Renal replacement therapy-requiring acute kidney injury due to tubulointerstitial nephritis and uveitis syndrome: case report.

BACKGROUND: Acute kidney injury is a major challenge for today's healthcare systems around the globe. Renal replacement therapy has been shown to be beneficial in acute kidney injury, but treatment highly depends on the cause of the acute kidney injury. One less common cause is tubulointerstitial nephritis, which comes in different entities. A very rare type of tubulointerstitial nephritis is tubulointerstitial nephritis and uveitis syndrome, in which the patient presents with additional uveitis. CASE PRESENTATION: A 19-year-old caucasian male presented with mild dyspnea, lack of appetite, weight loss, and moderate itchiness. Lab results showed an acute kidney injury with marked increase of serum creatinine. The patient was started on prednisolone immediately after admission. As the patient in this case showed symptoms of uremia on admission, we decided to establish renal replacement therapy, which is unusual in tubulointerstitial nephritis and uveitis syndrome. During his course of dialysis, the patient developed symptoms of sepsis probably due to a catheter-related infection requiring intensive care and antibiotic treatment, which had to be terminated early as the patient developed a rash. Intensified immunosuppression, combined with antibiotics, significantly resolved excretory kidney dysfunction. CONCLUSIONS: Since both the primary inflammatory process and the secondary infectious complication significantly impaired excretory kidney function, kidney function of younger individuals with new-onset anterior uveitis should be monitored over time and during follow-up.

Hemophagocytic lymphohistiocytosis and thrombotic microangiopathy after parvovirus B19 infection and renal transplantation: a case report.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening disease characterized by hyperactivation of the immune system that causes hypercytokinemia and potentially multi organ failure. HLH can occur in patients with underlying rheumatic or autoinflammatory disorders. Additionally, HLH can develop in patients during infections or malignancies without a known genetic predisposition. CASE PRESENTATION: We herein report a patient, who presented with fever, both acute kidney and liver injury, anemia, thrombocytopenia and HSV stomatitis. HLH was diagnosed based on clinical criteria and qPCR revealed an acute parvovirus B19 infection as potential underlying infectious trigger. Treatment was started with both IVIG and dexamethasone. Subsequently, kidney biopsy demonstrated TMA. CONCLUSIONS: In rare cases both HLH and aHUS can occur simultaneously in a patient as a consequence of viral infections. Insights from this unusual case might help physicians understand this complex symptom constellation.

COVID-19 effects on the kidney.

Apart from pulmonary disease, acute kidney injury (AKI) is one of the most frequent and most severe organ complications in severe coronavirus disease 2019 (COVID-19). The SARS-CoV­2 virus has been detected in renal tissue. Patients with chronic kidney disease (CKD) before and on dialysis and specifically renal transplant patients represent a particularly vulnerable population. The increasing number of COVID-19 infected patients with renal involvement led to an evolving interest in the analysis of its pathophysiology, morphology and modes of virus detection in the kidney. Meanwhile, there are ample data from several autopsy and kidney biopsy studies that differ in the quantity of cases as well as in their quality. While the detection of SARS-CoV­2 RNA in the kidney leads to reproducible results, the use of electron microscopy for visualisation of the virus is difficult and currently critically discussed due to various artefacts. The exact contribution of indirect or direct effects on the kidney in COVID-19 are not yet known and are currently the focus of intensive research.

[COVID-19 effects on the kidney]. / COVID-19-Auswirkungen auf die Niere.

Apart from pulmonary disease, acute kidney injury (AKI) is one of the most frequent and most severe organ complications in severe coronavirus disease 2019 (COVID-19). The SARS-CoV­2 virus has been detected in renal tissue. Patients with chronic kidney disease (CKD) before and on dialysis and specifically renal transplant patients represent a particularly vulnerable population. The increasing number of COVID-19 infected patients with renal involvement led to an evolving interest in the analysis of its pathophysiology, morphology and modes of virus detection in the kidney. Meanwhile, there are ample data from several autopsy and kidney biopsy studies that differ in the quantity of cases as well as in their quality. While the detection of SARS-CoV­2 RNA in the kidney leads to reproducible results, the use of electron microscopy for visualisation of the virus is difficult and currently critically discussed due to various artefacts. The exact contribution of indirect or direct effects on the kidney in COVID-19 are not yet known and are currently the focus of intensive research.

[COVID-19 and kidney involvement]. / COVID-19 und Nierenbefall: Pathologie.

Apart from the pulmonary disease, acute kidney injury is one of the most frequent and most severe organ complications in severe coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could also be detected in renal tissue. Patients with chronic kidney disease and on dialysis as well as kidney transplantation patients represent a particularly vulnerable population. The increasing number of patients infected with SARS-CoV­2 has aroused increased interest in the exact pathophysiology and morphology of kidney damage as well as the direct detection of the virus in the kidneys, which in contrast to the lungs is overall more difficult to perform. Meanwhile, data from several large autopsy and kidney biopsy studies are now available. While the detection of SARS-CoV­2 RNA in tissue leads to consistently reproducible results, the use of electron microscopy for visualization of the virus is critically discussed due to various artefacts. The exact and direct effects of SARS-CoV­2 on the kidneys are not yet known in detail and are currently the focus of intensive research.

[Side effects of novel cancer immunotherapies]. / Nebenwirkungen neuer onkologischer Immuntherapien.

Systemic treatment with immune checkpoint inhibitors (ICI) has revolutionized the treatment of hematological and oncological diseases in recent years. The mechanism of action hinges on enhancing the natural ability of the immune system to eliminate malignant cells. The most important substances in this arena include inhibitors of PD­1, PD-L1 and CTLA­4. As a consequence, the spectrum of treatment-associated adverse reactions is shifting away from classical cytotoxic effects (e.g. pancytopenia and polyneuropathy) towards novel entities of immune-mediated complex diseases. These so-called immune-related adverse events (irAEs) can involve any organ system and mimic known classical autoimmune conditions. Timely recognition of irAEs is the key for rapid initiation of a suitable treatment and is especially challenging in the clinical routine as it requires an intensive interdisciplinary management. Nephrologists are particularly confronted with this kind of problem due to the highly interdisciplinary nature of their work. This article summarizes the broad spectrum of currently known renal and more frequently occuring non-renal forms of irAEs and aims to prime the reader on diagnostic and therapeutic options.

[Membranoproliferative glomerulonephritis and C3 glomerulopathy]. / Membranoproliferative Glomerulonephritis und C3­Glomerulopathie.

Based on an increasingly better pathophysiological understanding over the last 10 years, in 2010 a new classification of glomerulonephritis with dominant or codominant C3 deposits was introduced and the predominant subgoup was termed C3 glomerulopathy (C3G). In the current classification, immune complex mediated membranoproliferative glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G) form a disease spectrum which is very heterogeneous in terms of pathophysiology and the clinical course. Recent evidence suggests that IC-MPGN and C3G share more pathophysiological aspects with respect to secondary causes, autoantibodies and genetic aspects than had been suggested with the creation of the new classification. Knowledge of the underlying pathophysiology is important for guiding the diagnostic steps for clarification of secondary causes. Comprehensive complement analysis, accompanied by antibody screening and genetic analysis, should be consistently carried out. Although not systematically validated in clinical trials, the published evidence provides a robust foundation for the use of available treatment approaches for these diseases that are often rapidly progressive and often return after renal transplantation.

[(Immuno­)Pathology of drug side effects in the kidney]. / (Immun­)Pathologie von Medikamentennebenwirkungen in der Niere.

Nephrotoxicity or renal side effects of drugs are frequent and may vary in their clinical presentation. Various types of acute and chronic kidney disease are known to develop as a consequence or side effect of a long list of drugs with nephrotoxicity most commonly being associated with injury in the tubulointerstitial compartment. In addition, drug-induced glomerular and vascular disease have also been reported, either as the result of direct cellular injury or immune-mediated injury to glomerular or endothelial cells. From a clinical point of view it is important to recognize such drug-induced nephropathies early in order to prevent or adequately treat them to favour kidney recovery and to avoid long-lasting negative consequences for kidney function.This article will focus on the typical morphology and pathogenesis of some frequent drug-induced renal diseases.

In-situ analysis of mast cells and dendritic cells in coronary atherosclerosis in chronic kidney disease (CKD).

AIMS: Mast cells (MC) and dendritic cells (DC) have immune modulatory function and can influence T-cell activity. Both cell types have been found in atherosclerotic plaques and are thought to play an important role for plaque stability. Compared to matched segments of the non-renal population, patients with chronic kidney disease (CKD) show a more pronounced and more aggressive course of atherosclerosis with higher plaque calcification and significantly higher complications rates. It was the aim of this study to analyze the number and localization of MCs and DCs, macrophages, T- and B-cells as well as the expression of markers of inflammation such as CRP and NFκB in calcified and non-calcified atherosclerotic plaques of patients with CKD and control patients. METHODS: Fifty coronary atherosclerotic plaques from patients with endstage CKD (CKD, n=25) and control (n=25) patients were categorized according to the Stary classification and investigated using immunohistochemistry (markers for MC, DC, T, B, macrophage and NFκB). Expression was analyzed separately for the complete plaque area as well as for the different plaque subregions and correlations were analyzed. RESULTS: We found only very few DCs and MCs per lesion area with slightly increased numbers in calcified plaques. MCs per plaque area were significantly more frequent in CKD than in control patients and this was independent of plaque calcification. MCs were most frequently found in the shoulder and basis of the plaque. DCs per plaque area were significantly less in calcified plaques of CKD compared to control patients. In control, but not in CKD patients, DCs were significantly more frequent in calcified than in non-calcified plaques. Within the plaques DCs were similarly distributed between all 4 subregions. CONCLUSIONS: Coronary atherosclerotic plaques of CKD patients showed a significantly higher number of MCs whereas DCs were less frequent compared to control patients particularly if plaques were calcified. These findings might indicate a potential proinflammatory role of MCs, but not of DCs in atherosclerotic lesions of CKD patients, adding another characteristic of advanced atherosclerosis in these patients.

First Treatment of Relapsing Rapidly Progressive IgA Nephropathy With Eculizumab After Living Kidney Donation: A Case Report.

BACKGROUND: IgA nephropathy (IGAN) rarely can present as a crescent and progressive form leading to end-stage renal disease (ESRD) in a short period of time. Recurrence of IGAN after kidney transplantation is frequent, and complement components such as C3, C4d, and C5 seem to be involved. We present a case of a young male patient with ESRD caused by rapidly progressive IGAN and who demonstrated rapid recurrence of crescentic IGAN after kidney donation. CASE REPORT: In September 2014, a 28-year-old male patient was hospitalized due to IGAN with 60% of crescents. Cyclophosphamide, steroids, and plasmapheresis did not prevent ESRD. After 8 months of peritoneal dialysis, the patient received a blood group-compatible living donor kidney from his 57-year-old mother. Immunosuppression consisted of tacrolimus, mycophenolic acid, and steroids without induction therapy. Acute graft failure occurred 2 months later, and graft biopsy results revealed recurrence of crescentic IGAN. Cyclophosphamide was added to tacrolimus and steroid treatment, but graft function could not be restored despite viable kidney tissue in repeated biopsy specimens. Rescue therapy with 4 single doses of eculizumab was introduced while hemodialysis had already been initiated. After a cumulative dose of 1800 mg of eculizumab, kidney function did not recover. CONCLUSIONS: In this case, eculizumab was not effective in treating IGAN recurrence after transplantation. Therapy was started late when hemodialysis had already been initiated; an earlier start of therapy might be more effective.

CD101 inhibits the expansion of colitogenic T cells.

CD101 exerts negative-costimulatory effects in vitro, but its function in vivo remains poorly defined. CD101 is abundantly expressed on lymphoid and myeloid cells in intestinal tissues, but absent from naïve splenic T cells. Here, we assessed the impact of CD101 on the course of inflammatory bowel disease (IBD). Using a T-cell transfer model of chronic colitis, we found that in recipients of naïve T cells from CD101(+/+) donors up to 30% of the recovered lymphocytes expressed CD101, correlating with an increased interleukin (IL)-2-mediated FoxP3 expression. Transfer of CD101(-/-) T cells caused more severe colitis and was associated with an expansion of IL-17-producing T cells and an enhanced expression of IL-2Rα/ß independently of FoxP3. The co-transfer of naïve and regulatory T cells (Treg) protected most effectively from colitis, when both donor and recipient mice expressed CD101. Although the expression of CD101 on T cells was sufficient for Treg-function and the inhibition of T-cell proliferation, sustained IL-10 production required additional CD101 expression by myeloid cells. Finally, in patients with IBD a reduced CD101 expression on peripheral and intestinal monocytes and CD4(+) T cells correlated with enhanced IL-17 production and disease activity. Thus, CD101 deficiency is a novel marker for progressive colitis and potential target for therapeutic intervention.

Macrophage polarisation changes within the time between diagnostic biopsy and tumour resection in oral squamous cell carcinomas--an immunohistochemical study.

BACKGROUND: The prognosis of solid malignancies has been shown to depend on immunological parameters, such as macrophage polarisation (M1/M2). Recently, it was reported that preoperative oral surgery leads to a worsening of oral squamous cell carcinomas (OSCC) prognosis. Diagnostic incision biopsies are oral surgery procedures that might lead to healing-associated M2 macrophage polarisation with a potential negative influence on tumour biology. No studies have compared macrophage polarisation in OSCC biopsies and tumour specimens. METHODS: Preoperative diagnostic incision biopsies (n=25) and tumour resection specimens (n=34) of T1/T2 OSCC were processed for immunohistochemistry to detect CD68-, CD11c-, CD163- and MRC1-positive cells. Samples were digitised using whole-slide imaging, and the expression of macrophage markers was quantitatively analysed. RESULTS: Carcinoma tissues obtained during OSCC tumour resections showed a significantly (P<0.05) increased CD163 cell count (M2 macrophages) compared with tissues obtained during preoperative incision biopsies. Additionally, the CD163/CD68 ratio (an indicator of M2 polarisation) was significantly (P<0.05) higher in tumour resection specimens than in biopsies. CONCLUSIONS: This study revealed for the first time an increase in M2 polarisation in samples obtained during OSCC tumour resection surgery compared with preoperative incision biopsies. The biopsy-induced tissue trauma might explain the observed shift in macrophage polarisation towards the tumour-promoting M2 type and could lead to accelerated tumour progression.

Molecular weight and molar substitution are more important in HES-induced renal impairment than concentration after hemorrhagic and septic shock.

BACKGROUND: Clinical studies have raised concerns about the safety of 6% hydroxyethylstarch (HES) 130/0.42, but the pathomechanisms of this renal impairment remain unknown. To evaluate the effects of different HES concentrations, molar substitutions and molecular weights in HES-induced renal impairment, we used a porcine two-hit model that combined haemorrhagic and septic shock. METHODS: We conducted a prospective, randomised, double-blinded, controlled study in a university animal laboratory. Thirty anaesthetised and ventilated pigs were randomised to receive volume replacement therapy using 6% HES130/0.42, 6% HES200/0.5, 10% HES130/0.42 or 10% HES200/0.5, all dissolved in 0.9% NaCl rather than 0.9% NaCl alone. First, we bled the animals until they reached half of their baseline mean arterial pressure (MAP) for 45 minutes followed by fluid resuscitation. As a second hit, sepsis was induced using an Escherichia coli-laden clot 6 hours after haemorrhagic shock. Volume resuscitation started with a delay of two hours and a central venous pressure goal of 12 mmHg. RESULTS: At the end of the study, the groups showed no difference in cardiac output or MAP, but the volume balance (mL/kg BW) was significantly higher in the 0.9% NaCl group (346±90; P≤0.05) than in the other groups (6% HES130, 125±26; 6% HES200, 105±15; 10% HES130, 114±17; 10% HES200, 96±23). Creatinine clearance (mL/min) was significantly lower in the 6% HES200 (26±33) and 10% HES200 (15±18) groups compared to the 0.9% NaCl group (104±46; P≤0.05) but not in the HES 130 formulations (6% HES130: 64±51; 10% HES130: 58±38) at the end of the study. CONCLUSION: In this porcine two-hit shock model, treatment with 0.9% NaCl, HES 130/0.42 or HES 200/0.5 led to a similar maintenance of haemodynamic values. Despite this similar maintenance of the haemodynamic values, volume replacement with 6% and 10% HES 200/0.5 led to an accumulation of HES, higher colloid osmotic pressure and significantly reduced renal function after haemorrhagic and septic shock. These facts support the presumption that not the concentration but the degree of substitution and the molecular weight play a decisive role in HES-induced renal impairment.

No evidence of pathogenic involvement of cathelicidins in patient cohorts and mouse models of lupus and arthritis.

Apart from their role in the immune defence against pathogens evidence of a role of antimicrobial peptides (AMPs) in autoimmune diseases has accumulated in the past years. The aim of this project was to examine the functional impact of the human cathelicidin LL-37 and the mouse cathelicidin-related AMP (CRAMP) on the pathogenesis of lupus and arthritis. Serum LL-37 and anti-LL-37 levels were measured by ELISA in healthy donors and patients with Systemic Lupus Erythematosus (SLE) and Rheumatoid arthritis (RA). Pristane-induced lupus was induced in female wild type (WT) and cathelicidin-deficient (CRAMP-/-) mice. Serum levels of anti-Sm/RNP, anti-dsDNA, and anti-histone were determined via ELISA, cytokines in sera and peritoneal lavages were measured via Multiplex. Expression of Interferon I stimulated genes (ISG) was determined by real-time PCR. Collagen-induced arthritis (CIA) was induced in male WT and CRAMP-/- mice and arthritis severity was visually scored and analysed histomorphometrically by OsteoMeasure software. Serum levels of anti-LL-37 were higher in SLE-patients compared to healthy donors or patients with RA. However, no correlation to markers of disease activity or organ involvement was observed. No significant differences of autoantibody or cytokine/chemokine levels, or of expression of ISGs were observed between WT and CRAMP-/- mice after pristane-injection. Furthermore, lung and kidney pathology did not differ in the absence of CRAMP. Incidence and severity of CIA and histological parameters (inflammation, cartilage degradation, and bone erosion) were not different in WT and CRAMP-/- mice. Although cathelicidins are upregulated in mouse models of lupus and arthritis, cathelicidin-deficiency did not persistently affect the diseases. Also in patients with SLE, autoantibodies against cathelicidins did not correlate with disease manifestation. Reactivity against cathelicidins in lupus and arthritis could thus be an epiphenomenon caused by extensive overexpression in blood and affected tissues. In addition, other cationic AMPs could functionally compensate for the deficiency of cathelicidins.

ANCA-positive vasculitis as a secondary autoimmune disease after autologous stem cell transplantation for systemic sclerosis: a case report.

Autologous stem cell transplantation (SCT) is increasingly used to treat autoimmune diseases (AD), in particular systemic sclerosis (SSc). Secondary autoimmune diseases are a known complication after autologous stem cell transplantations for any cause. A 43-year-old man had received an autologous stem cell transplantation for an aggressive diffuse cutaneous SSc. After mobilisation with cyclophosphamide and Granulocyte-Colony-Stimulating Factor stem cells were CD34-selected. The patient received a conditioning regimen with cyclophosphamide and Antithymocyte globulin. He had an excellent response with the modified Rodnan Skin Score decreasing from 34 to 3. One year and 4 months after SCT mild erythrocyturia without acanthocytes and proteinuria were seen for the first time on routine urinalysis. During the following year erythrocyturia increased to 131 erythrocytes /µl and protein excretion to 628 mg/g creatinine. At that time, acanthocytes of 25% finally could be detected. Due to the clearly nephritic constellation in urinalysis a renal biopsy was performed, which revealed mild global and focal-segmental sclerosing and focal-segmental proliferative glomerulonephritis without any signs of a IgA-nephropathy. The result was compatible with a renal manifestation of a small-vessel vasculitis. During the following laboratory workup ANCA of a perinuclear pattern with specificity for myeloperoxidase in high titers could be detected. Therefore the diagnosis of a p-ANCA-positive glomerulonephritis was established. As treatment, the patient received Rituximab, which turned out to be effective. We provide the first report of a patient who developed a p-ANCA-associated vasculitis after autologous stem cell transplantation for an autoimmune disease, namely systemic sclerosis.

[Changing spectrum of renal disease in HIV infection]. / Veränderungen im Spektrum der Nierenerkrankungen bei HIV-Infektion.

BACKGROUND AND OBJECTIVE: Renal disease is a common complication in HIV-infected patients. The causes and spectrum of kidney disease among these patients is extensive, including HIV-related and HIV unrelated causes. Our objective was to assess the changes in distribution of renal disease under antiretroviral therapy (ART). PATIENTS AND METHODS: Retrospective analysis of all patients from the Frankfurt HIV Cohort (FHC) who underwent renal biopsy because of chronic, progressive renal disease between 1989 and 2012. Two time periods were defined: 1989-2001 (early period) and 2000-2012 (late period). RESULTS: 69 HIV-infected patients, mostly Caucasian and male, underwent renal biopsy (early period: 22 patients, late period: 47 patients). During the total observation time immuncomplex-mediated glomerulonephritis (26.1 %), hypertensive (20.3 %) and diabetic nephropathy (20.3 %) were the most frequent causes of chronic renal disease. HIV-associated renal diseases were predominant in the first period, whereas hypertensive and diabetic kidney disease accounted for almost 50 % of cases diagnosed in the late period. Other types of renal disease frequently encountered during the late period include renal AA-amyloidosis and tenofovir-related kidney disease. CONCLUSION: The underlying pathology of renal disease in HIV-infected patients is highly variable and evolving. Since the introduction of HAART, renal disease not directly related to HIV has become the predominant cause, reflecting the growing burden of co-morbidities in this aging population.

Acute kidney injury caused by tenofovir disoproxil fumarate and diclofenac co-administration.

OBJECTIVES: The renal elimination of tenofovir (TFV) may be subject to renal drug-drug interactions that may increase the risk of kidney injury. Case reports indicated that diclofenac might increase TFV-associated nephrotoxicity via a drug-drug interaction, leading to an increased intracellular TFV concentration in proximal tubular cells. METHODS: A retrospective analysis of data for all patients from the Frankfurt HIV Cohort (FHC) who had diclofenac prescriptions between January 2008 and June 2012 was carried out. RESULTS: Among 89 patients with diclofenac use, 61 patients (68.5%) were treated with tenofovir disoproxil fumarate (TDF) and 28 patients (31.5%) were treated with TDF-sparing combination antiretroviral therapy (cART). Thirteen patients (14.6%) developed acute kidney injury (AKI) shortly after initiating diclofenac treatment. AKI occurred exclusively in TDF-treated patients, although all had previously stable renal function. All cases were accompanied by new onset of at least two parameters indicating proximal tubular damage, such as normoglycaemic-glucosuria and hypophosphataemia. TFV-associated nephrotoxicity was demonstrated by renal biopsy in four cases. Additionally, 11.5% of patients on TDF treatment developed new-onset proximal tubular damage, while having a preserved glomerular filtration rate. In contrast, diclofenac did not affect renal function in patients with TDF-sparing cART, as only one case of isolated hypophataemia was observed in these patients. In univariate analysis, risk factors for AKI were TDF-containing cART (P = 0.0076) and pre-existing hypophosphataemia (P = 0.0086). CONCLUSIONS: Drug-drug interaction caused by diclofenac could exacerbate TFV-associated nephrotoxicity. Diclofenac should be used with caution in patients on TDF therapy, especially in those with hypophosphataemia. Our findings need to be confirmed in larger studies.

[Histopathology of renal cell carcinoma]. / Histopathologie des Nierenzellkarzinoms.

By integrating genetic data into the traditional histology and immunohistochemistry-based classification system, the revised WHO classification of malignant tumors (2004) defined additional renal cell carcinoma subtypes, thereby enabling the application of additional diagnostic procedures.

[Personalized urooncology based on molecular uropathology: part 1: what is diagnostic routine?]. / Personalisierte Uroonkologie auf Grundlage einer molekularen Uropathologie : Teil 1: Was ist diagnostischer Alltag?

The approval of new therapeutic procedures for the three main malignancies of the urogenital tract in recent years has generated a need for personalization of urooncology. As a consequence the diagnostic procedures are no longer limited to histology and immunohistochemistry but also include the analysis of genetic alterations (mutations and chromosomal aberrations).