American Gastroenterological Association Institute Guideline on the Medical Management of Microscopic Colitis

This article has an accompanying continuing medical education activity on page e17. Learning Objective: Upon completion of this test, successful learners will be able to: (1) learn first-line treatment for the induction of remission in microscopic colitis; (2) identify the expected clinical benefi ts and adverse effects of induction therapy for microscopic colitis; (3) understand the in-dications for and dosing of maintenance therapy for microscopic colitis; (4) consider medications that may precipitate microscopic colitis especially in those who are refractory to medical therapy; and (5) become familiar with treatment strategies for microscopic colitis refractory to first-line therapy.

An AQP1 allele associated with co(a-b-) phenotype.

The Colton (CO) blood group system consists of four antigens, Co(a), Co(b), Co3, and Co4, located on aquaporin-1 (AQP1), with Co(a) highly prevalent in all populations (99.8%). The Colton null phenotype, Co(a-b-), is very rare, and individuals with this phenotype lack the high-prevalence antigen Co3. To date, only six Co(a-b-) probands have been reported and four silencing alleles characterized. We identified an AQP1-null allele in a white woman with anti-Co3 caused by deletion of a G at nucleotide 601 (nt601delG) that results in a frameshift and premature termination (Val201Stop). Available family members were tested for the allele. Although anti-Co3 has been associated with mild to severe hemolytic disease of the fetus and newborn, the antibody was not clinically significant as evidenced by a low titer and delivery of asymptomatic newborns with moderate to weakly positive direct antiglobulin tests for all four pregnancies.

Photodynamic therapy of intraductal papillary mucinous neoplasm.

Intraductal papillary mucinous neoplasm (IPMN) of the main pancreatic duct is usually treated by surgical excision of the affected pancreas. Nonoperative ablative therapies have not been described. We treated IPMN of the pancreatic duct with photodynamic therapy (PDT) in a patient who was a poor operative candidate. Porfimer sodium was administered intravenously, and laser light was delivered by a diffusing catheter placed in the pancreatic duct during endoscopic retrograde cholangiopancreatography (ERCP). Imaging and biopsy findings of IPMN resolved after PDT, and symptoms also resolved. Metastatic cancer was diagnosed 2 years after PDT had been initiated. Pancreatic PDT was well tolerated in this case, and may be a therapeutic option for selected patients with IPMN of the main pancreatic duct.

Metabolic and target organ outcomes after total pancreatectomy: Mayo Clinic experience and meta-analysis of the literature.

INTRODUCTION: Total pancreatectomy (TP) has been associated with substantial metabolic abnormalities and poor glycaemic control limiting its use. Because data reported to date are limited, we evaluated outcomes related to the diabetes mellitus obligated by TP. METHODS: A case series study of all patients who underwent TP from 01/01/1985 to 12/31/2006 at Mayo Clinic was conducted. TP cases were summarized according to perioperative procedures, mortality and morbidity after TP. To complement this retrospective examination, a survey was developed to measure DM treatment modality, target organ failure and complications in patients alive in 2007. We performed a meta-analysis to compare our results with similar previous studies and provide overall estimates of outcomes. RESULTS: A total of 141 cases were studied (97 malignant diseases, 44 benign diseases). The median survival was much less for malignant pathology (2·2 vs 8·7 years, Log rank P = 0·0009). In 2007, there were 59 patients that were presumed alive and 47 (80%) responded to the survey. Mean HbA1c at last follow-up was 7·5% with 89% of respondents on a complex insulin programme (mean daily insulin requirement 35 ± 13 units). Episodic hypoglycaemia was experienced by 37 (79%); 15 (41%) experienced severe hypoglycaemia. In contrast, diabetic ketoacidosis developed in only 2 (4%). Target organ complications and chronic diarrhoea developed in 13 patients (28%) each. CONCLUSION: The primary factor determining survival after TP is the aetiology necessitating TP, i.e. pancreatic malignancy. Most respondents used complex insulin programmes, but hypoglycaemia continues to be a problem.

Alloanti-c in a c-positive, JAL-positive patient.

BACKGROUND AND OBJECTIVES: In the Rh blood group system, partial D, C, and e antigens are well-known, but a partial c antigen resulting in the production of alloanti-c in a c+ individual is rare. One example of an alloanti-c in a c+ person was an anti-Rh26, which can appear as anti-c, and another was an alloanti-c in a c+ person with a presumed R(1)r phenotype. The finding of an apparent alloanti-c in a transfused c+ patient initiated this investigation. MATERIALS AND METHODS: Haemagglutination tests, DNA extraction, polymerase chain reaction (PCR)-based assays (PCR-restriction fragment length polymorphism, allele-specific PCR), reticulocyte mRNA extraction, reverse transcriptase (RT)-PCR and sequencing were performed by standard procedures. RESULTS: Plasma from a 64-year-old African American woman with a wound infection following a mastectomy contained anti-E, anti-S, anti-K, anti-Fy(a) and anti-Jk(b), reacting by the indirect antiglobulin test. In addition, the patient's plasma gave reactions that were consistent with an anti-c, while her pre-transfusion red blood cells typed c+ with some anti-c reagents. These results are consistent with a partial c antigen. The patient's red blood cells also typed V+(W)VS- and JAL+. Analyses of DNA and Rh-transcripts from this patient showed the presence of the following genes: RHD*D, RHD*DAU0, RHCE*Ce and RHCE*ce(S)(340). CONCLUSION: The nucleotide 340C>T change in RHCE exon 3 (predicted to encode 114Trp) of the RHCE*ce(S)(340) allele is associated with a JAL+ phenotype and the altered expression of the c, V and VS antigens. This alteration in the c antigen allowed the patient to make an alloanti-c. This case reveals that the RHCE*ce(S)(340) allele encodes a partial c antigen.

RHD deletion in a patient with chronic myeloid leukemia.

Anomalous expression of the Rh antigen, D, has occasionally been observed in patients with certain myeloproliferative disorders. Indeed, this phenomenon led to the tentative assignment of RH to the short arm of chromosome 1. PCR-based analyses were performed on DNA from an 82-year-old D+ Caucasian patient with chronic myeloid leukemia after her RBCs became D-. For nearly 7 years, the patient's RBCs typed as strongly D+, but in March 2006, they typed weakly D+ and in August 2006 typed D- by both direct hemagglutination and the IAT. The D- typing persisted until the patient's death in September 2006. To study the underlying cause of the change in D type, PCR-based assays were performed on DNA extracted from peripheral WBCs from the patient's sample collected in August 2006. No amplification was obtained using primers designed to amplify RHD exons 5, 8, or 10, and intron 4. Very weak amplification was obtained using primers designed to amplify RHD exons 3, 4, or 7. Two assays that detect the hybrid Rhesus box showed deletion of RHD. Amplification of RHCE in the patient's DNA was as efficient as that of control samples, and multiplex and PCR-RFLP assays predicted her RBCs would be C-E-c+e+. Based on finding a hybrid Rhesus box and absence of D-specific exons, we conclude that DNA from the patient's WBCs carries a deleted RHD. This explains the molecular mechanism underlying the change from D+ to D-.

Principles of PCR-based assays.

DNA-based assays are powerful tools to predict the blood group of an individual and are rapidly gaining in popularity. DNA, which can be extracted from various sources using commercial kits, is amplified by PCR to obtain a sufficient amount of the target of interest for analysis. There are different types of PCR assays: standard single PCR (followed by RFLP or sequencing), allele-specific PCR, multiplex PCR, and real-time PCR. Microarray platforms are a newer application of molecular testing, popular because they analyze multiple nucleotides in a single assay and have a high-throughput potential. This review briefly describes the principles of PCR-based assays that are commonly used in transfusion medicine.

Serologic and molecular genetic management of a pregnancy complicated by anti-Rh18.

Antibodies, such as anti-Rh18 (Hr/Hr(S)), that react with the common products of RHCE can cause HDN as well as severe hemolytic transfusion reactions. Individuals with anti-Rh18 antibodies can have different RHCE genetic backgrounds; therefore, sera and RBCs from these individuals may cross-react. In these situations, genotyping may be the best method to determine compatibility. We report a 26-year-old pregnant Puerto Rican woman who presented at 31 weeks' gestation with anti-E and anti-Rh18 in her serum. No potential donors were identified among family members or within the American Rare Donor Program; therefore, a unit of the patient's RBCs was collected one week before her planned caesarian section. To improve our ability to supply blood for this patient in the future, molecular testing was performed. The patient was found to be homozygous for an RH haplotype in which a variant RHD*DAR, is linked to a variant RHCE*ceAR. The DAR-ceAR haplotype has been described in Dutch-African populations, but this is the first report of an individual self-identified of Hispanic ethnicity. This case report demonstrates the clinical importance of molecular testing of patients with rare Rh phenotypes.

Molecular characterization of GYPB and RH in donors in the American Rare Donor Program.

Transfusion of patients with sickle cell disease (SCD) has been a challenge in clinical transfusion medicine, especially when the required donor RBCs must be U- and negative for high-prevalence Rh phenotypes (hr(B), hr(S)). It is now possible to genotype donors to identify or confirm Uvar and U- phenotypes, as well as Rh hr(B)- and hrS- phenotypes, and to characterize the different RH backgrounds found in these donors. In a preliminary study of donors registered in the American Rare Donor Program, twelve different RH backgrounds were identified in eighteen hr(B)- or hr(S)- donors. These results, summarized in the current report, confirm the heterogeneous nature of these phenotypes and are relevant for selection of donor units for patients with antibodies to high-prevalence Rh antigens. Not all phenotypically similar units will be compatible, and matching the Rh genotype of the donor to the patient is important to prevent further Rh sensitization. Most donors referred were hr(B)- and carry at least one hybrid RHD-CE(3-7)-D gene that encodes a variant C antigen linked to RHCE*ceS that encodes the VS+V- phenotype. Surprisingly, the majority of donors were heterozygous, some even carrying conventional alleles, suggesting that the loss of expression of the hr(B) epitopes on RBCs is a dominant phenotype. Although antigen-matching of patients with SCD with donors for C, E, and K antigens has decreased the incidence of alloimmunization, some patients still become immunized to Rh antigens, indicating the units were not truly matched. RH genotyping can identify those patients with SCD who carry RH alleles that encode altered C, e, or D who are at risk for production of "apparent auto" and alloantibodies to Rh antigens. RH genotyping of alloimmunized patients with SCD, partnered with genotyping of donors, can identify compatible units that would also eliminate the risk of further Rh alloimmunization.

DNA analysis for donor screening of Dombrock blood group antigens.

Due to the scarcity of reliable antibodies, RBC typing for Doa and Dob is notoriously difficult. Inaccurate typing can place patients at risk for hemolytic transfusion reactions. The molecular basis of the DOA/DOB polymorphism is associated with three nucleotide changes:378 C>T, 624 T>C,and 793 A>G of DO. While the 378 C>T and 624 T>C are silent mutations, the 793A>G polymorphism in codon 265 encodes asparagine for Doa and aspartic acid for Dob. We describe here the use of a PCR-RFLP assay as an alternative to traditional hemagglutination for typing donor blood for Dombrock. Primers were designed to amplify the region of DO containing the 793A>G polymorphism. DNA samples from blood donors were amplified and subjected to RFLP analysis. A total of 613 samples were tested for the Dombrock polymorphism (793 A>G) by PCRRFLP. PCR-RFLP can be used to screen for Do(a-) or Do(b-) donors. This approach overcomes the scarcity of the reagents required for testing by hemagglutination.

Dilation of proximal esophageal strictures following therapy for head and neck cancer: experience with Savary Gilliard dilators.

BACKGROUND: There is little information on dilation of proximal strictures following surgical and/or radiation therapy for head and neck cancer. We studied the feasibility and efficacy of dilating proximal strictures following therapy for head and neck cancer using Savary Gilliard dilators. METHODS: Twenty-one consecutive patients with proximal strictures resulting from surgery and/or radiation therapy of head and neck cancer were studied. Savary Gilliard dilation was performed using the standard and a modified method. Dysphagia was graded before and after dilation using a 5-point scale. RESULTS: Technical success, dysphagia relief, complications, and duration of relief were noted. Technical success was achieved in 20 (95%) patients. Adequate dysphagia relief was obtained in 15/20 (75%) patients, which lasted for 4-36 weeks (median 14 weeks). There were no perforations, bleeding, or deaths. Four patients required repeat dilation after a median interval of 12 weeks. CONCLUSIONS: Savary Gilliard dilation is a safe and effective method for dilating strictures caused by therapy for head and neck cancer.

The role of intraluminal radiotherapy and concurrent 5-fluorouracil infusion in the management of carcinoma esophagus: a pilot study.

Fifty patients with carcinoma of the esophagus were entered in a randomized pilot study to test the efficacy of intraluminal radiotherapy (ILRT) and concurrent 5-fluorouracil (5-FU) infusion. The median age was 65 years, with 80% having middle third lesions; in 62%, the lesions were longer than 5 cm. After external beam therapy of 50 Gy in 5 weeks, patients were randomized to receive chemotherapy. Significant improvement in dysphagia was recorded in 76% patients with complete response in 47 cases ranging from 6 to 27 months. The overall survival at 2 years was 15% with ILRT alone versus 22% with ILRT plus 5-FU infusion.