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Biomedical subjects

D J Conti

Publications and source records attributed to D J Conti.

At least 19 recordsLinked to original sources
PubMed2003

Sirolimus immunotherapy: the Albany Medical Center experience.

At the Albany Medical Center, we have a long-term experience, mean follow-up of 61 months, in 31 renal transplant recipients treated with sirolimus, cyclosporine microemulsion formulation, and prednisone. In these patients the rate of acute rejection was 13%, actual patient and graft survival at 1 year was 100%, and the mean serum creatinine at 1 year was 1.3 mg/dL. Furthermore, long-term graft survival was 90%. The success of this regimen stimulated us to evaluate a subsequent sirolimus-based protocol, initiated in April, 2001, which decreased exposure to calcincurin inhibitors at 3 months posttransplant (n = 50). At a mean follow-up of 10 months, graft survival was 96%. The rate of acute rejection was only 10% and the mean serum creatinine was 1.5 mg/dL. Furthermore, no acute rejection episodes have developed subsequent to the reduction in calcineurin inhibitor dosing at 3 months. Sirolimus is an effective immunosuppressive agent that safely allows for a reduction in calcineurin-inhibitor dosing.

Adult↗
PubMed2001

TNF-alpha, IL-6, IFN-gamma, and IL-10 gene expression polymorphisms and the IL-4 receptor alpha-chain variant Q576R: effects on renal allograft outcome.

BACKGROUND: There has been much interest recently in the effects of various cytokine gene expression polymorphisms on graft outcome. However, the results of these investigations reveal the outcomes to be organ-specific and center-specific. We sought to confirm and add to some of the earlier findings by studying the impact of tumor necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10), interferon-gamma (IFN-gamma), and interleukin-6 (IL-6) polymorphisms and the interleukin-4 (IL-4) receptor alpha-chain variant on posttransplant renal allograft outcome. METHOD: TNF-alpha, IL-6, IFN-gamma, and IL-10 gene promoter region polymorphisms were assayed genotypically by PCR-SSP on 120 patients transplanted at the Albany Medical Center. These patients were also typed for the IL-4 receptor alpha-chain variant Q576R. RESULTS: Producers of high levels of the proinflammatory cytokine TNF-alpha were found to be at increased risk for acute rejection episodes if the allograft was mismatched for the molecular products of the class II region of the human major histocompatibility complex (HLA-DR). Expression level polymorphisms of the IL-6, IFN-gamma, and IL-10 genes were not associated with acute rejection episodes, nor was the IL-4 receptor alpha-chain variant Q576R. CONCLUSIONS: These data would suggest that the production of high levels of the cytokine TNF-alpha is especially detrimental to graft survival when the recipient's T-helper lymphocytes are being activated by mismatched donor HLA-class II antigens. Typing all potential kidney recipients for TNF-alpha, and providing well-matched organs for high producers of this cytokines, may be expected to increase rejection-free graft survival in these patients.

Acute Disease↗
PubMed2001

Promoter-region alleles of the TNF-alpha and IL-10 genes have no effect on pretransplant alloantibody production.

BACKGROUND: The presence of high levels of alloantibodies are known to be a risk factor in renal graft outcome. Expression level polymorphisms in cytokine genes are also thought to have an effect on allograft outcome, but the studies examining this have been inconsistent. This may be due to center-specific differences in immunosuppressive protocols. Therefore, we studied the effects of these polymorphisms on pretransplant class I alloantibody production in nonexogenously immunosuppressed candidates. METHODS: Tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) gene polymorphisms were assayed genotypically by PCR-SSP on 177 renal transplant candidates. Candidates with a peak goat antihuman immunoglobulin-enhanced T-cell panel reactive antibody (PRA) of >or=10% were considered to be positive for alloantibody (32% of 177 total). RESULTS: Previous transplants, transfusions, or pregnancies were all associated with alloantibody production, but TNF-alpha and IL-10 phenotypes were not. High levels of alloantibody production (peak PRA >50%) were also not effected by cytokine phenotype. CONCLUSIONS: These data suggest that differences in TNF-alpha and IL-10 phenotype do not effect a patient's likelihood of becoming sensitized by transfusions, pregnancies, and prior transplants.

Alleles↗
PubMed2001

Prevalence of donor-specific anti-HLA antibodies during episodes of renal allograft rejection.

BACKGROUND: Recent studies suggest that the appearance of anti-HLA antibodies in the early posttransplant period is associated with an increased incidence of acute and chronic rejection months later. However, very little is known about the prevalence of anti-HLA antibodies at the time that the rejection episodes are diagnosed. The purpose of this study was to analyze retrospectively 420 sera from 263 renal allograft recipients who were readmitted to the hospital for any reason between 1989 and 1998 in order to determine if a correlation existed between the presence of donor-specific anti-HLA antibodies and graft rejection. METHODS: Sera were assayed for IgG HLA class I and II antibodies by ELISA. The ELISA results were analyzed using contingency tables with Fisher's exact test and compared with mismatched antigens in the donor. RESULTS: Antibodies to donor HLA class I molecules in the posttransplant sera were extremely rare, occurring in only 6 of the 420 sera (1.4%) analyzed. Antibodies to donor class II antigens were slightly more common, occurring in 25 of the 420 sera (6%). In 21 of these 25 cases (84%), the presence of donor-specific HLA class II antibodies was associated with episodes of either acute (n=14) or chronic rejection (n=7). Five patients had antibodies to both class I and class II donor antigens, and all five of them lost their grafts to rejection. CONCLUSION: Although the presence of donor-specific HLA antibodies presented a significant risk for acute or chronic rejection, 77% of all acute and chronic rejections occurred in patients without detectable HLA antibodies.

Antibodies↗
PubMed2001

The impact of allergies and allergy treatment on worker productivity.

Allergic disorders are a chronic and highly prevalent condition in the general population and the workforce. Their effect on workers and corporate costs go beyond the direct cost of treatment, as the condition can lower a worker's productivity. Previous research includes estimates of the decrease in productivity associated with allergic disorders. None of these studies, however, offered an objective measure of how worker productivity is affected by allergic disorders. In the present study, the productivity of telephone customer service representatives suffering from allergic disorders is examined before, during, and after the ragweed pollen season. In addition, these workers were surveyed as to the type of medication they used in response to their condition. A significant correlation was observed between an increase in pollen counts and a decrease in productivity for workers with allergies. Compared with workers without allergies, employees with allergies who reported using no medication showed a 10% decrease in productivity. No differences were observed among workers with allergies using different types of medications, although the medication groups had significantly higher productivity than the no-medication group. The expected lowered productivity of those workers with allergies who used sedating antihistamines may have been offset by their relatively lower level of symptom severity and by the nature of the job and the productivity measures used.

Absenteeism↗
PubMed2000

Failure of ganciclovir prophylaxis to completely eradicate CMV disease in renal transplant recipients treated with intense anti-rejection immunotherapy.

Ganciclovir prophylactic regimens have been shown to be effective in renal transplant recipients at risk for primary (donor seropositive/recipient seronegative) and secondary (recipient seropositive) cytomegalovirus (CMV) disease. However, in addition to serologic factors, the type and intensity of the administered immunosuppression is a strong risk factor for CMV disease. Since January 1995, we have utilized a potent immunosuppressive protocol selectively in recipients at high risk for immunologic graft loss, defined as retransplant recipients, recipients with delayed graft function, non-Caucasian recipients, and recipients suffering from acute rejection. Between January 1995 and December 1996, 110 consecutive renal transplants were performed in recipients who were either CMV seropositive or received an allograft from a CMV-seropositive donor. All recipients received ganciclovir prophylactic therapy for 3 months post-transplant. Group I (N = 43) consisted of recipients at high-immunologic risk for graft loss as defined above. These recipients were treated with an intense anti-rejection immunotherapeutic regimen consisting of Cellcept, Neoral, and prednisone, with the frequent addition of antilymphocyte antibody therapies and intravenous methylprednisolone. The remaining 67 recipients (group II) were treated with a less intense immunotherapeutic regimen consisting of azathioprine, Neoral, and prednisone. The incidence and severity of CMV disease and the patient and allograft survival were compared. The incidence of CMV syndrome was greater in group I (28%) compared with group II (7%), and was statistically significant (p < 0.05). The 1-yr patient and graft survival were similar, 95 and 91%, respectively, for group I compared with 97 and 97%, respectively, for group II. These data suggest that 3 months of ganciclovir prophylactic therapy is significantly less effective for the prevention of CMV disease in renal transplant recipients at high risk for acute rejection treated with an intense immunotherapeutic regimen. These data suggest that more effective prevention of CMV disease in these high-risk recipients will require the addition of other anti-viral agents, such as immunoglobulin preparation to the prophylactic regimen.

Adult↗
PubMed2000

Disability management: corporate medical department management of employee health and productivity.

This study describes a proactive in-house program for managing short-term disability (STD) in the workforce of a very large banking system. The goals of this program were to (1) minimize the personal and economic impacts of STD by early intervention, (2) validate the extent and duration of STD, and (3) coordinate medical services and provide guidance to managers that would facilitate an early return to work. This program was made possible by the installation of a comprehensive database, called Occupational Medicine and Nursing Information System. This database mainly includes employees' claims for inpatient and outpatient health services, disability and workers' compensation benefits, wellness program participation, medical examinations and laboratory tests, use of prescription drugs, and results of Health Risk Appraisals. As a result of these efforts, STD event duration declined after this STD management program was implemented in locations heretofore outside the system, and by providing full pay for part-time work after STD, within the system as well. Of note, the average number of STD days per employee showed substantial variation by health plan, including the fact that it was higher (3.9 STD days/employee) for health maintenance organization participants than for indemnity plan members (2.7 STD days/employee).

Adult↗
PubMed2000

Diverticulitis and polycystic kidney disease.

Patients with adult polycystic kidney disease (PKD) have previously been shown to have an increased incidence of complicated diverticulitis after renal transplantation. The purpose of this study was to assess the risk of diverticulitis in the PKD population. We retrospectively reviewed patients with advanced PKD, defined as end-stage renal failure requiring dialysis. Patients were obtained from a single nephrology group practice between January 1985 and January 1997, or from all patients being evaluated or actively considered for renal transplantation at our institution as of May 1997. The incidence and severity of diverticulitis in these patients was compared with that observed in a similar cohort of patients with end-stage renal disease due to other etiologies. The study population consisted of 184 renal failure patients, 59 with PKD and 125 with other causes of end-stage renal disease. Twelve (20%) patients with PKD had a history of active diverticulitis, whereas only 4 (3%) of the non-PKD controls had diverticulitis (P = 0.0003, Fisher's exact test). Six of the 12 PKD patients required surgical intervention. Patients with renal failure due to PKD experience a significantly higher rate of diverticulitis than do other patients with end-stage renal disease. Furthermore, diverticulitis is frequently severe in PKD patients, with 50 per cent requiring surgical intervention. These data suggest that diverticular disease may be an extrarenal manifestation of polycystic kidney disease.

Case-Control Studies↗
PubMed1999

The role of health risk factors and disease on worker productivity.

The costs attributed to employee health problems are usually measured by employers in terms of direct health care costs, such as medical plan claims. Although it has been understood that employee health problems also produce indirect costs for employers, their measurement has been far less frequent. At best, studies have recorded one component of indirect health costs: the time lost to employee absenteeism and disability. The study presented here includes a measure of the actual decrease in the productivity of employees while they are on the job, in addition to measures of absenteeism and disability. These three measurements were combined to produce a Worker Productivity Index (WPI). The WPIs of 564 telephone customer-service agents were correlated with the employees' number and type of health risks, as measured by a Health Risk Appraisal. Additionally, the WPI was also examined across different disease states in the same population of employees. As the number of health risks increased, an employee's productivity decreased. The nature of the health risk may also differentially affect the pattern of the decrease. Finally, disease states were also associated with different patterns of productivity reduction.

Absenteeism↗
PubMed1998

Complicated diverticulitis following renal transplantation.

PURPOSE: Colonic perforations in renal transplant recipients have historically been associated with mortality rates as high as 50 to 100 percent. However, these previous series generally predate the use of cyclosporine-based immunosuppressive protocols. METHODS: We retrospectively reviewed all patients who had undergone renal transplant from our institution and who developed complicated diverticulitis. Complicated diverticulitis was defined as diverticulitis involving free perforation, abscess, phlegmon, or fistula. Factors analyzed included the time interval since transplantation, use of cyclosporine, living-related vs. cadaveric donor, cause of renal failure, and presenting signs and symptoms. RESULTS: Between August 1969 and September 1996, 1,211 kidney transplants were performed in 1,137 patients. The first 388 patients (1969-1984) received prednisone and azathioprine, with cyclosporine added to the immunosuppressive regimen for the subsequent 823 recipients (1984-1996). Thirteen (1.1 percent) patients had episodes of complicated diverticulitis, occurring from 25 days to 14 years after transplant; all required surgical therapy. Clinical presentation was highly variable, ranging from asymptomatic pneumoperitoneum (2 patients) to generalized peritonitis. There was one perioperative mortality (7.7 percent). Patients with polycystic kidney disease as the cause of renal failure had a significantly higher rate of complicated diverticulitis. Specifically, patients with polycystic kidney disease (9 percent of the total transplant population) accounted for 46 percent of the cases of diverticulitis (P < 0.001, Fisher's exact probability test). Neither treatment with cyclosporine nor donor source had a significant effect on the rate of diverticular complications (P = 0.36 and P = 0.99, respectively, Fisher's exact probability test). CONCLUSION: Complicated diverticulitis following renal transplantation is rare, and the clinical presentation may be atypical in the immunosuppressed transplant recipient. Patients with polycystic kidney disease experience a significantly higher rate of complicated diverticulitis than do other transplant patients and, therefore, warrant aggressive diagnostic evaluation of even vague abdominal symptoms. In addition, pretransplant screening and prophylactic sigmoid resection in this high-risk population deserve consideration and further study.

Adult↗
PubMed1997

Comparative pharmacokinetics and renal effects of cyclosporin A and cyclosporin G in renal allograft recipients.

Cyclosporin G (CSG) has produced less nephrotoxicity than cyclosporin A (CSA) at equivalent doses in animal models. Conflicting results have been reported concerning differences in the pharmacokinetics of CSA and CSG in preclinical studies, and no data exist regarding the effect of steady-state oral administration of CSG on renal function in transplant patients or CSG-induced release of endothelin and nitric oxide (NO) in vivo. The objective of the study was to examine steady-state pharmacokinetic profiles of adult renal allograft recipients receiving CSA and CSG in relation to concentrations of endothelin-1 and NO2/NO3 in urine and plasma, creatinine clearance (Clcr), and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) 9 months after transplantation. Concentrations of CSA and CSG were measured in whole blood over a 12-hour dose interval by both a monoclonal and polyclonal fluorescence polarization radioimmunoassay for CSA. A metabolite fraction was defined as the numerical difference between the levels obtained at each time point by both assays. Patient groups were defined as follows: group 1: initial CSA (n = 6); group 2: initial CSG (n = 7); group 3: five of the seven patients in group 2 taking CSG subsequently undergoing conversion to CSA; group 4: the same five patients in group 3 restudied 1 month after 1:1 dosage conversion to CSA; and group 5: CSA groups 1 and 4 combined (n = 11). In group 1, the metabolite fraction accounted for 32% to 54% of the total measurable drug concentration at each time point, whereas in group 2, the metabolite fraction accounted for at most 10% to 15% of the total drug levels measurable by polyclonal fluorescence polarization radioimmunoassay. Although there were no significant differences in any of the mean pharmacokinetic parameters between groups using monoclonal fluorescence polarization radioimmunoassay, the normalized area under the concentration-time curve (NAUC) value was less in four of five patients after conversion from CSG to CSA, with a more variable and delayed time to reach peak concentration (tmax) but equivalent apparent oral clearance (Clpa) values. Clcr was found to change significantly with time in groups 1 and 5 but not in group 2, with CSA producing a more profound and sustained decrease than CSG. Endothelin-1 and NO2/NO3 levels in plasma and urine remained relatively constant after administration of both CSA and CSG, and there were no significant differences between groups 3 and 4 regarding mean endothelin-1 and NO2/NO3 concentrations in plasma, urinary release of endothelin-1 and NO2/NO3, and mean AUC of endothelin-1 and AUC of NO2/NO3. However, monoclonal NAUC correlated significantly with total urinary endothelin-1 within CSA groups 1 and 5 but not within CSG group 2. Metabolite NAUC correlated significantly with total urinary NAG within CSA group 1. Although limited by the small number of patients, this study suggests that 1) CSG may produce less of a reduction in Clcr over time after oral administration at steady state than does CSA, and 2) this beneficial effect of CSG may be in part due to decreased intrarenal release of endothelin-1, as urinary excretion of endothelin-1 seemed to correlate better with CSA than with CSG exposure.

Acetylglucosaminidase↗
PubMed1996

RO 31-8220, a novel protein kinase C inhibitor, inhibits early and late T cell activation events.

The improvement of graft survival over the past decade has mainly been due to the development of more highly specific immunosuppressive agents, such as cyclosporine (CsA) and FK506. CsA and FK506 inhibit T cell activation by interfering with the calcium-mediated pathway, one of two pathways needed for T cell activation. The other pathway, mediated by protein kinase C (PKC), is not currently a target of any clinically used immunosuppressive agent. The purpose of this study was to assess the immunosuppressive properties of Ro 31-8220, a member of a new family of potent and selective PKC inhibitors. Peripheral blood mononuclear cells were isolated from the blood of normal human donors and utilized in a series of standard immunological assays. Three discrete activation events were inhibited by Ro 31-8220: mitogen-induced interleukin (IL)-2 production (IC50 80 nM), IL-2-dependent T lymphoblast proliferation (IC50 350 nM), and IL-2Ralpha (CD25) expression (control cells were 83% CD25+, mean fluorescence intensity = 163 +/- 4, 400-nM-treated cells were 56% CD25+, mean fluorescence intensity = 130 +/- 7). Noninhibitory doses of CsA (8 nM) or FK506 (0.2 nM) suppressed mitogen-induced IL-2 production by 60-80% when combined with a noninhibitory dose (25 nM) of Ro 31-8220, indicating the potent synergy between these agents. The ability of Ro 31-8220 to inhibit both early and late activation events and to synergize with CsA/FK506 suggests that this family of compounds has great potential as immunosuppressive agents and as probes with which to elucidate the role of PKC in T cell activation.

Cyclosporine↗