Pancreatic Sufficient Patients Research Articles

GI Complications After Lung Transplantation in Patients With Cystic Fibrosis

Lung transplantation is now available for patients with cystic fibrosis (CF) and end-stage lung disease. While pulmonary graft function is often considered the major priority following transplantation, the nonpulmonary complications of this systemic disease also continue. We examined the GI complications in a cohort of patients who underwent transplantation. This was a retrospective study of all patients with CF who underwent transplantation between March 1988 and December 1998 in Toronto. Medical records were reviewed, and a short questionnaire was mailed to patients who were alive as of December 1998. There were 80 bilateral lung transplants performed in 75 patients. The questionnaire was distributed to 43 patients, of whom 27 patients (63%) responded. Pancreatic insufficiency requiring enzyme intake was evident in 72 of 75 patients (96%) at the time of surgery. Of three pancreatic-sufficient patients (4%), pancreatic insufficiency was diagnosed in two patients later. Biliary cirrhosis was diagnosed in three patients prior to transplantation. Distal intestinal obstruction syndrome (DIOS) was recorded for 15 patients (20%). Ten patients had a single episode, of which eight episodes occurred early in the postoperative period. Five patients had recurrent episodes. All were medically treated, except for two patients who underwent surgery. Other complications included cholecystitis (n = 3), mucocele of the appendix (n = 1), peptic ulcer disease (n = 3), and colonic carcinoma (n = 1). GI complications after lung transplantation are common in patients with CF, and attention should be paid to the risk for DIOS in the early postoperative period. Prevention and early medical treatment are important in order to avoid acute surgery. Close collaboration with the CF clinic, in order to diagnose and treat CF-related complications, is recommended.

Genotype and phenotype correlations in patients with cystic fibrosis and pancreatitis

Background & Aims: Pancreatitis is known to occur in some patients with cystic fibrosis (CF), but the prevalence, natural history, and genotypic basis are unclear. We examined a well-defined cohort of patients with CF to answer these questions. Methods: Patients with CF were identified from a computerized database (1966–1996). Chart audit identified all patients with CF and pancreatitis. Results: Among 1075 patients with CF, 937 (87%) were pancreatic insufficient at diagnosis, 28 (3%) were pancreatic sufficient but developed pancreatic insufficiency after diagnosis, and 110 (10%) have remained pancreatic sufficient. No patients with pancreatic insufficiency developed pancreatitis. Nineteen patients (17.3%) with pancreatic sufficiency experienced one or more attacks of pancreatitis. The mean age at diagnosis of pancreatitis was 22.7 ± 10.3 years (range, 10–35 years), and pancreatitis was recognized before the diagnosis of CF in 6 patients (32%). The diagnosis of CF in pancreatic-sufficient patients, with and without pancreatitis, was established at a significantly older age than in those with pancreatic insufficiency (P < 0.0001). Genotyped patients with pancreatic insufficiency carried 2 severe mutant alleles. All genotyped patients with pancreatic sufficiency and pancreatitis carried at least one mild mutation. No specific genotype was predictive of pancreatitis. Conclusions: Patients with CF with pancreatic sufficiency carry at least one mild mutant allele and are at a significant risk of developing pancreatitis. Symptoms of pancreatitis may precede the diagnosis of CF. Pancreatitis is associated with an otherwise mild CF phenotype.GASTROENTEROLOGY 2002;123:1857-1864

Urogenital abnormalities in male children with cystic fibrosis

Background: Congenital bilateral absence of the vas deferens (CBAVD) is presumed to occur prenatally and is present in over 99% of adult males with cystic fibrosis (CF). Aims: To describe...

Evaluation of fecal pancreatic elastase-1 as a measure of pancreatic exocrine function in children with cystic fibrosis.

Pancreatic elastase-1 (EL-1) is a specific human protease synthesised by the acinar cells. It is stable, unaffected by exogenous pancreatic enzyme treatment, and correlates well with stimulated pancreatic function tests. We report our experience of EL-1 measurements in 142 patients from a large cystic fibrosis (CF) clinic. The median patient age was 7.7 years (range, 0.1-20.8 years), 93 were homozygous and 38 heterozygous for DeltaF508, and 11 had other or unidentified mutations. There were 85 non-CF control subjects. Seven were pancreatic sufficient (PS). The median (quartile 1-quartile 3) fecal EL-1 of the 135 pancreatic insufficient (PI) patients was 10 microg/g stool (2.5-33); of the 7 PS patients, 698 microg/g stool (400.5-824.5), and of the non-CF controls, 615 microg/g stool (420-773). Using the Mann-Whitney U test, there was a statistically significant difference for fecal EL-1 activity between the PS and PI patients (P = 0.0001) and the PI and control group (P < 0.0001), but not between the control and PS groups (P = 0.63). Median (quartile 1-quartile 3) fecal EL-1 in the pancreatic insufficient DeltaF508 homozygotes was 10 microg/g stool (2-33), and in the heterozygotes 12 microg/g stool (4-39) (not significant, P = 0.62). We now use fecal EL-1 as evidence of PI in screened CF infants (reliable over the age of 2 weeks); in older CF patients at diagnosis; for confirming the need for pancreatic enzymes in patients referred to the clinic already taking enzymes; for annual monitoring of PS patients to detect the onset of PI; and as supporting evidence when excluding the diagnosis of CF in patients attending the pediatric gastroenterology clinic. The low values in the first 2 weeks in some normal and premature infants, and the persisting normal values in PS infants, make the fecal EL-1 test unsuitable for neonatal CF screening.

Serum lipase levels as a diagnostic marker in cystic fibrosis patients with normal or borderline sweat tests.

Patients with normal or borderline sweat test present a diagnostic challenge. In spite of the availability of different methods such as genetic analysis and measurements of nasal potential difference, uncertainty in diagnosing cystic fibrosis (CF) in some patients still exists. Neonates with CF have high serum lipase levels, which decline over time in pancreatic-insufficient patients, whereas pancreatic-sufficient patients demonstrate high serum lipase levels beyond infancy. Because patients with borderline or normal sweat test are almost always pancreatic sufficient, this study was aimed to assess whether serum lipase levels may be of help in establishing the diagnosis of CF in these patients. Serum lipase levels were measured in 100 CF patients and in 17 healthy individuals. Patients were grouped according to their genotype. Group A patients (n = 70) carried two mutations previously found to be associated with a pathologic sweat test and pancreatic insufficiency (delta F508, W1282X, G542X, N1303K, S549R). Group B (n = 30) were compound heterozygote patients who carried one mutation known to cause mild disease with borderline or normal sweat tests and pancreatic sufficiency (3849+10kb C-->T, 5T). Group C included 17 healthy controls. Serum lipase levels ranged between 2 and 104.4 U/L (mean +/- SD 16.9 +/- 14.7), 6.1-200 U/L (mean +/- SD 53.9 +/- 47.9), and 8.5-27.8 U/L (mean +/- SD 16.9 +/- 5.1) in Groups A, B, and C, respectively, with some overlapping between groups. The distribution of lipase levels was significantly different in Group B vs Groups A and C (P < 0.01). High lipase levels were found in 63.3% (19/30) of Group B patients, but in only 4.3% (3/70) and 0% (0/17) of Group A and C, respectively. Lipase levels were found to be inversely related to sweat chloride concentrations (r = -0.19, P < 0.05). Patients with borderline or normal sweat tests had high lipase levels, whereas low lipase levels were associated with pathologic sweat tests. Our findings indicate that the serum lipase level is genetically determined and that it has a useful role in the diagnosis of CF. Thus, in patients with borderline sweat tests and high lipase levels, the diagnosis of CF should be considered.

Prevalence of vitamin K deficiency in cystic fibrosis

Patients with cystic fibrosis (CF) are at risk of developing vitamin K deficiency because of pancreatic insufficiency, hepatobiliary disease, or both. Our objective was to determine the prevalence of vitamin K deficiency in unsupplemented patients with CF and to identify risk factors that might be associated with the deficiency. Ninety-eight patients with CF-83 who were pancreatic insufficient (age: 15.2 +/- 10.7 y; range: 0.6-45.8 y), 15 who were pancreatic sufficient (age: 26.2 +/- 11.6 y; range: 6.5-45.3 y), and 62 healthy individuals (age: 16.2 +/- 12. 8 y; range: 1-45 y)-were studied prospectively. None had taken vitamin K supplements. Eight pancreatic-insufficient patients had advanced CF-associated liver disease. Plasma prothrombin in vitamin K absence (PIVKA-II) was measured by immunoassay. All control subjects had PIVKA-II concentrations <3 microg/L. Seventy-eight percent of pancreatic-insufficient patients had PIVKA-II concentrations >/=3 microg/L (22.8 +/- 35.7 microg/L). All patients with CF-associated liver disease had abnormal PIVKA-II concentrations. The mean PIVKA-II concentration of pancreatic-insufficient patients with liver disease was greater than that of those without liver disease (46.6 +/- 65.3 compared with 15. 3 +/- 26.1 microg/L; P < 0.05). Five pancreatic-sufficient patients had mildly elevated PIVKA-II concentrations. Six (7%) pancreatic insufficient patients (3 with CF-associated liver disease) had mildly prolonged prothrombin time but no clinical bleeding. There was no correlation between PIVKA-II concentrations and severity of fat malabsorption or antibiotic use. Vitamin K deficiency is common in unsupplemented patients with CF and pancreatic insufficiency and routine supplementation should be considered in all of these patients.

Identification of three novel mutations in the dystrophin gene detected by the heteroduplex/SSCA screening procedure. Mutations in brief no. 222. Online.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked neuromuscular disorders associated with alterations in the dystrophin gene. Analysis of 45 DMD/BMD patients has identified 18 patients with no deletion in the dystrophin gene. Heteroduplex analysis (HD), single strand conformation analysis (SSCA), and subsequent sequencing, identified five mutations and nine polymorphisms. Three out of the 5 mutations (780C>G, 2501-1g-->t, 9812 9813ins9800-9812) are first reported here. Furthermore we compare the relative efficiencies of the two alternatives methods (HD and SSCA) for screening sequence alterations.

3849 + 10 kb C → T Splicing Mutation in Hispanic CF Patients

Seven patients compound heterozygous for the 3849 + 10kb C → T mutation in the CFTR gene were found among the 152 patients attending the CHLA CF Clinic. The frequency of this mutation accounts for 2.3 and 3.9% of thetotal and Hispanic CF alleles of CHLA patients. These are significantly higher than the 0.6% of the general CF population. The average age of diagnosis of this group of Hispanics is 3.1 years, which is much younger than that reported for CF patients of other ethnicities with the same mutation. Both pancreatic sufficient and pancreatic insufficient patients were observed. It is concluded that the 3849 + 10kb C → T mutation is associated with a variable but potentially mild type of CF.

FIFTEEN YEAR PROSPECTIVE STUDY OF PANCREATITIS IN A POPULATION OF PATIENTS WITH CYSTIC FIBROSIS

In Cystic Fibrosis (CF) pancreatic damage begins in utero. Pancreatic insufficiency (PI) is usually present at birth. In 15% of patients, the progression of pancreatic disease does not occur or is retarded. These patients are pancreatic sufficient (PS) and are susceptible to acute recurrent pancreatitis. The aim of this study is to investigate the frequency, natural history and outcome of pancreatitis in a CF population. Pancreatic function was assessed in 96 CF patients at diagnosis by measurement of serum pancreatic isoamylase activity (Phadebas PIA test, PIA normal values 40- 120 u/L). Fifteen CF patients (16%) who had pancreatic sufficiency (PS) (PIA 60-250 u/L) were followed up for episodes of pancreatic pain, evaluated with serial measurements of serum amylase, serum PIA and ultrasound of the pancreas. At the final phase, exocrine pancreatic function was monitored by serial fecal human pancreatic elastase (ELISA, Schebo-Tech, E1 normal values>200μg/gr stool). Clinical status was assessed by Schwachman score. Six of 15 patients with PS (40%) manifested recurrent, multiple episodes of acute pancreatic pain, marked elevation of pancreatic enzymes (PIA up to 2400 u/L) and evidence of pancreatitis on ultrasound. The episodes decreased gradually and serum PIA was stabilized at 60 to 90u/L. Gradual decline of fecal elastase to less than 200 (144, 170, 180) μg/gr stool was demonstrated in three while the remaining 12 PS patients had fecal elastase ranging from 257 to 2068μg/gr stool. Schwachman score in PS patients remained high throughout the observation period. It is concluded that acute recurrent pancreatitis occured in 6% of a CF population, exclusively in PS patients (40%). A subgroup of PS patients (20%) among those with recurrent pancreatitis developed PI and the need for pancreatic enzyme supplementation. Monitoring of exocrine pancreatic function in PS patients, especially in those with burnt out recurrent pancreatitis, is recommended.

Longitudinal evaluation of serum trypsinogen measurement in pancreatic-insufficient and pancreatic-sufficient patients with cystic fibrosis

We studied serial measurements of serum cationic trypsinogen in patients with cystic fibrosis to assess the predictability of changes in individuals and the value of longitudinal measurement in defining pancreatic status. Three hundred twenty-nine patients with cystic fibrosis, aged 3 days to 40 years, had serum levels of trypsinogen measured on 2 to 12 occasions for periods ranging from 1 week to 7 years. Patients were classified into three groups on the basis of 72-hour fecal fat studies performed at the time of diagnosis. Two hundred thirty-three patients had pancreatic insufficiency (PI), 78 had pancreatic sufficiency (PS), and 18 had PS at diagnosis but acquired PI during follow-up (PS→PI). Infants with PI had greatly elevated serum trypsinogen levels that fell sharply in the first years of life, so that by age 7 years more than 95% had subnormal values; individual patient values followed a predictable course similar to previously reported cross-sectional age-related values. In patients with PS, serum trypsinogen levels generally remained within or above the normal range and, after age 10 years, were well above the upper limit for PI patients. Within-patient variance was significantly greater ( p < 0.0001) in patients with PS than in those with PI who were older than 7 years of age. Changes in patients within PS→PI generally followed the pattern seen in patients with PI, but values in older patients tended to be in the higher range. We conclude that serial measurement of serum trypsinogen is a valuable tool for monitoring the pancreatic status of patients with cystic fibrosis and PS. (J P EDIATR 1995;127:408-13)

Search for mutations in pancreatic sufficient cystic fibrosis Italian patients: detection of 90% of molecular defects and identification of three novel mutations.

A cohort of 31 cystic fibrosis patients showing pancreatic sufficiency and bearing an unidentified mutation on at least one chromosome was analyzed through denaturing gradient gel electrophoresis of the whole coding region of the cystic fibrosis transmembrane conductance regulator gene, including intron-exon boundaries. Three new and 19 previously described mutations were detected. The combination of these with known mutations detected by other methods, allowed the characterization of mutations on 56/62 (90.3%) chromosomes. Among those identified, 17 can be considered responsible for pancreatic sufficiency, since they were found in patients carrying a severe mutation on the other chromosome. Among these presumed mild mutations, eight were detected more than once, R352Q being the most frequent in this sample (4.83%). Intragenic microsatellite analysis revealed that the six chromosomes still bearing unidentified mutations are associated with five different haplotypes. This may indicate that these chromosomes bear different mutations, rarely occurring among cystic fibrosis patients, further underlying the molecular heterogeneity of the genetic defects present in patients having pancreatic sufficiency.

Enzyme therapy for pancreatic insufficiency: present status and future needs.

Pancreatic enzyme extracts have been used for several decades to decrease maldigestion of macro- and micronutrients due to pancreatic insufficiency and to alleviate various abdominal symptoms, including the pain of alcohol-induced chronic pancreatitis and distal intestinal obstruction. Decreasing nutrient maldigestion and malabsorption in pancreatic insufficiency is of additional critical importance because improvement in nutritional status reduces morbidity and mortality. For example, pancreatic sufficient patients with cystic fibrosis (CF) demonstrate a slower decline in pulmonary function. In spite of the recognized importance of pancreatic enzymes, several problems exist with current preparations, and as newer enzyme preparations are marketed, proper evaluation becomes critical. There is a clear need to optimize the constituents of enzyme preparations, improve manufacturing processes, and find better sources of enzymes. Other issues that need addressing include standardization of the ratios of enzymes (lipase, amylase, protease) in these products; the stability of the enzymes at room temperature; the shelf life of the finished product; whether there are significant batch-to-batch differences; and the need for a USP reference standard.

Decline of exocrine pancreatic function in cystic fibrosis patients with pancreatic sufficiency.

Patients with cystic fibrosis and pancreatic sufficiency were investigated for evidence of progressive pancreatic disease. From a cohort of 630 patients, 20 pancreatic-sufficient patients became pancreatic insufficient after an average duration of 5.6 y (range 0.6-20.6 y) from diagnosis. Among 54 patients documented to be pancreatic sufficient by direct pancreatic stimulation test, 47 remained pancreatic sufficient and seven developed pancreatic insufficiency. The patients who ultimately developed pancreatic insufficiency were younger and had greatly reduced outputs of enzyme, fluid, and electrolytes. Those who remained pancreatic sufficient showed enzyme secretion close to or within the non-cystic fibrosis control range. Twenty of these patients underwent a second pancreatic stimulation test after an average interval of 4 y (range 1.3-6.2 y). No significant alteration in enzyme, fluid, or electrolyte output was seen in the patients who remained pancreatic sufficient, but there was further reduction in enzyme and fluid output in the patients who developed pancreatic failure. In conclusion, the majority of pancreatic-sufficient patients with pancreatic enzyme secretion within the control range showed no deterioration of function over an extended time period. However, a small number of pancreatic-sufficient patients with reduced enzyme and fluid secretion are at risk of pancreatic failure.

Correlation of intestinal lactulose permeability with exocrine pancreatic dysfunction

Increased intestinal permeability to lactulose has been reported in patients with cystic fibrosis (CF). To determine whether this finding is unique to CF or whether it is related to accompanying exocrine pancreatic dysfunction, we evaluated 31 patients with CF and 10 with Shwachman syndrome who had variable degrees of pancreatic dysfunction, together with 17 healthy control subjects. There was no significant difference in the mean urinary lactulose excretion, expressed as the percentage of dose recovered, between CF and non-CF patients with pancreatic insufficiency (2.1% +/- 1.2% and 1.9% +/- 0.8, respectively) or between CF and non-CF patients with pancreatic sufficiency (0.6% +/- 0.5% and 0.6% +/- 0.3%, respectively). However, there was a significant difference in mean lactulose excretion between the pancreatic-insufficient and the pancreatic-sufficient patients (both CF and non-CF groups; p less than 0.001 and p less than 0.013, respectively). We further analyzed the results from 26 of the 41 patients (16 patients with CF and 10 non-CF patients) with pancreatic dysfunction who had previously undergone quantitative pancreatic function testing. A nonlinear, inverse relationship was found between urinary lactulose excretion and exocrine pancreatic function determined by duodenal trypsin output. These data confirm a direct relationship between intestinal lactulose permeability and the degree of exocrine pancreatic dysfunction, unrelated to the cause of the pancreatic disease.

Pancreatic function and gene deletion F508 in cystic fibrosis.

In view of the possible relation between pancreatic function and cystic fibrosis (CF) gene mutations, a detailed study on Italian patients was performed. Seventy pancreatic insufficient and 48 pancreatic sufficient patients were included after very accurate characterisation of their pancreatic and digestive function, all performed in the same CF centre. The CF gene deletion F508 was tested to define the patients' genotypes. The results confirm that the mutation correlates with pancreatic insufficiency, and is recessive to other, as yet unreported, mutant alleles that determine pancreatic sufficiency. An indication that duodenal bicarbonate output is more severely reduced in the presence of deletion F508 is also presented. The data are discussed in relation to a hypothesis on the primary effects of CF gene deletion F508.

INTESTINAL LACTULOSE PERMEABILITY REFLECTS EXOCRINE PANCREATIC DYSFUNCTION

Our previous work suggested that increased intestinal permeability was related to the degree of exocrine pancreatic dysfunction in Cystic Fibrosis (CF). Others have suggested this finding represents a specific abnormality of CF. To further evaluate this question we studied CF (n=31) and non-CF (n=10) patients (Shwachman Syndrome) with variable degrees of exocrine pancreatic dysfunction They were categorized into pancreatic insufficient (PI) and pancreatic sufficient (PS) groups based on fecal fat balance studies. After an overnight fast, patients were fed 20 grams of lactulose and urine was collected for 8 hours. Urinary lactulose excretion (% intake) was determined by thin-layer chromatography. Mean urinary lactulose excretion was no different between CF and non-CF patients with either PI (2.10±1.21 and 1.92±0.76) or PS (0.63±0.49 and 0.61±0.34). There was a significant difference in lactulose excretion between PI and PS patients in CF and non-CF groups (p<0.0001 and p<0.013, respectively). This relationship was explained by comparing pancreatic function (trypsin output, units/kg/ hour) with urinary lactulose excretion in 26 patients. A non-linear inverse relationship was observed between the two parameters. A plot of the log(x) transformation of duodenal trypsin output against urinary lactulose excretion revealed a highly significant linear relationship (r=0.778, p=0.0001). These data confirm a direct relationship between intestinal lactulose permeability and the degree of exocrine pancreatic dysfunction, unrelated to etiology.

Genetic differences in cystic fibrosis patients with and without pancreatic insufficiency

To determine the number and frequency of mutations that occur at the cystic fibrosis locus (CF), we have examined the allele and haplotype frequencies of eight polymorphic DNA markers linked to CF in 163 Italian patients who were sub-divided according to their clinical presentations. The distribution of haplotypes for the tightly linked polymorphisms KM.19 and XV-2c differ significantly between patients with and those without pancreatic insufficiency. The haplotype found most commonly in CF chromosomes occurs much more frequently in pancreatic insufficient than in pancreatic sufficient patients. Among the 19 pancreatic sufficient patients, 6 (31.6%) show at least one copy of the rare KM.19 = 1, XV-2c = 2 haplotype, as against 16 of 138 patients (11.6%) with pancreatic insufficiency. In addition, only 5 pancreatic sufficient patients (26.3%) are homozygous for the common 2.1 haplotype, as compared with 88 patients (63.8%) with pancreatic insufficiency. These findings support the hypothesis of allelic heterogeneity at a single locus in CF and suggest that different mutations underlie the presence or absence of pancreatic insufficiency in this disorders.