RESULTS

Average daily fat intake was comparable between treatment groups within each age group (adults vs pediatric/adolescent), but placebo patients had a significant (p < 0.001) mean decrease in coefficient of fat absorption (adult, 36.9 percentage points; pediatric/adolescent, 34.9 percentage points) from open-label to double-blind treatment compared to pancrelipase patients (adult, 2 percentage points; pediatric/adolescent, 3.25 percentage points); this difference was caused by a greater (p < or = 0.001) increase in mean fecal fat excretion (grams per day) in the placebo groups compared to pancrelipase groups (adult: 61.9 vs 2.3; pediatric/adolescent: 45.4 vs 4.1). Change in mean stool frequency from open-label to double-blind phases was significantly different (p < or = 0.002) between treatment groups, with increases in placebo groups and no difference (adult) or decrease (pediatric/adolescent) in pancrelipase groups. Pancrelipase patients' stool consistency remained about the same from open-label to double-blind. Placebo patients' stool consistency decreased (became softer) from open-label pancrelipase to double-blind placebo. Clinical global improvement data showed that > or =83% of pancrelipase patients improved or remained unchanged.

CONCLUSIONS

Enteric-coated, delayed-release (Minimicrospheres) pancrelipase capsules are an effective treatment for steatorrhea associated with pancreatic insufficiency in patients with cystic fibrosis.

Abnormal serum uric acid levels in children

Measurement of the serum uric acid level, most commonly considered in adult patients, is frequently obtained inadvertently for pediatric patients because it is a standard component of many multichannel chemistry profiles offered by clinical laboratories. Most standard references for normal uric acid values do not take into account the impact of the metabolic changes in children at different ages on the uric acid level. A substantial number of childhood conditions may produce perturbations in the serum uric acid level. Knowledge of normal serum uric acid levels and of the conditions affecting those levels in children enables a more focused pursuit of underlying abnormalities.

Effectiveness and safety of small vs. large doses of enteric coated pancreatic enzymes in reducing steatorrhea in children with cystic fibrosis: a prospective randomized study

Among cystic fibrosis (CF) centers, usual doses of enteric coated (EC) pancreatic enzymes vary from one to six capsules per meal based upon arbitrary criteria for stool and growth patterns. Large doses of non-EC enzymes are associated with increased serum urate (SU) and urinary uric acid (UUA) but data are unavailable for EC enzymes. This study compared the effectiveness and safety of a relatively large dose (patient's usual dose) versus a small dose (1/4 usual dose) of EC enzymes in nine nourished children with CF, regarding decreasing fecal fat and stool nitrogen losses and maintaining normal SU and UUA concentrations. A crossover study design randomly assigned large or small doses to two consecutive 7 day treatment periods within each child. Large doses of EC enzymes reduced steatorrhea and increased SU and UUA. SU was normal with both treatments and UUA was normal, i.e., 17 of 18 values were between the 10th and 95th percentiles for healthy children eating a normal diet. When fat excretion was greater than 10% with small doses of EC enzymes, large doses resulted in reduced fat excretion and normal UUA. These data suggest that large doses of EC enzymes reduce steatorrhea and are safe in patients who have malabsorbtion with small doses.

Uric acid metabolism in children

The renal excretion of uric acid in children differs quantitatively, and perhaps qualitatively, from that in adult humans. The younger the child, the greater the renal clearance of uric acid and the greater the excretion of uric acid expressed as mg per kg body weight. During infancy, the reduced ability to maximally concentrate the urine may protect against precipitation of uric acid crystals within the kidney. Conversely, the extremely high urinary uric concentrations places the very small infant at jeopardy during sudden increases in the filtered load of uric acid. Understanding the pharmacologic and physiologic modulators of renal uric acid clearance will allow the pediatrician to minimize the risk of uric acid nephropathy, and to understand the implications of uric acid in the serum or urine in children with fluid and electrolyte disorders. Certainly evaluation of serum and urinary uric acid concentrations is essential in any child with acute renal failure.

Review: pancreatic enzyme replacement--applied physiology and pharmacology

The treatment of pancreatic steatorrhoea can often be improved by attention to the pathophysiological and pharmacological principles involved. Factors influencing the efficacy of pancreatic enzyme replacement include physiological characteristics of the individual patient and pharmaceutical characteristics of the supplement. Different patients may be best suited by different preparations and there is no overall 'best buy'. The new enteric-coated microsphere formulations are often most effective, but also more expensive than conventional preparations. Adjunctive H2-blockade can help appropriately selected patients with resistant steatorrhoea. Knowledge of the underlying cause may guide the choice of supplement and its dose, but trials of different regimens may prove necessary. Successful management, particularly of malnourished patients, involves optimization of dietary fat intake in addition to enzyme replacement.

Comparison of four pancreatic extracts in cystic fibrosis

Four different pancreatin products, Pancrease, Creon, Pancrex V Forte, and Pancreatin Merck, were compared in a random crossover trial in children with cystic fibrosis. The results of our study showed that patients who received Creon and Pancrease had fewer gastrointestinal symptoms than patients who received Pancrex V Forte and Pancreatin Merck. Fat absorption was significantly improved with Pancrease when compared with Pancrex V forte and Pancreatin Merck. Also the fat absorption with Creon was superior to that with Pancrex V Forte. There was no significant difference in fat absorption between Pancrease and Creon. Pancrex V Forte and Pancreatin Merck, or Pancreatin Merck and Creon. Faecal nitrogen content was less with both Creon and Pancrease compared with Pancreatin Merck. Creon and Pancrease allow the patient with cystic fibrosis to take a high energy diet without any dietary restrictions.

The musculoskeletal manifestations of cystic fibrosis

Twenty-seven patients with CF and joint complaints were reviewed. Twelve patients had arthritis, 11 had HPO, and four had symptoms of mechanical neck and back pain. We have confirmed the association of CF with an episodic form of arthritis. For the first time, we have reported that a subgroup of these patients later develop persistent synovitis with progressive asymmetric, erosive disease. The etiology of CF arthritis is unclear, but may relate to chronic infection and immune complex mechanisms. CF arthritis can be contrasted with CF induced HPO, which is associated with worse lung disease, a male predominance, and an older mean age of onset of symptoms. Mechanical neck and back pain may relate to an associated scoliosis or kyphosis in CF.

Effect of cimetidine on enzyme inactivation, bile acid precipitation, and lipid solubilisation in pancreatic steatorrhoea due to cystic fibrosis

In pancreatic steatorrhoea, both pH-dependent bile acid precipitation and enzyme inactivation may limit the efficacy of pancreatic enzyme supplements and both may be preventable by addition of cimetidine. To separate these effects we compared postprandial jejunal aspirate from eight adults with steatorrhoea due to cystic fibrosis on three randomised treatment regimens (pancreatin, cimetidine, and both together). We also compared the results with those of previous studies of patients on no treatment, and of healthy subjects. On pancreatin 60% of the test meal entered the jejunum at pH less than 5 compared with 17% in health. Lipase concentration and lipolysis increased over the values on no treatment (14.2 vs 4.4 U/l, p less than 0.01; 16% vs 11%, p less than 0.02) but bile acid precipitation was not reduced (38% vs 27%, NS), and aqueous-phase lipid concentration decreased (6.7 vs 8.6 mM/l, p less than 0.05). On cimetidine, bile acid precipitation fell (19% vs 38%, p less than 0.05); although lipase concentration and lipolysis were lower than on pancreatin (4.8 U/l vs 14.2 U/l, p less than 0.01; 9% vs 16%, p less than 0.01) lipid solubilisation increased (8.8 vs 6.7 mM/l, p less than 0.05). On the combination, there was a marked improvement (p less than 0.02) in lipid solubilisation (18.3 mM/l), reflecting the improvement both in lipase (38.4 U/l) and lipolysis (24%), and in bile acid precipitation (5.6%). We conclude that the efficacy of pancreatin is limited by pH-dependent bile acid precipitation in addition to enzyme inactivation. The action of cimetidine in improving the efficacy of pancreatin depends on prevention of both these effects.

Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

A study was conducted to examine renal function in 10 healthy control subjects and eight patients with cystic fibrosis in stable condition. Sequential bolus injections of 99mTc-DTPA and 125I-OIH were administered to assess glomerular filtration rate and effective renal plasma flow, respectively. Blood was subsequently collected for 3 hours, and urine for 24 hours. Renal clearances of both radioisotope markers were virtually identical in patients and controls. Inasmuch as neither glomerular filtration rate nor effective renal plasma flow was enhanced in patients with cystic fibrosis, increased clearance of drugs in these patients is unlikely to be the result of enhanced glomerular filtration or tubular secretion.

Ultrastructural changes in the small intestinal epithelium of suckling pigs affected with a transmissible gastroenteritis (TGE)-like disease

The small intestine of piglets collected during a sudden outbreak of diarrhoeal disease resembling transmissible gastroenteritis (TGE) was examined by light and electron microscopy. The principal histopathological changes were moderate infiltration by mononuclear cells in the lamina propria of the villi and cytoplasmic vacuolation. These were most pronounced in the epithelial cells covering the villous tips. By scanning electron microscopy, the intestinal villi were swollen and the transverse furrows disappeared. Microvilli were reduced in number leaving denuded areas on the brush border of the villous epithelial cells. The ultrastructural changes were restricted to the cytoplasm of affected villous epithelial cells. The cell organelles were missing in rounded areas leaving cleared areas in the cytoplasm. Parallel fascicles and bundles were seen in these areas. Viral particles with an average diameter of 70 nm were found within the dilated apical tubulo-vesicular system, free in the cytoplasm, among the microvilli, or lying free in the intestinal lumen. Viral particles surrounded a non-membrane bound viroplasm in some cases. The negatively stained particles showed a typical coronavirus morphology. These particles were found to be distinct from the known coronaviruses of swine, TGE virus and hemagglutinating encephalomyelitis virus by immune electron microscopy.