Impaired function of macrophage Fc gamma receptors in end-stage renal disease

Immunomodulation Driven by Theranova Filter during a Single HD Session

Background: Patients with end-stage kidney disease (ESKD) have altered immunity. Patients on hemodialysis (HD) present a coexistence of immunodeficiency and activation of the immune system. We evaluated the immunophenotypic profile induced by the medium cut-off of Theranova filter during a single HD session in the same individual. Methods: This pilot observational study explored 11 patients (75 ± 8 years and 73% male). Blood samples were collected prior to (predialytic, PRE) and after 4 h (postdialytic, POST) standard HD session with a medium cut-off, polyarylethersulfone and polyvinylpyrrolidone blend, BPA-free membrane. We performed an immunophenotyping characterization by using flow cytometry. We evaluated eryptosis RBCs and HLA-DR expression on monocytes and Treg cells. Results: The percentages of eryptosis in lymphocytes (CD3+), lymphocyte T helper (CD3+ and CD4+) cells, and monocytes (CD45+ and CD14+) were similar pre- and post-HD. On the contrary, HLA-DR expression and Treg cell numbers significantly decreased after HD. Conclusions: Many studies have focused on the comparison between healthy volunteers and HD patients, but very few have focused on the changes that occur after an HD session in the same individual. With this pilot observational study, we have revealed an immunomodulation driven by HD treatment with Theranova filter. Our preliminary results can be considered to be a hypothesis, generating and stimulating further studies with better designs and larger populations.

Device-related infection and mortality in patients with chronic kidney disease receiving cardiac implantable electronic devices: a propensity score-matched cohort study

BACKGROUND

Chronic kidney disease (CKD) was reported to be a risk factor of cardiac implantable electronic device (CIED) infection. The application of bundled skin antiseptic preparation before CIED implantation decreased the risk of CIED infection, even in patients undergoing complex procedures. However, the effect of bundled skin antiseptic preparation to prevent CIED infection in patients with CKD was not tested.

METHODS

Between July 2012 and December 2019, 1668 patients receiving CIEDs comprised this retrospective cohort study and were categorized into two groups by the diagnosis of CKD: group with CKD (n = 750, 45%) and group without CKD (n = 918, 55%). The primary outcome was clinical CIED infection, including major and minor infection, and the secondary outcomes were cardiovascular mortality and all-cause mortality. Propensity score matching (PSM) was applied to reduce selection bias between the study groups.

RESULTS

During a 4-year follow-up period, 30 patients (1.8%) had a CIED infection. After PSM, the incidence of CIED infection was similar between the patients with CKD and without CKD (1.0% vs. 1.8%). The incidences of cardiovascular mortality and all-cause mortality were higher in patients with CKD compared to patients without CKD (6.5% vs. 3.0%, P = 0.009; 22.8% vs. 11.8%, P < 0.001, respectively).

CONCLUSION

The incidence of clinical CIED infection in patients with CKD was as lower as in patients without CKD after applying the bundled skin antiseptic preparation strategy. The cumulative incidences of cardiovascular mortality and all-cause mortality were significantly higher in the matched CIED recipients with CKD compared to the matched cohort without CKD.

Preoperative chronic kidney disease and complications after pancreatoduodenectomy: a retrospective cohort study

BACKGROUND

Chronic kidney disease is a prevalent condition in surgical patients. Possible associations with increased postoperative morbidity and mortality have not been clearly demonstrated in patients undergoing pancreatoduodenectomy. The aim of this study was to assess the risk of postoperative complications in patients with reduced kidney function undergoing pancreatoduodenectomy.

METHODS

All patients undergoing pancreatoduodenectomy at Karolinska University Hospital between 2008 and 2019 were retrospectively included. The variable of interest was chronic kidney disease, based on preoperative estimated glomerular filtration rate measurements. Unadjusted and adjusted logistic regression analyses were performed for standardized postoperative complications.

RESULTS

A total of 971 patients were included in the study, of whom 92 (10%) had an estimated glomerular filtration rate < 60 mL/min/1.73m2 , equivalent to chronic kidney disease Stage 3a or worse. Patients with chronic kidney disease had a higher odds of longer hospital stay (adjusted odds ratio 1.58, 95% confidence interval 1.00-2.50) and postoperative weight increase (adjusted odds ratio 2.02, 1.14-3.56). A 10 unit increase of preoperative estimated glomerular filtration rate was associated to lower odds of intensive care unit admission (adjusted odds ratio 0.81, 0.69-0.95), delayed gastric emptying (adjusted odds ratio 0.90, 0.81-0.99), and post-operative pancreatic fistula (adjusted odds ratio 0.83, 0.74-0.94).

CONCLUSION

Patients undergoing pancreatoduodenectomy with decreased preoperative kidney function are more likely to experience major postoperative complications, and also postoperative weight increase. Preoperative kidney function assessment is important in risk stratification before pancreatoduodenectomies.

Association of lactate dehydrogenase with mortality in incident hemodialysis patients

BACKGROUND

Lactate dehydrogenase (LDH) plays a role in the glucose metabolism of the human body. Higher LDH levels have been linked to mortality in various cancer types; however, the relationship between LDH and survival in incident hemodialysis (HD) patients has not yet been examined. We hypothesized that higher LDH level is associated with higher death risk in these patients.

METHODS

We examined the association of baseline and time-varying serum LDH with all-cause, cardiovascular and infection-related mortality among 109 632 adult incident HD patients receiving care from a large dialysis organization in the USA during January 2007 to December 2011. Baseline and time-varying survival models were adjusted for demographic variables and available clinical and laboratory surrogates of malnutrition-inflammation complex syndrome.

RESULTS

There was a linear association between baseline serum LDH levels and all-cause, cardiovascular and infection-related mortality in both baseline and time-varying models, except for time-varying infection-related mortality. Adjustment for markers of inflammation and malnutrition attenuated the association in all models. In fully adjusted models, baseline LDH levels ≥360 U/L were associated with the highest risk of all-cause mortality (hazard ratios = 1.19, 95% confidence interval 1.14-1.25). In time-varying models, LDH >280 U/L was associated with higher death risk in all three hierarchical models for all-cause and cardiovascular mortality.

CONCLUSIONS

Higher LDH level >280 U/L was incrementally associated with higher all-cause and cardiovascular mortality in incident dialysis patients, whereas LDH <240 U/L was associated with better survival. These findings suggest that the assessment of metabolic functions and monitoring for comorbidities may confer survival benefit to dialysis patients.

Dysfunction of natural killer cells in end-stage kidney disease on hemodialysis

Natural killer (NK) cells are known to play an important role in defense against infection and tumors. Although there is no clear consensus, most studies have shown that the number and cytotoxicity of NK cells decreases in end-stage kidney disease (ESKD) patients undergoing hemodialysis. Uremic patients chronically suffer from oxidative stress, which could be responsible for downregulation of the activating receptors on NK cells and modulation of ligand expression for activating receptors. Theoretically, the reduced number of NK cells and decreased function might increase susceptibility to viral infections and cancer development in patients with ESKD. There is emerging evidence that NK cell numbers may be an outcome predictor in renal transplantation; however, the clinical significance of NK cell dysfunction in dialysis patients requires clarification. In this review, I describe NK cell number, cytotoxic activity, and activating mechanisms in the context of uremia and oxidative stress, which is anticipated to assist in elucidating the mechanisms underlying immunodeficiency in dialysis patients.

Peritoneal Dialysis in Liver Disorders

The purpose of this paper is to review the specific role of peritoneal dialysis (PD) in patients with liver disorders. We will pay attention to the confluence of liver diseases and situations for which chronic dialysis treatment is required.

Hemodialysis (HD) and peritoneal membranes are safe barriers against the passage of the hepatitis C virus; consequently, while peritoneal effluent or HD ultrafiltrate drained from hepatitis S patients/carriers is infective, that from hepatitis C patients does not appear to present this risk. An important issue is horizontal transmission, which appears to occur with both viruses in HD units, and which is absent in peritoneal dialysis units. The incidence of hepatitis C among continuous ambulatory peritoneal dialysis (CAPD) patients is quite low, while it may reach almost 50% -60% of HD patients in some units. While hepatitis C transmission mechanisms are not completely understood and a vaccine is not available, PD provides some degree of protection when compared with HD, for end-stage renal disease patients.

In summary, our experience and that of others, with a total of 19 PD-treated chronic liver disease patients, supports CAPD as the treatment of choice for cirrhotic patients with ascites who require chronic dialysis. Data on peritoneal diffusion of low molecular weight substances revealed a marked increase in most patients. The ultrafiltration capacity was clearly augmented with respect to noncirrhotic patients, making the use of hypertonic bags unnecessary. Hemodynamic tolerance was excellent. Complications and death were mainly related to liver disease complications.

Spontaneous bacterial peritonitis (SSP), caused by gram-negative germs, is the most important complication directly related to ascites and may have some points in common with PD-related peritonitis. However, and in contrast to most PD peritonitis, two pathogenetic mechanisms have been suggested for SSP: (1) translocation of bacteria from the gut to the mesenteric lymph nodes, and (2) bacteremia in these patients is secondary to the general abnormal host defense mechanisms. Local factors such as intrahepatic shunting and the impairment of bactericidal activity in ascitic fluid favor the bacteria ascites. The hypothesis of a direct transmural contamination from bowel to ascitic fluid has been relegated to secondary bacterial peritonitis. Would cirrhotic patients with temporal or permanent renal function compromise benefit from peritoneal catheter placement and other PD practices to perform repetitive small ascitic drainages at home? Perhaps the time has arrived when hepatologists and PD nephrologists begin to work shoulder to shoulder in this particular field, as we have a common problem, the peritoneal cavity filled with fluid.

Continuous Ambulatory Peritoneal Dialysis in Patients with Hepatitis B Liver Disease

Objective

We hypothesized that patients with hepatitis B virus infection and cirrhosis are more susceptible to peritonitis as a complication of peritoneal dialysis (PD).

Methods

A retrospective study was carried out to compare peritonitis rates between cirrhotic and non-cirrhotic patients with hepatitis B virus infection.

Results

Between 1994 and 2004, 25 PD patients with hepatitis B cirrhosis and 36 patients with hepatitis B without cirrhosis were included for analysis. Mean follow-up duration was 52 months. Subjects with hepatitis B cirrhosis consisted of more males and had higher total body weight. No cirrhotic patients (20 of them being Child–Pugh class A, 2 class B, and 3 class C) had undergone portosystemic shunting or liver transplantation. Cirrhotic patients had slightly higher bilirubin concentration than the non-cirrhotic group (22 ± 50 vs 9 ± 4 μmol/L, p = 0.16). There was no difference in median peritonitis-free survival between cirrhotic and non-cirrhotic patients (40 vs 37 months, p = 0.64 by log-rank test). The average peritonitis rate was 1 episode every 19.2 patient-months in the cirrhotic group and 1 episode every 20.5 patient-months in the non-cirrhotic group. Time to first peritonitis did not differ between the two groups with respect to gram-negative organisms ( p = 0.88) or gram-positive organisms ( p = 0.52). Cirrhotic patients had more frequent Streptococcus species peritonitis, which accounted for 13% of all peritonitis episodes, as opposed to 2% among the non-cirrhotic patients ( p = 0.01). Overall treatment response rate and outcome did not differ between patients with and patients without cirrhosis.

Conclusions

Peritonitis-free survival of cirrhosis patients infected by hepatitis B virus compares favorably with that in patients without cirrhosis. The presence of liver cirrhosis does not appear to compromise PD outcome.

Infectious Disease Risk in Dialysis Patients: A Transdisciplinary Approach

PURPOSE OF REVIEW

Infections are a major contributor to morbidity and mortality in end-stage renal disease (ESRD) patients. A better understanding of the interplay between infectious processes and ESRD may eventually lead to the development of targeted treatment strategies aimed at lowering overall disease morbidity and mortality. Monogenic causes are a major contributor to the development of adult chronic kidney disease (CKD). Recent studies identified a genetic cause in 10% to 20% of adults with CKD. With the introduction of whole-exome sequencing (WES) into clinical mainstay, this proportion is expected to increase in the future. Once patients develop CKD/ESRD due to a genetic cause, secondary changes, such as a compromised immune status, affect overall disease progression and clinical outcomes. Stratification according to genotype may enable us to study its effects on secondary disease outcomes, such as infectious risk. Moreover, this knowledge will enable us to better understand the molecular interplay between primary disease and secondary disease outcomes.

SOURCES OF INFORMATION

We conducted a literature review using search engines such as PubMed, PubMed central, and Medline, as well as cumulative knowledge from our respective areas of expertise.

METHODS

This is a transdisciplinary perspective on infectious complications in ESRD due to monogenic causes, such as autosomal dominant polycystic kidney disease (ADPKD), combining expertise in genomics and immunology.

KEY FINDINGS

In ADPKD, infection is a frequent complication manifesting primarily as lower urinary tract infection and less frequently as renal infection. Infectious episodes may be a direct consequence of a specific underlying structural abnormality, for example the characteristic cysts, among others. However, evidence suggests that infectious disease risk is also increased in ESRD due to secondary not-well-understood disease mechanisms. These disease mechanisms may vary depending on the underlying nature of the primary disease. While the infectious disease risk is well documented in ADPKD, there are currently insufficient data on the risk in other monogenic causes of ESRD. WES in combination with novel technologies, such as RNA sequencing and single-cell RNA sequencing, can provide insight into the molecular mechanisms of disease progression in different monogenic causes of CKD/ESRD and may lead to the development of novel risk-stratification profiles in the future.

LIMITATIONS

This is not a systematic review of the literature and the proposed perspective is tainted by the authors' point of view on the topic.

IMPLICATIONS

WES in combination with novel technologies such as RNA sequencing may enable us to fully unravel underlying disease mechanisms and secondary disease outcomes in monogenic causes of CKD and better characterize individual risk profiles. This understanding will hopefully facilitate the development of novel targeted therapies.

Usefulness of preoperative estimated glomerular filtration rate to predict complications after curative gastrectomy in patients with clinical T2-4 gastric cancer

BACKGROUND

Gastrectomy with systemic lymphadenectomy is the standard of care for resectable gastric cancer (GC), but it is sometimes associated with postoperative morbidity. Predicting complications is therefore an essential part of risk management in clinical practice. The renal function is routinely evaluated before surgery by blood examinations to determine dose of medication and infusion. However, the value of various parameters of renal function in prediction of postoperative complications remain unclear.

METHODS

We included 315 patients who underwent curative D2 gastrectomy for clinical T2-T4 GC without preoperative treatment, and evaluated the correlation between the incidence of postoperative complications and the indicators of renal function.

RESULTS

Forty-three patients experienced clinically relevant postoperative complications. Estimated glomerular filtration rate (eGFR) showed a higher area under the curve for predicting complications compared with urea nitrogen, creatinine, and creatinine clearance. The optimal eGFR cutoff value was 63.2 ml/min/1.73 m², and eGFR < 63.2 was an independent risk factor for postoperative complications in multivariable analysis (odds ratio 4.67; 95 % confidence interval 2.16-10.5; p < 0.001). Particularly, the incidence of anastomotic leakage was significantly higher in patients with eGFR < 63.2 than those with eGFR ≥ 63.2 (9.4 % vs. 3.5 %). eGFR < 63.2 was also associated with a higher incidence of postoperative complications independent of age, body mass index, operative procedure, and clinical disease stage. Postoperative hospital stay was significantly longer in the eGFR < 63.2 group.

CONCLUSIONS

Preoperative eGFR is a simple and useful predictor for complications after gastrectomy in patients with GC and may improve clinical care and the process of obtaining informed consent.

Potential Hepatoprotective Role of Galectin-3 during HCV Infection in End-Stage Renal Disease Patients

Hepatitis C virus infection (HCV), one of the greatest causes of liver disease, is a frequent complication in patients with end-stage renal disease (ESRD) on dialysis. ESRD is defined as decreased glomerular filtration and also accompanied by impaired function of the immune system. Galectin-3 is a β-galactoside-binding lectin, involved in various biological processes including pathogenesis of chronic renal disease. The aim of our study was to estimate disease severity in ESRD HCV⁺ patients and analyze the serum concentrations of IL-1β, IL-4, IL-23, and IL-6; anti-HCV antibodies; and galectin-3. Also, we attempted to determine potential correlation between galectin-3 level and parameters of disease severity ALT and AST. Our results showed decreased levels of ALT and AST (p = 0.00), demonstrating less liver destruction in ESRD HCV⁺ patients in comparison to HCV⁺ patients. Increased levels of IL-6 (p = 0.03) implicate a hepatoprotective role of IL-6 in these patients. Also, level of galectin-3 (p = 0.00) in the serum of ESRD HCV⁺ patients was higher than that of HCV⁺ patients. This alteration was accompanied with negative correlation between galectin-3 and AST and ALT, respectively (p = 0.029; p = 0.033). The presence of increased systemic levels of IL-6 and Gal-3 in ESRD HCV⁺ patients may be an attempt to counteract or limit ongoing proinflammatory processes and to downregulate chronic inflammation, suggesting the new aspects of HCV infection in ESRD patients.

Influence of chronic kidney disease on anticoagulation levels and bleeding after primary percutaneous coronary intervention in patients treated with unfractionated heparin

Unfractionated heparin (UFH) plasma protein binding and elimination might be impaired in patients with chronic kidney disease (CKD-defined as creatinine clearance <60 ml/min). It is currently unknown at which UFH bolus dose persistent prolongation of activated partial thromboplastin time (aPTT) occurs in ST-segment elevation myocardial infarction (STEMI) patients with CKD. We investigated the effect of different UFH bolus doses on the first aPTT measured within 6 and 12 h after PPCI in 1071 STEMI patients with and without CKD undergoing primary percutaneous coronary intervention (PPCI) between 1-1-2003 and 31-07-2008. In the first 6 h after PPCI, aPTT ratio was 5.1 for patients with CKD versus 3.4 for those without (p < 0.001). The proportion of patients with markedly high aPTTs (aPTT ratio ≥ 4 times control) increased with increasing heparin bolus and beyond 130 IU/kg there was a marked difference between patients with and without CKD (74.1 and 42.3 % respectively, p < 0.001). By multivariable analysis, CKD was associated with an increased risk of markedly high aPTTs (odds ratio (OR) 2.04; 95 % confidence interval (CI) 1.27-3.27), driven largely by an increased risk of aPTT prolongation in patients treated with UFH boluses ≥130 IU/kg (OR 3.69; 95 % CI 1.85-7.36; p for interaction = 0.009). In conclusion, CKD is associated with severe persistent aPTT prolongation in STEMI patients undergoing PPCI, possibly due to impaired plasma protein binding and reduced UFH elimination. A lower heparin bolus dose might result in lower aPTTs and less bleeding complications in patients with CKD undergoing PPCI.

p-Cresyl sulfate suppresses lipopolysaccharide-induced anti-bacterial immune responses in murine macrophages in vitro

p-Cresyl sulfate (pCS) is a known uremic toxin that is metabolized from p-cresol produced by intestinal bacteria. Abnormal accumulation of pCS in the blood is a characteristic of chronic kidney disease (CKD). pCS is suggested to cause immune dysfunction and increase the risk of infectious diseases in CKD patients. In this study, we focused on the effects of pCS on macrophage functions related to host defense. We evaluated the effects of pCS on cytokine production, nitric oxide (NO) production, arginase activity, expression of cell-surface molecules, and phagocytosis in the macrophage-like cell line, RAW264.7. pCS significantly decreased interleukin (IL)-12 p40 production and increased IL-10 production. pCS also decreased NO production, but did not influence arginase activity. pCS suppressed lipopolysaccharide-induced CD40 expression on the cell surface, but did not influence phagocytosis. We further assessed whether the effects of pCS observed in the macrophage-like cell line were consistent in primary macrophages. Similar to RAW264.7 cells, pCS decreased IL-12 p40 and p70 production and increased IL-10 production in primary peritoneal macrophages. These data indicate that pCS suppresses certain macrophage functions that contribute to host defense, and may play a role in CKD-related immune dysfunction.

Are postoperative complications more common following colon and rectal surgery in patients with chronic kidney disease?

AIM

According to National Kidney Foundation guidelines, early stages of chronic kidney disease (CKD) can be detected through the estimated glomerular filtration rate (eGFR). We assessed complications following colorectal surgery (CRS) in patients with CKD Stages 3 and 4, as defined by the eGFR.

METHOD

Patients with CKD were identified within our database. Patients with an eGFR of 15-59 ml/min (CKD Stages 3 and 4) formed the CKD group and were compared with American Society of Anesthesiology (ASA) score-matched controls with an eGFR of ≥ 60 ml/min. Assessments included demographics, comorbidity, ASA score, operative details and 30-day postoperative outcome.

RESULTS

Seventy patients in the CKD group were matched with 70 controls. ASA scores and length of stay did not differ significantly between the groups. CKD patients were older (mean age 76.5 years vs 71.1 years; P < 0.001) and had a lower mean body mass index (24.3 vs 28.2; P < 0.001) compared with controls. Compared with the CKD group, the mean operation time was longer in the control group (181.5 min vs 151.6 min; P = 0.02) and the estimated blood loss was greater (232 ml vs 165 ml; P = 0.004). Postoperative infection was more common in the CKD group (60%vs 40%; P = 0.01). There were no significant differences in reoperation rates, 30-day readmissions or the incidence of acute renal failure (ARF).

CONCLUSION

Patients with CKD Stages 3 and 4 had a higher incidence of postoperative infections than matched controls after colorectal surgery. ARF developed in 18.6% of patients. Preoperative optimization should include adequate hydration and assessment of potentially nephrotoxic substances for bowel preparation, preoperative antibiotics and pain control.

Abl family kinases regulate FcγR-mediated phagocytosis in murine macrophages

Phagocytosis of Ab-coated pathogens is mediated through FcγRs, which activate intracellular signaling pathways to drive actin cytoskeletal rearrangements. Abl and Arg define a family of nonreceptor tyrosine kinases that regulate actin-dependent processes in a variety of cell types, including those important in the adaptive immune response. Using pharmacological inhibition as well as dominant negative and knockout approaches, we demonstrate a role for the Abl family kinases in phagocytosis by macrophages and define a mechanism whereby Abl kinases regulate this process. Bone marrow-derived macrophages from mice lacking Abl and Arg kinases exhibit inefficient phagocytosis of sheep erythrocytes and zymosan particles. Treatment with the Abl kinase inhibitors imatinib and GNF-2 or overexpression of kinase-inactive forms of the Abl family kinases also impairs particle internalization in murine macrophages, indicating Abl kinase activity is required for efficient phagocytosis. Further, Arg kinase is present at the phagocytic cup, and Abl family kinases are activated by FcγR engagement. The regulation of phagocytosis by Abl family kinases is mediated in part by the spleen tyrosine kinase (Syk). Loss of Abl and Arg expression or treatment with Abl inhibitors reduced Syk phosphorylation in response to FcγR ligation. The link between Abl family kinases and Syk may be direct, as purified Arg kinase phosphorylates Syk in vitro. Further, overexpression of membrane-targeted Syk in cells treated with Abl kinase inhibitors partially rescues the impairment in phagocytosis. Together, these findings reveal that Abl family kinases control the efficiency of phagocytosis in part through the regulation of Syk function.

Defective antigen presentation by monocytes in ESRD patients not responding to hepatitis B vaccination: impaired HBsAg internalization and expression of ICAM-1 and HLA-DR/Ia molecules

This study was undertaken to evaluate the monocyte function of uraemic non-responders to hepatitis B vaccination. Therefore, some parameters concerning antigen processing by monocytes (Mo) as antigen presenting cells (APC) were analysed. It was found that in uraemic non-responders, (1) the internalization of HBsAg by monocytes was significantly decreasjed-HBsAg complexed with specific IgG or as immune complex isolated from patients is better internalized compared with free HBsAg; (2) during antigen presentation the expression of adhesion (ICAM-1) and accessory (HLA-DR/Ia) molecules was significantly decreased in uraemic patients, especially in non-responders; and (3) impaired internalization of HBsAg as well as a decrease in ICAM-1 and HLA-DR/Ia expression, correlated well with the blunted proliferation of CD4(+) T cells stimulated by autologous monocytes induced by HBsAg.

Candida bloodstream infections in hemodialysis recipients

Candidemia is a major cause of morbidity and mortality in patients undergoing hemodialysis but it has not been well defined in this patient population. We performed a retrospective case-control study to characterize the epidemiology, microbiology, and outcomes of hemodialysis-associated candidemia. All cases of candidemia at our institution were evaluated from 1 January 2000 until 1 September 2004. For each case, two non-candidemic dialysis patients served as controls. Among 350 cases of candidemia, 78 (22%) occurred in adult hemodialysis patients. Cases and controls were similar with respect to age, corticosteroid, antibiotics use, prevalence of diabetes mellitus, liver cirrhosis, surgical procedures, and cancer. Multivariate analysis found total parenteral nutrition (TPN) (19.5% vs. 1.3%; P<0.0001) and dialysis through a vascular catheter (74% vs. 46.8%; P=0.0001) to be independently associated with candidemia. Non-C.albicans Candida spp. particularly C. glabrata and C. krusei were more common in hemodialysis recipients than in candidemic patients not receiving hemodialysis (31% vs. 17% p = 0.009). In-hospital mortality was significantly elevated for candidemic vs. non-candidemic hemodialysis recipients (51.9% vs. 7.8%; P<0.0001). Candidemia in hemodialysis recipients is frequently caused by non-C. albicansCandida species, is associated with TPN and dialysis via a vascular catheter (vs. shunt or fistula) and carries a high mortality rate.

Invasive fungal infections in the ICU

Invasive fungal infections are major causes of morbidity and mortality in critically ill patients. Foremost among these is invasive candidiasis. In recent years, invasive aspergillosis (IA) and zygomycosis have emerged as major problems in susceptible, critically ill patients. Risk factors for invasive fungal infections, including disrupted anatomic barriers, suppressed antifungal host responses, and exposure to potentially opportunistic fungi are common in critically ill patients. The expanded antifungal armamentarium and advent of rapid diagnostic techniques are altering the approach to invasive fungal infections in the intensive care unit (ICU). Herein, we review recent developments in the field of antifungal host defenses, the changing epidemiology of fungal infections in the ICU, the pharmacology of antifungal agents of importance to critically ill patients, and the evolving approaches to therapy in this setting.

Oxidative stress mediates a reduced expression of the activating receptor NKG2D in NK cells from end-stage renal disease patients

To characterize the immune defect of patients with end-stage renal disease (ESRD), we performed NK cell subset analysis in 66 patients with ESRD treated by hemodialysis (n = 59) or peritoneal dialysis (n = 7). Compared with healthy blood donors, patients undergoing chronic dialysis showed a profound decrease in NKG2D(+) cells within both the CD8(+) T cell (58% vs 67%, p = 0.03) and NK cell (39% vs 56%, p = 0.002) populations. CD56(dim) cells, which comprise the majority of NK cells in the periphery, were more affected in this regard than were CD56(bright) cells. Uremic serum could decrease NKG2D expression on NK cells from healthy donors. Among factors that could contribute to the decrease in NKG2D expression in ESRD patients, reactive oxygen species (ROS) play a major role. We found that catalase could reverse the effects of uremic serum on NKG2D expression (p < 0.001) and that ROS down-regulated NKG2D at the mRNA level and at the NK cell surface. Additionally, ESRD patients had both increased membrane-bound MHC class I-related chain A (MICA) on monocytes (p = 0.04) and increased soluble MICA (203 pg/ml vs 110 pg/ml; p < 0.001). Both ROS and uremic serum could significantly increase in vitro the expression of the NKG2D ligand MICA on the renal epithelial cell line HK-2. Taken together, these studies suggest for the first time that both low NKG2D expression and up-regulation of its ligand MICA are related to ROS production and may be involved in the immune deficiency of ESRD patients.

Kidney graft survival in patients with hepatitis C: a single center experience

Hepatitis C virus (HCV) infection is highly prevalent in renal transplant candidates; however, its effect on the transplant outcome is still controversial. The aim of the present study was to determine the effect of HCV infection in the outcome of kidney transplantation in a single transplant center. The study population 144 HCV- randomized selected patients and 64 HCV+ patients transplanted from 1973 to 2000, followed for up to 60 months post-transplantation. This retrospective study included the following variables: type of dialysis, time on renal replacement therapy, number of transfusions before and after transplantation, number of transplants, type of donor, immunosuppression, and rejection episodes. The Kaplan-Meier method was used to estimate graft and patient survival. Log-rank test was used to assess the difference in survival between HCV+ and HCV-. A multivariate Cox proportional hazards model was used to analyze the relation between graft and patient survival. HCV+ and HCV- patients had similar demographic and clinical characteristics; however, a higher number of HCV+ patients received blood transfusions after transplantation. Patient survival was not significantly different in 39 HCV+ and 96 HCV- patients transplanted with living-related donors (71% and 77% at five yr, respectively). Similarly, there was not significant difference in 25 HCV+ and 48 HCV- patients transplanted with kidneys from deceased donors, although there was a tendency to better outcome in HCV- patients (55% and 72% at five yr respectively). Regarding graft survival, there was also no differences in HCV+ and HCV- recipients of living-related grafts (61% and 66% at five yr post-transplant, respectively) and recipients of kidneys from deceased donors (44% and 41%, respectively). The results show that HCV+ patients can be transplanted with the same success than HCV- patients.

Dysregulated chemokine receptor expression and chemokine-mediated cell trafficking in pediatric patients with ESRD

BACKGROUND AND OBJECTIVES

Children and adolescents with ESRD on dialysis are susceptible to serious bacterial infections (SBI). Chemokines and chemokine receptors play a critical role in modulating macrophage and neutrophil function. This study examined the hypothesis that expression and/or function of these molecules is dysregulated in patients with ESRD, contributing to leukocyte dysfunction. Design setting, participants, & measurements: Pediatric patients, age 6 mo to 18 yr, with ESRD treated with either hemodialysis or peritoneal dialysis were enrolled in this prospective, nontherapeutic study. Blood was collected for plasma chemokine levels, chemokine receptor profiling by flow cytometry, and functional chemotaxis studies on neutrophils and mononuclear cells.

RESULTS

ESRD in children was associated with reduced expression of the chemokine receptors CXCR1 and chemokine (C-C motif) receptor 2 (CCR2) on circulating neutrophils and monocytes, respectively. When ESRD patients were divided into two subgroups, those who were infection-free and those who had three or more SBI in the preceding year, the differences in chemokine receptor expression were statistically significant compared with control subjects only in those with recurrent infection. In addition to the effects of ESRD on baseline chemokine receptor expression, the hemodialysis procedure itself acutely lowered neutrophil CXCR1 and monocyte CCR2 expression. Furthermore, neutrophil and monocyte responsiveness to chemokine-mediated trafficking signals was impaired in all ESRD patients studied. This abnormality was independent of the level of chemokine receptor expression on the leukocytes.

CONCLUSIONS

The data presented in this study suggest that chemokine receptor dysregulation contributes to leukocyte dysfunction in patients with ESRD. This alteration is especially prominent in ESRD patients with recurrent infection.

The influence of uremic serum on interleukin-1beta and interleukin-1 receptor antagonist production by peripheral blood mononuclear cells

We investigated whether or not uremic serum has an influence on IL-1beta and IL-1Ra production by normal peripheral blood mononuclear cells (PBMC). Four groups of subjects were divided into healthy controls and non-dialyzed patients with chronic renal failure (CRF), patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) patients. We examined cytokine concentrations and cytokine production by PBMC from a normal subject at the density of 2.5 x 10(6) cells/mL incubated with 25% serum in the medium and serum containing polymyxin-B or lipopolysaccharides (LPS). IL-1Ra concentrations in the serum of the uremic groups were significantly higher than those of the controls. In IL-1beta production by PBMC in medium with both serum and serum containing polymyxin-B, these values in the uremic groups were significantly higher than in the controls. In IL-1Ra production with serum containing polymyxin-B, these values in the uremic groups were significantly higher than in the controls. In contrast, in IL-1Ra production by PBMC in medium with serum containing LPS, these values in the uremic groups were significantly lower than in the controls. It was concluded that uremic serum not only contains nonendotoxemic cytokine-inducing substances, but also shows impaired cytokine production by PBMC in response to LPS.

UNRESOLVED ISSUES IN DIALYSIS: Long-Term Management of the Tunneled Venous Catheter

Despite their propensity for significant complications, tunneled central venous catheters have become a common means of vascular access in the United States for patients requiring maintenance hemodialysis for end-stage renal disease (ESRD). Reasons for their use include advanced patient age, peripheral vascular disease (arterial and venous), late referral for creation of vascular access, and more importantly, the lack of an interdisciplinary service line on vascular access among vascular surgeons, radiologists, and nephrologists. This review article summarizes complications commonly encountered in dialysis patients who use tunneled central venous catheters for vascular access-mainly thrombosis, stenosis, and infection. Special attention is given to novel approaches for the prevention of catheter-associated infections. Effective prevention and timely treatment of common catheter-associated complications can reduce the substantial morbidity associated with the use of these devices. However, these measures should not detract from the goal of avoiding or limiting the long-term use of catheters, thereby optimizing vascular access management by ensuring the timely availability of functioning arteriovenous fistulas.

Comparison of microbial findings and resistance to antibiotics between transplant patients, patients on hemodialysis, and other patients with the diabetic foot

Infectious complications of the diabetic foot may be influenced by impaired renal function and by immunosuppression therapy.

AIMS

To assess differences in microbial findings and resistance to antibiotics between transplant recipients, hemodialysis patients, and other patients with the diabetic foot.

METHODS

207 patients treated in the foot clinic for diabetic ulcers from 12/1998 to 12/1999 were included into this retrospective study. Patients were divided into three groups (transplant, dialysis, and other patients). Occurrence of individual bacterial species and resistance to antibiotics was compared between study groups.

RESULTS

Study groups did not differ significantly in ulcer grades defined by the Wagner classification or in the mean number of pathogens per patient. The prevalence of individual microorganisms did not differ between the study groups. However, the study groups differed significantly in the occurrence of microbial resistance to antibiotics. Transplant patients had more frequently Staphylococcus aureus resistant to oxacillin (P<.01), imipenem (P<.01), co-trimoxazole (P<.01), Enterococcus species resistant to ampicillin (P<.01), piperacillin (P<.01), and dialysis patients had more frequently Pseudomonas species resistant to piperacillin (P<.05) and cefpirom (P<.05) in comparison with the other two groups.

CONCLUSIONS

Transplant patients had significantly more resistant microorganisms in comparison with dialysis and other patients with the diabetic foot. Empiric antibiotic selection based on general population data should be modified in transplant patients with diabetic foot according to actual susceptibility to antibacterial drugs.

Potential role of soluble CD40 in the humoral immune response impairment of uraemic patients

CD40/CD154 interaction is essential for both humoral and cellular immune response. We investigated whether this interaction could be altered in patients with kidney failure who are known to present an impaired immune response. To that aim, we measured the levels of the soluble form of CD40 (sCD40), which is known to interfere with CD40/CD154 interaction, in 43 chronic renal failure patients, 162 hemodialysed patients, and 83 healthy donors. Uraemic and haemodialysed patients presented a three- and fivefold increase, respectively, of the antagonist soluble form of CD40 in their serum, when compared to healthy subjects. Serum sCD40 levels correlated with those of creatinine in uraemic non-haemodialysed patients. While sCD40 is widely excreted in urine of healthy individuals, it is not eliminated by dialysis sessions on classic membranes. The return to a normal kidney function in nine haemodialysed patients who received renal transplantation, leads to a rapid decrease of serum sCD40 levels. This natural sCD40 exhibited multimeric forms and was able to inhibit immunoglobulin production by CD154-activated B lymphocytes in vitro. Furthermore, the positive correlation we observed between the serum levels of sCD40 and the deficient response to hepatitis B vaccination in uraemic patients suggests that sCD40 also compromises the humoral response in vivo.

Syk activation is a leukotriene B4-regulated event involved in macrophage phagocytosis of IgG-coated targets but not apoptotic cells

Macrophages are called upon to ingest both IgG-coated targets and apoptotic cells. Important roles for tyrosine kinase Syk and leukotriene B4 (LTB4) are recognized in FcgammaR-mediated phagocytosis. Here we evaluated the roles of Syk and LTB4 in macrophage phagocytosis of apoptotic thymocytes versus IgG-coated erythrocytes. Macrophage ingestion of apoptotic thymocytes was not influenced by exogenous or endogenous LTB4 nor associated with Syk activation (phosphorylation). By contrast, LTB4 dose-dependently amplified FcgammaR-mediated phagocytosis as well as Syk activation. Furthermore, a role for endogenous LTB4 in Syk activation during FcgammaR-mediated phagocytosis was demonstrated using pharmacologic and genetic abrogation of 5-lipoxygenase. LTB4 was unique among 5-lipoxygenase products in this regard, since LTD4 and 5-hydroxyeicosatetraenoic acid (HETE) were unable to amplify Syk activation in response to FcgammaR engagement. Ca2+ chelation studies revealed that FcgammaR-mediated Syk activation as well as LTB4 amplification thereof was Ca2+ regulated. These 2 parallel phagocytic processes therefore exhibit initial divergence in signal transduction events, with Syk activation being an LTB4-regulated event in FcgammaR-mediated but not apoptotic cell ingestion. As LTB4 is an important proinflammatory product of macrophages, we speculate that this divergence evolved to permit FcgammaR-mediated phagocytosis to proceed in an inflammatory milieu, while apoptotic cell clearance is noninflammatory.

Treatment with megestrol acetate improves human immunodeficiency virus-associated immune thrombocytopenia

Splenic macrophage Fc gamma receptors participate in the pathophysiology of immune cytopenias, and in such disorders, the beneficial effects of glucocorticoids are in part mediated by decreased expression of macrophage Fc gamma receptors. In the animal model, progesterones, like glucocorticoids, inhibit expression of these receptors. Megestrol acetate (MA) is a progesterone frequently used for treating human immunodeficiency virus (HIV)-associated anorexia-cachexia. Twenty-eight patients with HIV-associated thrombocytopenia with shortened platelet survival and increased platelet-associated immunoglobulin G (IgG) who were being treated with MA for anorexia-cachexia were prospectively studied for a 6-month period to assess the potential role of progesterones in the treatment of immune thrombocytopenia. Treatment with MA for non-consecutive periods of 2 months and 1 month significantly increased platelet count and platelet survival without significant alteration of platelet-associated immunoglobulin levels. Of the 28 patients studied, 22 presented a complete response, 19 presented a complete response 1 month after finishing the MA treatment regimen, and 12 remained in complete response for a further month. Expression of Fc gamma receptors (Fc gamma RI and Fc gamma RII) by peripheral blood monocytes and the in vitro recognition of IgG-sensitized cells by monocytes were significantly decreased by the MA treatment. Decreased expression and functioning of these receptors significantly correlated with platelet counts and survival times, but no relationship was found with platelet-associated immunoglobulin, circulating immune complexes, body mass index, plasma HIV load, or CD4 lymphocyte levels. These results suggest that treatment with progesterones, like MA, may be an alternative therapy for immune cytopenias, with few side effects.

Pattern and persistence of the epitope-specific IgM response against human cytomegalovirus in renal transplant patients

The humoral immune response against human cytomegalovirus (HCMV) was evaluated in immunocompromised patients by Western blotting (WB) based on recombinant viral envelope (gB and gH) and tegument (pp150 and pp65) proteins. Three groups of patients were investigated: (a) 74 renal transplant recipients; (b) 24 hemodialysis patients, both groups without clinical evidence of viral infections; and (c) 19 renal transplant patients with manifest HCMV infections. The results obtained suggest that (i) the WB is considerably more sensitive, recognizing the HCMV-specific IgM response rather than the enzyme-linked immunosorbent assays. An IgM response was detected in one-third of all clinically asymptomatic renal patients. (ii) The virus-specific IgM response is primarily directed against the pp150 epitope. (iii) In patients with clinically manifest HCMV disease, additional IgM reactivities are most frequently directed against the glycoprotein B epitope. (iv) The severity of HCMV infections correlates with the extent of the IgM antibody response, i.e. with the number of specific epitopes involved. (v) After transplantation, IgM reactivity and its epitope-specific pattern persist for years.

Acquired disorders of phagocyte function complicating medical and surgical illnesses

There is evidence that acquired dysfunction of neutrophils, monocytes, or macrophages is an important cause of infection in patients with diabetes mellitus, renal or hepatic failure, alcoholism, autoimmune diseases, influenza or human immunodeficiency virus infection, burns, and trauma. Distinguishable mechanisms of acquired phagocyte dysfunction include inhibitory effects of metabolic disturbances (e.g., hyperglycemia, uremia), chemical toxins (e.g., ethanol), viral proteins on phagocyte activation, and pathologic activation of phagocytes in the circulation (e.g., after hemodialysis, burns, or cardiopulmonary bypass). Although the burden of morbidity and mortality resulting from acquired phagocyte dysfunction appears to be vast, research in this area has been hampered by the complexity of the underlying illnesses and by limitations of laboratory assays and clinical study methodology. Given the advent of improved assays of phagocyte functions and treatments that can enhance these functions, there is a pressing need for more prospective studies of acquired phagocyte dysfunction.

Risk of death and liver cirrhosis in anti-HCV-positive long-term haemodialysis patients

BACKGROUND

Hepatitis C virus (HCV) infection is the most common cause of chronic liver disease in haemodialysis patients. The aim of this study was to assess the impact of HCV infection on patient survival in a cohort of long-term haemodialysis patients and to evaluate the percentage of anti-HCV-positive patients that evolve to liver cirrhosis.

METHODS

In 1992, 175 patients who had been on intermittent haemodialysis therapy for at least 6 months were included in the study (57 anti-HCV-positive and 118 anti-HCV-negative patients). Evaluation of patient outcome included date and cause of death, kidney transplantation, and the diagnosis of liver cirrhosis. Patient survival was estimated by the Kaplan-Meier method and compared by the log-rank test. The Cox proportional hazards model was used to estimate the risk of death among dialysis patients who were anti-HCV positive. Other prognostic variables studied included age, gender, diabetes mellitus as cause of end-stage renal disease (ESRD), history of previous transplant, transplantation during follow-up, and time on haemodialysis treatment. The diagnosis of liver cirrhosis was made based on clinical and/or histological criteria.

RESULTS

Eight-year patient survival in anti-HCV-positive subjects was lower (32%) than in anti-HCV-negative patients (52%) (log-rank, P=0.03). Four variables were found to be independent prognostic factors in patient survival: age (relative risk (RR) 1.04); diabetes as cause of ESRD (RR 3.6); transplantation during follow-up (RR 0.66) and presence of HCV antibodies (RR 1.62). The causes of death did not differ significantly between groups, except that four anti-HCV-positive patients died from liver disease. Ten (17.5%) of the 57 anti-HCV-positive patients were diagnosed to have liver cirrhosis at a median of 10 years after renal replacement therapy initiation and a median of 7 years after the first ALT level increase.

CONCLUSION

In conclusion, our study shows an increased risk of death among long-term haemodialysis patients infected with HCV compared with non-infected patients. This might be partly explained by the high proportion of these patients that evolve to liver cirrhosis.

Assessment of cytomegalovirus infections using neopterin and a new immunoblot

Human cytomegalovirus (HCMV) infections are a major cause of morbidity and mortality in immunocompromised patients despite advances in diagnostic tests and antiviral therapies. The underlying study investigates the diagnostic value of the immune marker neopterin and a recently developed HCMV-specific western blot to detect HCMV infections and to differentiate them into either syndromes or diseases. The mean period of observation was 1428 days. Thirteen HCMV diseases and nine syndromes were diagnosed retrospectively. The first appearance of clinical signs or symptoms was always associated with a marked increase of serum and urine neopterin. The HCMV-specific IgM response followed in the mean 9 days later. Median values and the course of the neopterin levels were significantly higher during the HCMV diseases. In addition, the strength of the humoral immune response was related to the severity of the HCMV infection. Patients with HCMV diseases developed antibodies against a higher number of epitopes. The anti-HCMV IgM response persisted in more than 80% of the patients for longer than 3 years. In conclusion, combining the HCMV-specific western blot and neopterin permit detection of the immune response against HCMV, reflect the severity of the infection and might guide the anti-viral therapy.

Enhancement of splenic-macrophage Fcgamma receptor expression by treatment with estrogens

Splenic-macrophage Fcgamma receptors (FcgammaRs) participate in the pathophysiologies of immune-complex diseases and in host defense against infection. Modulation of macrophage FcgammaR expression is an immuno-therapeutic target. Glucocorticoids, sex steroids, and dopaminergic drugs modulate macrophage FcgammaR expression. Previous data indicate that estradiol increases macrophage FcgammaR expression. Nevertheless, the effects of clinically used estrogens upon macrophage FcgammaR expression are unknown. We assessed the effects of treatment with commonly used estrogens on the expression of macrophage FcgammaRs using a guinea pig experimental model. Six estrogens have been studied: ethynylestradiol (Et), mestranol (M), chlortianisene (Ct), promestriene, 17-epiestriol, and 17beta-estradiol. Following in vivo treatment of guinea pigs, we determined the clearance of immunoglobulin G (IgG)-sensitized erythrocytes in vivo, the binding of IgG-sensitized erythrocytes by isolated splenic macrophages, and splenic-macrophage FcgammaR cell surface expression. Estrogens enhance the clearance of IgG-sensitized erythrocytes by increasing splenic-macrophage FcgammaR expression. Et, M, and Ct were more effective than the other estrogens. Flow cytometry and fluorescence microscopy with monoclonal antibodies demonstrated that estrogens increase the cell surface expression of FcgammaR1 and -2 more than that of FcgammaR2. These data indicate that treatment with commonly used estrogens enhances the clearance of IgG-sensitized cells by improving splenic-macrophage FcgammaR expression.

Apoptosis of leukocytes: basic concepts and implications in uremia

Circulating blood leukocytes have short life expectancies and end their lives by committing programmed cell death or apoptosis. Apoptosis is an active form of cell death that is initiated by a number of stimuli and is intricately regulated. Apoptosis in both excessive and reduced amounts has pathological implications. Evidence suggests that apoptosis may play a role in the pathophysiology of immune dysfunction in uremia. Indeed, accelerated programmed cell death has been observed in lymphocytes, monocytes, and polymorphonuclear leukocytes among patients with chronic renal failure. This may be due in part to the retention of uremic toxins. The aim of this article is to review the evidence for accelerated leukocyte apoptosis, key regulatory apoptotic pathways, and the possible role of this highly organized process in the pathogenesis of immune dysfunction in uremia.

Interleukin-1 receptor antagonist synthesis by peripheral blood mononuclear cells: a novel predictor of morbidity among hemodialysis patients

Proinflammatory cytokines have been implicated in the short- and long-term morbidity experienced by hemodialysis (HD) patients. The present study, which is based on long-term follow-up of a cohort of 37 patients, relates peripheral blood mononuclear cell (PBMC) interleukin-1 receptor antagonist (IL-1Ra) synthesis (a reliable marker of IL-1beta synthesis in HD patients) and plasma levels of an acute phase reactant, lipopolysaccharide binding protein (LBP), to clinical outcomes. In July 1993, predialysis blood samples from these patients were collected and IL-1Ra synthesis by PBMC and plasma LBP was measured. Hospital records were reviewed and patient follow-up data were obtained until December 1997 (54 mo) or death, whichever occurred earlier. The effect of age, diabetes, endotoxin- and IgG-stimulated IL-1Ra synthesis, and plasma LBP levels on mortality was assessed using the Cox proportional hazard regression model. Poisson regression was used to determine potential relationships between the number of outcome events and each continuous risk factor. Twenty-two patients (59%) died during the follow-up period. Mortality was unrelated to IL-1Ra synthesis but did increase with age (relative risk, 1.05/yr; P: = 0.01) and diabetes (relative risk, 3.00/yr; P: = 0.03). Cardiovascular event rates were higher among older individuals and in those with higher endotoxin-stimulated PBMC IL-1Ra synthesis. Cardiovascular events increased with plasma LBP levels in the range of 9,000 to 12,000 pg/ml but then seemed to decrease. In contrast, older age and low IgG-stimulated IL-1Ra synthesis were associated with an increased risk of infectious events. The results of this study demonstrate an interesting link between stimulus-dependent variability in IL-1Ra synthesis by PBMC and clinical outcomes among patients on chronic HD and provide interesting targets for therapeutic interventions in this vulnerable patient population.

Simultaneous cadaver pancreas living-donor kidney transplantation: a new approach for the type 1 diabetic uremic patient

OBJECTIVE

To review the authors' experience with a new approach for type I diabetic uremic patients: simultaneous cadaver-donor pancreas and living-donor kidney transplant (SPLK).

SUMMARY BACKGROUND DATA

Simultaneous cadaver kidney and pancreas transplantation (SPK) and living-donor kidney transplantation alone followed by a solitary cadaver-donor pancreas transplant (PAK) have been the transplant options for type I diabetic uremic patients. SPK pancreas graft survival has historically exceeded that of solitary pancreas transplantation. Recent improvement in solitary pancreas transplant survival rates has narrowed the advantage seen with SPK. PAK, however, requires sequential transplant operations. In contrast to PAK and SPK, SPLK is a single operation that offers the potential benefits of living kidney donation: shorter waiting time, expansion of the organ donor pool, and improved short-term and long-term renal graft function.

METHODS

Between May 1998 and September 1999, the authors performed 30 SPLK procedures, coordinating the cadaver pancreas transplant with simultaneous transplantation of a laparoscopically removed living-donor kidney. Of the 30 SPLKs, 28 (93%) were portally and enterically drained. During the same period, the authors also performed 19 primary SPK and 17 primary PAK transplants.

RESULTS

One-year pancreas, kidney, and patient survival rates were 88%, 95%, and 95% for SPLK recipients. One-year pancreas graft survival rates in SPK and PAK recipients were 84% and 71%. Of 30 SPLK transplants, 29 (97%) had immediate renal graft function, whereas 79% of SPK kidneys had immediate function. Reoperative rates, early readmission to the hospital, and initial length of stay were similar between SPLK and SPK recipients. SPLK recipients had a shorter wait time for transplantation.

CONCLUSIONS

Early pancreas, kidney, and patient survival rates after SPLK are similar to those for SPK. Waiting time was significantly shortened. SPLK recipients had lower rates of delayed renal graft function than SPK recipients. Combining cadaver pancreas transplantation with living-donor kidney transplantation does not harm renal graft outcome. Given the advantages of living-donor kidney transplant, SPLK should be considered for all uremic type I diabetic patients with living donors.

Effects of androgen treatment on expression of macrophage Fcgamma receptors

Macrophage Fcgamma receptors (FcgammaRs) play an important role in the host defense against infection and in the pathophysiology of immune cytopenias. Modulation of macrophage FcgammaR expression is a potential therapeutic approach to immune disorders. Glucocorticoids and progesterones decrease macrophage FcgammaR expression. We assessed the effect of treatment with androgens and antiandrogens on the expression of macrophage FcgammaRs using an experimental guinea pig model. Four androgens (testosterone, dihydrotestosterone, mesterolone, and danazol) and five antiandrogens (flutamide, nilutamide, cyproterone acetate, spironolactone, and finasteride) were studied. Following in vivo treatment of guinea pigs, we determined the clearance of immunoglobulin G (IgG)-sensitized erythrocytes in vivo, the binding of IgG-sensitized erythrocytes by isolated splenic macrophages, and splenic macrophage FcgammaR cell surface expression. All of the androgens impaired the clearance of IgG-sensitized erythrocytes by decreasing splenic macrophage FcgammaR expression. Dihydrotestosterone and mesterolone were more effective than testosterone or dihydrotestosterone. Flow cytometry and fluorescence microscopy with monoclonal antibodies demonstrated that the androgens decreased the cell surface expression of FcgammaR1,2 more than that of FcgammaR2. Antiandrogens did not significantly alter macrophage FcgammaR expression. Nevertheless, antiandrogens counteracted the effects of androgens on macrophage FcgammaR expression. These data indicate that androgens impair the clearance of IgG-coated cells by decreasing splenic macrophage FcgammaR expression. Thus, androgens other than danazol are candidate drugs for the treatment of immune disorders.

Enhanced Liver Uptake of Opsonized Red Blood Cells After In Vivo Transfer of FcγRIIA cDNA to the Liver

Fcγ receptors convey to phagocytic cells the ability to recognize, bind, and internalize IgG-coated cells and microorganisms. The present study demonstrates the use of adenovirus (Ad)-mediated gene transfer of human Fcγ receptor IIA cDNA to convert normally nonphagocytic cells (hepatocytes) into functional equivalents of phagocytic cells. Ad vector in vitro transfer and expression of FcγRIIA cDNA in primary rat hepatocytes was confirmed by flow cytometry anti-FcγRIIA immunodetection, and the function of the receptor was demonstrated by enhanced binding and phagocytosis of 51Cr-labeled IgG-opsonized erythrocytes. After in vivo gene transfer to rats, expression of FcγRIIA cDNA in hepatocytes was confirmed by Northern analysis and immunohistochemistry. Rats infected with the Ad vector carrying the FcγRIIA cDNA demonstrated enhanced clearance of opsonized erythrocytes, but not nonopsonized erythrocytes, from the circulation with increased sequestration within the liver. Together, these data demonstrate that Ad-mediated FcγRIIA gene transfer can convert normally IgG-nonphagocytic cells into phagocytic cells capable of recognizing, binding, and ingesting an opsonized particulate antigen, suggesting that gene transfer strategies might be used to transiently augment host defense by enhancing the clearance of immune complexes.