Gastrointestinal infections in solid organ transplant recipients:

Cerebral toxoplasmosis requiring urgent brain biopsy

A 39-yerar-old man was admitted to our hospital with behavioral disturbances and generalized headaches. He was diagnosed with CNS toxoplasmosis after performing a brain biopsy. He found to be HIV positive with a CD4 of 14/uL He was started on ant toxoplasmosis along with antiretroviral therapy. He presented 6 weeks after discharge with worsening headache thought to be related to relapse of toxoplasmosis. However, he found to have severe anemia related to CMV-induced gastrointestinal bleeding. He was started on anti-cytomegalovirus drugs and has finally achieved significant improvement.

Pneumatosis intestinalis with pneumoperitoneum mimicking intestinal perforation in a patient with myelodysplastic syndrome after hematopoietic stem cell transplantation

Pneumatosis intestinalis (PI) is an uncommon disorder characterized by an accumulation of gas in the bowel wall, and has been associated with a variety of disorders and procedures. We describe a 35-year-old man who undertook hematopoietic stem cell transplantation due to myelodysplastic syndrome. An abdominal X-ray demonstrated extensive PI with pneumoperitoneum mimicking hollow organ perforation. However, the patient had no abdominal symptoms and there was no evidence of peritoneal inflammation. After two weeks of conservative management, including bowel rest and antibiotics, his pneumoperitoneum resolved spontaneously without any complications. Of the many factors that affect the gastrointestinal tract mucosal integrity, intramural pressure, and bacterial flora-produced intraluminal gas interact to produce PI. If the condition is accompanied by bowel ischemia, portomesenteric venous gas, metabolic acidosis, and abdominal sepsis, or if PI is severe in extent immediate surgical intervention is indicated. The described case supports that a mechanical rather than a bacterial etiology underlies the pathogenesis of PI.

Risk Factors and Impact of .BETA.-D Glucan on Invasive Fungal Infection for the Living Donor Liver Transplant Recipients

Invasive fungal infection is a fatal complication in liver transplantation and it is very difficult to diagnose at the early stage. The aim of this study was to review our experience with invasive fungal infections in living donor liver transplantation (LDLT) and to analyze the risk factors and the impact of beta-D glucan. From 1991 to 2005, 96 LDLTs were performed in our institution and we measured the serum level of beta-D glucan in order to clarify the diagnosis. Invasive fungal infection was diagnosed based on clinical symptoms, culture, radiological evidence and beta-D glucan. Active fungal infection was treated with fluconazole, amphotericin B, flucytosine and micafungin. Risk factors both pre- and post- LDLT were analyzed. Candida albicans was the most frequently isolated species (70%). The risk factors identified by univariate analysis include the following four conditions: acute blood purification (plasma exchange with or without continuous hemodiafiltration), hepatic vein complications, renal failure and respiratory failure. By logistic regression analysis, hepatic vein complications and respiratory failure were identified as independent risk factors. The risk factors for invasive fungal infection of LDLT in Japan have not been well analyzed and this report will provide valuable information for the prevention of the fungal infection.

Gastrointestinal complications in renal transplant recipients

Gastrointestinal complications are frequent in renal transplant recipients and can include oral lesions, esophagitis, peptic ulcer, diarrhea, colon disorders and malignancy. Oral lesions may be caused by drugs such as cyclosporine and sirolimus, by virus or fungal infections. Leukoplakia may develop in patients with Epstein-Barr virus (EBV) infection. The commonest esophageal disorder is represented by fungal esophagitis usually caused by candida. A number of patients may suffer from nausea, vomiting and gastric discomfort. These disorders are more frequent in patients treated with mycophenolate mofetil (MMF). Peptic ulcer is more rare than in the past. Patients with a history of peptic ulcer are particularly prone to this complication. Other gastroduodenal disorders are caused by cytomegalovirus (CMV) and herpes simplex infection. Diarrhea is a frequent disorder which may be caused by pathogen microorganisms or by immunosuppressive agents. The differential diagnosis may be difficult. Colon disorders mainly consist of hemorrhage, usually sustained by CMV infection, or perforation which may be caused by diverticulitis or intestinal ischemia. Colon cancer, anal carcinoma, and EBV-associated lymphoproliferative disorders are particularly frequent in transplant recipients. A particular gastric lymphoma called mucosa-associated lymphoid tissue (MALT) lymphoma may develop in renal transplant patients. It usually responds to the eradication of Helicobacter pylori.