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Biomedical subjects

A Humar

Publications and source records attributed to A Humar.

At least 37 records · Page 2Linked to original sources
PubMed2001

Predictors of virological response in HIV-infected patients to salvage antiretroviral therapy that includes nelfinavir.

Different salvage strategies have been used to regain control in patients with HIV who have virological failure on combination antiretroviral therapy. We conducted a cohort study of 63 extensively antiretroviral pretreated patients who initiated nelfinavir as part of salvage therapy, to determine predictors of virological response. The maximum HIV RNA response was >0.5 log10 copies/ml reduction in 43 patients (68%), including 21 patients (33%) who had suppression to <500 copies/ml. Corresponding response rates at 24 weeks were 41 and 19%, respectively. Responders and non-responders could not be distinguished by mean baseline HIV RNA or CD4 cell count, duration of prior protease inhibitor (PI) use, introduction of an initial non-nucleoside reverse transcriptase inhibitor or the number of antiretroviral agents changed when nelfinavir was added, likely reflecting the homogeneity of the population studied. The only parameter predictive of response was virus genotype. Response rates were lower in patients with increasing numbers of primary (P=0.045) or secondary (P=0.001) PI mutations. The addition of increasing numbers of reverse transcriptase mutations further impaired response rates (P=0.004).

Adult↗
PubMed2000

Optimal timing for a pancreas transplant after a successful kidney transplant.

BACKGROUND: For certain uremic, diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive option. But how long to wait after the kidney transplant before proceeding with a pancreas transplant is unclear. We studied outcomes in recipients of a pancreas at varying times after a kidney to determine the optimal timing for the second transplant. METHODS: We compared pancreas after kidney (PAK) transplants performed early (< or =4 months) and late (>4 months) after the kidney transplant to determine any significant differences in surgical complications or outcomes between the two groups. RESULTS: Between January 1, 1994, and September 30, 1998, we performed 123 cadaver PAK transplants. Of these, 25 (20%) were early and 98 (80%) were late. Characteristics of the two recipient groups were similar. We found no significant differences in outcome between the two groups. The incidence of surgical complications (bleeding, leaks, thrombosis, infections) and of opportunistic infections (such as cytomegalovirus) did not significantly differ between the two groups. Graft and patient survival rates were also equivalent (P=NS). The incidence of acute rejection by 3 months posttransplant was 20% in both groups. CONCLUSION: The timing of the pancreas transplant for PAK recipients does not seem to influence outcome. As long as an acceptable organ is available and the recipient is clinically stable, a PAK transplant can be performed relatively soon after the kidney transplant.

Adult↗
PubMed2000

Prospective randomized trial of 10% povidone-iodine versus 0.5% tincture of chlorhexidine as cutaneous antisepsis for prevention of central venous catheter infection.

A multicenter prospective, randomized, controlled trial, with 0.5% tincture of chlorhexidene versus 10% povidone-iodine as cutaneous antisepsis for central venous catheter (CVC) insertion, was conducted for patients in intensive care units. Of 374 patients, 242 had a CVC inserted for >3 days and were used for the primary analysis. Outcomes included catheter-related bacteremia, significant catheter colonization (> or = 15 colony-forming units [cfu]), exit-site infection, serial quantitative exit-site culture (every 72 h), and molecular subtyping of all isolates. Patients in both study groups were comparable with respect to age, sex, underlying disease, length of hospitalization, reason for line insertion, and baseline APACHE II score. Documented catheter-related bacteremia rates were 4.6 cases per 1000 catheter-days in the chlorhexidine group (n=125) and 4.1 cases per 1000 catheter-days in the povidone-iodine group (n=117; not significant [NS]). Significant catheter-tip colonization occurred in 24 (27%) of 88 patients in the povidone-iodine group and in 31 (34%) of 92 patients in the chlorhexidine group (NS). A mean exit-site colony count of 5.9 x 10(5) cfu/mL per 25 cm(2) of the surface area of skin in the povidone-iodine group versus 3.1 x 10(5) cfu/mL per 25 cm(2) in the chlorhexidine group (NS) was found. There was a trend toward fewer exit-site infections in the chlorhexidine group (0 of 125 patients) versus those in the povidone-iodine group (4 of 117 patients; P=.053). Results of an intention-to-treat analysis were unchanged from the primary analysis. No difference was demonstrable between 0.5% tincture of chlorhexidine and 10% povidone-iodine when used for cutaneous antisepsis for CVC insertion in patients in the intensive care unit.

Adult↗
PubMed2000

Pre-emptive transplants for patients with renal failure: an argument against waiting until dialysis.

BACKGROUND: Pre-emptive kidney transplants have not been favored in some centers because of concern about possible increased noncompliance and allegedly inferior long-term results. We analyzed our experience with pre-emptive kidney transplants to determine whether such concerns are justified. PATIENTS AND METHODS: Between January 1, 1984, and June 30, 1998, we performed 1849 adult primary kidney transplants: 385 pre-emptive (recipients not undergoing dialysis, ND) and 1464 non-pre-emptive (recipients undergoing dialysis, D). Results were subdivided by donor source: cadaver (CAD) and living donor (LD). ND recipients tended to be younger, but otherwise, the two groups were similar. Posttransplantation quality of life in recipients was evaluated using the nationally standardized Short Form Health Survey (SF-36). The posttransplantation employment status of the recipients was also evaluated. RESULTS: The patient survival rate 5 years posttransplantation was significantly better for ND (vs. D) recipients for both CAD (92.6% vs. 76.6%, P=0.001) and LD (93.3% vs. 89.5%, P=0.02) transplants. The 5-year patient survival rate was significantly higher for ND recipients compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation for both CAD (P=0.0005) and LD (P=0.0001) transplants. The graft survival rate 5 years posttransplantation was similar between ND and D recipients for CAD transplants, but significantly better for ND (vs. D) recipients of LD transplants (92.3% vs. 84.8%, P=0.006). For CAD transplants, the 5-year graft survival rate was not different when ND recipients were compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation; for LD transplants it was significantly higher for ND recipients compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation (P=0.04). The incidence of acute and chronic rejection was no different between ND and D recipients for either CAD or LD transplants, and it was also not affected by the pretransplantation time undergoing dialysis. Graft loss secondary to the recipient's discontinuation of immunosuppressive therapy (a crude estimate of compliance) was similar between ND and D recipients. Five years posttransplantation, the SF-36 scores regarding the recipient's quality of life and the employment status were similar for ND compared with D recipients, regardless of donor source. CONCLUSIONS: ND recipients do not seem to have higher rates of noncompliance than D recipients. Results for ND recipients seem to be superior than for D recipients, supporting the contention that renal failure patients should, if possible, undergo transplantation before dialysis.

Actuarial Analysis↗
PubMed2000

Increased incidence of cardiac complications in kidney transplant recipients with cytomegalovirus disease.

BACKGROUND: The transplant literature has not shown cytomegalovirus (CMV) disease to be a significant risk factor for posttransplant cardiac complications. A large number of nontransplant studies have, however, reported an association between coronary heart disease (CHD) and CMV disease. Pathology studies have demonstrated a high incidence of CMV in atheromatous plaques from the coronary circulation. METHODS: We performed multivariate analysis to determine if posttransplant CMV disease was a significant risk factor for cardiac complications in kidney transplant recipients. We also performed univariate analysis to determine which cardiac complications were more common in the recipients with CMV disease. RESULTS: Between January 1, 1984 and June 30, 1997, 1859 adults underwent kidney transplants at our institution. Of these, 377 developed one of the following cardiac complications posttransplant: myocardial infarction, angina, arrhythmia, congestive heart failure, and angiographic vessel occlusion. By multivariate analysis, significant risk factors for one of the above cardiac complications were recipient age >50 years [odds ratio (OR)=2.5, P=0.0001], diabetes (OR=1.99, P=0.0001), a history of cardiac disease pretransplant (OR= 1.34, P=0.04), and CMV disease (OR=1.5, P=0.01). Univariate analysis demonstrated that recipients with CMV disease had a higher overall incidence of cardiac complications. Arrhythmias, congestive heart failure, and vessel occlusion were more common in those with CMV disease. The incidence of myocardial infarction, angina, and cardiac arrest did not differ between the two groups (recipients with versus without CMV disease). CONCLUSIONS: CMV disease is associated with an increased risk of cardiac complications in kidney transplant recipients. In our series, angiographic vessel occlusion was more common in recipients with CMV disease. This interesting finding may support the theory that CMV plays some role in the pathogenesis of CHD.

Adult↗
PubMed2000

Clinical determinants of multiple acute rejection episodes in kidney transplant recipients.

BACKGROUND: Recipients with multiple (more than one) acute rejection (AR) episodes have significantly lower graft survival rates than those with no AR or only one treated episode. However, fewer than 50% of recipients treated for one AR episode will have another episode. METHODS: We studied recipients with at least one AR episode to determine whether any clinical features could identify risk factors for multiple AR. RESULTS: Between January 1, 1984, and June 30, 1997, a total of 1793 recipients underwent a kidney transplant at our institution. Of these, 354 were treated for one AR episode, 307 for more than one. By multivariate analysis, recipients at highest risk for multiple AR episodes were those with initial delayed or slow graft function (relative risk=1.5, P=0.05), those with initially severe AR (as judged by vascular involvement or steroid resistance), and those with an initial early AR episode (<6 months posttransplant). The remaining variables tested were not significant. Graft survival in recipients with more than one AR episode was significantly lower than in those with only one AR episode. Graft survival at 5 years posttransplant was 52.5% in recipients with more than one AR episode and 85.1% in recipients with one AR episode (P=0.0001). Chronic rejection as a cause of graft loss was significantly more common in recipients with more than one vs. only one AR episode (34.8% vs. 8.9%, P=0.001). CONCLUSION: Clinical features may be used to identify recipients at higher risk for multiple AR episodes. These recipients can then be targeted with more aggressive or novel immunosuppressive regimens in an attempt to reduce the likelihood of another AR episode.

Acute Disease↗
PubMed2000

Living unrelated donors in kidney transplants: better long-term results than with non-HLA-identical living related donors?

BACKGROUND: Given the severe organ shortage and the documented superior results obtained with living (vs. cadaver) donor kidney transplants, we have adopted a very aggressive policy for the use of living donors. Currently, we make thorough attempts to locate a living related donor (LRD) or a living unrelated donor (LURD) before proceeding with a cadaver transplant. METHODS: We compared the results of our LURD versus LRD transplants to determine any significant difference in outcome. RESULTS: Between 1/1/84 and 6/30/98, we performed 711 adult kidney transplants with non-HLA-identical living donors. Of these, 595 procedures used LRDs and 116 used LURDs. Immunosuppression for both groups was cyclosporine-based, although LURD recipients received 5-7 days of induction therapy (antilymphocyte globulin or antithymocyte globulin), whereas LRD recipients did not. LURD recipients tended to be older, to have inferior HLA matching, and to have older donors than did the LRD recipients (all factors potentially associated with decreased graft survival). Short-term results, including initial graft function and incidence of acute rejection, were similar in the two groups. LURD recipients had a slightly higher incidence of cytomegalovirus disease (P=NS). We found no difference in patient and graft survival rates. However, the incidence of biopsy-proven chronic rejection was significantly lower among LURD recipients (16.7% for LRD recipients and 10.0% for LURD recipients at 5 years posttransplant; P=0.05). LRD recipients also had a greater incidence of late (>6 months posttransplant) acute rejection episodes than did the LURD recipients (8.6% vs. 2.6%, P=0.04). The exact reason for these findings is unknown. CONCLUSION: Although LURD recipients have poorer HLA matching and older donors, their patient and graft survival rates are equivalent to those of non-HLA-identical LRD recipients. The incidence of biopsy-proven chronic rejection is lower in LURD transplants. Given this finding and the superior results of living donor (vs. cadaver) transplants, a thorough search should be made for a living donor-LRD or LURD-before proceeding with a cadaver transplant.

Adult↗
PubMed2000

Lamivudine for hepatitis B in liver transplantation: a single-center experience.

BACKGROUND: Liver transplantation for hepatitis B virus (HBV) has been associated with a high rate of reinfection and graft failure. Lamivudine, a potent inhibitor of HBV replication, has been shown to prevent viral recurrence after transplantation. METHODS: The effectiveness of lamivudine monotherapy for the management of HBV recurrence after liver transplantation was assessed. Lamivudine was used in three patient groups: (1) patients started before transplantation and continued after transplantation (n = 13); (2) patients treated after transplantation (n = 15); and (3) patients with de novo hepatitis B after transplantation (n = 4). RESULTS: Median follow-up on lamivudine was 24 months. Active viral replication (HBV-DNA+) was seen in 17 (53%) of 32 at treatment initiation. All lost HBV-DNA at a mean of 2.4+/-1.6 months after lamivudine initiation. Twenty-six (81%) patients remain free of viral recurrence. Six (19%) patients have evidence of breakthrough infection with the YMDD mutant of HBV, two of whom progressed to graft failure. All four patients in group 1 who developed breakthrough had evidence of hepatitis B surface antigen expression in the explanted liver by immunohistochemistry despite being serum HBV-DNA negative before transplantation. No difference was observed among the three groups in DNA clearance or breakthrough rates. CONCLUSIONS: Lamivudine achieves viral DNA clearance in almost all patients. Expression of viral antigens in the liver seems to identify patients at risk of developing HBV-DNA recurrence. Disease-free survival of 81% at 22 months is similar to data with hepatitis B immunoglobulin therapy. Given the safe clinical profile and high efficacy in the prevention of disease recurrence, lamivudine will favorably change the outlook of liver transplantation for HBV.

Adult↗
PubMed2000

Human herpesvirus-6 is associated with cytomegalovirus reactivation in liver transplant recipients.

Human herpesvirus-6 (HHV-6) may be a risk factor for cytomegalovirus (CMV) disease in posttransplant patients, possibly through a direct interaction or through a general immunomodulatory effect. To examine this possibility, 88 liver transplant recipients were monitored with serial HHV-6 polymerase chain reaction (PCR), CMV antigenemia, and CMV plasma viral load. HHV-6 infection was defined by a positive PCR of peripheral blood lymphocytes. Forty-eight (54.4%) of 88 patients had at least 1 positive HHV-6 PCR. CMV recurrence was significantly more common in patients with HHV-6 infection (38/48 patients [79. 2%]), compared with recurrence in those without HHV-6 infection (18/40 patients [45%]; P=.001). Peak CMV viral load was 24, 147+/-6799 copies/mL in patients with HHV-6 infection versus 8391+/-4598 copies/mL in patients without HHV-6 infection (P=.001). Symptomatic CMV disease was more common in patients with HHV-6 infection than it was in those without infection (15/48 patients [31. 3%] vs. 4/10 patients [10.0%]; P=.013). In a multivariate analysis including other risk factors for CMV, HHV-6 infection remained an independent risk factor for CMV disease (P=.013; odds ratio, 7.26; 95% confidence interval, 1.52-34.72). HHV-6 is associated with CMV infection and disease, thus supporting an interaction between these viruses.

Adolescent↗
PubMed2000

Immunologic and nonimmunologic factors: different risks for cadaver and living donor transplantation.

BACKGROUND: There is a debate about the relative contribution of immunologic (rejection) and nonimmunologic (limited nephron mass) factors in long-term graft survival. METHODS: Using multivariate analysis, we studied the association of the following variables with outcome: delayed graft function (DGF), acute rejection, recipient race (black vs. nonblack), donor age (<50 vs. > or =50), donor race, and donor and recipient gender. Because of the association between DGF and rejection, recipients were grouped as follows: DGF, rejection; DGF, no rejection; no DGF, rejection; no DGF, no rejection. Data were analyzed on 1199 first kidney transplants in adults (752 living donor, 447 cadaver donor) done between January 1, 1985 and December 31, 1996. Two analyses were done: first, all transplants; second, only those with > or =1 year survival. For both, there was no difference in risk factors if death with function was or was not censored. RESULTS: For all cadaver transplant recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50. For living donor recipients, only acute rejection was a risk factor. When only 1-year graft survivors were considered, risk factors were the same: for cadaver recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50; for living donor recipients the risk factor was rejection. CONCLUSION: We found immunologic factors (rejection with or without DGF) to be significant in both living donor and cadaver donor transplants. Nonim. munologic factors (donor age, recipient race) were significant only in cadaver donor transplants.

Acute Disease↗
PubMed2000

Living liver donor surgery: report of initial anesthesia experience.

The charts and anesthetic records of 12 patients who donated the left lateral segment of their liver to a related infant or child to treat liver failure were retrospectively reviewed. Blood loss, need for transfusion, fluids administered, surgical length, and perioperative complications were investigated. The records also were examined to determine the hemodynamic stability of patients undergoing donor hepatectomy to assess their need for invasive monitoring. There were no episodes of hypotension or hemodynamic instability. The average operating time was 9.6 +/- 1.1 hours. The blood loss was 562 +/- 244 mL (range 300 to 1100 mL). Four patients received their own cell saver blood (200 mL, 220 mL, 300 mL, 475 mL), and one patient received 1 U (350 mL) of predonated autologous blood. The average hemoglobin decreased significantly (p = 0.001) from a preoperative value of 14.1 +/- 1.2 to 12.3 +/- 1.8 g/dL in the recovery room. All patients were extubated in the operating room or recovery room. Patients were discharged home in 6.9 +/- 1.3 days (range 5 to 9 days). Living-related liver resection can be performed with noninvasive monitoring and without the need for heterologous blood products.

Adult↗
PubMed2000

Living related liver transplantation in infants and children: report of anesthetic care and early postoperative morbidity and mortality.

STUDY OBJECTIVE: To determine those infants at high risk for perioperative complications and mortality following living, related liver transplantation. DESIGN: Retrospective chart review. SETTING: Large metropolitan teaching hospital. MEASUREMENTS AND MAIN RESULTS: The charts and anesthetic records of the 12 infants and children who received the left lateral hepatic segment from a living relative the past 2 years at our institution were reviewed. The records were examined to determine the causes of perioperative morbidity and to identify patients at high risk for serious complications and mortality. All infants and children (mean +/- SD age, 29+/-30 months; weight, 13.6 +/-6.8 kg) survived the operation (8.3+/-1.7 hours) without intraoperative complications. The average blood loss, including 500 mL of recipient blood used to flush the liver before reperfusion, was 1483 +/-873 mL (119+/-70 mL/kg). Three infants developed portal vein thrombosis, and one of these infants also had hepatic artery thrombosis. The risk of vessel thrombosis was significantly higher (3/3 vs. 0/9; p<0.0045) in infants less than 9 kg body weight, as was the risk of death (2/3 vs. 0/9; p<0.045). Both children who died had vascular thrombosis. Other serious complications were bleeding, 6; infection, 7; acute rejection, 3; and bile leak, 2. CONCLUSIONS: Infants and children can successfully undergo living, related liver transplantation. However, the risks of vascular complications and death are greater in infants less than 9 kg body weight.

Anesthesia↗
PubMed2000

Steroid withdrawal in pancreas transplant recipients.

BACKGROUND: Numerous studies of steroid withdrawal have been carried out in kidney and liver transplant recipients, but only a few in pancreas transplant recipients. Yet, pancreas transplant recipients could have significant long-term benefits from steroid withdrawal. METHODS: We performed a retrospective analysis to determine the feasibility of steroid withdrawal in pancreas transplant recipients. RESULTS: Of 360 recipients who underwent a pancreas transplant between January 1, 1994 and June 30, 1998, 14 attempted steroid withdrawal (12 simultaneous pancreas-kidney [SPK]; 2 pancreas transplant alone [PTA]). Reasons for steroid withdrawal were bone fractures (n = 3), psychiatric disorders (n = 2), severe acne (n = 1), recurrent infections (n = 4), and problems with hypercholesterolemia or hypertension (n = 4). All 14 were maintained on tacrolimus and mycophenolate mofetil (MMF) immunosuppression, except for 1 who was on tacrolimus and azathioprine (AZA). Of the 14 recipients, 11 had no episodes of acute rejection before steroid withdrawal. The remaining 3 had one or more acute rejection episodes. Of the 14 recipients, 10 (72%) currently remain off steroids (mean follow-up 18 months, range 5-51 months). However, 4 recipients have resumed steroids: 2 after an acute rejection episode (at 2 and 21 months post-withdrawal) and 2 because of leukopenia (WBC < 3000) and an inability to tolerate full-dose MMF. Steroid withdrawal was unsuccessful in both PTA recipients and in 2 of the 12 SPK recipients. All 14 recipients currently have a functioning pancreas graft. However, 1 of the SPK recipients, in whom steroid withdrawal failed, has developed chronic kidney rejection and is now back on hemodialysis awaiting a retransplant. CONCLUSION: Steroid withdrawal is possible in up to 70% of pancreas transplant recipients. Further studies are necessary to define ideal candidates for steroid withdrawal. Based on the results of this analysis, we have launched a prospective, randomized trial of steroid withdrawal in pancreas transplant recipients.

Adult↗
PubMed2000

Should I accept this kidney?

BACKGROUND: Transplant candidates frequently ask whether they should, based on information available at the time, accept a cadaver kidney or wait for a potentially better one. METHODS: We analyzed 937 first and second cadaver transplants done between January 1, 1984 and December 31, 1997 to determine if information available at the time an offer is made could be used to predict long-term graft survival. RESULTS: By Cox regression, risk factors for worse long-term graft survival were older donor age, cardiovascular or cerebrovascular cause of donor death, and delayed graft function (DGF). HLA-ABDR mismatch was marginally significant. Whether DGF will occur is not known at the time of an offer, but risk factors can be determined; we found these to be older donor age and > 10% panel-reactive antibodies (PRA) at transplantation (by Cox regression). Using these variables (PRA, ABDR mismatch, donor age, and donor cause of death) known at the time of an offer, we calculated the relative risk of worse long-term graft survival for each subgroup (Table 3 in manuscript). In general, older age and donor death from cardiovascular or cerebrovascular disease were associated with worse outcome. Kidneys from donors of < 50 yr had the best outcome, irrespective of match. CONCLUSION: The data provided can be used to help guide patients as to whether they are better off accepting an offered kidney or waiting for a potentially better one. If an offer is declined, the next kidney may have a potentially worse outcome.

Adolescent↗