High risk clear cell renal cell carcinoma microenvironments contain protumour immunophenotypes lacking specific immune checkpoints.

Perioperative immune checkpoint inhibitor (ICI) trials for intermediate high-risk clear cell renal cell carcinoma (ccRCC) have failed to consistently demonstrate improved patient outcomes. These unsuccessful ICI trials suggest that the tumour infiltrating immunophenotypes, termed here as the immune cell types, states and their spatial location within the tumour microenvironment (TME), were unfavourable for ICI treatment. Defining the tumour infiltrating immune cells may assist with the identification of predictive immunophenotypes within the TME that are favourable for ICI treatment. To define the immunophenotypes within the ccRCC TME, fresh para-tumour (pTME, n = 2), low-grade (LG, n = 4, G1-G2) and high-grade (HG, n = 4, G3-G4) tissue samples from six patients with ccRCC presenting at a tertiary referral hospital underwent spatial transcriptomics sequencing (ST-seq). Within the generated ST-seq datasets, immune cell types and states, termed here as exhausted/pro-tumour state or non-exhausted/anti-tumour state, were identified using multiple publicly available single-cell RNA and T-cell receptor sequencing datasets as references. HG TMEs revealed abundant exhausted/pro-tumour immune cells with no consistent increase in expression of PD-1, PD-L1 and CTLA4 checkpoints and angiogenic genes. Additional HG TME immunophenotype characteristics included: pro-tumour tissue-resident monocytes with consistently increased expression of HAVCR2 and LAG3 checkpoints; an exhausted CD8+ T cells sub-population with stem-like progenitor gene expression; and pro-tumour tumour-associated macrophages and monocytes within the recurrent TME with the expression of TREM2. Whilst limited by a modest sample size, this study represents the largest ST-seq dataset on human ccRCC. Our study reveals that high-risk ccRCC TMEs are infiltrated by exhausted/pro-tumour immunophenotypes lacking specific checkpoint gene expression confirming that HG ccRCC TME are immunogenic but not ICI favourable.

Spatially Resolved Transcriptomes of Mammalian Kidneys Illustrate the Molecular Complexity and Interactions of Functional Nephron Segments.

Available transcriptomes of the mammalian kidney provide limited information on the spatial interplay between different functional nephron structures due to the required dissociation of tissue with traditional transcriptome-based methodologies. A deeper understanding of the complexity of functional nephron structures requires a non-dissociative transcriptomics approach, such as spatial transcriptomics sequencing (ST-seq). We hypothesize that the application of ST-seq in normal mammalian kidneys will give transcriptomic insights within and across species of physiology at the functional structure level and cellular communication at the cell level. Here, we applied ST-seq in six mice and four human kidneys that were histologically absent of any overt pathology. We defined the location of specific nephron structures in the captured ST-seq datasets using three lines of evidence: pathologist's annotation, marker gene expression, and integration with public single-cell and/or single-nucleus RNA-sequencing datasets. We compared the mouse and human cortical kidney regions. In the human ST-seq datasets, we further investigated the cellular communication within glomeruli and regions of proximal tubules-peritubular capillaries by screening for co-expression of ligand-receptor gene pairs. Gene expression signatures of distinct nephron structures and microvascular regions were spatially resolved within the mouse and human ST-seq datasets. We identified 7,370 differentially expressed genes (p adj < 0.05) distinguishing species, suggesting changes in energy production and metabolism in mouse cortical regions relative to human kidneys. Hundreds of potential ligand-receptor interactions were identified within glomeruli and regions of proximal tubules-peritubular capillaries, including known and novel interactions relevant to kidney physiology. Our application of ST-seq to normal human and murine kidneys confirms current knowledge and localization of transcripts within the kidney. Furthermore, the generated ST-seq datasets provide a valuable resource for the kidney community that can be used to inform future research into this complex organ.

Adipocyte Atrophy Mimicking Signet Ring Cell Carcinoma of the Gallbladder.

Signet ring cell morphology may result from a variety of causes and ranges from a benign reactive phenomenon to being indicative of highly aggressive malignancy. Benign epithelial signet ring cell change is well described in a variety of tissues, but nonepithelial signet ring cell change is a rare morphologic adaptation of adipose tissue principally described in the setting of cachexia. The location of these atrophic adipocytes outside the plane of normal epithelial layers may raise concern for invasive or metastatic malignancy, and consideration of a benign reactive process is critical to avoid catastrophic overdiagnosis and overtreatment. Further, this change is itself associated with significant mortality related to the underlying cachexia and may be important to highlight to treating clinicians. Compared to malignant signet ring cell carcinoma, benign signet ring cell change is more likely to retain normal lobulated architecture without mass formation, lack significant atypia, have myxoid stroma with a prominent capillary network, and show positive staining S100 protein with negative staining for cytokeratins and mucin. To our knowledge, we present the first described case of nonepithelial signet ring cell change involving the gallbladder, detected as an incidental finding following routine cholecystectomy in an elderly cachectic man.

Is sclerotherapy with polidocanol a better treatment option for aneurysmal bone cyst compared to conventional curettage and bone grafting?

BACKGROUND: The standard treatment of Aneurysmal bone cyst is curettage and grafting and is associated with high morbidity. Hence minimal invasive alternative treatment methods such as sclerotherapy are gaining much popularity. Though sclerotherapy has been attributed to reasonable cure rates, undetermined tissue diagnosis often impedes with initiation of treatment. This study examines if sclerotherapy with polidocanol based on clinic-radiological picture is comparable with the standard intralesional curettage and bone grafting. Attempting biopsy and treatment simultaneously based on the clinico-radiological presentation makes this study unique. METHODS: We divided 48 patients into two treatment groups. Group 1 treated with percutaneous sclerotherapy using polidocanol and group 2 those treated with extended curettage and bone grafting. We assessed time to healing and recurrence, pain relief, and radiological outcome using modified Neer's criteria for the radiological healing of the bone cysts. 31 patients from Group 1 and 17 from Group 2 were available for study. The minimum follow-up was 2 years. RESULTS: At last follow-up, 100% in Group 1 and 82% in Group 2 had achieved complete healing and there was no statistical difference in outcome at 24 months (p = 0.255). Complications in Group 1 were injection site necrosis, pain and hypopigmentation, all of which resolved spontaneously. In Group 2, three patients had recurrence. Despite similar healing rates, we found higher incidence of clinically pertinent complications, poor functional outcomes and increased cost of treatment associated with intralesional excision.Three cases were excluded from sclerotherapy group as the final diagnosis turned up to be secondary ABC. CONCLUSIONS: Percutaneous sclerotherapy using polidocanol is a highly effective, cost efficient and safe treatment option with good cosmesis and reduced morbidity. In this study, we found comparable outcomes for both treatment methods however this will require confirmation in larger studies.

Oxidative stress and inflammasome activation in human rhabdomyolysis-induced acute kidney injury.

Acute kidney injury (AKI) is a life-threatening complication of rhabdomyolysis. The pathophysiological mechanisms of rhabdomyolysis-induced AKI (RIAKI) have been extensively studied in the murine system, yet clinical translation of this knowledge to humans is lacking. In this study, we investigated the cellular and molecular pathways of human RIAKI. Renal biopsy tissue from a RIAKI patient was examined by quantitative immunohistochemistry (Q-IHC) and compared to healthy kidney cortical tissue. We identified myoglobin casts and uric acid localised to sites of histological tubular injury, consistent with the diagnosis of RIAKI. These pathological features were associated with tubular oxidative stress (4-hydroxynonenal staining), regulated necrosis/necroptosis (phosphorylated mixed-lineage kinase domain-like protein staining) and inflammation (tumour necrosis factor (TNF)-α staining). Expression of these markers was significantly elevated in the RIAKI tissue compared to the healthy control. A tubulointerstitial inflammatory infiltrate accumulated adjacent to these sites of RIAKI oxidative injury, consisting of macrophages (CD68), dendritic cells (CD1c) and T lymphocytes (CD3). Foci of inflammasome activation were co-localised with these immune cell infiltrate, with significantly increased staining for adaptor protein ASC (apoptosis-associated speck-like protein containing a caspase activation and recruitment domain) and active caspase-1 in the RIAKI tissue compared to the healthy control. Our clinical findings identify multiple pathophysiological pathways previously only reported in murine RIAKI, providing first evidence in humans linking deposition of myoglobin and presence of uric acid to tubular oxidative stress/necroptosis, inflammasome activation and necroinflammation.

Protocol and establishment of a Queensland renal biopsy registry in Australia.

BACKGROUND: Renal biopsy is often required to obtain information for diagnosis, management and prognosis of kidney disease that can be broadly classified into acute kidney injury (AKI) and chronic kidney disease (CKD). The most common conditions identified on renal biopsy are glomerulonephritis and tubulo-interstitial disorders. There is a paucity of information on management strategies and therapeutic outcomes in AKI and CKD patients. A renal biopsy registry will provide information on biopsy-proven kidney disorders to improve disease understanding and tracking, healthcare planning, patient care and outcomes. METHODS: A registry of patients, that includes biopsy-proven kidney disease, was established through the collaboration of nephrologists from Queensland Hospital and Health Services and pathologists from Pathology Queensland services. The registry is in keeping with directions of the Advancing Kidney Care 2026 Collaborative, established in September 2018 as a Queensland Health initiative. Phase 1 of the registry entailed retrospective acquisition of data from all adult native kidney biopsies performed in Queensland, Australia, from 2002 to 2018. Data were also linked with the existing CKD.QLD patient registry. From 2019 onwards, phase 2 of the registry involves prospective collection of all incident consenting patients referred to Queensland public hospitals and having a renal biopsy. Annual reports on patient outcomes will be generated and disseminated. DISCUSSION: Establishment of the Queensland Renal Biopsy Registry (QRBR) aims to provide a profile of patients with biopsy-proven kidney disease that will lead to better understanding of clinico-pathological association and facilitate future research. It is expected to improve patient care and outcomes.

T-cell adoptive immunotherapy for BK nephropathy in renal transplantation.

INTRODUCTION: BK virus (BKPyV) nephropathy occurs in 1%-10% of kidney transplant recipients, with suboptimal therapeutic options. CASE: A 54-year-old woman received a transplant in March 2017. BKPyV was detected at 1.5 × 102  copies/mL within a month, necessitating halving of mycophenolate and addition of leflunomide. Allograft histology in December showed polyomavirus nephropathy treated with intravenous immunoglobulin and cessation of mycophenolate. In February 2018, cidofovir and ciprofloxacin were commenced. In April, tacrolimus was reduced while introducing everolimus. A second graft biopsy in August showed increasing polyoma virus infection and a subsequent biopsy in September for worsening renal function showed 30% of tubular reactivity for simian virus 40 (SV40). Allogeneic BKPyV-reactive T cells were generated from the patient's daughter and infused over 10 sessions starting late September. The fourth allograft biopsy in November 2018 demonstrated involvement of BKPyV in 50% of tubules. Allograft function continued to decline, requiring hemodialysis from December 2018. Allograft nephrectomy after 6 months showed <1% SV40 in preserved tubules and 80% interstitial fibrosis. DISCUSSION: We conclude that the T-cell adoptive immunotherapy reduced BKPyV load significantly despite extensive infection, but attendant fibrosis and tubular atrophy led to graft failure. Early intervention with T-cell therapy may prove efficacious in BKPyV nephropathy.

Role of inflammation and inflammasome activation in human bile cast nephropathy.

Bile cast nephropathy (BCN) is an underdiagnosed cause of acute kidney injury (AKI). The precise pathogenesis of bilirubin tubular toxicity remains unknown. The aim of this study is to explore the cellular and molecular pathophysiology of human BCN. Paraffin-embedded sections of renal biopsy tissue from a BCN patient were stained by immunohistochemistry (IHC) for oxidative stress (4-hydroxynonenal), immune cell subpopulations, including dendritic cells (CD1c), macrophages (CD68) and T cells (CD3), and inflammasome activation by staining for active-caspase-1 and the inflammasome adaptor protein, ASC (apoptosis-associated speck-like protein containing a caspase activation and recruitment domain). Quantitative analyses of IHC staining were compared to healthy renal cortical tissue. We identified yellow to brown granular casts within the BCN case, consistent with the presence of bile pigment. The presence of bile pigment was associated with strong tubular 4-hydroxynonenal staining intensity, a marker of oxidative stress. Diffuse tubulointerstitial inflammatory cell infiltrate was detected, with elevated CD1c, CD68 and CD3 staining. Foci of inflammasome activity were co-localized with this intense immune cell infiltration, with increased active-caspase-1 and ASC staining. Our findings are the first to suggest that bile casts may lead to oxidative stress and trigger the inflammasome signalling cascade, leading to interstitial inflammation and driving AKI pathobiology. SUMMARY AT A GLANCE The report suggests that bile casts may lead to oxidative stress and trigger the inflammasome signalling cascade, leading to interstitial inflammation and driving bile cast nephropathy pathobiology.

Adult-Diagnosed Nonsyndromic Nephronophthisis in Australian Families Caused by Biallelic NPHP4 Variants.

There is increasing appreciation of nephronophthisis (NPHP) as an autosomal recessive cause of kidney failure and earlier stages of chronic kidney disease among adults. We identified 2 families with presumed adult-diagnosed nonsyndromic NPHP and negative diagnostic genetic testing results from our Renal Genetics Clinic. Both had 2 affected siblings without extrarenal phenotypes. After informed consent, research whole-genome sequencing was undertaken. Biallelic NPHP4 variants were identified in trans and clinically confirmed in all 4 affected individuals, confirming a genetic diagnosis. Participant 1 of the first family (F1P1) had kidney failure diagnosed at 19 years of age. An affected younger sibling (F1P2) reached kidney failure at age 15 years after kidney biopsy suggested NPHP. Pathogenic variants detected in NPHP4 in this family were NM_015102.4:c.3766C>T (p.Gln1256*) and a 31-kb deletion affecting exons 12 to 16. In the second family, F2P3 reached kidney failure at age 27 years having undergone kidney biopsy suggesting NPHP. An affected younger sibling (F2P4) has chronic kidney disease stage 4 at age 39 years. The NPHP4 variants detected were NM_015102.4:c.1998_1999del (p.Tyr667Phefs*23) and c.3646G>T (p.Asp1216Tyr). The latter variant was initially missed in diagnostic sequencing due to inadequate NPHP4 coverage (94.3% exonic coverage). With these reports, we identify NPHP4 as an appreciable genetic cause for adult-diagnosed nonsyndromic NPHP that should be considered by adult nephrologists.

Pharmacokinetic and Pharmacodynamic Properties of a Micro-Dose Nasal Spray Formulation of Desmopressin (AV002) in Healthy Water-Loaded Subjects.

PURPOSE: Antidiuretic therapy with desmopressin for nocturia has been hampered by formulations with high doses, low bioavailability and variable pharmacokinetics. AV002 (SER120), a novel, emulsified, microdose desmopressin nasal spray, with a permeation enhancer (cylcopentadecanolide), was developed to have pharmacokinetic characteristics suitable for nocturia treatment. METHODS: Twelve healthy subjects participated in an open-label, dose-escalating study. Water-loaded subjects were sequentially dosed every 48 h with AV002 0.5, 1.0, 2.0 µg and 0.12 µg desmopressin subcutaneous (SC) bolus injection. RESULTS: AV002 intranasal administration produced a time-to-maximum concentration (Tmax) between 15 and 30 min and a maximum concentration (Cmax) <10 pg/mL. Cmax and area under the curve showed dose proportionality. Coefficient of variation for AV002 was similar to that observed for the SC dose. Bioavailability of AV002 was approximately 8% compared to SC injection. AV002 demonstrated pharmacodynamic effects within 20 min of dosing and showed increasing magnitude and duration with escalating doses. AV002 2.0 µg had maximum median urine osmolality of 629 mOsm/kg and median urine output ≤2 mL/min for 5-6 h. CONCLUSIONS: AV002 demonstrated rapid absorption, high bioavailability, limited duration of action, and low coefficient of variation, suggesting it may be a suitable formulation for nocturia treatment. Trial registration not required (single-center, phase 1).

Paraneoplastic immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in asymptomatic low volume B-cell lymphoma - a case report.

BACKGROUND: Paraneoplastic glomerulonephritis is rare in haematological malignancies and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma. CASE PRESENTATION: A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio of 662 mg/mmol) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: < 6%), hypertension, obesity (body mass index: 47.6 kg/m2) and degenerative spine disease. Bone marrow biopsy diagnosed a low grade B-cell lymphoma and renal biopsy was consistent with immunoglobulin A nephropathy. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to normalisation of urinary protein excretion (urine protein creatinine ratio: 14 mg/mmol at 26 months post-chemotherapy). CONCLUSION: Paraneoplastic immunoglobulin A nephropathy can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with immunoglobulin A nephropathy. Recognition of paraneoplastic immunoglobulin A nephropathy and early diagnosis of associated malignancy can be life-saving.

The increasing rates of acute interstitial nephritis in Australia: a single centre case series.

BACKGROUND: The Australian Institute of Health and Welfare's first report into acute kidney injury demonstrated a significant increase in the incidence of acute-tubulo interstitial nephritis, the ICD-10 code representing both acute interstitial nephritis and pyelonephritis, in women aged less than 55 years. In contrast, recent case series have reported rising rates of drug induced acute interstitial nephritis predominantly among elderly patients. Due to several limitations with the Australian Institute of Health and Welfare report, this new trend requires further investigation to determine if rates of acute interstitial nephritis are truly increasing among younger Australian women. METHODS: Patients who underwent a renal biopsy at a single center from 2000 to 2015 were reviewed and those with biopsy confirmed acute interstitial nephritis were selected. Cause of acute interstitial nephritis, patient demographics, co-morbidities and renal indices for these patients when available were recorded and compared. RESULTS: Eight hundred ninety-eight patients who underwent renal biopsy from 2000 to 2015 were reviewed and 40 patients were identified with biopsy confirmed acute interstitial nephritis. The rate of acute interstitial nephritis increased significantly over the study period (4 patients/2.2% of biopsies performed in 2000-03 vs. 19 patients/6.7% of all biopsies performed in 2012-15; p = 0.002). There was a marked increase in the number of women with AIN in the last four years of the study (2 patients and 2.1% of biopsies performed in women in 2000-2003 compared with 13 patients and 9.0% of biopsies performed in women in 2012-2015). Immune mediated causes of acute interstitial nephritis and NSAID associated AIN were more common in women (9 females vs. 3 males), occurred more frequently in the last eight years of the study and predominantly in patients under 55 years of age. CONCLUSIONS: Our study demonstrates a significant increase in the number of patients with biopsy confirmed AIN. Also, we provide preliminary evidence in support of an increase in rates of younger women with immune mediated acute interstitial nephritis. These results support the findings of the Australian Institute of Health and Welfare and suggest that younger women may be at higher risk of immune mediated and NSAID associated acute interstitial nephritis.

Epidemiology of biopsy-proven glomerulonephritis in Queensland adults.

AIM: There is a paucity of data pertaining to the incidence of biopsy-proven glomerulonephritis (GN) in Australia. This retrospective study aims to review the data from all adult native renal biopsies performed in the state of Queensland from 2002 to 2011--comparing results with centres from across the world. METHODS: Pathology reports of 3697 adult native kidney biopsies were reviewed, of which 2048 had GN diagnoses. Age, gender, clinical indication and histopathology findings were compared. RESULTS: The average age at biopsy was 48 ± 17 years. Male preponderance was noted overall (∼60%), with lupus nephritis being the only individual GN with female predilection. The average rate of biopsy was 12.04 per hundred thousand people per year (php/yr). Nephrotic and nephritic syndromes comprised approximately 75% of all clinical indications that lead to GN diagnoses. IgA nephropathy (1.41 php/yr) was the most common primary GN followed by focal segmental glomerulosclerosis (1.02 php/yr) and crescentic GN (0.73 php/yr). Diabetic nephropathy (0.84 php/yr), lupus nephritis (0.69 php/yr) and amyloidosis (0.19 php/yr) were the most commonly identified secondary GN. CONCLUSION: IgA nephropathy is the predominant primary GN in Queensland, and nephrotic syndrome the most common indication for a renal biopsy. While crescentic GN incidence has significantly increased with time, focal segmental glomerulosclerosis incidence has not shown any trend. Incidence of GN overall appears to increase with age. The annual rate of biopsy in this study appears lower than previously published in an Australian population.

Sclerosing Paragangliomas of the Carotid Body: A Series of a Rare Variant and Review of the Literature.

The incidence of carotid body tumors is less than 1 in 30,000. Histologically, they present with a classic pattern of tumor cells arranged in "zellballen" or nests. A new extremely rare sclerosing subtype has been described in the literature with distinct stromal sclerosis and hyalinization, differentiating it from conventional paragangliomata. We present a case series of 3 patients with this rare variant and also discuss the diagnosis and management of carotid body parangliomas.