Targeted cyst wall puncture and aspiration during EUS-FNA increases the diagnostic yield of premalignant and malignant pancreatic cysts

BACKGROUND

Characterization of pancreatic cysts by using EUS-FNA includes chemical and cytologic analysis.

OBJECTIVE

To evaluate whether material obtained from FNA of the cyst wall increases diagnostic yield.

DESIGN

Prospective series.

SETTING

Tertiary referral center.

PATIENTS

Consecutive patients with pancreatic cysts referred for EUS-FNA between March 2010 and March 2011.

INTERVENTION

FNA was performed with aspiration of cyst fluid for carcinoembryonic antigen (CEA) and cytology, followed by cyst wall puncture (CWP). CWP is defined as puncturing the far wall of the cyst and moving the needle back and forth through the wall to sample the wall epithelium.

MAIN OUTCOME MEASUREMENTS

The diagnostic yield for mucinous cystic pancreatic neoplasms by CEA and cytology obtained from cyst fluid compared with cytology obtained from CWP. CEA ≥192 ng/mL was considered mucinous.

RESULTS

A total of 69 pancreatic cysts from 66 patients were included. Adequate amounts of fluid were aspirated for CEA, amylase, and cytology in 60 cysts (81%). Cellular material adequate for cytologic assessment from CWP was obtained in 56 cysts (81%). Ten (30%) of 33 cysts with CEA <192 ng/mL and negative results of cyst fluid cytology had a mucinous diagnosis from CWP; 6 of 9 (67%) cysts with an insufficient amount of fluid for CEA analysis and cyst fluid cytology had a mucinous diagnosis from CWP. Furthermore, 4 malignant cysts were independently diagnosed by CWP cytology. The incremental diagnostic yield of CWP for mucinous or malignant cysts was therefore 29% (20 of 69 cysts, P = .0001). An episode of pancreatitis (1.45%) occurred.

LIMITATION

Lack of surgical criterion standard.

CONCLUSIONS

CWP during EUS-FNA is a safe and effective technique for improving the diagnostic yield for premalignant and malignant pancreatic cysts.

Rapid salivary pepsin test: blinded assessment of test performance in gastroesophageal reflux disease

OBJECTIVE/HYPOTHESIS

Pepsin lateral flow device (LFD) is a rapid noninvasive test to detect salivary pepsin as a surrogate marker for gastroesophageal reflux disease (GERD). We aimed to establish the test sensitivity, specificity, positive and negative predictive values (PPV, NPV) in patients with symptomatic and objective evidence of GERD compared to healthy controls.

STUDY DESIGN

Prospective, blinded, controlled cohort study.

METHODS

A total of 230 samples were analyzed. In vitro bench testing was conducted on 52 gastric juice and 54 sterile water samples to assess test sensitivity and specificity. Saliva was collected from 58 patients with GERD and 51 controls. All patients with GERD underwent esophagogastroduodenoscopy (EGD) and wireless 48-hour pH monitoring off acid suppressive therapy. PPV and NPV were calculated based on disease definition of esophagitis and/or abnormal pH monitoring.

RESULTS

Receiver operating characteristics analysis of in vitro samples found assay sensitivity and a specificity of 87%. There were 6/51 (12%) control subjects and 13/58 (22%) patients with GERD who tested positive for salivary pepsin (P = .25). There was a step-wise increase in the prevalence of positive salivary pepsin: esophagitis (55%), abnormal pH monitoring (43%), GERD symptoms only (24%) (P < .001). Salivary pepsin test showed a PPV of 81% and NPV of 78% for those with objective evidence of GERD (abnormal pH and/or esophagitis).

CONCLUSIONS

Rapid LFD for salivary pepsin has acceptable test characteristics in patients with GERD. A positive salivary pepsin test in this group may obviate the need for more expensive diagnostic testing by EGD or pH monitoring.

Increased expression and cellular localization of spermine oxidase in ulcerative colitis and relationship to disease activity

BACKGROUND

Polyamines are important in cell growth and wound repair, but have also been implicated in inflammation-induced carcinogenesis. Polyamine metabolism includes back-conversion of spermine to spermidine by the enzyme spermine oxidase (SMO), which produces hydrogen peroxide that causes oxidative stress. In ulcerative colitis (UC), levels of spermine are decreased compared to spermidine. Therefore, we sought to determine if SMO is involved in UC.

METHODS

Colon biopsies and clinical information from subjects undergoing colonoscopy for evaluation of UC or colorectal cancer screening were utilized from 16 normal controls and 53 UC cases. Histopathologic disease severity was graded and the Mayo Disease Activity Index (DAI) and endoscopy subscore assessed. SMO mRNA expression was measured in frozen biopsies by TaqMan-based real-time polymerase chain reaction (PCR). Formalin-fixed tissues were used for SMO immunohistochemistry.

RESULTS

There was a 3.1-fold upregulation of SMO mRNA levels in UC patients compared to controls (P = 0.044), and a 3.7-fold increase in involved left colon versus paired uninvolved right colon (P < 0.001). With worsening histologic injury in UC there was a progressive increase in SMO staining of mononuclear inflammatory cells. There was a similar increase in SMO staining with worsening endoscopic disease severity and strong correlation with the DAI (r = 0.653, P < 0.001). Inflammatory cell SMO staining was increased in involved left colon versus uninvolved right colon.

CONCLUSIONS

SMO expression is upregulated in UC tissues, deriving from increased levels in mononuclear inflammatory cells. Dysregulated polyamine homeostasis may contribute to chronic UC by altering immune responses and increasing oxidative stress.

Increased serum levels of L-arginine in ulcerative colitis and correlation with disease severity

BACKGROUND

L-arginine (L-Arg) is a semi-essential amino acid that is the substrate for both nitric oxide and polyamine synthesis. Cellular uptake of L-Arg is an active transport process that is subject to competitive inhibition by L-ornithine (L-Orn) and L-lysine (L-Lys). We investigated L-Arg utilization in patients with ulcerative colitis (UC).

METHODS

Serum was collected from 14 normal controls and 22 UC patients with pancolitis of moderate or severe activity by histopathology score. The Mayo Disease Activity Index (DAI) and endoscopy subscore were assessed. Serum amino acid levels were measured by high-performance liquid chromatography. Arginine availability index (AAI) was defined as [L-Arg]/([L-Orn] + [L-Lys]).

RESULTS

Serum L-Arg levels were significantly associated with histopathologic grade (P = 0.001). L-Arg levels were increased in subjects with severe colitis when compared to those with moderate colitis or normal mucosa. L-Orn + L-Lys levels were also increased in severe colitis, so that AAI was not significantly increased. L-Arg levels were also strongly associated with the endoscopy subscore (P < 0.001). There was a strong correlation between DAI and L-Arg levels (r = 0.656, P < 0.001).

CONCLUSIONS

Serum L-Arg levels correlate with UC disease severity but availability is not increased due to competitive inhibition by L-Orn and L-Lys. Our findings suggest that L-Arg uptake by cells in the inflamed colon is defective, which may contribute to the pathogenesis of UC. Studies delineating the mechanism of uptake inhibition could enhance our understanding of UC or lead to novel treatment options.