Down-Regulation-Resistant STAT4 Risk Haplotype Contributes to Lupus Nephritis Through CD4+ T Cell Interferon-γ Production.

OBJECTIVE: Variants in STAT4 are associated with systemic lupus erythematosus (SLE) and other autoimmune diseases. We undertook this study to investigate how disease-associated variants affect STAT4 expression, in particular in CD4+ T cells where STAT4 plays an essential role. METHODS: We compared Th1 differentiation between naive CD4+ T cells from healthy donors homozygous for the risk (R/R) or nonrisk (NR/NR) alleles. We analyzed epigenetic marks in STAT4 and evaluated the relevance of its third intron, assessed the consequences of Stat4 overexpression in vivo in mice, and analyzed the effects of the STAT4 genotype in patients with lupus nephritis. RESULTS: Naive CD4+ T cells from NR/NR healthy donors down-regulated STAT4 in response to interleukin-12 (IL-12). In contrast, cells from R/R healthy donors maintained high levels. R/R cells exhibited a higher abundance of transcriptionally active STAT4 and increased interferon-γ production. Accordingly, R/R healthy donors exhibited a stronger induction of local active enhancer marks. Genetic editing confirmed the presence of a negative regulatory region in the STAT4 third intron, where most of the SLE-associated STAT4 single-nucleotide polymorphisms (SNPs) are located. In vivo forced expression demonstrated that increases in Stat4 levels in T cells enhanced glomerulonephritis in mice. Accordingly, the R/R genotype was associated with suboptimal response to treatment and with worse clinical outcomes in patients with proliferative lupus nephritis. CONCLUSION: The SLE-associated STAT4 haplotype correlates with an abnormal IL-12-mediated STAT4 transcriptional regulation. Carriers of the risk variant exhibit exaggerated CD4+ proinflammatory capacities that, in the context of SLE, contribute to more severe disease. R/R patients may benefit from blockade of the IL-12/STAT4 pathway.

Is the Sars-CoV-2 virus a possible trigger agent for the development of achalasia?

BACKGROUND: Achalasia is an autoimmune disease whose probable causal agent is a neurotropic virus that chronically infects the myenteric plexus of the esophagus and induces the disease in a genetically susceptible host. The association between achalasia and coronaviruses has not been reported. AIMS: To evaluate the presence of the SARS-CoV-2 virus, the ACE2 expression, the tissue architecture, and immune response in the lower esophageal sphincter muscle (LESm) of achalasia patients who posteriorly had SARS-CoV-2 (achalasia-COVID-19) infection before laparoscopic Heller myotomy (LHM) and compare the findings with type II achalasia patients and transplant donors (controls) without COVID-19. METHODS: The LESm of 7 achalasia-COVID-19 patients (diagnosed by PCR), ten achalasia patients, and ten controls without COVID-19 were included. The presence of the virus was evaluated by in situ PCR and immunohistochemistry. ACE2 receptor expression and effector CD4 T cell and regulatory subsets were determined by immunohistochemistry. KEY RESULTS: Coronavirus was detected in 6/7 patients-COVID-19. The SARS-CoV-2 was undetectable in the LESm of the achalasia patients and controls. ACE2 receptor was expressed in all the patients and controls. One patient developed achalasia type II post-COVID-19. The percentage of Th22/Th17/Th1/pDCreg was higher in achalasia and achalasia-COVID-19 pre-HLM vs. controls. The Th2/Treg/Breg cell percentages were higher only in achalasia vs. controls. CONCLUSION & INFERENCES: SARS-CoV2 and its receptor expression in the LESm of achalasia patients who posteriorly had COVID-19 but not in the controls suggests that it could affect the myenteric plexus. Unlike achalasia, patients-COVID-19 have an imbalance between effector CD4 T cells and the regulatory mechanisms.

Leukocyte Chemotactic Factor 2 Amyloidosis (ALECT2) Distribution in a Mexican Population.

OBJECTIVES: To assess the prevalence of leukocyte cell-derived chemotactic 2 (LECT2), its organ involvement, and its clinical association in autopsies from an ethnically biased population. METHODS: The tissues from all autopsies of individuals diagnosed with amyloidosis were reassessed and typed for amyloid light chain (AL) amyloidosis, amyloid A (AA) amyloidosis, transthyretin amyloidosis (ATTR), and leukocyte chemotactic factor 2 amyloidosis (ALECT2) by immunohistochemistry. Organ involvement was described and correlated with its clinical associations. RESULTS: Of 782 autopsies, 27 (3.5%) had a confirmed diagnosis of amyloidosis. Of these, 14 (52%) corresponded to ALECT2, 5 (19%) to AL amyloidosis, 2 (7%) to ATTR amyloidosis, 1 (4%) to AA amyloidosis, and 5 (21%) as undetermined-type amyloidosis. The LECT2 amyloid deposits were found in the kidneys, liver, spleen, and adrenal glands in most individuals. Except for the kidneys, there were no clinical signs suggestive of amyloid deposition in most of the affected organs. LECT2 amyloidosis was not associated with the cause of death in any case. No cases had heart or brain involvement. Potential subclinical effects of amyloid deposition in organs such as adrenal glands and spleen require further study. CONCLUSIONS: This autopsy study confirms the high prevalence of LECT2 amyloidosis in the Mexican population, with frequent amyloid deposition in the kidneys, liver, spleen, and adrenal glands.

ANCA-associated vasculitis and IgG4-related disease overlap syndrome: a case report and literature review.

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides are infrequent autoimmune diseases characterized by inflammation of the walls of small vessels leading to tissue and endothelial damage. On the other hand, IgG4-related disease is a fibroinflammatory disease characterized histologically by lymphoplasmacytic infiltrates with IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis that may affect nearly every organ of the body. There are similarities in clinical, serological, radiological, and histopathological features between both diseases, and hence, they usually mimic each other complicating the differential diagnosis. Furthermore, reports of patients with the coexistence of both conditions (overlap syndrome) have been reported. We herein report a patient with an unequivocal diagnosis of ANCA-associated vasculitis, specifically granulomatosis with polyangiitis (posterior uveitis, polyneuropathy, pauci-immune glomerulonephritis with crescent formation and granulomas, and MPO-ANCA positivity) and IgG4-related disease (thoracic aortitis, tubulointerstitial nephritis with prominent IgG4+ plasma cell infiltration, fibrosis, and obliterative arteritis, high levels of serum IgG4, and eosinophilia) overlap syndrome.

Sub-classification of borderline changes into diffuse or focal and its impact on long-term renal transplant outcomes.

BACKGROUND: Borderline changes (BL) with stable renal function is a controversial category in renal transplantation, given its contradictory outcomes. The aim of this study was to compare the clinical outcomes of BL in patients with stable renal function classified as focal and diffuse according to the extent of tubulitis. METHODS: Patients with no history of rejection with a surveillance graft biopsy at 3 or 12 months showing BL (n = 40), acute cellular rejection (n = 20) or normal biopsies (n = 20), were included in this study. Biopsies with BL were divided into diffuse BL (BLD) and focal BL (BLF) according to the extent of tubulitis. Because of the low frequency of subclinical ACR (ACRND) (n = 12), biopsies with ACR and graft dysfunction (ACRD) (n = 8) were also included. A composite outcome that included the presence of rejection in subsequent biopsies, graft loss, patient death, decrease in GFR ≥30% or presence of de novo DSA (dnDSA) during the first year of follow-up was evaluated. RESULTS: The primary composite outcome occurred in five patients of each of the Normal, BLF and ACRND, eight patients with BLD and six patients with ACRD (p = 0.105). A trend towards more rejection episodes was observed in the ACRND and ACRD. Also, a shorter time to rejection in the BLD, ACRND and ACRD groups compared to BLF and Normal groups (p = 0.039) was observed. During the first year of follow-up, no patient in the ACRND group developed dnDSA, compared to 15-25% in the other groups. The median time of dnDSA development in the BLF group was 45 months, and in the BLD group was 10 months (p = 0.020). CONCLUSION: Classifying BL biopsies with stable renal function into focal and diffuse categories, is a simple and feasible strategy that helps to differentiate between BLD with a phenotype that shows a trend towards worse outcomes, and BLF that behaves more similar to normal biopsies.

Autoantigen characterization in the lower esophageal sphincter muscle of patients with achalasia.

BACKGROUND: Serum anti-myenteric autoantibodies define autoimmune achalasia and tissue MMP-9 activity may locally process autoantigenic proteins in the muscle of the lower esophageal sphincter (LES) of achalasia patients. METHODS: Biopsies of the LES muscle from 36 achalasia patients, 6 esophagogastric junction outflow obstruction (EGJOO) patients, and 16 transplant donors (TD) were compared in a blind cross-sectional study. Histological characteristics such as inflammation, fibrosis, presence of ganglion cells, cells of Cajal, GAD65, PNMA2, S-100, P substance, and MMP-9 proteoforms in tissue were assessed by H&E and Picrosirius Red staining and immunohistochemistry analysis. Anti-neuronal antibodies, onconeural antigens, recoverin, SOX-1, titin, zic4, GAD65, and Tr were evaluated by immunoblot/line assay. KEY RESULTS: Tissue of achalasia patients had heterogeneous inflammatory infiltrates with fibrosis and contrasting higher levels of activated MMP-9, as compared with EGJOO and TD. Moreover, lower ganglion cell percentages and cell of Cajal percentages were determined in esophageal tissues of achalasia patients versus TD. The tissues of achalasia versus EGJOO patients had higher GAD65 and PNMA2 protein expression. Unexpectedly, these proteins were absent in TD tissue. S-100 and P substance had similar expression levels in tissues of achalasia patients versus TD and EGJOO. Most of the achalasia sera had anti-GAD65 (83%) and anti-PNMA2 (90%) autoantibodies versus EGJOO (17% and 33%, respectively) and healthy volunteers (10% and 0%, respectively). CONCLUSIONS AND INFERENCES: Tissue-specific ectopic expression of GAD65 and PNMA/Ta2 and active MMP-9, associated with the presence of specific autoantibodies directed against these proteins, might participate in the pathophysiology of achalasia triggering and/or perpetuating autoimmune disease.

Clinicopathologic characteristics of severe COVID-19 patients in Mexico City: A post-mortem analysis using a minimally invasive autopsy approach.

OBJECTIVE: Describe the histological findings of minimally ultrasound-guided invasive autopsies in deceased patients with severe SARS-CoV-2 and compare the diagnostic yield with open autopsies. DESIGN: Observational post-mortem cohort study. Minimally invasive ultrasound-guided autopsies were performed in fourteen deceased patients with a confirmed diagnosis of SARS-CoV-2 pneumonia. Histological and clinical findings of lung, kidney, and liver tissue are described and contrasted with those previously reported in the literature. SETTING: Single-center COVID-19 reference center in Mexico City. RESULTS: Fourteen minimally invasive autopsies revealed a gross correlation with open autopsies reports: 1) Lung histology was characterized mainly by early diffuse alveolar damage (12/13). Despite low lung compliances and prolonged mechanical ventilation, the fibrotic phase was rarely observed (2/13). 2) Kidney histopathology demonstrated acute tubular injury (12/13), interstitial nephritis (11/13), and glomerulitis (11/13) as the predominant features 3) Liver histology was characterized by neutrophilic inflammation in all of the cases, as well as hepatic necrosis (8/14) despite minimal alterations in liver function testing. Hepatic steatosis was observed in most cases (12/14). SARS-CoV-2 positivity was widely observed throughout the immunohistochemical analysis. However, endothelitis and micro thrombosis, two of the hallmark features of the disease, were not observed. CONCLUSION: Our data represents the largest minimally invasive, ultrasound-guided autopsy report. We demonstrate a gross histological correlation with large open autopsy cohorts. However, this approach might overlook major histologic features of the disease, such as endothelitis and micro-thrombosis. Whether this represents sampling bias is unclear.

Alternative complement pathway activation in thrombotic microangiopathy associated with lupus nephritis.

INTRODUCTION/OBJECTIVE: Thrombotic microangiopathy (TMA) in systemic lupus erythematosus is a rare manifestation associated with activation of the complement system. This study aimed to compare plasma and urine complement activation products between patients with active lupus nephritis (aLN) and those with acute TMA plus concomitant active LN (aTMA+aLN). METHODS: Plasma and urine samples were obtained from 20 patients with aTMA+aLN, 20 patients with aLN matched by the histological activity index, 5 patients with chronic TMA, 20 patients with inactive LN, and 10 kidney donors. Complement fragments C3a, C4a, C4d, Ba, C5a, C5bC9, and factor H were determined by ELISA; and kidney C4d deposition was detected by immunohistochemistry. Patients were followed for > 12 months and complement activation products re-measured after treatment in 10 aTMA+aLN patients. RESULTS: Both aTMA+aLN and aLN groups had increased circulating C3a, Ba, and C5bC9; and decreased circulating C3, C4, C4a, C4d, and factor H. Urinary C3a, C5a, Ba, and C5bC9 were higher in patients with aTMA+aLN than in aLN. After treatment, levels of circulating C3, C4, and factor H increased; while levels of urinary C3a, C5a, Ba, and C5bC9 decreased in patients with aTMA+aLN. These changes were observed at each aTMA episode in two patients studied during repeated TMA episodes. There was no difference in C4d deposition in glomerular capillaries, tubular basement membrane, peritubular capillaries, and arterioles between patients with aLN and those aTMA+aLN. CONCLUSIONS: Circulating and urine complement activation products suggest that thrombotic microangiopathy associated with LN is mediated through activation of the alternative complement pathway. Key Points • Immune-complex kidney disease in systemic lupus erythematosus (SLE) is associated with activation of the classical, lectin, and alternative complement pathways • Indirect evidence from measurement of circulating and urinary complement pathway activation products suggests that renal acute thrombotic microangiopathy in SLE is mediated by activation of the alternative complement pathway • C4d kidney immunohistochemistry may be positive in both immune complex nephritis and thrombotic microangiopathy. Therefore, it is not a specific marker of renal thrombotic microangiopathy in SLE.

Nephrotic syndrome in the setting of LECT2 amyloidosis: Take a look at the podocyte.

Amyloid light-chain (AL) amyloidosis represents the most common type of amyloid affecting the kidneys. As AL amyloidosis is frequently clinically manifested as nephrotic syndrome, this glomerular syndrome has been improperly linked to all other types of kidney amyloidosis. In this report, we highlight the importance of amyloid typing, as the deposition of several amyloidotic proteins in the kidneys is not associated with heavy proteinuria. We present two cases of patients who presented with sudden-onset nephrotic syndrome and kidney biopsies showing interstitial, vascular, and/or mesangial LECT2 amyloidosis. Further examination by electron microscopy demonstrated diffuse foot process effacement consistent with minimal change disease and no amyloid deposition in the glomerular basement membrane. Both patients had complete remission after glucocorticoid treatment. We conclude that the presence of nephrotic syndrome in a patient with LECT2 amyloidosis must alert for a potential concurrent podocytopathy.

IgG4-related kidney disease: experience from a Mexican cohort.

To evaluate the clinical/serological phenotype and outcomes of IgG4-related kidney disease. Case series of IgG4-related kidney disease from a cohort of 69 patients with IgG4-related disease. We defined kidney involvement as the presence of at least one of the following conditions: (A) laboratory parameters of kidney injury (proteinuria and/or elevated creatinine levels and/or hematuria); and/or (B) contrast-enhanced computed tomography features (multiple low-density lesions and/or nephromegaly and/or hypovascular solitary mass and/or renal pelvic lesion and/or perinephric lesions). We identified 17 patients with kidney involvement (24.6%), with a mean age of 53.6 ± 11.3 years; thirteen (76.5%) were male. Six patients fulfilled the laboratory criteria, six the imaging criteria, and five both. Five patients had a renal biopsy, the main histopathological diagnosis being IgG4 tubulointerstitial nephritis. Sixteen patients received glucocorticoids and 12 also immunosuppressors and/or biologics. Sixteen patients presented either total or partial renal remission at a median follow-up of 26 months, while one patient developed end-stage renal disease. Patients with kidney disease, as opposed to patients without kidney involvement, had a higher number of involved organs, higher IgG4-related disease responder index and IgG4 and IgG1 serum levels, higher prevalence of rheumatoid factor, and lower C3 and C4 levels. Our study emphasizes the systemic nature of IgG4-related disease, highlighting that renal involvement is usually present in a subset of patients with multisystemic disease, high IgG1 and IgG4 levels, and hypocomplementemia. Key Points • IgG4-RKD presents at a younger age in Mexican mestizo patients. • IgG4-RKD presents with proteinuria and kidney injury or as an asymptomatic imaging finding. • IgG4-RKD presents in the context of multisystemic disease, hypocomplementemia, and high IgG1 and IgG4 levels.

Esophagogastric junction outflow obstruction: Characterization of a new entity? Clinical, manometric, and neuroimmunological description.

OBJECTIVE: To determine the differences between clinical, manometric, and neuroimmunological profile of esophagogastric junction outflow obstruction (EGJOO) and achalasia patients. METHODS: Seven EGJOO and 27 achalasia patients were enrolled in a blind cross-sectional study. Peripheral blood (PB) of 10 healthy donors and 10 lower esophageal sphincter (LES) muscle biopsies from organ transplant donors were included as controls. The presence of ganglion cells, cells of Cajal, Th22/Th7/Th2/Th1/Tregs/Bregs/pDCregs in tissue, and PB was assessed by immunohistochemistry and flow cytometry. Serum concentration of IL-22/IL-17A/IL-17F/IL-4/IFN-γ/IL-1ß/IL-6/IL-23/IL-33/TNF-α/IL-10 was determined using bioplex plates. ANAs and antineuronal antibodies were evaluated by immunofluorescence and Western blot. KEY RESULTS: EGJOO and achalasia patients had lower ganglion cells and cells of Cajal percentage vs. controls, while fibrosis was present only in achalasia patients. EGJOO and controls had lower cell percentage of Th22/Th17/Th2 vs. achalasia. EGJOO tissue had lower Th1/Treg cell number vs. achalasia, but higher levels vs. control group. Bregs and pDCregs percentage was higher in EGJOO vs. control group. Percentage of PB subpopulations in EGJOO was not significantly different from control group. Serum cytokine levels were higher for IL-1ß/IL-6/TNF-α, while IL-17A levels were lower in EGJOO vs. achalasia and control group. EGJOO group was negative for ANAs, while in achalasia group, 54% were positive. GAD65 and PNMa/Ta2 antibodies were present in achalasia, whereas Yo and recoverin were positive in EGJOO group. CONCLUSIONS AND INFERENCES: Although EGJOO shares some clinical characteristics with achalasia, the neuroimmunological profile is completely different, suggesting that EGJOO might be a different entity.

A potential role of neutrophil extracellular traps (NETs) in kidney acute antibody mediated rejection.

BACKGROUND: The aim of this study was to evaluate neutrophil extracellular traps (NETs) in kidney transplant recipients (KTR) and their potential involvement in acute antibody-mediated rejection (AAMR). METHODS: We studied 3 groups: KTR with AAMR (KTR-Cases, n = 14); KTR without any immunologic event (KTR-Controls, n = 14) and donors (n = 12). Spontaneous and lipopolysaccharide-induced NETosis were evaluated by immunofluorescence indirect (IFI) (NET/cells ratio). Plasmatic cH3-DNA complexes were evaluated by ELISA, (Optic Density Index - ODI). The expression of MPO and citrullinated histone 4 (cH4) was evaluated in renal biopsies. RESULTS: We found an enhanced spontaneous NETosis in KTR regardless of whether they had rejection. The Nets/cells ratio in spontaneous NETosis was 0.203 (IQR 0.12-0.34) in Total-KTR and 0.094 (IQR 0.01-0.17) in donors, p = .011. Likewise, the ODI of cH3-DNA was 1.41 (IQR 0.94-1.72) in Total-KTR, and 0.95 (IQR 0.83-1.27) in donors, p = .019. KTR-Cases had the higher amount of NETs 1.70 (IQR 1.19-1.91). In two KTR-Cases, expression of MPO and cH4 was found in biopsies. CONCLUSIONS: KTR show enhanced NETosis. This may indicate a permanent activation of neutrophils. Although more studies are needed, the higher amount of NETs and netting neutrophils in biopsies of KTR-Cases suggest a role of NETosis in AAMR.

Systemic BK Virus Infection in a Pediatric Patient With Severe Combined Immunodeficiency.

Human BK virus (BKV) infection is known to occur mostly during childhood with the establishment of latent infection with no tissue damage or clinical manifestations. However, conditions causing immunosuppression can lead to increased virus replication and tissue damage. Although the tissues most commonly involved are the kidneys, bladder, ureters and, to some extent, brain tissue, there are some reports that suggest that BKV may cause multisystemic infections. In this case, a 12-month-old child was seen to suffer from multiple gastrointestinal infections. This prompted a search for immunodeficiencies, which revealed the presence of severe combined immunodeficiency. The child was eventually hospitalized and continued showing recurrent bouts of gastroenteritis as well as lower respiratory infection. After multiple antibiotic courses, he developed acute kidney injury, a hemophagocytic syndrome, and eventually respiratory failure, which led to his death a year later. Autopsy findings revealed the presence of a disseminated BKV infection involving the kidneys, ureters, leptomeninges, and pancreas. Analysis of the literature failed to show any previous case of BKV pancreatitis. The present case suggests that BKV can damage more tissues than previously reported and may be responsible for systemic infections in immunosuppressed patients.

LECT2 Amyloidosis in Kidney Transplantation: A Report of 5 Cases.

Leukocyte chemotactic factor 2 (LECT2) amyloidosis is a recently recognized entity that often affects the kidneys. Little information is available regarding kidney transplant outcomes in patients with LECT2 amyloidosis or who received kidney allografts containing LECT2 amyloid. We present clinical findings and allograft outcomes of 5 patients who received kidneys with donor-derived LECT2 amyloidosis. In all 5, LECT2 amyloidosis was discovered during protocol biopsies or in evaluation of suspected rejection. Less than 10% of kidney parenchyma was involved, with mostly interstitial and vascular deposits. Allograft function was not impaired and the amyloid deposits persisted for up to 8 years of follow-up. We conclude that kidneys with limited and localized LECT2 amyloid deposits that are otherwise suitable for transplantation need not be automatically discarded.

Calcineurin Inhibitors With Reduced-Dose Steroids as First-Line Therapy for Focal Segmental Glomerulosclerosis.

INTRODUCTION: High-dose corticosteroids remain the first-line therapy for focal and segmental glomerulosclerosis (FSGS), whereas calcineurin inhibitors (CNIs) are reserved for those patients resistant to corticosteroid therapy. METHODS: This is a retrospective cohort analysis in patients with primary FSGS diagnosed between 2007 and 2014. According to the administered treatment, patients were segregated into 3 groups: high-dose prednisone, first-line CNIs plus low-dose prednisone, and rescue CNIs. Cumulative corticosteroid doses were compared as well as response to therapy and long-term renal survival by Cox regression analysis. RESULTS: A total of 66 patients were included (39 treated with high-dose prednisone, 11 treated with first-line CNI, 16 treated with high-dose prednisone followed by rescue CNI). Cumulative doses of prednisone in the high-dose group were 9.3 g (interquartile range [IQR] = 7.5-12.5 g), compared to 2.5 g (IQR = 1.82-3.12 g) in the first-line CNI plus low-dose corticosteroid group and 13.8 g (IQR = 9.2-15.8 g) rescue CNI groups, respectively (P < 0.001). Time under corticosteroid management was also higher in the high-dose prednisone group compared to the first-line CNI group. There was a response to treatment in 76.9%, 72.7%, and 87.5% of high-dose prednisone, first-line CNI and rescue CNI groups, with complete remission in 48.7%, 36.4%, and 31.3% respectively. There was no difference in relapse incidence after treatment (48.4%, 44.4%, and 46.7%) or in 5-year renal survival (87.2%, 81.8%, and 87.5%). Baseline proteinuria, biopsy chronicity score, and response to therapy were independent predictors of renal survival. CONCLUSION: An initial CNI plus low-dose corticosteroid approach in primary FSGS reduces corticosteroid exposure with a response-to-therapy rate similar to that of the currently recommended high-dose corticosteroid regimen. These findings justify a randomized trial to formally test this hypothesis.

Pretransplant angiotensin II type 1-receptor antibodies point to an increase in renal graft sub-intimal fibrosis in living- donor kidney transplant recipients.

The association between anti-AT1Rabs and microvascular injury observed in antibody-mediated rejection has been described in kidney graft Biopsies (KGBx). METHODS: We herein describe the histopathologic findings of KGBx performed during the first year of transplantation (Tx) in 134 patients tested for pre-Tx anti-AT1Rabs in cryopreserved sera (04/2009 to 09/2013). Protocol KGBx before implantation (time-zero), 1 year after Tx and for cause KGBx were included. 21/134 Tx patients were anti-AT1Rab positive (≥17 U/mL); 7/21 experienced acute rejection. For comparison a control group with anti-AT1Rabs <17 U/mL, with (n = 16) and without (n = 31) acute rejection was included. RESULTS: Preimplantation KGBx showed no differences in inflammatory and chronic findings, nor in subintimal fibrosis (25 vs 12.8%, p = .42) between patients with anti-AT1Rabs ≥17 U/mL and those with <17 U/mL. Follow-up KGBx revealed a significantly greater proportion of arterial sub-intimal fibrosis (52.3 vs. 27.6%, p = .049) and extension (15.7 vs. 5.3, p = .015) in anti-AT1Rabs ≥17 U/mL compared to anti-AT1Rabs <17 U/mL KGBx. No differences were observed in microcirculation inflammation, nor in interstitial fibrosis or tubular atrophy between groups. Also, anti-AT1Rabs ≥17 U/mL (ß 10.1, 2.3 to 17.8, p = .012) and more importantly anti-AT1Rabs ≥ 30 U/mL (ß12.1, 3.1 to 20.9, p < .01), were independent risk factors associated with vascular occlusion resulting from sub-intimal fibrosis. CONCLUSION: Our study findings have shown that anti-AT1Rab values ≥17 U/mL are significantly associated to sub-intimal fibrosis and a greater percentage of vessel occlusion in kidney graft biopsies obtained during the first year posttransplant, particularly in coexistence with inflammation and de novo DSA.

Immune gene expression in kidney biopsies of lupus nephritis patients at diagnosis and at renal flare.

BACKGROUND: Up to 50% of lupus nephritis (LN) patients experience renal flares after their initial episode of LN. These flares contribute to poor renal outcomes. We postulated that intrarenal immune gene expression is different in flares compared with de novo LN, and conducted these studies to test this hypothesis. METHODS: Glomerular and tubulointerstitial immune gene expression was evaluated in 14 patients who had a kidney biopsy to diagnose LN and another biopsy at their first LN flare. Ten healthy living kidney donors were included as controls. RNA was extracted from laser microdissected formalin-fixed paraffin-embedded kidney biopsies. Gene expression was analyzed using the Nanostring nCounter® platform and validated by quantitative real-time polymerase chain reaction. Differentially expressed genes were analyzed by the Ingenuity Pathway Analysis and Panther Gene Ontology tools. RESULTS: Over 110 genes were differentially expressed between LN and healthy control kidney biopsies. Although there was considerable molecular heterogeneity between LN biopsies at diagnosis and flare, for about half the LN patients gene expression from the first LN biopsy clustered with the repeated LN biopsy. However, in all patients, a set of eight interferon alpha-controlled genes had a significantly higher expression in the diagnostic biopsy compared with the flare biopsy. In contrast, nine tumor necrosis factor alpha-controlled genes had higher expression in flare biopsies. CONCLUSIONS: There is significant heterogeneity in immune-gene expression of kidney tissue from LN patients. There are limited but important differences in gene expression between LN flares, which may influence treatment decisions.