Owing to the need of lifelong immunosuppression, solid-organ transplant recipients are known to have an increased risk of posttransplant malignancies including lung cancer. Posttransplant neoplastic transformation of donor-derived cells giving rise to hematopoietic malignancies, Kaposi sarcoma, and basal cell carcinoma in nongraft tissues has been reported. The goal of this study was to assess the cell origin (donor versus recipient derived) of posttransplant non–small cell lung carcinomas (NSCLCs) in kidney and heart transplant recipients. An institutional database search identified 2557 kidney and heart transplant recipients in 8 consecutive years. Among this cohort, 20 (0.8%) renal and 18 (0.7%) heart transplant recipients developed NSCLC. The study cohort comprised 6 of 38 NSCLCs arising in donor-recipient sex-mismatched transplant patients. The tumor cell origin was evaluated by chromogenic in situ hybridization with Y-chromosome probe on formalin-fixed, paraffin-embedded tissues. Y-chromosome was identified in 97% ± 1% (range from 92% to 99%) of all types of nucleated cells in male control tissues. In all 5 NSCLCs from male recipients of female donor organ, Y-chromosome was identified in 97% ± 2% (range from 92% to 100%) of tumor cells, statistically equivalent to normal control (P < .001). No Y-chromosome was identified in NSCLC cells from a female recipient of male kidney. These findings suggest a recipient derivation of NSCLC arising in kidney and heart transplant recipients. A combination of histologic evaluation and chromogenic in situ hybridization with Y-chromosome analysis allows reliable determination of tissue origin in sex-mismatched solid-organ transplant recipients and may aid in management of posttransplant malignancy in such cases.
Post–solid-organ transplantation lung cancer; Chromogenic in situ hybridization for Y-chromosome
Glomerular disease is a complex and evolving topic. In evaluating a specific case it is not unusual for the clinician to ask: Am I missing something? Should I biopsy? When? Should I treat first, then biopsy? This work, which is both evidence based and experience based, is intended to address each of these concerns, and many other issues relevant to the differential diagnosis of glomerular disease.
The central approach is the use of diagnostic algorithms that are based on quantitative measures routinely obtained early in the course of the diagnostic evaluation. The algorithms are designed to be easy to navigate, systematic, and inclusive. Also provided is a detailed and prioritized list of recommended diagnostic testing, and the rationale for each test.
This work is intended to facilitate accurate diagnosis in the individual patient presenting with evidence of glomerular disease.
glomerular disease; proteinuria; glomerulonephritis
Spironolactone is often used to treat hypertension caused by hyperaldosteronism, and as a result, can form concentrically laminated electron dense spironolactone body inclusions within the adrenal gland. Spironolactone bodies have not been investigated in a contemporary cohort or in patients treated with the more recently approved aldosterone antagonist, eplerenone.
Spironolactone bodies were retrospectively investigated in patients treated for hyperaldosteronism (n = 15) from 2012-2013 that underwent a subsequent adrenalectomy.
Inclusions were identified in 33% of patients treated with aldosterone antagonists, far less than previously reported. Remarkably, 50% of patients treated with spironolactone had inclusions while no patients using eplerenone alone had inclusions. Two patients treated with spironolactone had bodies present longer than the duration described in prior studies. Inclusions unexpectedly persisted in 1 patient despite increased duration of discontinued pharmacological treatment. A spectrum of histologic and ultrastructural findings were encountered within an adrenal cortical adenoma from a patient treated with both spironolactone and eplerenone. Ultrastructural examination revealed laminated electron dense bodies with the appearance of classic spironolactone inclusions as well as electron dense bodies without laminations and laminated bodies without electron dense cores.
Our incidence rate of spironolactone bodies was much lower than previously reported, with no inclusions seen in patients treated solely with the newer aldosterone antagonist, eplerenone. Pathologists should be aware of these infrequently encountered inclusions, particularly as the clinical history of hyperaldosteronism and pharmacologic treatment may not be provided.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4597918761268031
Adrenal; Spironolactone; Eplerenone; Ultrastructural; Inclusions
Acute pyelonephritis (APN) versus acute rejection (AR) is a frequently encountered diagnostic and therapeutic dilemma in kidney transplants. Variable culture results, overlapping histologic features, and persistent graft dysfunction despite antibiotics are frequently encountered. Therefore, we explored the utility of intragraft microRNA profiles to distinguish between allograft APN and AR.
Materials and Methods
Between 2003 and 2011, we identified 49 patients with biopsy features of APN, within the first 2 years posttransplant. MicroRNA profiling was performed on 20 biopsies (normal kidney, n=4; unequivocal AR, n=5; features of APN, n=11).
Only 32% (16/49) of the patients had concomitant positive urine cultures at biopsy, and in 8 of 16 patients, colony count was less than 105 CFU/mL. In 14 of 49 patients, positive urine culture did not coincide with the biopsy, and in 19 of 49 patients, urine cultures were negative. On microRNA profiling, good clustering was seen among the normal kidneys and among AR biopsies. Among the 11 biopsies with features of APN, 4 biopsies showed good clustering with a pattern distinct from AR; (these patients recovered graft function with antibiotics); 7 of 11 biopsies showed heterogeneity in microRNA profiles and variable outcomes with antibiotic treatment. We identified a panel of 25 microRNAs showing statistical difference in expression between AR and APN. MiR-99b, miR-23b let-7b-5p, miR-30a, and miR-145 were validated using qPCR.
Allograft pyelonephritis can be a diagnostic and therapeutic challenge. A gestalt approach is required. In addition to histology and cultures, differential intragraft microRNA expression may prove helpful to distinguish APN from AR in renal allograft biopsies.
Acute pyelonephritis; Acute rejection; microRNA; Renal allograft biopsy; NanoString
Familial Amyloidosis of Finnish type (FAF) is a rare type of autosomal dominant hereditary amyloidosis associated with genetic variants of gelsolin. Three amyloidogenic mutations have previously been reported characteristically presenting with ophthalmologic abnormalities, progressive cranial neuropathy and cutis laxa. We report a novel gelsolin variant in a 62 year old man with nephrotic range proteinuria of 13.2 grams/day as the only presenting symptom. Renal biopsy followed by laser microdissection and mass spectrometry showed amyloidosis derived from gelsolin. DNA sequencing revealed the novel gelsolin mutation (c.633C>A) encoding p.N211K protein variant. Four of 13 asymptomatic family members were found to be heterozygous for the p.N211K mutation, three of whom had proteinuria of varying degree including one who proceeded to renal biopsy and was confirmed to have renal amyloidosis. Follow up of these cases might give us more insight into pathogenicity and potential treatment strategy of this atypical presentation of gelsolin amyloidosis.
Amyloidosis; Gelsolin; Proteinuria
Although systemic amyloidosis commonly presents with renal disease, cardiac involvement usually determines the patient's prognosis. Cardiac involvement is seen in AL and transthyretin amyloidosis. Distinguishing between these is critical because prognosis and treatment differ. Our study demonstrates the unreliability of transthyretin immunostaining in subtyping cardiac amyloid. Between January 2003 and August 2010, we retrieved 229 native endomyocardial biopsies, 24 had amyloid. Immunohistochemistry for kappa, lambda, transthyretin and serum amyloid A protein were performed on formalin fixed paraffin-embedded sections. Staining was graded as weak (trace to 1+); or strong (2 to 3+). Mass spectrometry (MS) based proteomic typing of microdissected amyloid material was performed on selected cases. Fifteen of the patients had monoclonal gammopathy/plasma cell dyscrasia with cardiac amyloid. Eight of them (53%) showed strong transthyretin staining in the cardiac amyloid deposits. MS was performed in five out of these eight biopsies, and all five revealed AL type amyloid. Two of these five AL amyloid biopsies did not even have concomitant strong staining for the appropriate light chain. Among the 15 cases with plasma cell dyscrasia, only seven biopsies showed strong staining for the corresponding monoclonal light chain.
Strong false positive immunostaining for transthyretin in cardiac amyloid is a potential pitfall, augmented by the frequent lack of staining for immunoglobulin light chains. Therefore, the presence of amyloid in the cardiac biopsy should prompt a search for plasma cell dyscrasia irrespective of transthyretin staining. Confirmation with MS should be sought particularly if there is any discrepancy between kappa/lambda staining and serum immunofixation results.
cardiac amyloid; transthyretin; immunohistochemistry
An acute increase in the international normalized ratio (INR; a comparison of prothrombin time to monitor the effects of warfarin) over 3 in patients with chronic kidney disease (CKD) is often associated with an unexplained acute increase in serum creatinine (SC) and an accelerated progression of CKD. Kidney biopsy in a subset of these patients showed obstruction of the renal tubule by red blood cell casts, and this appears to be the dominant mechanism of the acute kidney injury. We termed this warfarin-related nephropathy (WRN), and previously reported cases of WRN only in patients with CKD. We now assess whether this occurs in patients without CKD, its risk factors, and consequences. In 15,258 patients who initiated warfarin therapy during a 5-year period, 4006 had an INR over 3 and SC measured at the same time; however, the large data set precluded individual patient clinical assessment. A presumptive diagnosis of WRN was made if the SC increased by over 0.3 mg/dl within 1 week after the INR exceeded 3 with no record of hemorrhage. WRN occurred in 20.5% of the entire cohort, 33.0% of the CKD cohort, and 16.5% of the no-CKD cohort. Other risk factors included age, diabetes mellitus, hypertension, and cardiovascular disease. The 1-year mortality was 31.1% with compared with 18.9% without WRN, an increased risk of 65%. Thus, WRN may be a common complication of warfarin therapy in high-risk patients and CKD doubles this risk. The mechanisms of these risks are unclear.
acute kidney injury; mortality; warfarin
Background: Relapse or worsening of nephrotic syndrome (NS) in idiopathic membranous nephropathy (IMN) is generally assumed to be due to recurrent disease. Here we document that often that may not be the case. Subjects and Methods: This is a prospective study of 7 consecutive IMN patients whose renal status improved, then worsened after completing a course of immunosuppressive therapy. Each underwent detailed testing and repeat kidney biopsy. Results: In 4 patients (group A), the biopsy showed recurrent IMN (fresh subepithelial deposits). Immunosuppressive therapy was begun. In the other 3 patients (group B), the biopsy showed that the deposits had been eradicated. However, the glomerular basement membrane (GBM) was thickened and vacuolated. Immunosuppressive therapy was withheld. Groups A and B were comparable except that group B had very high intakes of salt and protein, based on 24-hour urine testing. Reducing their high salt intake sharply lowered proteinuria to the subnephrotic range and serum creatinine stabilized. Conclusion: This work is the first to demonstrate that relapse/worsening of NS can occur in IMN even though the GBM deposits have been eradicated. High salt and protein intake in combination with thickened and vacuolated GBM appears to be the mechanism.
Relapse of membranous nephropathy; Salt intake; Eradication of GBM deposits
After the introduction of novel effective immunosuppressive therapies, kidney transplantation became the treatment of choice for end stage renal disease. While these new therapies lead to better graft survival, they can also cause a variety of complications. Only small series or case reports describe pulmonary pathology in renal allograft recipients on mTOR inhibitor inclusive therapies. The goal of this study was to provide a systematic review of thoracic biopsies in kidney transplant recipients for possible association between a type of immunosuppressive regimen and pulmonary complications.
A laboratory database search revealed 28 of 2140 renal allograft recipients (18 males and 10 females, 25 to 77 years old, mean age 53 years) who required a biopsy for respiratory symptoms. The histological features were correlated with clinical findings including immunosuppressive medications.
The incidence of neoplasia on lung biopsy was 0.4% (9 cases), which included 3 squamous cell carcinomas, 2 adenocarcinomas, 1 diffuse large B-cell lymphoma, 1 lymphomatoid granulomatosis, and 2 post transplant B-cell lymphoproliferative disorders. Diffuse parenchymal lung disease was identified in 0.4% (9 cases), and included 5 cases of pulmonary hemorrhage, 3 cases of organizing pneumonia and 1 case of pulmonary alveolar proteinosis. Five (0.2%) cases showed histological features indicative of a localized infectious process. Patients on sirolimus had neoplasia less frequently than patients on other immunosuppressive combinations (12.5% vs. 58.3%, p = 0.03). Lung biopsies in 4 of 5 patients with clinically suspected sirolimus toxicity revealed pulmonary hemorrhage as the sole histological finding or in combination with other patterns.
Our study documents a spectrum of neoplastic and non-neoplastic lesions in renal allograft recipients on current immunosuppressive therapies. Sirolimus inclusive regimens are associated with increased risk of pulmonary toxicity but may be beneficial in cases of posttransplant neoplasia.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3320012126569395.
Kidney transplantation; Pulmonary neoplasia; Pulmonary hemorrhage; Mammalian target of rapamycin (mTOR) inhibitors; Sirolimus
Sarcoidosis is an idiopathic multisystem disease characterized by noncaseating granulomatous inflammation. Renal biopsy is often performed to evaluate the patient with sarcoidosis and acute kidney injury (AKI). Diagnosis rests on the demonstration of noncaseating granulomas and exclusion of other causes of granulomatous inflammation. This paper reports a patient with pulmonary sarcoidosis and AKI whose renal function improved after prednisone therapy despite the absence of kidney biopsy findings characteristic of sarcoidosis.
A 63-year-old Caucasian male with history of hypertension was treated for pulmonary sarcoidosis with a 6-month course of prednisone. His creatinine was 1.6 mg/dL during the course. Two months after finishing treatment, he presented with creatinine of 4 mg/dL. A kidney biopsy was performed, which showed nonspecific changes without evidence of granuloma or active interstitial inflammation. He was empirically started on prednisone for presumed renal sarcoidosis, even with a nondiagnostic kidney biopsy finding. Within a month of treatment, his serum creatinine improved to 2 mg/dL, though not to baseline. He continues to be stable on low-dose prednisone. With this case as a background, we aimed to determine the incidence of inconclusive kidney biopsies in patients with sarcoidosis presenting with AKI and to identify the various histological findings seen in this group of patients.
In this retrospective study, all patients who had native renal biopsies read at The Ohio State University over the period of 6 years were identified. Those patients with a diagnosis of sarcoidosis, presenting with AKI, were included for further review.
Out of 21 kidney biopsies done in patients with sarcoidosis over a period of 6 years, only four (19%) showed granulomatous interstitial nephritis (GIN). An equal number of patients (4 [19%]) had presence of membranous nephropathy. Nephrocalcinosis was seen in three patients (14%). Almost half of the biopsies had findings suggestive of diabetic nephropathy or other nonspecific changes not characteristic of renal sarcoidosis (48%).
Renal sarcoidosis can be focal in nature and characteristic lesions can be missed in a small-needle core biopsy. Inconclusive renal biopsies with only nonspecific findings are frequent in patients with sarcoidosis and AKI. The presence of GIN on renal biopsy, although classic, is uncommon. Renal sarcoidosis remains a presumptive clinical diagnosis and empiric treatment with steroids may be initiated in cases with a strong clinical suspicion even in the absence of characteristic renal biopsy findings.
sarcoidosis; renal sarcoidosis; kidney biopsy; granulomatous interstitial nephritis; acute kidney injury
We had previously reported that acute kidney injury (AKI) in warfarin-treated chronic kidney disease (CKD) patients may occur shortly after an acute increase in the International Normalization Ratio (INR) >3.0 with formation of occlusive red blood casts. Recovery from this warfarin-associated AKI is poor. Here we investigated whether excessive warfarin therapy could accelerate the progression of CKD.
We analyzed serum creatinine (SC) and INR in 103 consecutive CKD patients on warfarin therapy in our Nephrology program from 2005 to the present.
Forty-nine patients experienced at least 1 episode of INR >3.0. Of these, 18 patients (37%, Group 1) developed an unexplained increase in SC ≥0.3 mg/dl coincident with INR >3.0 (mean SC increase 0.61 ± 0.44 mg/dl); 31 patients (63%, Group 2) showed stable SC (mean SC change 0.04 ± 0.19 mg/dl). Subsequent CKD progression was accelerated in Group 1, but not in Group 2. The 2 groups were not different with respect to demographics, comorbidities, blood pressure, or therapies. However, African Americans were overrepresented in Group 1 (p = 0.035).
Overanticoagulation is associated with faster progression of CKD in a high percentage of patients. Our results indicate the need for prospective trials. Nevertheless, we suggest that our findings are sufficiently compelling at this point to justi- fy extra caution in warfarin-treated CKD patients to avoid overanticoagulation.
Warfarin; Serum creatinine; Acute kidney injury; Chronic kidney disease
Despite the recognition that humoral rejection is an important cause of allograft injury, the mechanism of antibody-mediated injury to allograft parenchyma is not well understood. We used a well-characterized murine hepatocellular allograft model to determine the mechanism of antibody-mediated destruction of transplanted liver parenchymal cells. In this model allogeneic hepatocytes are transplanted into CD8-deficient hosts in order to focus on CD4-dependent, alloantibody-mediated rejection. Host serum alloantibody levels correlated with in vivo allospecific cytotoxic activity in CD8 KO hepatocyte rejector mice. Host macrophage depletion, but not CD4+ T cell, NK cell, neutrophil, or complement depletion, inhibited in vivo allocytotoxicity. Recipient macrophage deficiency delayed CD4-dependent hepatocyte rejection and inhibited in vivo allocytotoxicity without influencing alloantibody production. Furthermore, hepatocyte coincubation with alloantibody and macrophages resulted in antibody-dependent hepatocellular cytotoxicity in vitro. These studies are consistent with a paradigm of acute humoral rejection in which CD4+ T cell-dependent alloantibody production results in the targeting of transplanted allogeneic parenchymal cells for macrophage-mediated cytotoxic immune damage. Consequently, strategies to eliminate recipient macrophages during CD4-dependent rejection pathway may prolong allograft survival.
macrophages; alloantibody; hepatocytes; antibody-mediated cellular cytotoxicity; transplantation
Cytomegalovirus (CMV) reactivation is a well described complication of solid organ transplantation. These studies were performed to 1.) determine if cardiac allograft transplantation of latently infected recipients results in reactivation of CMV, and 2.) determine what impact CMV might have on development of graft acceptance/tolerance. BALB/c cardiac allografts were transplanted into C57BL/6 mice with/without latent murine CMV (MCMV). Recipients were treated with gallium nitrate induction and monitored for graft survival, viral immunity, and donor reactive DTH responses. Latently infected allograft recipients had ∼80% graft loss by 100 days after transplant, compared with ∼8% graft loss in naïve recipients. PCR evaluation demonstrated that MCMV was transmitted to cardiac grafts in all latently infected recipients, and 4/8 allografts had active viral transcription compared to 0/6 isografts. Latently infected allograft recipients showed intragraft IFN-α expression consistent with MCMV reactivation, but MCMV did not appear to negatively influence regulatory gene expression. Infected allograft recipients had disruption of splenocyte DTH regulation, but recipient splenocytes remained unresponsive to donor antigen even after allograft losses. These data suggest that transplantation in an environment of latent CMV infection may reactivate virus, and that intragraft responses disrupt development of allograft acceptance.
Lupus nephritis is a frequent and serious complication of systemic lupus erythematosus (SLE). Treatment often requires the use of immunosuppression, and may be associated with severe side effects. The ability to predict relapse, relapse severity, and recovery could be used to more effectively implement therapy and reduce toxicity. We postulated that a proteomic analysis of the low-molecular weight urine proteome using serial urine samples obtained before, during, and after SLE nephritis flares would demonstrate potential biomarkers of SLE renal flare. This study was undertaken to test our hypothesis.
Urine from 25 flare cycles of 19 WHO Class III, IV, and V SLE nephritis patients was used. Urine samples included a baseline, and pre-flare, flare, and post-flare specimens. The urines were fractionated to remove proteins larger than 30 kDa, and spotted onto weak cation exchanger (CM10) protein chips for analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS).
SELDI-TOF MS screening showed 176 protein ions between 2-20 kDa of which 27 were found to be differentially-expressed between specific flare intervals. On-chip peptide sequencing by integrated tandem mass spectrometry was used to positively identify selected differentially-expressed protein ions. The identified proteins included the 20 and 25 amino acid isoforms of hepcidin, a fragment of α1-antitrypsin, and an albumin fragment. Hepcidin 20 increased 4 months pre-flare and returned to baseline at renal flare, whereas hepcidin 25 decreased at renal flare and returned to baseline 4 months post-flare.
Using SELDI-TOF urine protein profiling in lupus nephritis, several candidate biomarkers of renal flare were found. To verify these candidates as true biomarkers, further identification and validation are needed in an independent SLE cohort.
lupus nephritis; biomarker; SELDI
MHC mismatched DBA/2 renal allografts are spontaneously accepted by C57BL/6 mice by poorly understood mechanisms, but both immune regulation and graft acceptance develop without exogenous immune modulation. Previous studies have shown that this model of spontaneous renal allograft acceptance is associated with TGF-β dependent immune regulation, suggesting a role for T-regulatory (Treg) cells. The current study shows that TGF-β immune regulation develops 30 days post-transplant, but is lost by 150 days post-transplant. Despite loss of detectable TGF-β immune regulation, renal allografts continue to function normally for >200 days post-transplantation. Because of its recently described immunoregulatory capabilities, we studied indoleamine 2,3-dioxygenase (IDO) expression in this model, and found that intragraft IDO gene expression progressively increases over time, and that IDO in “regulatory” dendritic cells (RDC) may contribute to regulation associated with long-term maintenance of renal allografts. Immunohistochemistry evaluation confirms presence of both Foxp3+ T-cells and IDO+ DCs in accepted renal allografts, and localization of both cell types within accepted allografts suggests the possibility of synergistic involvement in allograft acceptance. Interestingly, at the time when RDCs become detectable in spleens of allograft acceptors, ~30% of these mice challenged with donor-matched skin allografts accept these skin grafts, demonstrating progression to “true” tolerance. Together, these data suggest that spontaneous renal allograft acceptance evolves through a series of transient mechanisms, beginning with TGF-β and Treg cells, which together may stimulate development of more robust regulation associated with RDC and IDO.