The need for kidney biopsy in the management of side effects of target and immunotherapy.

Introduction: The introduction of innovative therapies, resulting from revisiting cancer as a disease of the immune system, has changed the scenario of complications. These new classes of drugs, such as targeted therapies and immune checkpoint inhibitors, assure substantial advantages in cancer therapy, despite some side effects affecting various organs, including the kidney. Histological evaluations of kidney disorders induced by targeted/immunotherapy are limited. Method: In this study we examined the histological features of patients treated with new cancer agents who underwent a kidney biopsy for new onset kidney failure and/or urinary abnormalities. Results: The cohort included 30 adult patients. The most frequently administered therapies were immunotherapy (30%), targeted therapy (26.7%), immunotherapy plus targeted therapy (13.3%), immunotherapy plus chemotherapy (13.3%), targeted therapy plus chemotherapy (16.7%). The most common histological finding was tubular interstitial nephritis (30%) that was associated with acute tubular necrosis in 4 cases, and thrombotic microangiopathy (23.3%). After kidney biopsy, 16 of the 30 patients were treated according to the histological diagnosis. Fourteen patients were treated with steroids. One patient with membranous nephropathy was treated with a single dose of rituximab. A patient with severe thrombotic microangiopathy requiring dialysis received a treatment with eculizumab for 3 months. Overall some renal response was obtained in all patients treated with glucocorticoids, while complete kidney response was achieved in the patient treated with rituximab. Cancer treatment was resumed without change in 21 out of 30 patients. Conclusion: Kidney biopsy is critical for the management of kidney toxicities and should be strongly encouraged for patients showing adverse kidney effects of novel cancer agents.

Daratumumab monotherapy for refractory lupus nephritis.

Treatment-refractory lupus nephritis (LN) has a high risk of a poor outcome and is often life-threatening. Here we report a case series of six patients (one male and five females) with a median age of 41.3 years (range, 20-61 years) with refractory LN who received renal biopsies and were subsequently treated with intravenous daratumumab, an anti-CD38 monoclonal antibody (weekly for 8 weeks, followed by eight biweekly infusions and up to eight monthly infusions). One patient did not show any improvement after 6 months of therapy, and daratumumab was discontinued. In five patients, the mean disease activity, as assessed by the Systemic Lupus Erythematosus Disease Activity 2000 index, decreased from 10.8 before treatment to 3.6 at 12 months after treatment. Mean proteinuria (5.6 g per 24 h to 0.8 g per 24 h) and mean serum creatinine (2.3 mg dl-1 to 1.5 mg dl-1) also decreased after 12 months. Improvement of clinical symptoms was accompanied by seroconversion of anti-double-stranded DNA antibodies; decreases in median interferon-gamma levels, B cell maturation antigen and soluble CD163 levels; and increases in C4 and interleukin-10 levels. These data suggest that daratumumab monotherapy warrants further exploration as a potential treatment for refractory LN.

New Onset Biopsy-Proven Nephropathies after COVID Vaccination.

INTRODUCTION: To date, almost 7 billion doses of the different types of vaccine against SARS-CoV-2 have been administered worldwide. Although the severity of new cases of SARS-CoV-2 has progressively decreased, and the pressure on national health systems has declined, the development of de novo glomerular injuries has been suggested. METHODS: This study aimed to examine the patients who were hospitalized in our Unit between April and November 2021 and underwent renal biopsy for new-onset urinary abnormalities (UA) and/or renal impairment within 3 months of SARS-CoV-2 vaccination. RESULTS: We identified 17 patients who developed UA and/or renal insufficiency within 3 months of vaccination. Minimal change disease was the most common disease in our cohort (5 patients, 29.4%) followed by acute tubulointerstitial nephritis (TIN; 3 patients, 17.6%), membranous nephropathy (3 patients, 17.6%), and rapidly progressive IgA nephropathy (2 patients, 11.8%). The other 4 patients had a diagnosis of membranoproliferative glomerulonephritis (1 patient), systemic lupus erythematosus (1 patient), ANCA-associated vasculitis (1 patient), and tip-variant focal segmental glomerulosclerosis (1 patient), respectively. Eight out of the 17 patients (47.1%) developed acute kidney injury. Two patients with acute TIN had to start hemodialysis that was discontinued after 1 and 2 months, respectively, due to the recovery of renal function. All patients underwent treatment with corticosteroids and/or immunosuppressants. DISCUSSION: Although it is not possible to conclusively determine whether there is a causal relationship between SARS-CoV-2 vaccination and new-onset nephropathies, based on the appearance of UA and/or renal insufficiency shortly after vaccination, we hypothesize that the immune response to the COVID-19 vaccine may be a trigger of nephropathies. Therefore, our results highlight the need for pharmacovigilance. However, this report should not lead to vaccine hesitation during this pandemic as the benefits of vaccination strongly outweigh the potential risks.

Management of acute kidney injury in frail patients with biopsy-proven cast nephropathy: a combined approach with chemotherapy plus Supra-hemodiafiltration with post-adsorption endogenous reinfusion.

BACKGROUND: Patients with multiple myeloma often have kidney involvement with acute kidney injury which is frequently due to cast nephropathy. Hemodiafiltration with endogenous reinfusion (HFR) allows removal from the circulation of significant amounts of free light chains (FLCs) responsible for tubular damage. METHODS: Between 2014 and 2018, 13 patients affected by multiple myeloma (64% λ chain and 36% k), including 10 cases with biopsy-proven cast nephropathy, were treated with this technique. Each patient had high free light chains levels at diagnosis: median 8586 mg/l for λ and 4200 mg/l for k, and stage III acute kidney injury (median serum creatinine 7.5 mg/dl). We initially performed daily HFR-Supra sessions and then modulated them based on renal response (mean 10 sessions/patient). At the same time, the patients also received various chemotherapy regimens, depending on their hematological criteria. RESULTS: Forty-six percent of patients showed at least partial renal function recovery within the third month, thus allowing dialysis discontinuation; 38% remained on dialysis. Two patients died. The mean reduction rate of free light chains at the end of the HFR-Supra cycle was 85% (k) and 40% (λ), respectively. Serum albumin remained stable during the whole treatment. DISCUSSION: In our experience, the synergistic effect of chemotherapy and HFR-Supra led to a recovery of renal function in 6 out of 13 patients presenting with severe dialysis-requiring acute kidney injury. HFR-Supra allowed stable albumin levels, with high free light chains removal rate, at a relatively low costs.

Efficacy of low or standard rituximab-based protocols and comparison to Ponticelli's regimen in membranous nephropathy.

BACKGROUND: Patients (pts) with primary Membranous nephropathy (MN) have an autoimmune disease caused by autoantibodies against podocyte antigens and 60-80% of them have antibodies directed against the M-type phospholipase A2 receptor (PLA2R). Immunosuppressive treatment is recommended in high-medium risk pts. Recently the use of rituximab (RTX), has emerged as an important therapeutic option in pts with primary MN. The appropriate cumulative dose of RTX in PMN pts is still uncertain, and favorable outcomes even with low-dose of RTX has been described. We compared efficacy and safety of 3 different treatment regimens: low-dose RTX (Protocol 1, one dose of RTX 375 mg/m2), standard RTX protocol (Protocol 2, four weekly doses of rituximab 375 mg/m2) and Ponticelli's regimen. METHODS: 42 pts with primary MN and nephrotic syndrome were assigned to Protocol 1 (14 pts) or Protocol 2 (14 pts). All patients were followed for 24 months after RTX. Fourteen pts, matched for age and baseline serum creatinine (sCr) and proteinuria, treated with Ponticelli's regimen were examined as controls. RESULTS: At 24 months, a significant improvement in proteinuria levels was observed in pts treated with Protocol 1 (7.5 ± 4.8 at T0; 0.21 ± 0.15 at T24, p < 0.01), Protocol 2 (5.1 ± 1.41 g/24 at T0; 0.35 ± 0.39 at T24 p < 0.01) and controls (8.27 ± 4.78 T0; 2.2 ± 1.9 g/24 h at T24, p < 0.01). No differences in clinical response (p = 0.53) was observed comparing the 3 groups. CONCLUSIONS: Our data suggest that the RTX is a promising alternative to Ponticelli's regimen even at low-doses. This makes RTX a cost-effective treatment of primary MN in the short and medium terms.

The Challenging Management of Cancer: An Immunonephrologist's Perspective.

INTRODUCTION: Onconephrology is an emerging medical subspecialization that focuses on the numberless interrelations between cancer and kidney diseases. Tumor cells evade immune surveillance through activation of immune checkpoint pathways that suppress antitumor immune responses. By blocking checkpoints, new anticancer agents disrupt immune homeostasis but potentially induce immune-mediated diseases. Nephrologists and nephroimmunologists should be able to treat the nephrotoxic sequelae of cancer therapy and ensure continuation of the life-saving treatment. METHODS: Thirty-seven renal biopsies have been carried out over 42 months in oncologic patients, that is, 5.2% of the total native renal biopsies were carried out in the same period. The commonest diagnoses (>6 cases) were interstitial tubular nephritis, membranous glomerulopathy, IgA nephropathy, vasculitis, and focal and segmental glomerulosclerosis. CASE PRESENTATION: Three example cases, including focusing on key questions which could involve the nephrologists are reported in detail. They include a cancer-related Goodpasture Syndrome, the peculiar toxic effects of pemetrexed on tubular cells, and the intriguing relationship between bevacizumab and cryoglobulinemic glomerulonephritis. CONCLUSION: As shown by these 3 example cases, nephrologists need to be open-minded with regard to kidney biopsy in order to get a timely diagnosis. Nephrologists also need to improve their knowledge of cancer biology and therapy in order to prevent kidney problems, manage therapy-related immune-mediated disorders, and improve patient life expectancy.

Long-term effects of intensive B cell depletion therapy in severe cases of IgG4-related disease with renal involvement.

IgG4-related disease (IgG4-RD) is an immune-mediated disorder often showing elevated serum IgG4 concentrations, dense T and B lymphocyte infiltration, and IgG4-positive plasma cells and storiform fibrosis. We prospectively evaluated for 4 years 5 patients with histologically proven IgG4-RD of whom 3 had tubulointerstitial nephritis (TIN) and 2 had retroperitoneal fibrosis (RPF). They received an intensive B depletion therapy with rituximab. The estimated glomerular filtration rate of TIN patients after 1 year increased from 9 to 24 ml/min per 1.73 m2. IgG/IgG4 dropped from 3236/665 to 706/51 mg/dl, C3/C4 went up from 49/6 to 99/27 mg/dl, and the IgG4-RD responder index fell from 10 to 1. CD20+ B cells decreased from 8.7 to 0.5%. A striking drop in interstitial plasma cell infiltrate as well as normalization of IgG4/IgG-positive plasma cells was observed at repeat biopsy. Both clinical and immunological improvement persisted over a 4-year follow-up. Treating these patients who were affected by aggressive IgG4-RD with renal involvement in an effort to induce a prolonged B cells depletion with IgG4 and cytokine production decrease resulted in a considerable rise in eGFR, with IgG4-RD RI normalization and a noteworthy improvement in clinical and histological features. Furthermore, the TIN subgroup was shown not to need for any maintenance therapy.

Rituximab in severe immunoglobulin-A vasculitis (Henoch-Schönlein) with aggressive nephritis.

OBJECTIVES: Immunoglobulin-A vasculitis (IgAV) is a systemic small-vessel vasculitis in which renal involvement indicates severity of illness, and chronic kidney disease represents the most serious long-term complication. No treatment at present is specifically recommended for IgAV. Recently, rituximab (RTX) has been shown to be effective in case series of adults with IgAV. However, long term results are lacking. Aim of the study is to evaluate the effectiveness of RTX as induction therapy and maintenance of remission in adults with severe IgAV and aggressive glomerulonephritis. METHODS: This study included 12 adult-onset patients, 8 males and 4 females, mean age 45.1 years (range 19-75) with a mean follow-up duration of 33.7 months (range 6-144). All patients had a severe IgAV with biopsy proven crescentic nephritis. RTX was given for the treatment of a refractory disease or because of definite contraindications to standard therapies. RESULTS: Eleven patients (91.7%) achieved a clinical response at 6 months. Ten patients had a complete response (CR) while one had a partial response and was given an additional dose of RTX after 12 months for persistent proteinuria (1gr/24 hrs) despite systemic remission. He achieved a CR 6 months later. One patient was considered unresponsive to RTX and was switched to MMF. Among the 10 patients with CR, 1 needed maintenance doses of RTX every 6 months for iterative relapsing of severe purpura, 1 relapsed after 15 months and received a new induction course showing a CR again. A significant decrease in BVAS (p=0.031) and 24-hour-proteinuria (p=0.043) from RTX initiation through the last follow-up has been detected. One patient, who had a CR with RTX alone died after 6 months for therapy-unrelated cardiovascular cause. CONCLUSIONS: RTX proved to be effective and safe for induction and maintenance of long-lasting remission in severe IgAV with aggresive renal involvement. Data also suggest that RTX can be indicated not only for refractory cases, but can be also proposed as a first line therapy.

Monoclonal Gammopathy of Renal Significance: Clinical and Histological Efficacy of a Bortezomib-Based Regimen.

Monoclonal Gammopathy of Renal Significance (MGRS) is a group of heterogeneous disorders characterized by renal dysfunction secondary to the production of a monoclonal immunoglobulin by a nonmalignant B cell or plasma cell clone. We report the clinical and histological outcomes of two patients with biopsy-proven MGRS: one patient showed membranoproliferative glomerulonephritis with monoclonal k-light chain and C3 deposits, the second patient showed immunotactoid glomerulopathy. Both patients were treated with a 9-month chemotherapy protocol including bortezomib, cyclophosphamide, and dexamethasone. Renal biospy was repeated after 1 year. The estimated glomerular filtration rate (eGFR) increased from 22.5 (baseline) to 40 ml/min per 1.73 m2 after 12 months, then to 51.5 ml/min per 1.73 m2 after 24 months; proteinuria decreased from 4.85 (baseline) to 0.17 g/day after 12 months, then to 0.14 g/day after 24 months. Repeat renal biopsies showed a dramatic improvement of the glomerular proliferative lesions and near complete disappearance of the immune deposits. A bortezomib-based treatment proved very effective and was well-tolerated in the two patients presenting with clinically and histologically aggressive MGRS.

IgG4-related kidney disease: the effects of a Rituximab-based immunosuppressive therapy.

IgG4-related disease (IgG4-RD) is a recently recognized disorder, characterized by elevated serum IgG4 concentrations, dense tissue infiltration of IgG4-positive plasma cells and storiform fibrosis. Treatment is usually based on steroids, however, relapses and long-term adverse effects are frequent. We prospectively studied 5 consecutive patients with histologically-proven IgG4-RD and renal involvement, treated with an extended Rituximab protocol combined with steroids. Two doses of intravenous cyclophosphamide were added in 4 patients. Five patients with IgG-RD were investigated: three had tubulointerstitial nephritis (TIN), while two had retroperitoneal fibrosis (RPF). In the patients with TIN, renal biospy was repeated after 1 year. In the patients with TIN, estimated glomerular filtration rate (eGFR) at 12 months increased from 9 to 24 ml/min per 1.73 m2; IgG/IgG4 decreased from 3,236/665 to 706/51 mg/dl; C3/C4 increased from 49/6 to 99/27 mg/dl; CD20+ B-cells decreased from 8.7% to 0.5%; Regulatory T-cells decreased from 7.2% to 2.5%. These functional and immunologic changes persisted at 24 months and in two patients at 36 months. A repeat renal biopsy in the patients with TIN showed a dramatic decrease in interstitial plasma cell infiltrate with normalization of IgG4/IgG positive plasma cells. The patients with RPF showed a huge regression of retroperitoneal tissue. In this sample of patients with aggressive IgG4-RD and renal involvement, treatment aimed at depleting B cells and decreasing antibody and cytokine production was associated with a substantial, persistent increase in eGFR, and a definite improvement in immunologic, radiologic and histological parameters.