Error codes at autopsy to study potential biases in diagnostic error.

OBJECTIVES: Current autopsy practice guidelines do not provide a mechanism to identify potential causes of diagnostic error (DE). We used our autopsy data registry to ask if gender or race were related to the frequency of diagnostic error found at autopsy. METHODS: Our autopsy reports include International Classification of Diseases (ICD) 9 or ICD 10 diagnostic codes for major diagnoses as well as codes that identify types of error. From 2012 to mid-2015 only 2 codes were used: UNDOC (major undocumented diagnoses) and UNCON (major unconfirmed diagnoses). Major diagnoses contributed to death or would have been treated if known. Since mid-2015, codes included specific diagnoses, i.e. undiagnosed or unconfirmed myocardial infarction, infection, pulmonary thromboembolism, malignancy, or other diagnosis as well as cause of death. Adult autopsy cases from 2012 to 2019 were assessed for DE associated with reported sex or race (nonwhite or white). 528 cases were evaluated between 2012 and 2015 and 699 between 2015 and 2019. RESULTS: Major DEs were identified at autopsy in 65.9 % of cases from 2012 to 2015 and in 72.1 % from 2015 to 2019. From 2012 to 2015, female autopsy cases showed a greater frequency in 4 parameters of DE, i.e., in the total number of cases with any error (p=0.0001), in the number of cases with UNDOC errors (p=0.0038) or UNCON errors (p=0.0006), and in the relative proportions of total numbers of errors (p=0.0001). From 2015 to 2019 undocumented malignancy was greater among males (p=0.0065); no other sex-related error was identified. In the same period some DE parameters were greater among nonwhite than among white subjects, including unconfirmed cause of death (p=0.035), and proportion of total error diagnoses (p=0.0003), UNCON diagnoses (p=0.0093), and UNDOC diagnoses (p=0.035). CONCLUSIONS: Coding for DE at autopsy can identify potential effects of biases on diagnostic error.

Small Molecule Inhibitors of Nuclear Export and the Amelioration of Lupus by Modulation of Plasma Cell Generation and Survival.

OBJECTIVE: To investigate the hypothesis that selective inhibitors of nuclear export (SINE compounds), recently approved for treatment of refractory plasma cell (PC) malignancy, may have potential in the treatment of lupus. METHODS: Female NZB/NZW mice were treated with the SINE compound KPT-350 or vehicle control. Tissue specimens were harvested and analyzed by flow cytometry, using standard markers. Nephritis was monitored by determining the proteinuria score and by histologic analysis of kidney specimens. Serum anti-double-stranded DNA (anti-dsDNA) levels were measured by enzyme-linked immunosorbent assay, and total numbers of IgG-secreting and dsDNA-specific antibody-secreting cells were assessed by enzyme-linked immunospot assay. RESULTS: KPT-350 abrogated murine lupus nephritis at both early and late stages of the disease and rapidly impaired generation of autoreactive PCs in germinal centers (GCs). SINE compounds inhibited the production of NF-κB-driven homeostatic chemokines by stromal cells, altering splenic B and T cell strategic positioning and significantly reducing follicular helper T cell, GC B cell, and autoreactive PC counts. KPT-350 also decreased levels of cytokines and chemokines involved in PC survival and recruitment in the kidney of lupus-prone mice. Exportin 1, the target of SINE compounds, was detected in GCs of human tonsils, splenic B cells of lupus patients, and multiple B cell subsets in the kidneys of patients with lupus nephritis. CONCLUSION: Collectively, our results provide support for the therapeutic potential of SINE compounds, via their targeting of several molecular and cellular pathways critical in lupus pathogenesis, including autoantibody production by plasma cells.

The spectrum of macrophage-predominant inflammatory myocardial disease presenting as fulminant heart failure.

BACKGROUND: Endomyocardial biopsy results are integral for diagnosis and management of myocarditis. Current diagnostic classifications of myocarditis are based on the microscopic and immunochemical characterization of inflammation do not include monocyte/macrophage-predominant (i.e. "histiocytic") myocarditis as a histologic subtype. METHODS: Endomyocardial biopsies from 6 patients with sudden heart failure were reviewed by 3 cardiac pathologists. Routine stains and immunostains to identify T cells and monocytes/macrophages, complement C4d, and endothelium were applied. Electron microscopy was performed in 2 cases. RESULTS: The 6 patients included 2 with diagnoses of systemic lupus erythematosus (SLE) and 4 without known disease. Microscopy showed space-occupying inflammation in 2 cases and interstitial inflammation in 4. No giant cell myocarditis or eosinophilic myocarditis was found. Immunostains showed infiltration predominantly by macrophages and/or monocytes with markedly fewer T cells. In 4 of 6 cases necrotic cells were immunopositive for complement C4d. Monocytes we identified immunochemically within the microvasculature in 5 cases and by electron microscopy in 2. Patients with SLE had microvascular C4d positivity or interstitial/sarcolemmal staining. Clinical outcomes ranged from spontaneous resolution to persistent heart failure requiring an internal cardioverter/defibrillator. CONCLUSIONS: (1) Heart failure with CD68 predominant inflammation ("histiocytic" myocardial inflammatory disease, HMID) occurs with variable clinical presentation and outcome; (2) HMID may be primary or secondary; (3) some cases of HMID show features suggestive of antibody and/or complement mediated myocardial injury, and (4) HMID is a diagnosis distinct from those in classification systems currently in use.

Prednisone-induced sustained remission in a patient with familial fibronectin glomerulopathy (GFND).

Glomerulopathy with Fibronectin Deposits (GFND) is a rare, autosomal dominant disease characterized by proteinuria, hematuria and progressive renal failure associated with glomerular deposition of fibronectin, frequently resulting in end-stage renal disease (ESRD). There is no established treatment for this condition beyond conservative measures such as blood pressure control and the use of angiotensin-converting enzyme (ACE) inhibitors. We present a case of GFND associated with progressive chronic kidney disease (CKD) and nephrotic range proteinuria showing a sustained response to prednisone treatment. A 27-year-old G2P2 Caucasian female presented with 3 g/day of proteinuria, serum creatinine (Cr) 0.7 mg/dL, inactive urinary sediment and normotension without medication. She was part of a large family with glomerular disease, including three members who died of cerebral hemorrhage or stroke in their thirties. The patient's kidney biopsy showed mesangial deposition of fibronectin consistent with GFND. No interstitial fibrosis was seen. Genotyping revealed the Y973C FN1 gene mutation. Despite maximal tolerable ACE inhibition, proteinuria increased to 4-6 g/g Cr and serum Cr increased to 1.0 mg/dL. She was treated with prednisone 60 mg (~ 1 mg/Kg) daily for 2 mos and then tapered by ~ 0.2 mg/Kg every month for 6 mos of total therapy. Proteinuria decreased to ~ 1 g/g Cr for > 5 years and serum Cr stabilized in the 1.2 mg/dL range with treatment. No significant side effects were encountered. In conclusion, this protocol should be considered in GFND patients with nephrotic range proteinuria despite maximal angiotensin system inhibition who have relatively preserved renal function.

Potassium conservation is impaired in mice with reduced renal expression of Kir4.1.

To better understand the role of the inward-rectifying K channel Kir4.1 (KCNJ10) in the distal nephron, we initially studied a global Kir4.1 knockout mouse (gKO), which demonstrated the hypokalemia and hypomagnesemia seen in SeSAME/EAST syndrome and was associated with reduced Na/Cl cotransporter (NCC) expression. Lethality by ~3 wk, however, limits the usefulness of this model, so we developed a kidney-specific Kir4.1 "knockdown" mouse (ksKD) using a cadherin 16 promoter and Cre-loxP methodology. These mice appeared normal and survived to adulthood. Kir4.1 protein expression was decreased ~50% vs. wild-type (WT) mice by immunoblotting, and immunofluorescence showed moderately reduced Kir4.1 staining in distal convoluted tubule that was minimal or absent in connecting tubule and cortical collecting duct. Under control conditions, the ksKD mice showed metabolic alkalosis and relative hypercalcemia but were normokalemic and mildly hypermagnesemic despite decreased NCC expression. In addition, the mice had a severe urinary concentrating defect associated with hypernatremia, enlarged kidneys with tubulocystic dilations, and reduced aquaporin-3 expression. On a K/Mg-free diet for 1 wk, however, ksKD mice showed marked hypokalemia (serum K: 1.5 ± 0.1 vs. 3.0 ± 0.1 mEq/l for WT), which was associated with renal K wasting (transtubular K gradient: 11.4 ± 0.8 vs. 1.6 ± 0.4 in WT). Phosphorylated-NCC expression increased in WT but not ksKD mice on the K/Mg-free diet, suggesting that loss of NCC adaptation underlies the hypokalemia. In conclusion, even modest reduction in Kir4.1 expression results in impaired K conservation, which appears to be mediated by reduced expression of activated NCC.

Neutrophils Slow Disease Progression in Murine Lupus via Modulation of Autoreactive Germinal Centers.

Neutrophils are well characterized as mediators of peripheral tissue damage in lupus, but it remains unclear whether they influence loss of self-tolerance in the adaptive immune compartment. Lupus neutrophils produce elevated levels of factors known to fuel autoantibody production, including IL-6 and B cell survival factors, but also reactive oxygen intermediates, which can suppress lymphocyte proliferation. To assess whether neutrophils directly influence the progression of autoreactivity in secondary lymphoid organs (SLOs), we characterized the localization and cell-cell contacts of splenic neutrophils at several stages in the progression of disease in the NZB/W murine model of lupus. Neutrophils accumulate in SLO over the course of lupus progression, preferentially localizing near T lymphocytes early in disease and B cells with advanced disease. RNA sequencing reveals that the splenic neutrophil transcriptional program changes significantly over the course of disease, with neutrophil expression of anti-inflammatory mediators peaking during early-stage and midstage disease, and evidence of neutrophil activation with advanced disease. To assess whether neutrophils exert predominantly protective or deleterious effects on loss of B cell self-tolerance in vivo, we depleted neutrophils at different stages of disease. Neutrophil depletion early in lupus resulted in a striking acceleration in the onset of renal disease, SLO germinal center formation, and autoreactive plasma cell production. In contrast, neutrophil depletion with more advanced disease did not alter systemic lupus erythematosus progression. These results demonstrate a surprising temporal and context-dependent role for neutrophils in restraining autoreactive B cell activation in lupus.

Inhibition of G Protein ßγ Subunit Signaling Abrogates Nephritis in Lupus-Prone Mice.

OBJECTIVE: Despite considerable advances in the understanding of systemic lupus erythematosus (SLE), there is still an urgent need for new and more targeted treatment approaches. We previously demonstrated that small-molecule blockade of G protein ßγ subunit (Gßγ) signaling inhibits acute inflammation through inhibition of chemokine receptor signal transduction. We undertook this study to determine whether inhibition of Gßγ signaling ameliorates disease in a mouse model of SLE. METHODS: Lupus-prone (NZB × NZW)F1 female mice were prophylactically or therapeutically treated with the small-molecule Gßγ inhibitor gallein. Tissue samples were analyzed by flow cytometry and immunohistochemistry. The development and extent of nephritis were assessed by monitoring proteinuria and by immunohistochemical analysis. Serum immunoglobulin levels were measured by enzyme-linked immunosorbent assay, and total IgG and anti-double-stranded DNA (anti-dsDNA) antibody-secreting cells were measured by enzyme-linked immunospot assay. RESULTS: Gallein inhibited accumulation of T cells and germinal center (GC) B cells in the spleen. Both prophylactic and therapeutic treatment reduced GC size, decreased antibody-secreting cell production in the spleen, and markedly decreased accumulation of autoreactive anti-dsDNA antibody-secreting cells in kidneys. Gallein also reduced immune complex deposition in kidneys. Finally, gallein treatment dramatically inhibited kidney inflammation, prevented glomerular damage, and decreased proteinuria. Mechanistically, gallein inhibited immune cell migration and signaling in response to chemokines in vitro, which suggests that its mechanisms of action in vivo are inhibition of migration of immune cells to sites of inflammation and inhibition of immune cell maturation. CONCLUSION: Overall, these data demonstrate the potential use of gallein or novel inhibitors of Gßγ signaling in SLE treatment.

Beneficial effect of novel proteasome inhibitors in murine lupus via dual inhibition of type I interferon and autoantibody-secreting cells.

OBJECTIVE: To investigate the hypothesis that proteasome inhibition may have potential in the treatment of SLE, by targeting plasmacytoid dendritic cells (PDCs) and plasma cells, both of which are critical in disease pathogenesis. METHODS: Lupus-prone mice were treated with the nonselective proteasome inhibitors carfilzomib and bortezomib, the immunoproteasome inhibitor ONX 0914, or vehicle control. Tissue was harvested and analyzed by flow cytometry using standard markers. Nephritis was monitored by evaluation for proteinuria and by histologic analysis of kidneys. Serum anti-double-stranded DNA (anti-dsDNA) levels were measured by enzyme-linked immunosorbent assay (ELISA), and total IgG and dsDNA antibody-secreting cells (ASCs) by enzyme-linked immunospot assay. Human peripheral blood mononuclear cells or mouse bone marrow cells were incubated with Toll-like receptor (TLR) agonists and proteasome inhibitors, and interferon-α (IFNα) levels were measured by ELISA and flow cytometry. RESULTS: Early treatment of lupus-prone mice with the dual-targeting proteasome inhibitors carfilzomib or bortezomib or the immunoproteasome-specific inhibitor ONX 0914 prevented disease progression, and treatment of mice with established disease dramatically abrogated nephritis. Treatment had profound effects on plasma cells, with greater reductions in autoreactive than in total IgG ASCs, an effect that became more pronounced with prolonged treatment and was reflected in decreasing serum autoantibody levels. Notably, proteasome inhibition efficiently suppressed production of IFNα by TLR-activated PDCs in vitro and in vivo, an effect mediated by inhibition of both PDC survival and PDC function. CONCLUSION: Inhibition of the immunoproteasome is equally efficacious as dual targeting agents in preventing lupus disease progression by targeting 2 critical pathways in disease pathogenesis, type I IFN activation and autoantibody production by plasma cells.

Prolonged effects of short-term anti-CD20 B cell depletion therapy in murine systemic lupus erythematosus.

OBJECTIVE: Although B cells are implicated in the pathogenesis of systemic lupus erythematosus, the role of B cell depletion (BCD) as a treatment is controversial, given the variable benefit in human disease. This study was undertaken to test the effects of BCD therapy in a murine lupus model to better understand the mechanisms, heterogeneity, and effects on disease outcomes. METHODS: (NZB x NZW)F(1) female mice with varying degrees of disease severity were treated with an anti-mouse CD20 (anti-mCD20) antibody (IgG2a), BR3-Fc fusion protein (for BAFF blockade), or control anti-human CD20 monoclonal antibody (approximately 10 mg/kg each). Tissue samples were harvested and analyzed by flow cytometry. The development and extent of nephritis were assessed by monitoring proteinuria (using a urine dipstick) and by immunohistochemical analysis of the kidneys. Serum immunoglobulin levels were measured by enzyme-linked immunosorbent assay. RESULTS: After a single injection of anti-mCD20, BCD was more efficient in the peripheral blood, lymph nodes, and spleen compared with the bone marrow and peritoneum of normal mice as well as younger mice with lupus. Since depletion of the marginal zone and peritoneal B cells was incomplete and variable, particularly in older mice with established nephritis, a strategy of sequential weekly dosing was subsequently used, which improved the extent of depletion. BAFF blockade further enhanced depletion in the spleen and lymph nodes. Early BCD therapy delayed disease onset, whereas BCD therapy in mice with advanced disease reduced the progression of nephritis. These effects were long-lasting, even after B cell reconstitution occurred, and were associated with a reduction in T cell activation but no significant change in autoantibody production. CONCLUSION: The lasting benefit of a short course of BCD therapy in lupus-prone mice with an intact immune system and established disease highlights the validity of this treatment approach.

Unusual features of malignant pleural mesothelioma metastatic to the mediastinal lymph nodes.

Malignant pleural mesothelioma (MPM) is a rare cancer that metastasizes to mediastinal lymph nodes (MLNs). The diagnosis of MPM metastatic to MLNs may not be straightforward. We describe 3 cases to highlight unusual entities of MPM metastatic to MLNs as follows. One patient with a history of T3N1M0, poorly differentiated esophageal adenocarcinoma and malignant melanoma presented with shortness of breath, mediastinal lymphadenopathy, and pleural effusion; metastatic disease was clinically suspected. Unexpectedly, immunohistochemical studies supported the diagnosis of MPM metastatic to the MLN on biopsy. In another case, mesothelial cell inclusions were initially diagnosed based on the light microscopy, immunohistochemistry, and lack of pleural thickening on computed tomography studies. Subsequent fine needle aspiration of an enlarged cervical lymph node found an atypical mesothelial proliferation, and metastatic mesothelioma was strongly suspected. Video-assisted thoracoscopic examination showed small visceral nodules, and pleural biopsy was diagnosed as malignant epithelioid mesothelioma. The mediastinal and cervical lymph node biopsies were reinterpreted as positive for MPM. In the last case, MLN biopsy showed a malignant epithelioid cell proliferation. Calretinin, CK5/6, WT-1, D2-40, p63, and CD5 were immunohistochemically detected in the tumor but epithelial markers and TTF-1 were negative. Metastatic mesothelioma was considered based on immunohistochemistry and computerized tomography finding of pleural thickening even though p63 and CD5 positivity were unusual. In summary, MPM may present as mediastinal lymphadenopathy with metastases or it may be a concurrent neoplasm with other malignancies or shows an unusual immunohistochemical staining pattern. Caution should be used when diagnosing mesothelial cell inclusions in MLNs.

Human myocardial cell lines generated with SV40 temperature-sensitive mutant tsA58.

Conditionally transformed human myocardial cell lines would be a valuable resource for studying human cardiac cell biology. We generated clonal human fetal cardiocyte cell lines by transfection of fetal ventricular cardiac cell clones with a plasmid containing a replication-defective mutant of the temperature-sensitive SV40 strain tsA58. Multiple resulting cell lines showed similar features, namely: (1) T antigen (TAg) expression at both permissive (34 degrees C) and restrictive (40.5 degrees C) temperatures; (2) extended growth capacity in comparison with parental wild type, when grown at the permissive temperature; (3) both temperature-dependent and serum-responsive growth, and; (4) an incompletely differentiated fetal phenotype which was similar at both permissive and restrictive temperatures and in the presence and absence of serum. The transformed myocyte phenotype was demonstrated using immunocytochemistry, Western and Northern blotting, and reverse transcription-polymerase chain reaction (RT-PCR). Cell lines expressed skeletal alpha-actin, atrial natriuretic peptide (ANP), and keratins, but no sarcomeric myosin heavy chain or desmin. Immunoreactive sarcomeric actin was expressed predominantly as a truncated protein of approximately 38 kD. The phenotype of the transformed cells differs from that of the wild-type parental cells as well as from those reported by others who have used TAg to immortalize rodent or human ventricular myocytes. Our cell lines should provide a useful tool for study of the molecular mechanisms regulating growth and differentiation in human cardiac muscle cells.

Potential suitability for transplantation of hearts from human non-heart-beating donors: data review from the Gift of Life Donor Program.

BACKGROUND: Organ availability limits use of heart transplantation for treatment for end-stage heart disease. Hearts are currently obtained from donors declared brain dead (heart-beating donors [HBDs]). Although use of hearts from non-heart-beating donors (NHBDs) could reduce the shortage, they are considered unusable because of possible peri-mortem ischemic injury. METHODS: To project how use of NHBD hearts could increase heart donation, we retrospectively reviewed donor databases from the Gift of Life Donor Program (GLDP), our local organ procurement organization, from 2001 through 2003. We screened the NHBD population using conservative donor criteria, assuming an acceptable hypoxic/ischemic time (time from withdrawal of care to cross-clamp) of 30 minutes. RESULTS: During the study period, there were 894 HBDs, 334 heart transplants and 119 NHBDs. NHBDs were similar to HBDs with respect to gender and ethnicity, but NHBDs were proportionately younger. Of 119 NHBDs, 55 did not meet the age criteria (< or =45 years) and 20 were eliminated because of incomplete data. Eighty-two NHBDs were cross-clamped within 30 minutes of care withdrawal. Twenty NHBDs met all cardiac donor criteria, and 14 of these 20 had hypoxic/ischemic times < or =30 minutes. Pro rata estimation for the 20 NHBDs with incomplete data suggested 7 potential additional donors. CONCLUSIONS: Based on our assumptions, 12% to 18% of NHBDs in the study period (14 to 21 of 119 total) were potential heart donors, representing a 4% to 6% increase over of the number of heart transplants performed during the same time interval.

Effects of nutrient and hemoglobin enriched cell free perfusates upon ex vivo isolated rat heart preparation.

We evaluated the effects of nutrient enriched medium and hemoglobin based oxygen carrier (HBOC) upon myocardial functional recovery after 15 minutes of warm ischemia in an isovolumic Langendorff rat heart model. Hearts (n = 8/group) were perfused at constant pressure (90 mm Hg) with Krebs-Henseleit buffer or HEPES modified cell culture medium (M199) in the absence and presence of HBOC. Hearts received 15 minutes of normothermic no flow ischemia followed by 60 minutes reperfusion. Hemodynamics, coronary flow, and tissue water content were measured, and microscopic evidence of injury including TUNEL assay was assessed. Preischemic left ventricular performance (left ventricular developed pressure and maximum rate of positive and negative change in systolic pressure) and coronary flow were similar among groups. At 60 minutes of reperfusion, M199 alone provided more stable and complete left ventricular systolic and diastolic functional recovery than any other perfusate. Coronary flow rates reflected left ventricular function observed under each perfusate condition. TUNEL assay showed arterial endothelial cell death in some hearts perfused with HBOC. Tissue water content did not reflect functional recovery. The combination of M199 and HBOC was associated with poor recovery and elevated perfusate methemoglobin. In this system, postischemic dysfunction is prevented by components in M199. Added HBOC does not improve functional recovery and negates the salutary effects of M199, possibly by augmenting methemoglobin formation.

Regionally heterogeneous tissue mechanics in cardiac amyloidosis.

OBJECTIVE: The goal of this study was to examine in vitro tissue stiffness and contractile performance in myocardial amyloidosis. BACKGROUND: Primary systemic amyloidosis involves the deposition of amyloid protein in mesodermal tissues including the heart. Functional assessment of cardiac amyloidosis is usually performed using echocardiography. However, this technique does not involve assessment of preload-dependent contractile reserve (the Frank-Starling mechanism). METHODS: At the time of heart transplantation, isolated myocardial trabeculae were dissected from the right ventricle of a patient with primary systemic amyloidosis. In vitro length-tension experiments were performed and trabeculae were subsequently fixed, sectioned and stained with crystal violet to determine amyloid deposition. RESULTS: Among the nine trabeculae capable of generating force transients, various combinations of myocardial stiffness and contractile performance were observed including normal stiffness and contractility, severely increased stiffness with impaired contractility and hybrid patterns. Histological analysis demonstrated varying degrees of amyloid deposition among sampled trabeculae. CONCLUSIONS: Our findings extend previous reports of functional heterogeneity among patients by demonstrating functional heterogeneity within a single patient's heart. Our findings also highlight the functional interdependence of passive stiffness and systolic performance in the diseased myocardium and demonstrate the value of dynamic assessments of myocardial performance.

Effect of older donor age on risk for mortality after heart transplantation.

BACKGROUND: Despite the increasingly common use of donor hearts at least 50 years of age, controversy still remains regarding long-term outcome. Our goal was to determine if older donor age is associated with an increased risk of mortality and specifically if the use of donor hearts at least 50 years of age reduces survival. METHODS: We retrospectively studied records of all primary heart transplants performed between January 1990 and July 2002. Fifty-six patients who had received donor hearts at least 50 years of age were compared with 611 recipients of donor hearts less than 50 years of age. Clinicopathologic parameters were analyzed for their effect on mortality using the Cox proportional hazard model with calculation of hazard ratios (HR). Cut-point analysis of donor age was used to determine which donor age is associated with the greatest risk of mortality after transplant. RESULTS: Recipients of donor hearts at least 50 years of age were older (58.5 years +/- 7.0 vs 53.2 +/- 11.6; mean +/- standard deviation [SD]; p < 0.0001), suffered more often from ischemic cardiomyopathy (69% vs 50%, p = 0.01), and experienced a longer waiting time (192.2 days +/- 301.0 vs 138.6 +/- 190.8, p < 0.0001). Donor hearts at least 50 years of age (age 54.1 +/- 3.5 years) were more often female (50% vs 34%, p = 0.03), died less often of "head trauma" (9% vs 42%, p < 0.0001), and exhibited fewer cytomegalovirus (CMV) mismatches (29% vs 39%, p = 0.04) than donor hearts less than 50 years of age (age 26.8 +/- 12.3 years). Multivariate predictors of mortality were rejection index (HR 1.90 per unit [rejections/100 survival days], p < 0.0001), donor age (HR 1.16 per 10-year increment, p = 0.002), and recipient age (HR 1.24 per 10-year increment, p = 0.04). Recipients of donor hearts at least 50 years of age had reduced 1-year and 5-year survival ([65.7% vs 81.7%, p < 0.05] and [48.3% vs 68.4%, p < 0.05], respectively), as well as a higher proportion of deaths occurring within 1 month of transplant (41% of total deaths vs 23%, p = 0.06). Cut-point analysis indicated the characteristic of donor age of at least 40 years (categorical variable) to predict mortality with the same degree of fit as age used as a continuous variable. CONCLUSIONS: Although we observed a substantial reduction in survival among patients who were allocated donor hearts at least 50 years of age, this difference was not solely attributable to the categorical variable of donor age 50 in this group. Donor age as a continuous variable, however, was determined to be a notable predictor of survival and use of the donor age cut-point of 40 years (categorical variable) allowed risk stratification with similar accuracy. The use of a donor age cut-point of 40 years may be a useful clinical criterion for graft-related risk assessment.

Identical alpha-chain T-cell receptor transcripts are present on T cells infiltrating coronary arteries of human cardiac allografts with chronic rejection.

Chronic cardiac allograft rejection is characterized by graft arteriopathy and is a major obstacle of graft survival. We investigated T-cell receptor (TCR) alpha-chain transcripts of T cells infiltrating human epicardial coronary arteries from cardiac allografts with chronic rejection. The non-palindromic adaptor-polymerase chain reaction (NPA-PCR) was used to specifically amplify TCR alpha-chain transcripts from five explanted cardiac allografts with chronic rejection. The amplified products were cloned and sequenced to obtain the entire ValphaJalpha region. Immuno-histochemistry was used to identify the mononuclear cell infiltrates in the coronary arteries. All the five coronary artery specimens exhibited large populations of infiltrating mononuclear cells, which were primarily comprised of T cells and macrophages. In three specimens, high proportions ( approximately 80%) of identical alpha-chain TCR transcripts were detected. In peripheral blood mononuclear cells from a healthy individual, alpha-chain TCR transcripts were unique when compared to each other. Endomyocardial biopsies collected from one patient six months before the allograft was explanted, contained identical alpha-chain TCR transcripts to those found to be clonally expanded in the coronary arteries from this patient. These results indicate that T cells infiltrating the epicardial arteries of cardiac allografts with chronic rejection undergo proliferation and clonal expansion in response to a specific antigen, which very likely is an (allo)antigen(s).