Successful lung transplantation in the presence of pre-existing donor-specific cytotoxic HLA Class II antibodies.

Pre-existing HLA antibodies are a well-established causal factor for rejection and graft dysfunction after solid-organ transplantation. In lung transplant recipients, the significance of HLA antibodies has not been fully established. Although rare, several cases of hyperacute rejection of the lung allograft due to pre-existing donor-specific HLA antibodies have been described. In contrast, we describe successful lung transplantation in a patient with pre-existing donor-specific HLA antibodies. Routine screening prior to lung transplantation revealed cytotoxic HLA Class II antibodies, directed against the alpha chain of HLA-DQ, induced by a previous liver transplant. Due to clinical deterioration, it was decided to accept a lung offer without virtual crossmatching for DQ compatibility. Cytotoxic antibodies against the lung donor were confirmed retrospectively, resulting in strong positive B-cell crossmatches. Interestingly, the patient showed no clinical or histologic signs of rejection. This case demonstrates that the presence of high levels of pre-existing donor-specific HLA antibodies does not necessarily lead to rejection and graft failure. Although screening for antibodies prior to transplantation remains crucial, this study shows that we are thus far not able to predict the effect of pre-existing HLA Class II antibodies on allograft survival in individual patients.

CCR5Δ32 genotype leads to a Th2 type directed immune response in ESRD patients.

BACKGROUND: In patients with end stage renal disease (ESRD) we observed protection from inflammation-associated mortality in CCR5Δ32 carriers, leading to CCR5 deficiency, suggesting impact of CCR5Δ32 on inflammatory processes. Animal studies have shown that CCR5 deficiency is associated with a more pronounced Th2 type immune response, suggesting that in human CCR5Δ32 carriers the immune response may be more Th2 type directed. So, in the present study we determined the Th1-Th2 type directed immune response in ESRD patients carrying and not carrying the CCR5Δ32 genetic variant after stimulation. METHODOLOGY/PRINCIPAL FINDINGS: We tested this hypothesis by determining the levels of IFN-γ and IL-4 and the distribution of Th1, Th2 and Th17 directed circulating CD4+ and CD8+ T cells and regulatory T cells (Tregs) after stimulation in ESRD patients with (n = 10) and without (n = 9) the CCR5Δ32 genotype. The extracellular levels of IFN-γ and IL-4 did not differ between CCR5Δ32 carriers and non carriers. However, based on their intracellular cytokine profile the percentages IL-4 secreting CD4+ and CD8+ T cells carrying the CCR5Δ32 genotype were significantly increased (p = 0.02, respectively p = 0.02) compared to non carriers, indicating a more Th2 type directed response. Based on their intracellular cytokine profile the percentages IFN-γ and IL-17 secreting T cells did not differ between carriers and non-carriers nor did the percentage Tregs, indicating that the Th1, Th17 and T regulatory response was not affected by the CCR5Δ32 genotype. CONCLUSIONS/SIGNIFICANCE: This first, functional human study shows a more pronounced Th2 type immune response in CCR5Δ32 carriers compared to non carriers. These differences may be involved in the previously observed protection from inflammation-associated mortality in ESRD patients carrying CCR5Δ32.

Latent cytomegalovirus infection is an independent risk factor for late graft failure in renal transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) is a risk factor for rejection and mortality soon after renal transplantation. Little is known about its consequences longer after transplantation. We prospectively investigated whether latent CMV infection is a risk factor for graft failure and mortality long after transplantation. MATERIAL/METHODS: Our study included 606 renal transplant recipients (RTR) with a functioning graft for >1 year. CMV serology was determined using ELISA. RTRs were divided into CMV-seronegative and latent CMV (seropositive + seroconverted). RESULTS: We measured CMV IgG at 6.0 [2.6-11.4] years post-transplant. During follow-up (7.0 [6.2-7.5] years), 54 (9%) RTRs experienced graft failure and 137 (23%) RTRs died. Risk for graft failure and mortality was significantly higher in RTRs with latent CMV compared to CMV-seronegative RTRs (HR=3.1, P=0.005 and HR=2.0, P=0.002, respectively). After adjustment for potential confounders, latent CMV infection remained an independent risk factor for graft failure (HR=4.6, P=0.001), but not for mortality (HR=1.4, P=0.2). CONCLUSIONS: Latent CMV is an independent risk factor for graft failure long after renal transplantation and carries a higher risk for graft failure than for mortality. These findings confirm the notion that latent CMV can be harmful in transplanted kidneys.

High plasma hemopexin activity is an independent risk factor for late graft failure in renal transplant recipients.

Chronic low-grade inflammation is involved in late renal transplant dysfunction. Recent studies suggest a role for hemopexin, an acute phase protein, in kidney damage. We investigated whether hemopexin activity (Hx) predicts graft failure in renal transplant recipients (RTRs). In 557 RTRs with functioning grafts for >or=1 year, Hx was measured in citrate-plasma. RTRs were divided according to Hx into two groups; A: sextile 1-5 (464 RTRs, 83%) and B: sextile 6 (92 RTRs, 17%). Hx [median (IQR) 11.1 (3.3-19.1) arbitrary units] was measured at 6.0 (2.6-11.5) years post-transplant. RTRs with high Hx (group B) had significantly higher urinary protein excretion (UP) and diastolic blood pressure than group A, despite significantly more prevalent use of renin-angiotensin-aldosterone system inhibitors. After follow-up [4.6 (3.8-5.2) years], incidence of graft failure in group A was 25 (5%) and in group B 14 (15%,P = 0.0009) After adjustment for high-sensitivity C-reactive protein (hsCRP), UP and other potential confounders, Hx remained an independent predictor of graft failure [HR = 2.5 (95% CI 1.2-5.3), P = 0.01]. In conclusion, elevated Hx predicts late graft failure in RTRs, independent of hsCRP and UP. This suggests that Hx measurement, next to measurement of creatinine clearance and UP, could be of value for the identification of RTRs at risk for graft failure.

Copeptin, a surrogate marker of vasopressin, is associated with accelerated renal function decline in renal transplant recipients.

BACKGROUND: Chronically elevated vasopressin (VP) plasma levels have been shown to induce accelerated renal function decline in rats with chronic renal failure. Whether endogenous VP is a renal risk factor in humans has not been investigated yet. We aimed to investigate whether, in renal transplant recipients, VP concentration is associated with change in renal function during follow-up. METHODS: In this prospective study, all consecutive patients visiting our kidney transplant outpatient clinic between August 2001 and July 2003 were asked to participate. Serum creatinine was assessed at baseline and at follow-up. Copeptin, the C-terminal portion of the precursor of VP, was determined at baseline (immunoassay). Univariate and multivariate regression analyses were performed to investigate the association between copeptin and renal function decline. RESULTS: Overall, 548 patients were included 6.0 (2.8-11.6) years after transplantation (men 54%, age 52 [43-60] years). Median follow-up was 3.2 (2.7-3.7) years. Median copeptin level was 9.1 (5.0-18.6) pmol/L at baseline. Copeptin was significantly associated with change in estimated Glomerular Filtration Rate (eGFR; MDRD) during follow-up. When our study population was subdivided according to gender-stratified tertiles of increasing copeptin concentration, mean changes in eGFR during follow-up were -0.03, -0.44, and -1.06 mL/min/1.73 m2 per year. In multivariate regression analysis, the association of copeptin at baseline with change in eGFR during follow-up remained significant after adjustment for age, gender, baseline eGFR, and known risk factors for renal function decline. CONCLUSIONS: These findings suggest that in renal transplant patients, VP may play a role in renal function decline.

HLA-DR4, DR13(6) and the ancestral haplotype A1B8DR3 are associated with ANCA-associated vasculitis and Wegener's granulomatosis.

OBJECTIVES: As the HLA system is involved in recognition of self and non-self, an association with the development of ANCA-associated vasculitis (AAV) seems probable. In this study, the relation between HLA antigens and AAV and it's severity were investigated. METHODS: Consecutive patients diagnosed with AAV at our centre, who were followed for at least 2 years, were included. The frequency of HLA antigens of AAV and WG patients was compared with 5872 healthy blood donors from the same region and with 4000 healthy Dutch controls originating from a Eurotransplant database. RESULTS: From 304 AAV patients, sufficient data were available. We found DR13(6) to be less prevalent and both DR4 and the ancestral haplotype A1B8DR3 more prevalent in patients with AAV compared with controls, particularly in patients with WG. In addition, DR1 was less prevalent in patients with WG in comparison with controls. Further, DR8 was more prevalent in patients with CSS compared with other forms of vasculitis and controls. There were no associations between HLA antigens and disease characteristics or course of AAV or WG. CONCLUSIONS: AAV is associated with increased prevalence of DR4 and the ancestral haplotype A1B8DR3 and with decreased prevalence of DR13(6), particularly in patients with WG. In patients with WG, prevalence of DR1 was decreased, whereas in patients with CSS DR8 was increased. No associations between HLA antigens and disease characteristics or course of AAV were found.

The effect of HLA mismatches, shared cross-reactive antigen groups, and shared HLA-DR antigens on the outcome after pediatric liver transplantation.

The aim of this study was to analyze the effect of human leukocyte antigen (HLA) class I and HLA-DR mismatching, sharing cross-reactive antigen groups (CREGs), and sharing HLA-DR antigens on the outcome after pediatric liver transplantation. Outcome parameters were graft survival, acute rejection, and portal fibrosis. A distinction was made between full-size (FSLTx) and technical-variant liver transplantation (TVLTx). A total of 136 primary transplants were analyzed. The effect of HLA on the outcome parameters was analyzed by adjusted multivariate logistic and Cox regression analysis. HLA mismatches, shared CREGs, and shared HLA-DR antigens affected neither overall graft survival nor survival after FSLTx. Survival after TVLTx was superior in case of 2 mismatches at the HLA-DR locus compared to 0 or 1 mismatch (P = 0.01) and in case of no shared HLA-DR antigen compared to 1 shared HLA-DR antigen (P = 0.004). The incidence of acute rejection was not influenced by HLA. The incidence of portal fibrosis could be analyzed in 62 1-yr biopsies and was higher after TVLTx than FSLTx (P = 0.04). The incidence of portal fibrosis after TVLTx with 0 or 1 mismatch at the HLA-DR locus was 100% compared to 43% with 2 mismatches (P = 0.004). After multivariate analysis, matching for HLA-DR and matching for TVLTx were independent risk factors for portal fibrosis. In conclusion, an overall beneficial effect of HLA matching, sharing CREGs, or sharing HLA-DR antigens was not observed. A negative effect was present for HLA-DR matching and sharing HLA-DR antigens on survival after TVLTx. HLA-DR matching might be associated with portal fibrosis in these grafts.

HLA antigens and post renal transplant lymphoproliferative disease: HLA-B matching is critical.

Although several risk factors for posttransplant lymphoproliferative disease (PTLD) after solid organ transplantation have been identified, the immunosuppressive regimen probably as most important one, their exact pathogenic role and relevance is still unclear. In hematopoietic stem cell transplantation, HLA mismatching also is a risk factor. We analyzed factors possibly associated with development of PTLD in patients receiving a kidney transplant at our hospital between 1985 and 2002. PTLD was observed in 20 out of 1,013 patients (2.0%). Mismatches at the HLA-B locus, but not at the HLA-A or HLA-DR loci, and anti T-cell antibody therapy were both independently associated with development of PTLD. Hazard ratios increased from 1.4 (0.5-4.1) with one mismatch to 5.1 (1.4-19.0) in case of two HLA-B mismatches. Decreased surveillance by T-cells with dual specificity for Epstein-Barr virus (EBV) as well as for allo HLA antigens on the allograft might facilitate clonal expansion of B-cells latently infected with EBV.

Survival benefit of cardiopulmonary bypass support in bilateral lung transplantation for emphysema patients.

BACKGROUND: This study is designed to examine a possible association of cardiopulmonary bypass (CPB) support and outcome of lung transplantation in a well-balanced group of emphysema patients. METHODS: We performed a retrospective analysis of 62 consecutive primary bilateral lung transplantations for emphysema. Risk factors for their possible association with patient survival were analyzed by multivariate logistic regression. RESULTS: The use of CPB support was associated with improved survival (odds ratio=0.25; P=0.038). The actuarial survival at 1 year was 97% for patients treated with CPB and 77% for patients treated without CPB support. In 28 patients (45%), 2 human leukocyte antigen (HLA)-DR mismatches between donor and recipient occurred, whereas 34 patients had 0 or 1 HLA-DR mismatches. The use of CPB support in the group with two HLA-DR mismatches was associated with improved survival (odds ratio=0.06; P=0.020). This association was not present in the group with 0 or 1 HLA-DR mismatches. CONCLUSIONS: These results demonstrate a significant survival benefit of CPB support during bilateral lung transplantation in emphysema patients. The difference in survival benefit of CPB support between the patients with 0 or 1 HLA-DR mismatches and the patients with 2 HLA-DR mismatches indicates that the immunosuppressive effect of CPB support might be responsible for this survival benefit. The underlying immunological mechanism might be important in the future treatment of organ transplantation.

Identification of respiratory vagal feedback in awake normal subjects using pseudorandom unloading.

Evidence of the Hering-Breuer reflex has been found in humans during anesthesia and sleep but not during wakefulness. Cortical influences, present during wakefulness, may mask the effects of this reflex in awake humans. We hypothesized that, if lung volume were increased in awake subjects unaware of the stimulus, vagal feedback would modulate breathing on a breath-to-breath basis. To test this hypothesis, we employed proportional assist ventilation in a pseudorandom sequence to unload the respiratory system above and below the perceptual threshold in 17 normal subjects. Tidal volume, integrated respiratory muscle pressure per breath, and inspiratory time were recorded. Both sub- and suprathreshold stimulation evoked a significant increase in tidal volume and inspiratory flow rate, but a significant decrease in inspiratory time was present only during the application of a subthreshold stimulus. We conclude that vagal feedback modulates respiratory timing on a breath-by-breath basis in awake humans, as long as there is no awareness of the stimulus.

Inheritance of a stable mutation in a family with early-onset disease.

Autosomal/dominant polycystic kidney disease (ADPKD) exhibits a high inter- and intrafamilial heterogeneity partly explained by the involvement of at least 3 different genes in the disorder transmission. PKD1, the major locus, is located on chromosome 16p. The occurrence of very early-onset cases of ADPKD (sometimes in utero) in a few PKD1 families or the increased severity of the disease in successive generations raise the question of anticipation. This is a subject of controversial discussion. This report deals with the molecular analysis in families with very early-onset ADPKD. The finding of the same stable mutation with such different phenotypes rules out a dynamic mutation. The molecular basis of severe childhood PKD in typical ADPKD families remains unclear; it may include segregation of modifying genes or unidentified factors and the two-hit mechanism.

Lithium has no direct effect on cardiac function in the isolated, perfused rat heart.

To determine if lithium exerts direct cardiac toxicity, using an isolated, perfused rat heart model, paced and unpaced beating rat hearts were perfused with Krebs-Henseleit bicarbonate solution and left ventricular pressures were measured via a balloon-tipped catheter positioned in the left ventricle via the mitral valve. Following a stabilization period, hearts were then perfused with Krebs-Henseleit bicarbonate solution containing 1, 10, and 100 mM ionized lithium chloride or lithium carbonate in an antecedent dose-response protocol and perfused for 10 min. at each dose. To control for the possibility of osmotic effects from the high dose of lithium, an additional group was studied in which hearts were perfused with Krebs-Henseleit bicarbonate solution for an initial stabilization period, then perfused for an additional 20 min. with Krebs-Henseleit bicarbonate solution alone, and finally with Krebs-Henseleit bicarbonate solution containing mannitol (200 mOsm/l) for 10 min. Lithium did not have any effect on left ventricular peak systolic pressure, left ventricular end diastolic pressure, heart rate or coronary haemodynamics at concentrations of 1 or 10 mM. At 100 mM LiCl and Li2CO3, left ventricular peak systolic pressure decreased transiently during the first minute of lithium infusion, but recovered significant function by 10 min. Heart rate decreased significantly by 10 min. of infusion. These effects were also seen in the osmotic controls and thus do not appear to be a direct effect of lithium. At the doses tested, lithium had no direct effect on cardiac function which could not be explained by an osmotic effect.

Vagal feedback in the entrainment of respiration to mechanical ventilation in sleeping humans.

We studied the capacity of four "normal" and six lung transplant subjects to entrain neural respiratory activity to mechanical ventilation. Two transplant subjects were studied during wakefulness and demonstrated entrainment indistinguishable from that of normal awake subjects. We studied four normal subjects and four lung transplant subjects during non-rapid eye movement (NREM) sleep. Normal subjects entrained to mechanical ventilation over a range of ventilator frequencies that were within +/-3-5 breaths of the spontaneous respiratory rate of each subject. After lung transplantation, during which the vagi were cut, subjects did demonstrate entrainment during NREM sleep; however, entrainment only occurred at ventilator frequencies at or above each subject's spontaneous respiratory rate, and entrainment was less effective. We conclude that there is no absolute requirement for vagal feedback to induce entrainment in subjects, which is in striking contrast to anesthetized animals in which vagotomy uniformly abolishes entrainment. On the other hand, vagal feedback clearly enhances the fidelity of entrainment and extends the range of mechanical frequencies over which entrainment can occur.

Treatment of Helicobacter pylori infection in rhesus monkeys using a novel antiadhesion compound.

BACKGROUND & AIMS: Helicobacter pylori can be eradicated by administration of antimicrobials, but resistant strains have emerged, and there is a need for novel therapeutic approaches against this infection. This study aimed to determine the safety and efficacy of 3'-sialyllactose sodium salt (3'SL), an oligosaccharide that occurs naturally in human and bovine milk and that can inhibit the adhesion of H. pylori to human epithelial cells in vitro. METHODS: Twelve H. pylori-positive rhesus monkeys were given 3'SL, either alone (regimens 1 and 2; n = 6) or in combination with omeprazole (regimen 3; n = 4), or bismuth subsalicylate (regimen 4; n = 6). Videogastroscopies were performed before, during, and after treatment, and gastric biopsy specimens were obtained for quantitative cultures and histology. The H. pylori strains colonizing the animals were genotyped. RESULTS: After regimen 1 or 2, 2 of 6 animals were cured permanently, and a third animal was transiently cleared. The 3 other animals remained persistently colonized and did not respond to regimen 3. Regimen 4 resulted in transient decreases in colony counts in 3 of 6 other animals. Gastritis was suppressed only in the 2 animals who became persistently H. pylori negative. There was no apparent relation between 3'SL efficacy and any of the H. pylori tested genotypes. No side effects were observed in any of the animals receiving 3'SL. CONCLUSIONS: Antiadhesive therapy is safe; it can cure or decrease H. pylori colonization in some rhesus monkeys, but the addition of a proton pump inhibitor or bismuth subsalicylate does not increase cure rate.

Entrainment of respiration in humans by periodic lung inflations. Effect of state and CO(2).

Lack of synchrony between a patient and the mechanical ventilator occurs when the respiratory rhythm of the patient fails to entrain to machine inflations. Entrainment implies a resetting of the respiratory rhythm such that a fixed temporal relationship exists between the onset of inspiratory activity and the onset of a mechanical breath. We examined the entrainment response to mechanical ventilation of normal humans over a range of machine rates during wakefulness and during isocapnic and hypercapnic NREM sleep. Wakefulness facilitated 1:1 entrainment of the respiratory rhythm to the mechanical ventilator over a wider range of machine frequencies than during NREM sleep (p < 0.001); isocapnic and hypercapnic conditions did not differ (p = 0.95). To evaluate the Hering-Breuer reflexes in the resetting of the respiratory rhythm during sleep, we examined changes in neural inspiratory time (TI) as the relationship between inspiratory efforts and onset of machine inflations changed. As inspiratory efforts extended into the machine inflation cycle, neural TI shortened. We conclude that entrainment responses of normal humans to mechanical ventilation differ depending on state, but mild increases in respiratory drive caused by CO(2) stimulation do not affect these entrainment responses. Furthermore, the changes in neural TI are consistent with observations in animal studies in which Hering-Breuer reflexes mediated entrainment.

DGGE screening of PKD1 gene reveals novel mutations in a large cohort of 146 unrelated patients.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most commonly inherited renal diseases. ADPKD is a genetically heterogeneous disorder involving at least three different genes. PKD1, the major locus mapped to chromosome 16p13.3 accounts for approximately 85% of ADPKD cases. The search for mutations is a very important step in understanding the molecular mechanisms underlying ADPKD. Despite intense screening by many groups, only a small number of mutations have been described so far. We undertook the first study using denaturing gradient gel electrophoresis (DGGE) to scan for mutations in the non-duplicated region of the PKD1 gene in a large cohort of 146 French unrelated ADPKD patients. We successfully identified novel mutations: 3 are frameshift mutations, 2 nonsense mutations, 2 missense mutations, 1 is an insertion in the frame of 9 nucleotides, 3 intronic variations and several polymorphisms. One of these mutations is the fourth de novo mutation described in this gene. We also describe a family with possible clinical anticipation. DGGE is an effective method for detecting nucleotide changes in the PKD1 gene.

Intravenous infusion of Galalpha1-3Gal oligosaccharides in baboons delays hyperacute rejection of porcine heart xenografts.

BACKGROUND: Hyperacute rejection (HAR) of pig-to-primate discordant xenografts is caused by the deposition of preexisting natural antibodies that recognize Galalpha1-3Gal (alphaGal)-terminating oligosaccharides on glycoproteins and glycolipids, followed by complement-mediated lysis of the graft's endothelium. In vitro, these natural xenoantibodies can be blocked by alphaGal-containing oligosaccharides. We undertook in vivo pig-to-baboon cardiac xenotransplantation experiments to evaluate free oligosaccharides as inhibitors of HAR. METHODS: Initial 15-min intravenous infusions of alphaGal-oligosaccharides into baboons were used to measure pharmacokinetic parameters, and to assess the extent of neutralization of anti-alphaGal antibody activity. AlphaGal trisaccharide (Galalpha1-3Galbeta1-4GlcNAc) or pentasaccharide (Galalpha1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc ) was administered at 0.5 mmol/kg into baboons. Next, two baboons that received porcine heterotopic heart xenografts were continuously infused with alphaGal pentasaccharide for 4-5 hr, maintaining the serum oligosaccharide concentration in the millimolar range. RESULTS: Pharmacokinetic analysis indicated that the oligosaccharides were rapidly cleared from the blood, with a serum half-life of 50 min. In the period during which blood oligosaccharide concentration was above 1 mM, as determined by high-pressure liquid chromatography, the serum cytotoxic activity against porcine cells was completely abolished. HAR of the xenograft was inhibited during the infusions, although there was some histological and immunohistological evidence of antibody-mediated injury on biopsies taken at the end of this period. CONCLUSIONS: Intravenous alphaGal oligosaccharides, by inhibiting anti-alphaGal antibody activity, delay but do not abolish the onset of HAR.

Fatal case of swine influenza virus in an immunocompetent host.

Swine influenza virus (SIV), a common zoonotic infection, affects swine, particularly during late autumn and winter. Transmission of SIV from pigs to humans has been reported occasionally; most cases are mild infections and rarely lead to death. Herein we describe an immunocompetent woman in whom the adult respiratory distress syndrome developed; she died of a fulminant course of swine influenza. The documented pathogen was the H1N1 strain of SIV. To our knowledge, only four other deaths in immunocompetent adults have been previously reported in the literature. Our patient had a hemophagocytic syndrome, which may have contributed to her death.

Barriers to school-based health care programs.

Although school-based health care programs (SBHCPs) provide affordable and accessible health care to children and adolescents and are known to improve school attendance, a variety of barriers affect their development. Focus groups were conducted in three schools in Louisiana to demonstrate how barriers can affect the initiation and development of SBHCPs. Each school-based program was in a different stage of development. Identifying potential barriers and developing strategies to overcome them can enhance already existing SBHCPs and make it easier for new programs to begin. The social worker serves as an important ally in the development of SBHCPs and is a necessary part of the school-based health care team.