Recurrence of primary sclerosing cholangitis after liver transplantation

Seeking beyond rejection: an update on the differential diagnosis and a practical approach to liver allograft biopsy interpretation

Pathologic evaluation of liver allograft biopsies plays an integral role in the management of patients after liver transplantation. This review summarizes the clinical context and classical histology of different types of allograft rejection and also the common entities that enter the differential diagnosis of allograft rejection, and provides practical approaches to liver allograft biopsy interpretation. In addition, some of the new developments in the field of liver transplant pathology are updated. The purpose of this review is to provide guidance for pathologists interpreting liver allograft biopsies, particularly those interested in developing expertise in the field of liver transplant pathology.

Biliary hemorrhage after removal of an expandable metallic stent during liver transplantation

The self-expandable metallic stent (SEMS) has become a common device for palliative treatment of malignant biliary obstructions or benign strictures. Despite the ease of placement of SEMSs, their removal has been reported to be very difficult. Here, we report a case with primary sclerosing cholangitis who developed massive hemorrhage after intraoperative removal of a SEMS. Possible living donor liver transplantation (LT) was considered for a 49-year-old female with primary sclerosing cholangitis. However, her general condition did not meet the criteria for LT; therefore, she was referred back to her primary physician. Two years later, she developed jaundice, and her primary physician placed multiple SEMSs, 1 of which was placed across the papilla of Vater. She was evaluated rapidly, and underwent living donor LT. During the operation, the common bile duct was examined and an incision was made. A stent was found firmly embedded in the bile duct. Each wire of the SEMS was pinched and then successfully pulled out 1 by 1. Finally, all parts of the SEMS were removed. Before creating the Roux-en-Y limb, hemorrhage from the remnant bile duct was confirmed by examination of the duodenum and bile duct stump. The bile duct was sewn internally with monofilament stitches and compressed for 10 minutes. Finally, hemostasis was brought about and transplantation was completed successfully. Despite some reports regarding successful endoscopic removal of SEMSs, its removal in patients with portal hypertension coagulopathy is risky. SEMSs should not be placed in patients who are candidates for LT.

Transplantation in autoimmune liver diseases

Liver transplantation remains an effective treatment for those with end-stage disease and with intractable liver-related symptoms. The shortage of organs for transplantation has resulted in the need for rationing. A variety of approaches to selection and allocation have been developed and vary from country to country. The shortage of donors has meant that new approaches have to be adopted to make maximal use of the available organs; these include splitting grafts, use of extended criteria livers, livers from non-heart-beating donors and from living donors. Post transplantation, most patients will need life-long immunosuppression, although a small proportion can have immunosuppression successfully withdrawn. Newer immunosuppressive drugs and different strategies may allow a more targeted approach with a reduction in side-effects and so improve the patient and graft survival. For autoimmune diseases, transplantation is associated with significant improvement in the quality and length of life. Disease may recur after transplantation and may affect patient and graft survival.

The impact of disease recurrence on graft survival following liver transplantation: a single centre experience

Many diseases that cause liver failure may recur after transplantation. A retrospective analysis of the rate and cause of graft loss of 1840 consecutive adults receiving a primary liver transplant between 1982 and 2004 was performed to evaluate the rate of graft loss from disease recurrence. The risk of graft loss from recurrent disease was greatest, when compared to primary biliary cirrhosis (PBC), in those transplanted for hepatitis C virus (HCV) [hazard ratio (HR) 11.6; 95% confidence interval (CI) 5.1-26.6], primary sclerosing cholangitis (PSC) (HR 6.0; 95% CI 2.5-14.2) and autoimmune hepatitis (AIH) (HR 4.1; 95% CI 1.3-12.6). The overall risk of graft loss was also significantly greater in HCV (HR 2.1 vs. PBC; 95% CI 1.5-3.0), PSC (HR 1.6 vs. PBC; 95% CI 1.2-2.3) and AIH (HR 1.6; 95% CI 1.0-2.4) than in PBC. There was no statistically significant difference in the risk of graft loss because of recurrent disease, when compared with PBC, for patients transplanted for alcohol related liver disease, nonalcoholic steatohepatitis and fulminant hepatic failure. Disease recurrence is a significant cause of graft loss particularly in HCV, PSC and AIH. Recurrent disease, in part, explains the increased overall risk of graft loss in these groups.

Risk factors for recurrence of primary sclerosing cholangitis after liver transplantation

Liver transplantation (LT) is the only therapeutic option for end-stage primary sclerosing cholangitis (PSC), but PSC can recur (rPSC) in some patients after LT. The aim of our study was to evaluate the risk factors associated with rPSC. Between 1989 and 2004, 69 patients receiving transplantation for PSC (42 male, mean age 41.9 yr). Clinical and laboratory data, activity/extension and treatment of ulcerative colitis (UC), post-LT cytomegalovirus (CMV) infection, and immunosuppression were evaluated. Determination of rPSC was made by radiological and histological findings. Exclusion criteria were ABO blood group incompatibility, hepatic artery stenosis, and biliary strictures occurring in <3 months post-LT. A total of 48 (70%) patients had PSC and UC pre-LT. rPSC occurred in 7 of 53 (13.5%, 2 patients with de novo UC) who were alive 1 yr after LT and/or met inclusion/exclusion criteria: median 60 (4-120) months. No patient without post-LT UC had rPSC: 0 of 20 vs. 7 of 26 with post-LT UC (P = 0.027). The multivariate logistic regression analysis showed that maintenance steroids for UC (>3 months) post-LT was the only risk factor significantly associated with rPSC (P = 0.025). In conclusion, the presence of UC post-LT, and the need for maintenance steroids post-LT, which is an independent factor, are associated with rPSC. These findings could help elucidate a possible mechanism of PSC pathogenesis.

Intrahepatic cholestasis after liver transplantation

Biochemical cholestasis after liver transplantation is common and often has no clinical significance if biliary anastomosis strictures and leaks have been excluded. There is no agreed upon definition for severe cholestasis, but it is associated with a worse mortality. There has been little evaluation on risk factors, but these include cryoprecipitate and platelet transfusion intraoperatively, nonidentical blood group, suboptimal graft appearance, inpatient status before transplant, and bacteremia within the first month. Associated causes considered as early (<6 months) include ischemia-reperfusion injury, primary nonfunction, small-for-size graft syndrome, infection, drugs and acute cellular rejection. Late causes include hepatic artery thrombosis, chronic rejection, biliary complications, recurrent viral and cholestatic disease, and posttransplant lymphoproliferative disorder.

Management of biliary complications after orthotopic liver transplantation: The role of endoscopy

Biliary complications are significant causes of morbidity and mortality after orthotopic liver transplantation (OLT). The estimated incidence of biliary complications after OLT ranges between 10%-25%, however, these numbers continue to decline due to improvement in surgical techniques. The most common biliary complications are strictures (both anastomotic and non-anastomotic) and bile leaks. Most of these problems can be appropriately managed with endoscopic retrograde cholangiography (ERC). Other complications such as bile duct stones, bile casts, sphincter of Oddi dysfunction, and hemobilia, are less frequent and also can be managed with ERC. This article will review the risk factors, diagnosis, and endoscopic management of the most common biliary complications after OLT.

Recurrence of primary biliary cirrhosis and primary sclerosing cholangitis after liver transplantation in Japan

Although there was some initial controversy, there is now a consensus that primary biliary cirrhosis (PBC) does indeed recur in both cadaveric and living donated allografts. Recurrence rate after deceased donor liver transplantation (LT) was reported to be 10.9-23% at 5 years. In the present study, we reviewed 221 PBC patients who underwent living-donor liver transplantation (LDLT) in Japan. The 5-year overall survival rate was 79%, and the rate of recurrence based on histological findings was 10% (7/70) after a median time of 36 months. Primary immunosuppression, withdrawal of corticosteroids and human leukocyte antigen matches were not associated with the recurrence. Recurrent PBC appears to have little impact on graft function and survival, but this may become a greater problem with longer follow up. It is noteworthy that the 10-year survival of primary sclerosing cholangitis (PSC) patients who underwent LDLT wasfound to be only 39.1% in Japan, whereas that of PBC was 72.9%. Factors associated with the poor prognosis include biliary strictures, hepatobiliary and colorectal malignancies, and recurrence of PSC. In our study, we reviewed 66 patients with PSC who underwent LDLT in Japan. The 5-year survival rate was 72%, and the rate of recurrence diagnosed on histological and cholangiographic findings was 25% (11/44). Well-defined diagnostic criteria and longer studies are required to characterize the nature of recurrent PSC and its impact on graft survival in more detail.

General aspects and pitfalls in liver transplant pathology

Pathology in a liver transplant setting addresses four different topics: establishment of a definite diagnosis of the liver disease before listing for transplantation, evaluation of the donor liver with regard to pre-existing diseases, in particular macrovesicular steatosis and fibrosis, assessment of the hepatectomy specimen, and post-transplant biopsy evaluation. Of these, post-transplant biopsy evaluation is the most challenging and clinically the most relevant issue. It requires fast diagnoses to facilitate specific treatment and it has to incorporate a broad spectrum of differential diagnoses. Precise knowledge about rejection, post-transplant therapy, pathology of immunosuppression, and recurrence of the initially underlying liver disease including the characteristic time peaks and atypical histological presentations (e.g., fibrosing cholestatic hepatitis) is needed to evaluate specific and combined histological pictures of liver damage. For adequate interpretation of post-transplant biopsies the hepatopathologist has to be informed about the essential clinico-anamnestic aspects such as time course, medication, imaging results, and serology.

Biliary complications after deceased-donor orthotopic liver transplantation

A wide range of potential biliary complications can occur after orthotopic liver transplantation (OLT). The most common biliary complications are bile leaks, anastomotic and intrahepatic strictures, stones, and ampullary dyfunction, which may occur in up to 20%-40% of OLT recipients. Leaks predominate in the early posttransplant period; stricture formation typically develops gradually over time. However, with the advent of new techniques, such as split-liver, reduced-size, and living-donor liver transplantation, the spectrum of biliary complications has changed. Risk factors for biliary complications comprise technical failure; T-tube or stent-related complications; hepatic artery thrombosis; bleeding; ischemia/reperfusion injury; and other immunological, nonimmunological, and infectious complications. Noninvasive diagnostic methods have been established and treatment modalities have been modified towards a primarily nonoperative, endoscopy-based strategy. Besides, the management of biliary complications after OLT requires a multidisciplinary approach, in which interventional and endoscopic treatment options have to be weighed up against surgical treatment options. The etiology and spectrum of bile duct complications, their diagnosis, and their treatment will be reviewed in this article.

Distinguishing between recurrent primary sclerosing cholangitis and chronic rejection

1. Recurrent primary sclerosing cholangitis (PSC) is extremely difficult, if not impossible, to distinguish from other causes of biliary strictures or sclerosing cholangitis in allografts using needle biopsy evaluation alone. Technical problems with biliary reconstruction, long cold ischemic times, non-heart beating donors, ABO blood group incompatibility, antibody-mediated rejection, and small-for-size syndrome in reduced-size or living donor livers can also cause similar manifestations in a peripheral core biopsy. 2. Some difficulties in distinguishing between sclerosing cholangitis and chronic rejection (CR) arise because: a) at risk populations are similar; b) both can cause "cholestatic" elevation of liver injury tests; and c) both can lead to intrahepatic cholestasis and small bile duct loss. 3. Etiopathogenesis and pathology of CR and sclerosing cholangitis have some overlapping features, but show distinct differences that result in significantly different and discriminating pathologic manifestations. 4. Clues in the clinical history, evaluation of serial biopsies, and histopathology can be used to distinguish with confidence between sclerosing cholangitis and CR. 5. Potential discriminating features include liver size and gross appearance, and histopathology findings in the arterial tree, hilar lymph nodes, large and small bile ducts, interface zone, lobular, and perivenular regions.

A difficult case of primary sclerosing cholangitis

1. The immediate postoperative concerns in a patient with primary sclerosing cholangitis. 2. Recognize the difficulties in assessing biliary health in patients that have had complicated postoperative biliary concerns. 3. Recognize the difficulty in ascertaining the presence of chronic rejection vs. recurrent primary sclerosing cholangitis.

Primary sclerosing cholangitis: summary of a workshop

Primary sclerosing cholangitis (PSC) is a rare but important liver disease that leads to cirrhosis and need for liver transplantation in a high proportion of cases. The disease occurs in approximately 1 per 100,000 population per year, usually presents in adulthood, and affects men more often than women. Typical serum biochemical results, autoantibodies and liver biopsy are suggestive but not diagnostic of PSC, the diagnosis requiring cholangiographic demonstration of stricturing and dilatation of the intra- and/or extra-hepatic bile ducts. The natural history of PSC is variable, the average survival being 12 to 17 years. The cause of PSC is still unknown. Although considered an autoimmune disease, PSC has several atypical features and a strong genetic component. The therapy of PSC is unsatisfactory. Standard doses of ursodeoxycholic acid (UDCA) lead to improvements in biochemical abnormalities but not in histology, cholangiographic appearance or survival. Several innovative therapies have been tried in PSC, but with scant evidence of benefit. For patients with high grade strictures, endoscopic dilatation is beneficial. Liver transplantation is successful for end-stage liver disease due to PSC and improves survival. PSC may recur after transplantation but is rarely progressive. The most dreaded complication of PSC is cholangiocarcinoma. Diagnosis of this highly malignant tumor is difficult, and there are no biomarkers for its early detection. Liver transplantation for cholangiocarcinoma has an exceedingly poor outcome, although transplantation with neoadjuvant chemoirradiation holds promise in selected patients. Thus, significant opportunities remain for basic and clinical research into the cause, natural history, and therapy of PSC.

Recurrence of diseases following orthotopic liver transplantation

Long-term graft survival and mortality after liver transplantation continue to improve. However, disease recurrence remains a major stumbling block, especially among patients with hepatitis C. Chronic hepatitis C recurs to varying degrees in nearly all patients who undergo transplantation. Transplantation for hepatitis C is associated with higher rates of graft failure and death compared with transplantation for other indications, and retransplantation for hepatitis C related liver failure remains controversial. Recurrence of hepatitis B has been markedly reduced with improved prophylactic regimens. Further, rates of hepatocellular carcinoma recurrence have also decreased, as improved patient selection criteria have prioritized transplantation for those with a low risk of recurrence. Primary biliary cirrhosis recurs in some patients, but it is often relatively mild. Autoimmune liver disease has also been shown to have a relatively benign post-transplantation course, but some studies have indicated that it slowly progresses in most recipients. It has been recently reported that alcoholic liver disease liver transplant recipients who return to drinking have worsened mortality. In such patients worse outcomes are not due to graft failure, but instead to other comorbidities. Recurrences of other diseases, including nonalcoholic steatohepatitis and primary sclerosing cholangitis, are now being recognized as having potentially detrimental effects on graft survival and mortality. Expert clinical management may help prevent and treat complications associated with disease recurrence.

Bile duct complications after liver transplantation

Complications involving the biliary tract after orthotopic liver transplantation (OLT) have been a common problem since the early beginning of this technique. Biliary complications have been reported to occur at a relatively constant rate of approximately 10-15% of all deceased donor full size OLTs. There is a wide range of potential biliary complications which can occur after OLT. Their incidence varies according to the type of graft, type of donor, and the type of biliary anastomosis performed. The spectrum of biliary complications has changed over the past decade because of the establishment of split liver, reduced-size, and living donor liver transplantation. Apart from technical developments, novel diagnostic methods have been introduced and evaluated in OLT, the most prominent being magnetic resonance imaging (MRI). Treatment modalities have also changed over the past years towards a primarily nonoperative, endoscopy-based strategy, leaving the surgical intervention for lesions which otherwise are not curable. The management of biliary complications after OLT requires a multidisciplinary approach. Conservative, interventional, and endoscopic treatment options have to be weighed up against surgical re-intervention. In the following the spectrum of specific bile duct complications after OLT and their treatment options will be reviewed.

Review article: current management of primary sclerosing cholangitis

The management of primary sclerosing cholangitis (PSC) is hindered by incomplete understanding of the pathogenesis of the disease and the lack of good prognostic models. Few large randomized controlled trials of drug therapy have been published. Best practice in the management of PSC is currently based therefore on careful interpretation of the available evidence, close observation of individual patients and clinical experience of the disease. Drug therapy is useful for alleviating symptoms. Ursodeoxycholic acid may slow progression of the disease and reduce the frequency of complications. Consensus is emerging on the issues of screening for the malignant complications of PSC and the indications for liver transplantation are becoming broader and encompassing the earliest stages of cholangiocarcinoma. In view of the rarity of the disease in the general population, large international collaborations to study PSC are necessary to provide clearer answers in areas of uncertainty, and these are now beginning to emerge.

Treatment of Biliary Problems in Inflammatory Bowel Disease

The most common biliary problem in patients with inflammatory bowel disease is primary sclerosing cholangitis (PSC). The treatment of this disease is multifaceted and frequently requires a multidisciplinary approach involving internists, nutritionists, gastroenterologists, and surgeons. Unfortunately, other than liver transplantation, no therapy that is currently available has been proven to alter the natural history of PSC or prolong survival. Ursodeoxycholic acid is currently the most promising pharmacologic treatment option for slowing disease progression and should be used in higher than usual doses (20 to 30 mg/kg/d). Treatment of symptoms due to cholestasis, such as pruritis and steatorrhea, is an important aspect of the medical care of patients with PSC. Our preferred treatment of pruritis due to cholestasis is with bile acid binding exchange resins such as cholestyramine or colestipol (which is generally better tolerated than cholestyramine). Endoscopic therapy should be reserved for patients with obstructive jaundice, cholangitis, or symptomatic dominant biliary strictures. We recommend dilation of dominant strictures with graduated or balloon dilators followed by temporary stenting if the postdilation cholangiographic appearance is not improved or adequate biliary drainage cannot be assured. There is indirect evidence that the combination of ursodeoxycholic acid and endoscopic therapy to maintain biliary patency may improve transplant-free survival in patients with PSC, although this remains to be proven. Liver transplantation remains the only effective treatment of advanced PSC, and should be considered in patients with complications of cirrhosis or intractable pruritis or fatigue.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the intra- and extrahepatic bile ducts. An estimated 80% of patients in North America and Europe have coexistent inflammatory bowel disease (IBD). The underlying pathophysiology of PSC remains poorly understood. As a result, there is currently no effective medical therapy to halt disease progression. Important complications from PSC include metabolic bone disease, colorectal neoplasia, and cholangiocarcinoma. Liver transplantation remains the only successful treatment option for patients with advanced liver disease from PSC. A diagnosis of PSC should be considered among individuals with IBD and elevated serum liver biochemical tests.

Duct-to-duct biliary anastomosis for patients with sclerosing cholangitis undergoing liver transplantation

BACKGROUND

Due to the association of strictures within the biliary ductal system, Roux-en-Y choledochojejunostomy has been the preferred method of anastomosis for liver transplant recipients with primary sclerosing cholangitis (PSC). The aim of this study was to evaluate duct-to-duct anastomosis in patients with PSC who undergo liver transplantation.

METHODS

Data were collected and evaluated based on demographics, type of anastomosis preformed, malignancies, outcomes comparisons, and survival.

RESULTS

Of the 60 patients transplanted for PSC, 58 were diagnosed PSC prior to transplantation and 2 were diagnosed on explant. The Roux-en-Y group (n = 38) were similar in age, gender, and race when compared to the duct-to-duct (d-d) group (n = 22). There were similar rates of anastomotic revisions when comparing d-d anastomosis with Roux-en-Y (2 [9.1%] versus 2 [5.3%], P = NS) owing to bile leaks. Based on radiologic interventions of the bile ducts, seven (18.4%) in the Roux-en-Y group had interventions compared to two (9.1%) in the duct-to-duct group (P = NS). There was also no difference in recurrence of PSC: three (7.9%) in the Roux-en-Y group compared to two (5.3%) in the duct-to-duct group (P = NS). Survival at 4 years were similar between each group (76.5% [+/- 0.07] Roux-en-Y versus 84.9% [+/- 0.08] duct-to-duct, P = NS).

CONCLUSION

Duct-to-duct anastomosis at the time of liver transplantation is both safe and efficacious when used in patients with PSC. Outcomes as described by surgical interventions, radiologic interventions, retransplantation, and survival were similar between groups.

Results of liver transplantation according to indications for orthotopic liver transplantation

OBJECTIVE

This study assessed the results of liver transplantation in patients with a variety of different indications.

METHODS

From 1989 to April 2003, 209 orthotopic liver transplantations (OLTx) were performed on 196 patients, including 178 cases. The diagnoses were: PBC (n = 34); PSC (n = 13); elective postinflammatory cirrhosis in the course of hepatitis C (n = 29); hepatitis B (n = 16); postalcoholic cirrhosis (n = 23), autoimmune cirrhosis (n = 11); Wilson's disease (n = 6); cirrhosis of unknown etiology (n = 10); secondary biliary cirrhosis (n = 5); Budd-Chiari syndrome (n = 6); and benign liver neoplasms (n = 7).

RESULTS

The 3-year survival rate in the group of patients transplanted electively was 74.1%. In other groups it was: PBC, 91.4%; PSC, 69.2%; hepatitis C, 69.6%; hepatitis B, 55.5%; postalcoholic cirrhosis, 80%; autoimmune cirrhosis, 81.8%; Wilson's disease, 57.1%; secondary biliary cirrhosis, 40%; Budd-Chiari syndrome, 66.6%; hemochromatosis, 100%; benign neoplasms of the liver, 87.5%; and liver cysts, 100%.

CONCLUSIONS

Results of liver transplantation were closely related to the urgency of the procedure. Better results were achieved in patients operated upon routinely compared with in those operated upon emergently (74.1% vs 50%). The best results of liver transplantation were achieved in patients transplanted on a routine basis with a diagnosis of PBC (91.4%), autoimmunologic cirrhosis (81.1%), postalcoholic cirrhosis (80%), or hemochoromatosis (100%). Patients with liver insufficiency due to hepatitis B and Wilson's disease have an increased risk of graft destruction, and the rate of survival in these patients is significantly lower than in other patients.

Sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disorder characterized by strictures and dilatations of the biliary tree. The median survival has been reported to be 12 years from diagnosis but patients diagnosed during the last decade have been shown to have longer survival of a median of 18 years. Small duct PSC seems to be an entity of its own and rarely progresses to large duct PSC and the prognosis of small duct PSC is much better than in large duct disease. Cholangiocarcinoma does not develop in patients with small duct PSC according to recently published studies. Autoantibodies binding to biliary epithelial cells have been demonstrated in sera from patients with PSC but the pathogenic role of these remains to be determined. It is suggested that inflammatory bowel disease is accelerated after orthotopic liver transplantation. MR cholangiopancreatography is increasingly used in clinical practice and has been reported to have similar diagnostic accuracy as ERCP. However, lack of standardization of this novel technology makes it unclear if it can supersede ERCP as a diagnostic tool in PSC at the present time. Better diagnostic tests to detect cholangiocarcinoma in patients with PSC are urgently needed.

Treatment Options for Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are chronic cholestatic liver diseases that affect 0.5 to 40 per 100,000 and 1 to 6 per 100,000 Americans, respectively. Prompt recognition and management of the clinical manifestations of these diseases is essential for the patients' well-being and ultimate outcome. Ursodeoxycholic acid (UDCA), 13 to 15 mg/kg per day, is the standard therapy for PBC and should be offered to every patient. It has been shown to slow progression of the disease and prevent the need for liver transplantation, which is the last recourse for patients with end-stage disease. However, there is no effective therapy for PSC yet. Patients are managed symptomatically, with surgical or endoscopic interventions as needed in cases of significant biliary obstruction. Complications of chronic cholestasis are seen in both PBC and PSC, with pruritus and fatigue being the most common complaints. The first choice for the treatment of pruritus is still cholestyramine, starting at 4 g/d. The pathogenesis of fatigue is poorly understood in this population; unrecognized hypothyroidism should be excluded. The use of antidepressants is currently under evaluation, but there is no specific therapy for fatigue as of yet. For prevention of severe osteoporosis, we recommend supplementation with 800 IU vitamin D and 1500 mg calcium/d. In patients with PBC and established osteoporosis, the use of alendronate and vitamin K appears to cause an increase in bone mineral density. Further studies are necessary before either of these drugs is routinely recommended. Finally, fat-soluble vitamin deficiencies are noted with more advanced disease. We recommend that serum levels be checked in high-risk patients, and that vitamins are replaced as appropriate with water-soluble supplements. However, other causes of malabsorption must be ruled out, including pancreatic insufficiency and celiac sprue.