Early-Onset Acute Recurrent and Chronic Pancreatitis Is Associated with PRSS1 or CTRC Gene Mutations.

OBJECTIVES: To assess whether the age of onset was associated with unique features or disease course in pediatric acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP). STUDY DESIGN: Demographic and clinical information on children with ARP or CP was collected at INSPPIRE (INternational Study Group of Pediatric Pancreatitis: In Search for a CuRE) centers. The Cochran-Armitage trend test and Jonckheere-Terpstra test were used to examine for differences between pediatric age groups (<6, 6-11, and ≥12 years). RESULTS: Between September 2012 and March 2016, 342 children with ARP or CP were enrolled; 129 (38%) were <6 years of age at the time of first diagnosis of acute pancreatitis, 111 (32%) were 6-11 years of age, and 102 (30%) were ≥12 years of age. Early-onset disease was associated with mutations in cationic trypsinogen (PRSS1) (P < .01), chymotrypsin C (CTRC) (P = .01), family history of acute pancreatitis (P = .02), family history of CP (P < .01), biliary cysts (P = .04), or chronic renal failure (P = .02). Later-onset disease was more commonly present with hypertriglyceridemia (P = .04), ulcerative colitis (P = .02), autoimmune diseases (P < .0001), or medication use (P < .01). Children with later-onset disease also were more likely to visit the emergency department (P < .05) or have diabetes (P < .01). CONCLUSIONS: Early-onset pancreatitis is associated strongly with PRSS1 or CTRC mutations and family history of pancreatitis. Children with later-onset disease are more likely to have nongenetic risk factors. Future studies are needed to investigate whether the disease course, response to therapy, or clinical outcomes differ relative to the timing of disease onset.

Masking of syndrome of inappropriate antidiuretic hormone secretion: the isonatremic syndrome.

OBJECTIVE: To determine whether the administration of isotonic saline in patients undergoing spinal fusion surgery prevents the development of hyponatremia, thus masking the detection of syndrome of inappropriate antidiuretic hormone secretion (SIADH). STUDY DESIGN: Prospective observational cohort study conducted in pediatric patients undergoing spinal fusion surgery. Using established criteria for diagnosing SIADH with the exception of serum sodium as a criterion, we separated patients into those with and without masked SIADH. Random cortisol levels were measured in the perioperative period to test for adrenal insufficiency to exclude it as a cause for natriuresis and hyponatremia. RESULTS: Of the 40 patients included in the study, 13 (32%; 95% CI, 19%-49%) met study criteria for masked SIADH. The serum sodium levels between the 2 groups were not different throughout the postoperative period. The antidiuretic hormone levels were increased at 24-48 hours after surgery (20.4 pg/mL in masked SIADH group vs 6.6 pg/mL in no masked SIADH group, P = .04). Subjects with masked SIADH demonstrated a tendency for weight gain (3.9 kg vs 2.5 kg, P = .058), which was maximal on postoperative day 2. Cortisol levels were similar between the groups. CONCLUSION: Masked SIADH (SIADH-like state without hyponatremia) commonly occurs in the postoperative period in children and young adults undergoing spinal fusion surgery. Early postoperative evaluation and recognition may result in appropriate management of patient's fluid balance.