Alexandra K. Tsaroucha

Unexpected augmentation of mycophenolic acid pharmacokinetics in renal transplant patients receiving tacrolimus and mycophenolate mofetil in combination therapy, and analogous in vitro findings

Mycophenolate mofetil (MMF) a potent immunosuppressive agent, has recently been approved for clinical use (CellCept) in renal transplant patients in combination with cyclosporine (CsA). With the expanded use of tacrolimus (Prograf) as well in renal transplant patients, there is a lack of pharmacokinetic studies clarifying drug interactions between the three agents. A pharmacokinetic study was performed on 18 stable renal transplant patients receiving MMF and tacrolimus together, and four control groups, one receiving tacrolimus alone, two receiving CsA, in combination with MMF (1.0 or 1.5 g bid), and one receiving CsA microemulsion (Neoral). Area-under-the-curve values were calculated for each drug to assess if there was a reciprocal effect on the respective bioavailability of each. In vitro, the immunosuppressive effect of trough level plasma from each patient group was studied using mixed lymphocyte culture (MLC), as well as MLC reactions spiked with various combinations of each drug. There was a minimal effect of MMF on tacrolimus pharmacokinetics. However, patients receiving tacrolimus and MMF displayed significantly higher levels (Cmin and area under the curve) of mycophenolic acid (MPA) than those receiving CsA (Sandimmune or Neoral) and the same dose of MMF (50.2 +/- 16.5 vs 32.1 +/- 16.7 micrograms h/ml AUC, p < 0.02). Equivalent MPA levels could be attained in patients receiving CsA if the MMF dose was increased by 50% (1.5 g bid). There were also significantly lower levels of the glucuronide metabolite of MPA (MPAG) (755 +/- 280 vs 1230 +/- 250 micrograms h/ml AUC, p = 0.02), suggesting a specific inhibition (either direct or indirect) of the conversion of MPA to MPAG in tacrolimus patients, as opposed to those receiving CsA. For each drug combination, there was a positive correlation between the plasma immunosuppressive effect seen in MLC assays and the MMF dose. In addition, trough plasma from patients receiving tacrolimus and MMF was significantly more MLC inhibitory than from those receiving CsA or CsA microemulsion and equivalent-dose MMF. Culture media containing MPA and tacrolimus equal to clinical therapeutic trough concentrations (10 ng/ml) were significantly more MLC inhibitory than CsA at equivalent clinical therapeutic trough concentrations (200 ng/ml) with equivalent MPA levels. These studies in renal transplant patients suggest that tacrolimus in combination with MMF may result in a greater degree of immunosuppression than may be anticipated.

Evidence that tacrolimus augments the bioavailability of mycophenolate mofetil through the inhibition of mycophenolic acid glucuronidation.

We previously reported an unexpected augmentation of mycophenolic acid (MPA) levels (trough and AUC0-12) in patients receiving mycophenolate mofetil (MMF) in combination with tacrolimus versus patients receiving the same dose of MMF in combination with cyclosporin A (CsA). This finding was accompanied by a corresponding reduction of the inactive glucuronide metabolite of MPA (MPAG) in patients, suggesting that tacrolimus may effect the conversion of MPA to MPAG by the enzyme UDP-glucuronosyltransferase (UDPGT). To investigate this possibility directly, UDPGT was extracted from human liver and kidney tissue and its activity was characterized using MPA as a substrate in vitro, assessing the conversion of MPA to MPAG using analysis by high-performance liquid chromatography. With crude microsomal preparations, amounts of UDPGT at least 100 times higher in specific activity (i.e., units to milligrams of protein) could be extracted per gram of tissue from kidney as opposed to liver. This result did not appear to be related to the coextraction of a liver-specific UDPGT inhibitor because initial enzyme kinetic values (Vmax and km) were identical for kidney and liver extracts, and further purification of the liver enzyme did not enhance activity (as is seen when inhibitors are removed during purification). With further UDPGT purification (approximately 200-fold) from kidney extracts using a combination of ammonium sulfate precipitation, followed by anion exchange, hydroxyapatite, and size exclusion chromatography, the enzyme was more than 80% pure when assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Initial enzyme kinetic analysis of this purified product showed a km value for MPA of 35.4+/-5.7 microg/mL and a Vmax of 2.87+/-0.31 MPAG produced per hour (n = 7). The addition of clinically relevant concentrations of CsA (200-1,000 ng/mL) or tacrolimus (10-25 ng/mL) resulted in a dose-dependent inhibition of the UDPGT enzyme by both agents with tacrolimus, which was approximately 60-fold more efficient as an inhibitor. The calculated inhibition constants (KI) of tacrolimus and CsA for the purified UDPGT were 27.3+/-5.6 ng/ml and 2,518+/-1473 ng/ml. respectively. Both agents displayed an inhibition profile characteristic of a competitive inhibitor (substrate) that could be demonstrated in a reciprocal experiment with CsA as a substrate, but not with tacrolimus. This finding suggested that the significantly more efficient inhibition of UDPGT by tacrolimus may occur by a more complicated mechanism that is yet to be determined.

Impact of Breast Cancer Surgery on the Self-Esteem and Sexual Life of Female Patients

Patient satisfaction with cosmetic outcome and the psychological impact of breast cancer surgery were evaluated. A total of 207 patients with primary breast cancer, treated with either breast-conserving surgery (n = 83), modified radical mastectomy without reconstruction (n = 108), or mastectomy with delayed breast reconstruction (n = 16) rated their cosmetic outcome and satisfaction following surgery, and the impact of surgery on their self-esteem and sexual life, by questionnaire. Patients undergoing breast-conserving surgery were most satisfied with their surgery and body image, followed by those treated with mastectomy with delayed reconstruction. Although diagnosis of breast cancer had a negative impact on the psychology of all patients, those undergoing breast-conserving surgery or mastectomy with delayed reconstruction were more satisfied and reported a lower impact on their self-esteem and sexual life versus those who only had mastectomy. Diagnosis of breast cancer has a negative psychological impact on the patient, but the type of surgery has a significant role in post-operative self-esteem and sexual life.

Hydatid Disease of the Abdomen and Other Locations

We present patients treated for hydatid disease in our hospital (in northeastern Greece) over the last 20 years. In the period from 1984 to 2003, a total of 135 patients (54 male, 81 female) were treated for echinococcal disease (age 15–85 years). In 111 (82.2%) patients only the liver was affected; 9 (6.7%) patients had concomitant hepatic and extrahepatic hydatid disease; and 15 (11.1%) patients had only extrahepatic disease. Clinical symptoms in patients with hepatic locations of the disease included abdominal pain localized in the epigastrium or right upper quadrant of the abdomen, tenderness, hepatomegaly with palpable abdominal mass, jaundice, fever, and anaphylactic reaction. All the patients were treated surgically. Surgical techniques included partial cystectomy and drainage, cystectomy and capitonage, cystectomy and omentoplasty, only drainage, left lateral hepatectomy, total pericystectomy, and laparoscopic pericystectomy. Rupture into the bile duct was managed by T-tube drainage or biliodigestive anastomosis. Symptoms and surgical treatment for extrahepatic cysts varied according to the location of the cyst. The median cyst diameter of all patients was 11 cm. The postoperative complication rate was 17.0%. Two patients died (1.5%). The median hospital stay was 18 days. The recurrence rate was 6.7%. The study suggests that treatment of this benign disease should be the less radical surgical technique combined with pre- and postoperative anthelmintic administration. The surgical treatment should be combined with careful use of scolicidal fluids and aspiration of the cyst to avoid contamination and minimize the risk of recurrence.

Thrombocytopenia after liver transplantation.

BACKGROUND Thrombocytopenia after orthotopic liver transplantation (OLT) is a well recognized and prevalent early postoperative complication. The etiology, as well as the effect of this phenomenon on transplant outcome, however, are vague. The aims of this study are to identify factors contributing to thrombocytopenia and to ascertain whether there is any correlation with early rejection and ultimate survival. METHODS This study examines 541 OLTs (541 grafts in 494 patients) that were transplanted at the University of Miami during the 3-year period from June 1994 to September 1997. The patients with severe postoperative thrombocytopenia (nadir platelet count [PLT] < 20,000/mm3), as well as the whole group of patients, were analyzed. The preoperative PLT, intra-operative platelet transfusion requirements, cross-match, recipient and donor cytomegalovirus (CMV) status, infusion of donor bone marrow cells (DBMC), occurrence of early rejection episodes (in the first posttransplant month), and re-transplantation were factors examined for any association with thrombocytopenia. Total bilirubin (TB) and direct bilirubin (dB), hematocrit, white blood cell count (WBC), aspartate aminotransferase and alanine aminotransferase, determined on the day that platelets reached a nadir (nadir day), were also analyzed. RESULTS In 90.9% of the cases, there was a 56.5%+/-23.5% fall in platelets in the immediate posttransplant period (first 2 weeks), but the mean PLT exceeded preoperative levels during the 3rd and 4th postoperative weeks. The nadir of the drop in the PLT most commonly occurred on posttransplant day 4. For preoperative PLT, platelet transfusions during the operation, re-transplantation, early rejection, cross-match, and recipient CMV status, there was significant statistical correlation with any degree of postoperative thrombocytopenia. Four of these factors, preoperative PLT, intra-operative platelet transfusions, re-transplantation, and early rejection, were found to be independently associated with thrombocytopenia in general. None of them was found to be independently correlated with severe thrombocytopenia. A statistically significant correlation between bilirubin and WBC on the nadir day and the degree of thrombocytopenia was observed. No correlation was found between infusion of DBMC or donor CMV serology and thrombocytopenia. Both the nadir PLT and the percentage of the platelet fall were independent predictive factors (p<0.01 and 0.005, respectively) of patient and graft survival. CONCLUSIONS Thrombocytopenia in the immediate posttransplant period is correlated with low preoperative PLT, massive platelet transfusions, and re-transplantation. These factors reflect a poor preoperative condition. There is also a correlation with allograft dysfunction, rejection, and poorer patient and graft survival. A rise in the mean PLT after the 2nd postoperative week reflects proper graft function.

Mucocele of the appendix: a report of five cases

Abstract.Mucocele of the appendix is an uncommon disorder, characterized by a cystic dilatation of the lumen. It is often diagnosed clinically from signs and symptoms of acute appendicitis or, if it is asymptomatic, as an incidental finding during ultrasonography, computed tomography, and radiographic examinations of the gastrointestinal tract, or laparotomy. The incidence of mucocele ranges from 0.2% to 0.3% of all appendectomy specimens. We report five cases of appendiceal mucocele (all women, aged 19–90 years), who were admitted from January 1993 to January 2003 to our hospital. These cases represent 0.29% of the 1720 appendectomies performed during this period. Three of the patients were symptomatic and had appendectomies. The final diagnosis for mucocele was given at laparotomy. No colon neoplasms were identified during surgery, and subsequent colonoscopic examinations were also negative. The other two patients were asymptomatic of appendiceal tumor. Colonoscopy revealed two colonic malignant tumors in one patient and an adenocarcinoma of the sigmoid colon in the other. Mucocele of the appendix was diagnosed pre–operatively by ultrasound and computed tomography. One of the two patients underwent a right hemicolectomy and sigmoidectomy; the other one underwent an appendectomy, cecostomy and sigmoidectomy. Four of the patients recovered and are doing well today; one patient died on the twenty–fifth postoperative day. The most common symptom of mucocele is abdominal pain, although many patients may be asymptomatic. Mucocele is often associated with concomitant colon cancer, thus patients with this tumor should be systematically checked for other colonic lesions.

Cystadenocarcinoma of the appendix: an incidental imaging finding in a patient with adenocarcinomas of the ascending and the sigmoid colon

BackgroundPrimary adenocarcinomas of the appendix are uncommon. Mucoceles that result from mucinous adenocarcinomas of the appendix may be incidentally detected on imaging.Case presentationA case of a mucocele of the appendix, due to cystadenocarcinoma, is presented as an incidental imaging finding in a female, 86-year-old patient. The patient was admitted due to rectal hemorrhage and underwent colonoscopy, x-ray, US and CT. Adenocarcinoma of the ascending colon, adenomatous polyp of the sigmoid colon and a cystic lesion in the right iliac fossa were diagnosed. The cystic lesion was characterized as mucocele. The patient underwent right hemicolectomy, excision of the mucocele and sigmoidectomy. She recovered well and in two-year follow-up is free from cancer.ConclusionsPreoperative diagnosis of an underlying malignancy in a mucocele is important for patient management, but it is difficult on imaging studies. Small lymph nodes or soft tissue stranding in the surrounding fat on computed tomography examination may suggest the possibility of malignancy.

Levels of mycophenolic acid and its glucuronide derivative in the plasma of liver, small bowel and kidney transplant patients receiving tacrolimus and cellcept combination therapy.

In order to help assess the usefulness of mycophenolate mofetil (MMF) as an immunosuppressive agent in recipients of organs other than kidneys, we measured the trough levels of the active metabolite of MMF, mycophenolic acid (MPA), and its inactive glucuronide derivative (MPAG), in the plasma of liver (n = 83) and small bowel transplant patients (n = 15) receiving MMF in combination with tacrolimus. These levels were compared with a group of renal transplant patients (n = 25) receiving the same drug regimen. All patient groups were otherwise comparable except the small bowel patient group which contained more pediatric patients (average age 18.7 +/- 3.9 years), and, therefore, received a higher average drug dose (in mg/kg). Despite this, these patients displayed the lowest levels of MPA of any group (0.39 +/- 0.08 microg/ml, P < 0.001 vs. 1.10 +/- 0.17 microg/ml for liver transplant patients, P < 0.001 or 2.46 +/- 0.37 microg/ml for renal transplant patients, P < 0.001). There were no statistically significant differences in MPAG levels between any of the groups. Although preliminary, these data demonstrate significant transplanted organ-specific differences in MMF pharmacology and/or bioavailability, and suggest the need for separate evaluation of MMF dosing for each transplant type.

B7H4, HSP27 and DJ-1 molecular markers as prognostic factors in pancreatic cancer

OBJECTIVES Pancreatic cancer (PC) is one of the most lethal tumors of the gastrointestinal tract. The ability to predict which patients would benefit most from surgical intervention and chemotherapy would be a great clinical tool. A large number of potential markers have been identified lately in pancreatic cancer and their clinical utilities as prognostic tools are under investigation. METHODS We recruited 41 patients who had undergone radical surgical resection for PC between 2003 and 2010. To investigate the prognostic factors, we evaluated 3 possible markers: B7H4, HSP27 and DJ-1 protein expressions in the tissue specimens of these 41 patients by immunohistochemistry and analyzed the clinical and pathological features of these specimens. RESULTS The expression of the three antigens was independently associated with a negative impact of chemotherapy with gemcitabine on patients survival. Moreover, patients who overexpressed B7H4 had worse prognosis than the ones who did not. CONCLUSIONS B7H4, DJ-1 and HSP27 may be used in the future as prognostic markers that express resistance of pancreatic cancer patients to chemotherapy with gemcitabine.

Laparoscopic Cholecystectomy in a Patient with Situs Inversus Using Ultrasonically Activated Coagulating Scissors. Report of a Case and Review of the Literature

Abstract Situs inversus totalis is a rare defect with a genetic predisposition, which can present difficulties in the management of abdominal pathology, especially in laparoscopic surgery, due to the mirror-image anatomy. Herein, we report on a patient with situs inversus totalis and symptomatic cholelithiasis. The patient had a successful laparoscopic cholecystectomy, using ultrasonically activated coagulating scissors. Diagnostic pitfalls and technical details of the laparoscopic cholecystectomy are discussed and a review of the relevant literature is presented.