Reply to the comments on "Coffee bean sign, steel pan sign and whirl sign in sigmoid volvulus".

We thank Prof. Atamanalp and colleagues for their interest and valuable comments on our article. The authors have highlighted important considerations in the diagnosis of sigmoid volvulus (SV). We would like to respond to their comments. Firstly, although we agree with their opinion that CT, MRI, and endoscopy are more reliable diagnostic tools than plain radiography, we still emphasize that diagnostic imaging for SV is initially based on plain radiography, as recommended by the WSES consensus guidelines. Since SV is the third most common cause of colonic obstruction worldwide, the accessibility of plain radiography is crucial. Among the many plain radiographic signs of SV, Levsky et al. reported that the most sensitive signs were absence of rectal gas, followed by inverted-U appearance and coffee bean sign. Understanding these signs may lead to early detection of SV and further CT evaluation for ischemia or perforation. Despite the high value of plain radiography, there is a global tend to use CT instead from the outset. Secondly, we agree with their opinion that endoscopy is not only a therapeutic, but also a diagnostic procedure to assess mucosal viability. In addition, we believe that endoscopy is also useful in ruling out other obstructive lesions, including colorectal neoplasia and complicated sigmoid diverticular disease. In the clinical setting, endoscopy is performed after the diagnosis of SV by plain radiography or CT and serves as the first line of decompression of SV when ischemia or perforation is not suspected. Finally, we congratulate Prof. Atamanalp and colleagues for their dedicated contribution to the large-scale SV studies in Eastern Anatolia, Turkey, where SV is endemic.

Chinese dragon sign of ulcerative colitis.

We present a case of a 17-year-old woman with ulcerative colitis (UC) presented with abdominal pain and hematochezia. A CT scan showed active bowel inflammation, presenting the Chinese dragon sign. A diagnosis of exacerbation of UC was made. This sign refers to tortuous thick-walled sigmoid colon and rectum with narrow lumen resembles the body of the dragon and hypervascularity of the involved mesenteric vessels as bright dots next to the outer wall resemble the legs and skin spikes. Although this sign is nonspecific and may appear in ischemic colitis, ischemic colitis usually does not have rectal involvement and can be differentiated from typical UC.

Comb sign in Crohn's disease.

We present a case of a 13-year-old boy with Crohn's disease (CD) who presented with abdominal pain and diarrhea. On examination, there was tenderness on the lower abdomen. Laboratory examinations showed elevated inflammatory parameters. A CT scan showed active inflammation of the ileum and rectosigmoid colon with the comb sign. A diagnosis of exacerbation of CD was made. The comb sign refers to hypervascularity of the mesentery with vascular dilatation, tortuosity, and wide spacing of the vasa recta that are aligned as the teeth of a comb. This sign is not always pathognomonic for CD; however, it may help identification of acute exacerbation in known CD and differentiating active CD from hypovascular disease such as lymphoma. The comb sign can be highly correlated with the endoscopic severity rather than mural thickening in CD.

Coffee bean sign, steel pan sign, and whirl sign in sigmoid volvulus.

A 66-year-old man presented with abdominal distension. A plain radiograph showed the coffee bean sign, suggesting sigmoid volvulus (SV). The CT scans disclosed the steel pan sign, the whirl sign, and the beak-shaped transition point, confirming SV. He improved with colonoscopic decompression and detorsion. Characteristic radiographic signs of SV are briefly discussed.

Distribution of cytomegalovirus genotypes among ulcerative colitis patients in Okinawa, Japan.

BACKGROUND/AIMS: To determine the prevalence of glycoprotein B (gB), glycoprotein N (gN), and glycoprotein H (gH) genotypes of human cytomegalovirus (HCMV) superimposed on ulcerative colitis (UC) patients in Japan. METHODS: Four archived stool samples and 7-archived extracted DNA from stool samples of 11 UC patients with positive multiplex polymerase chain reaction (PCR) results for HCMV were used UL55 gene encoding gB, UL73 gene encoding gN, and UL75 gene encoding gH were identified by PCR. Genotypes of gB and glycoprotein N were determined by sequencing. RESULTS: Among 11 samples, 8 samples were amplified through PCR. gB, gN, and gH genotypes were successfully detected in 3 of 8 (37.5%), 4 of 8 (50%), and 8 of 8 (100%), respectively. The distribution of gB and gN genotypes analyzed through phylogenetic analysis were as follows: gB1 (2/3, 66.7%), gB3 (1/3, 33.3%), gN3a (2/4, 50%), and gN3b (2/4, 50%). Other gB genotypes (gB2 and gB4) and gN genotypes (gN1, gN2, and gN4) were not detected in this study. Out of successfully amplified 8 samples of gH genotype, gH1 and gH2 were distributed in 12.5% and 75% samples, respectively. Only 1 sample revealed mixed infection of gH genotype. The distribution of gH1 and gH2 differed significantly (1:6, P<0.05) in UC patients. The distribution of single gH genotype also revealed significant difference in UC patients who were treated with immunosuppressive drug (P<0.05). CONCLUSIONS: In this study, gB1, gN3, and gH2 gene were determined as the most frequently observed genotypes in UC patients, which suggest that there might be an association between these genotypes of HCMV and UC.

Confounding effects of microbiome on the susceptibility of TNFSF15 to Crohn's disease in the Ryukyu Islands.

Crohn's disease (CD) involves chronic inflammation in the gastrointestinal tract due to dysregulation of the host immune response to the gut microbiome. Even though the host-microbiome interactions are likely contributors to the development of CD, a few studies have detected genetic variants that change bacterial compositions and increase CD risk. We focus on one of the well-replicated susceptible genes, tumor necrosis factor superfamily member 15 (TNFSF15), and apply statistical analyses for personal profiles of genotypes and salivary microbiota collected from CD cases and controls in the Ryukyu Islands, southernmost islands of the Japanese archipelago. Our association test confirmed the susceptibility of TNFSF15 in the Ryukyu Islands. We found that the recessive model was supported to fit the observed genotype frequency of risk alleles slightly better than the additive model, defining the genetic effect on CD if a pair of the chromosomes in an individual consists of all risk alleles. The combined analysis of haplotypes and salivary microbiome from a small set of samples showed a significant association of the genetic effect with the increase of Prevotella, which led to a significant increase of CD risk. However, the genetic effect on CD disappeared if the abundance of Prevotella was low, suggesting the genetic contribution to CD is conditionally independent given a fixed amount of Prevotella. Although our statistical power is limited due to the small sample size, these results support an idea that the genetic susceptibility of TNFSF15 to CD may be confounded, in part, by the increase of Prevotella.

Evaluation of a multiplex PCR assay for detection of cytomegalovirus in stool samples from patients with ulcerative colitis.

AIM: To evaluate a multiplex PCR assay for the detection of bacterial and viral enteropathogens in stool samples from patients with ulcerative colitis (UC). METHODS: We prospectively analyzed 300 individuals, including immunocompetent patients, immunocompromised patients, and patients with UC. Stool samples were collected from the recto-sigmoid region of the colon by endoscopy. The samples were qualitatively analyzed for bacterial and viral enteropathogens with a multiplex PCR assay using a Seeplex(®) Kit. Additional clinical and laboratory data were collected from the medical records. RESULTS: A multiplex PCR assay detected 397 pathogens (191 bacteria and 206 viruses) in 215 samples (71.7%). The most frequently detected bacteria were Escherichia coli H7, 85 (28.3%); followed by Aeromonas spp., 43 (14.3%); and Clostridium perfringens, 36 (12.0%) samples. The most prevalent viruses were Epstein-Barr virus (EBV), 90 (30.0%); followed by human herpes virus-6 (HHV-6), 53 (17.7%); and cytomegalovirus (CMV), 37 (12.3%) samples. The prevalence rate of CMV infection was significantly higher in the immunocompromised group than in the immunocompetent group (P < 0.01). CMV infection was more common in patients with UC (26/71; 36.6%) than in the immunocompetent patients excluding UC (6/188; 3.2%) (P < 0.01). CMV infection was more prevalent in UC active patients (25/58; 43.1%) than in UC inactive patients (1/13; 7.7%) (P < 0.05). Among 4 groups which defined by the UC activity and immunosuppressive drugs, the prevalence rate of CMV infection was highest in the UC active patients with immunosuppressive drugs (19/34; 55.8%). Epstein-Barr virus (EBV) infection was more common in the immunocompromised patients excluding UC (18/41; 43.9%) than in the immunocompetent patients excluding UC (47/188; 25.0%) (P < 0.05). The simultaneous presence of CMV and EBV and/or HHV6 in UC active patients (14/58; 24.1%) was greater than in immunocompromised patients excluding UC (5/41; 12.2%) (P < 0.05). CONCLUSION: The multiplex PCR assay that was used to analyze the stool samples in this study may serve as a non-invasive approach that can be used to exclude the possibility of CMV infection in patients with active UC who are treated with immunosuppressive therapy.

Dysbiosis of salivary microbiota in inflammatory bowel disease and its association with oral immunological biomarkers.

Analysis of microbiota in various biological and environmental samples under a variety of conditions has recently become more practical due to remarkable advances in next-generation sequencing. Changes leading to specific biological states including some of the more complex diseases can now be characterized with relative ease. It is known that gut microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD), mainly Crohn's disease and ulcerative colitis, exhibiting symptoms in the gastrointestinal tract. Recent studies also showed increased frequency of oral manifestations among IBD patients, indicating aberrations in the oral microbiota. Based on these observations, we analyzed the composition of salivary microbiota of 35 IBD patients by 454 pyrosequencing of the bacterial 16S rRNA gene and compared it with that of 24 healthy controls (HCs). The results showed that Bacteroidetes was significantly increased with a concurrent decrease in Proteobacteria in the salivary microbiota of IBD patients. The dominant genera, Streptococcus, Prevotella, Neisseria, Haemophilus, Veillonella, and Gemella, were found to largely contribute to dysbiosis (dysbacteriosis) observed in the salivary microbiota of IBD patients. Analysis of immunological biomarkers in the saliva of IBD patients showed elevated levels of many inflammatory cytokines and immunoglobulin A, and a lower lysozyme level. A strong correlation was shown between lysozyme and IL-1ß levels and the relative abundance of Streptococcus, Prevotella, Haemophilus and Veillonella. Our data demonstrate that dysbiosis of salivary microbiota is associated with inflammatory responses in IBD patients, suggesting that it is possibly linked to dysbiosis of their gut microbiota.