Cystic fibrosis presenting as recurrent pancreatitis in a young child with a normal sweat test and pancreas divisum: a case report

Calcium, mitochondria and the initiation of acute pancreatitis

Acute pancreatitis is characterized by necrosis of its parenchymal cells and influx and activation of inflammatory cells that further promote injury and necrosis. This review is intended to discuss the central role of disorders of calcium metabolism and mitochondrial dysfunction in the mechanism of pancreatitis development. The disorders are placed in context of calcium and mitochondria in physiologic function of the pancreas. Moreover, we discuss potential therapeutics for preventing pathologic calcium signals that injure mitochondria and interventions that promote the removal of injured mitochondria and regenerate new and heathy populations of mitochondria.

Genotype-phenotype correlations of cystic fibrosis in siblings compound heterozygotes for rare variant combinations: Review of literature and case report

Here, we describe a cystic fibrosis (CF) family with affected siblings, two of whom have a combination of I1234V and 1677delTA variants with classic CF features, the third child with a combination of I1234V and L997F variants with atypical CF, and the apparently healthy mother with a combination of 1677delTA and L997F alleles. Interestingly, the sibling with I1234V and L997F variants had normal sweat test results and had a much milder phenotype than the other two siblings with I1234V and 1677delTA variants, suggesting that this combination is causative for atypical CF. The fact that their mother with the combination of 1677delTA and L997F appears to be healthy suggests that the L997F variant causes different phenotypes in different allele combinations. The current cases show that there is a genotype-phenotype correlation in this disease and underline the importance of genotyping individuals with suspected CF to allow prediction of disease severity and effective treatment.

Acute Recurrent and Chronic Pancreatitis as Initial Manifestations of Cystic Fibrosis and Cystic Fibrosis Transmembrane Conductance Regulator-Related Disorders

OBJECTIVES

Recurrent pancreatitis is considered a rare manifestation of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction; this case series highlights that pancreatitis can be a presenting symptoms of cystic fibrosis (CF) or a CFTR-related disorder (CFTR-RD).

METHODS

Retrospective review of patients younger than 30 years diagnosed as having acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP) and subsequently diagnosed as having CF or CFTR-RD.

RESULTS

Among 18 patients, median time from diagnosis of ARP/CP to diagnosis of CF was 0.4 years (range, 0-33 years). Eight were classified as having CF by elevated sweat chloride testing (SCT). Five had intermediate SCT (30-59 mmol/L) with 2 pathogenic mutations. Five had CFTR-RD with intermediate SCT and 0 to 1 pathogenic mutations. Eight patients (44%) had exocrine pancreatic insufficiency, and pancreatic fluid collections were more common in this group. Based on the CFTR mutation, 6 patients were eligible for CFTR potentiator therapy, although none received it during the study period. Nine of the 18 had ≥1 other likely CF manifestations, including sinusitis (33%), nasal polyps (11%), pneumonia (22%), and gallbladder disease (22%).

CONCLUSIONS

Cystic fibrosis or CFTR-RD can present as ARP/CP. Complete diagnostic testing for CFTR-RD in patients with ARP/CP will broaden treatment options and help to identify comorbid illness.

A patient with pancreas divisum, recurrent acute pancreatitis, and homozygosity for the cystic fibrosis transmembrane regulator-associated protein 5T allele

Mutations in the gene encoding the cystic fibrosis transmembrane regulator (CFTR) have been reported to increase the risk of recurrent acute pancreatitis in patients with pancreas divisum. We assessed the CFTR gene in a young male patient with pancreas divisum and recurrent acute pancreatitis. Magnetic resonance cholangiopancreatography and computed tomography revealed that the patient had pancreas divisum, with an enlarged and tortuous pancreatic duct; he also had positive results from the cystic fibrosis sweat test. Genetic analysis did not identify any common CFTR mutations, but did show that he was homozygous for the 5T allele in intron 8 IVS8 5T-12TG (which affects splicing at intron 8). Endoscopic sphincterotomy and stenting of papilla minor was performed. The IVS8 5T-12TG variant has been associated with abnormal organ development, therefore it is possible that CFTR has an important role in the development of the pancreatic duct. We propose this patient has recurrent acute pancreatitis resulting from a developmental defect associated with a suboptimal CFTR function.

Pancreas divisum is not a cause of pancreatitis by itself but acts as a partner of genetic mutations

OBJECTIVES

The role of pancreas divisum (PD) as a cause of acute recurrent or chronic pancreatitis (AR/CP) is still a matter of debate.

METHODS

The aims of this study were to evaluate the frequency of PD diagnosed using magnetic resonance cholangiopancreatography (MRCP) in patients with AR/CP of unknown origin (n=40) after careful exclusion of all known causes and to test the hypothesis of an interaction between anatomical (PD) and functional genetic anomalies (SPINK1, PRSS1, or CFTR gene mutations or polymorphisms (n=19, 25, and 30, respectively)) that could result in AR/CP. Patients with alcohol-induced pancreatitis (n=29) and subjects who had MRCP for a nonpancreatic disease (n=45) served as controls.

RESULTS

PD frequency was 7% in subjects without pancreatic disease, 7% in patients with alcohol-induced pancreatitis, and 5, 16, 16, and 47% in those with idiopathic, and PRSS1-, SPINK1-, and CFTR-associated pancreatitis, respectively (P<0.0001). There was no significant difference between idiopathic pancreatitis and the two control groups. The frequency of PD was higher in patients with CFTR gene-associated pancreatitis as compared with those with idiopathic and alcoholic pancreatitis (P<0.0001) and with those with SPINK1 and PRSS1 gene-associated pancreatitis (P<0.02).

CONCLUSIONS

The frequency of PD was not different in patients with idiopathic pancreatitis as compared with controls, demonstrating that PD by itself is not a cause of pancreatitis. PD frequency was higher in patients with genetic pancreatitis, especially in those with CFTR mutations or polymorphisms, suggesting a cumulative effect of these two cofactors.

[Pancreatitis in cystic fibrosis: association with genotype and pancreatic status]

INTRODUCTION

Pancreatitis is an uncommon complication of cystic fibrosis (CF). Either single or recurrent acute episodes can occur and it occasionally may follow a protracted course with relentless destruction of the pancreas. Moreover mild mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) have been found in many cases of idiopathic chronic pancreatitis. We describe a group of patients with CF who had one or more episodes of pancreatitis. We have estimated its prevalence in a large population of patients with CF across Spain.

METHODS

A retrospective descriptive study was conducted by collecting the demographic, clinical and laboratory data, pancreatic status and genotype of CF patients who attended the CF Units in 5 Spanish hospitals.

RESULTS

The overall number of CF patients under follow-up in the five centres was 520, of which 17 cases with pancreatitis were identified. The prevalence of pancreatitis in this population was 3.3%, higher than previously reported. Noticeably eight of the 17 patients (47.06%) had pancreatic insufficiency. This appears to be, partly, in contrast with that classically found, as this complication is usually associated with patients with a certain level of pancreatic reserve. No associations with genotype, age, gender or other factors were found.

CONCLUSIONS

The prevalence of pancreatitis in our CF patients was higher than that found in other CF populations, and was not limited to patients with pancreatic sufficiency. It occurred mostly in teenagers and young adults often with mild pulmonary disease. The CF genotype was variable. The course of the patients should be carefully monitored, and further information on the long-term outcome of larger cohorts of patients is needed.

A new complex allele of the CFTR gene partially explains the variable phenotype of the L997F mutation

PURPOSE

To evaluate the role of complex alleles, with two or more mutations in cis position, of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in the definition of the genotype-phenotype relationship in cystic fibrosis (CF), and to evaluate the functional significance of the highly controversial L997F CFTR mutation.

METHODS

We evaluated the diagnosis of CF or CFTR-related disorders in 12 unrelated subjects with highly variable phenotypes. According to a first CFTR mutational analysis, subjects appeared to be compound heterozygotes for a classic mutation and the L997F mutation. A further CFTR mutational analysis was conducted by means of a protocol of extended sequencing, particularly suited to the detection of complex alleles.

RESULTS

We detected a new [R117L; L997F] CFTR complex allele in the four subjects with the highest sweat test values and CF. The eight subjects without the complex allele showed the most varied biochemical and clinical outcome and were diagnosed as having mild CF, CFTR-related disorders, or even no disease.

CONCLUSIONS

The new complex allele partially explains the variable phenotype in CF subjects with the L997F mutation. CFTR complex alleles are likely to have a role in the definition of the genotype-phenotype relationship in CF. Whenever apparently identical CFTR-mutated genotypes are found in subjects with divergent phenotypes, an extensive mutational search is mandatory.