The risks associated with percutaneous native kidney biopsies: a prospective study

BACKGROUND

The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy.

METHODS

The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression.

RESULTS

Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08-1.17], liver disease (OR 2.27, 95% CI 1.21-4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07-1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92-0.99) were protective.

CONCLUSIONS

This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

The Role of Rituximab in Primary Focal Segmental Glomerular Sclerosis of the Adult

Introduction

Primary focal segmental glomerular sclerosis (FSGS) is a rare, likely immune-mediated disease. Rituximab (RTX) may play a role in management, although data in adults are scanty.

Methods

We collected cases of RTX-treated primary FSGS within the Italian Society of Nephrology Immunopathology Working Group and explored response rate (24-hour proteinuria <3.5 g and <50% compared with baseline, stable estimated glomerular filtration rate).

Results

A total of 31 patients were followed for at least 12 months; further follow-up (median 17 months, interquartile range [IQR] 15–33.5) was available for 11. At first RTX administration, median creatinine and 24-hour proteinuria were 1.17 mg/dl (IQR 0.83–1.62) and 5.2 g (IQR 3.3–8.81), respectively. Response rate at 3, 6, and 12 months was 39%, 52%, and 42%, respectively. In the first 12 months, creatinine level remained stable whereas proteinuria and serum albumin level improved, with an increase in the proportion of patients tapering other immunosuppressants. There were 6 patients who were retreated with RTX within 12 months, either for proteinuria increase or refractory disease; only the 2 responders to the first RTX course experienced a further response. At univariate analysis, 6-month response was more frequent in steroid-dependent patients (odds ratio [OR] 7.7 [95% CI 1.16–52.17]) and those with proteinuria <5 g/24 h (OR 8.25 [1.45–46.86]). During long-term follow-up, 4 of 5 responders at 12 months maintained a sustained response, either without further immunosuppression (2 of 4) or with pre-emptive RTX (2 of 4); 1 relapsed and responded to RTX retreatment.

Conclusion

RTX may be an option in primary FSGS, especially in steroid-dependent patients, with 24-hour proteinuria <5 g and previously responders to RTX. Optimal long-term management for responders is unclear, with some patients experiencing sustained remission and others requiring RTX retreatment, either preemptive or after rising proteinuria.

Rituximab or Cyclophosphamide in the Treatment of Membranous Nephropathy: The RI-CYCLO Randomized Trial

BACKGROUND

A cyclic corticosteroid-cyclophosphamide regimen is the first-line therapy for membranous nephropathy. Compared with this regimen, rituximab therapy might have a more favorable safety profile, but a head-to-head comparison is lacking.

METHODS

We randomly assigned 74 adults with membranous nephropathy and proteinuria >3.5 g/d to rituximab (1 g) on days 1 and 15, or a 6-month cyclic regimen with corticosteroids alternated with cyclophosphamide every other month. The primary outcome was complete remission of proteinuria at 12 months. Other outcomes included determination of complete or partial remission at 24 months and occurrence of adverse events.

RESULTS

At 12 months, six of 37 patients (16%) randomized to rituximab and 12 of 37 patients (32%) randomized to the cyclic regimen experienced complete remission (odds ratio [OR], 0.4; 95% CI, 0.13 to 1.23); 23 of 37 (62%) receiving rituximab and 27 of 37 (73%) receiving the cyclic regimen had complete or partial remission (OR, 0.61; 95% CI, 0.23 to 1.63). At 24 months, the probabilities of complete and of complete or partial remission with rituximab were 0.42 (95% CI, 0.26 to 0.62) and 0.83 (95% CI, 0.65 to 0.95), respectively, and 0.43 (95% CI, 0.28 to 0.61) and 0.82 (95% CI, 0.68 to 0.93), respectively, with the cyclic regimen. Serious adverse events occurred in 19% of patients receiving rituximab and in 14% receiving the cyclic regimen.

CONCLUSIONS

This pilot trial found no signal of more benefit or less harm associated with rituximab versus a cyclic corticosteroid-cyclophosphamide regimen in the treatment of membranous nephropathy. A head-to-head, pragmatic comparison of the cyclic regimen versus rituximab may require a global noninferiority trial.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Rituximab versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO), NCT03018535.

P0372RITUXIMAB IN IDIOPATHIC FOCAL SEGMENTAL GLOMERULOSCLEROSIS OF THE ADULT: A MULTICENTRE RETROSPECTIVE SURVEY OF 31 PATIENTS

Background and Aims

Idiopathic Focal Segmental Glomerulosclerosis (FSGS) is a rare glomerulonephritis often complicated by a chronic relapsing course frequently characterized by dependency or resistance to immunosuppressive treatment. Moreover, about half of the patients with active disease would develop end-stage renal disease within 10 years from the diagnosis, highlighting the need of novel therapeutic approaches. Rituximab (RTX), a chimeric monoclonal antibody against CD20, showed promising results in pediatric steroid-dependent/frequently relapsing FSGS and in post-transplantation recurrence. However, evidence about its role in the FSGS of the adult is still lacking with small case series suggesting conflicting results. In this study we assess the efficacy of RTX in the largest cohort of adults with FSGS currently available in literature.

Methods

Adults with biopsy proven idiopathic FSGS treated with RTX were retrospectively identified among several Italian nephrology units. Response to RTX was evaluated at 3, 6, 12 months and, when available, during the long-term follow-up. A positive response (POR) was defined as: (1) proteinuria &lt;3.5 g/die with a decrease &gt;50% compared to baseline, (2) stable renal function (3) decreased or stable dose of glucocorticoids and other immunosuppressants. Severe Adverse Events (SAEs) have been recorded.

Results

31 patients have been identified: 18 steroid-dependent, 11 steroid-resistant, and 2 patients with major contraindication to steroid therapy. RTX has been administered at a median of 87 months (IQR 54–96) from the diagnoses using heterogeneous schedules of administration. Overall, the POR rate at 6 months was 52% (steroid-dependent=69%; steroid-resistant=22%). At univariate analyses, POR to RTX at 6 months was associated to the steroid-dependent status (p=0.0347) and a proteinuria at RTX &lt;5 g/die (p=0.0173); a trend towards better response was observed in patients with IgG at RTX &lt;500 mg/dl (p=0.0774). Over the first year of follow-up, the proteinuria and serum albumin significantly improved (respectively, p=0.0021 and p=0.0277 at 12 months), while serum creatinine remained stable (figure). Among treated patients, the median dose of prednisone decreased from 15 mg/die (IQR 12.5–25) at baseline to 10 mg/die (IQR 5–15) at 12 months, while the proportion of patients free from glucocorticoids respectively increased from 42% to 54%. Six patients have been retreated within a year since the first RTX: of these only the 2 patients who have experienced a POR to the first administration obtained a further POR after retreatment. After the 12th month, 11 patients have been followed for a median time of 17 months (IQR 15–33.5): of the 5/11 with a POR at the 12th month, 2/5 maintained a POR without needing further immunosuppression, 2/5 maintained a POR with a pre-emptive RTX based maintenance treatment, 1/5 experienced a relapse successfully managed with RTX needing then a pre-emptive RTX based maintenance therapy able to allow a persistent POR. Overall, 9 SAEs have been recorded with requirement of hospital admission for clinical deterioration being the most frequent.

Conclusion

RTX may be an option in the FSGS of the adult, especially in the steroid-dependent patients and the ones with less severe nephrotic syndrome. In the responders, a RTX based maintenance therapy may be required.

[Survey on the Prevalence of Rare Kidney Diseases in Sicily]

Renal Diseases represent almost 6% of all Rare Diseases but are often misdiagnosed. In a survey made in Sicily in 2016, based on cases reported from all public hospitals according to a list of rare kidney diseases, we were able to collect 337 cases (199 males and 138 females). The highest prevalence was detected in children: 13.9 cases in 100.000 children; the mean age was 10, and the median 5 years, at the time of the diagnosis. Comparing our data with those available in the Sicilian Register of Rare Diseases we found that only 141 cases (54%) were present in the register. Promoting regional registries of rare kidney diseases in Italy may be useful for epidemiologic studies.

[Membranous glomerulonephritis with crescent overlapping]

Acute crescentic transformation is a rare but well described event in patients with membranous glomerulonephritis. We report our experience with a 66-year-old Caucasian man presented for rapid decline in renal function. For nearly 10 years, he was suffering from hypertension and mixed sensori-motor polyneuropathy. He performed therapy with prednisone and azathioprine, suspended 1 year before presentation. Moreover, six months before presentation, laboratory tests showed a serum creatinine concentration 220 mol/L and a 24-h protein excretion 0,75 g/d. The physical examination showed oedema and severe hypertension; the 24-h protein excretion was 1,1 gr/d and creatinine concentration was 550.8 mol/L; ANCA and other immunological tests were negative. There was no evidence of SLE, infection or malignancy. The kidney biopsy highlighted a membranous GN with crescentic overlap. The patient was treated with steroid and cyclophosphamide. Because there was no sign of improvement after 2 months, we stopped the cyclophosphamide therapy and the patient started chronic haemodialysis treatment. Unlike membranous nephropathy, patients with superimposed crescentic glomerulonephritis appear to have a more aggressive clinical course. The importance of recognizing this group of patients with membranous nephropathy and crescentic glomerulonephritis is that immunosuppressive therapy may ameliorate the progression of renal damage and in some cases early treatment was associated with useful recovery of renal function.

Acute kidney injury in a patient with metabolic syndrome

Introduction: The metabolic syndrome (MS) encompasses many metabolic abnormalities and the insulin resistance is considered as one of the most significant denominators. The chronic kidney disease (CKD) is an emerging health problem but only few patients would reach the end stage renal disease. There exists an increasing strong association between MS and CKD, but up until now the link between MS and CKD is unclear and there are few studies regarding the renal histology in MS.

Methods: We describe an acute tubulointerstitial nephritis case, due to both infective and pharmacological aetiology, overlapping relevant histological changes (focal segmental glomerulosclerosis [FSG], hyaline arteriosclerosis) in a patient with MS and previously normal renal function. Despite the severe vascular finding (elevated renal arterial resistive index), the patient recovered a normal renal function.

Results: We reviewed the kidney pathological studies in MS and analyzed the principal renal histological images of glomerulomegaly, segmental glomerulosclerosis, and obesity-related glomerulopathy.

Conclusion: Despite the strong association, the renal involvement in MS has not been proven. A greater knowledge of the combination of histological renal changes in MS can help to understand the pathophysiological mechanism(s) of MS.

[Renal involvement in Erdheim-Chester disease]

The Erdheim-Chester disease is a rare form of Langherans cells. Since 1987 it is distinguished from other istiocytosis previously identified. The diagnosis of the disease relies on defined radiological (bone imaging) and pathological (histiocytic infiltration) criteria. Bone disease is crucial but systemic manifestations are reported more frequently at onset. Renal involvement is always asymptomatic at onset of disease or in the follow-up. In this review we analyze the reports of the literature; we highlight 3 pathological mechanisms of renal involvement: renal and retroperitoneal infiltration, urinary tract obstruction, renal arteries stenosis. No treatment to date has demonstrated an improvement in survival of patients with EC. Renal involvement is therefore symptomatic (ureteral stenting, percutaneous nephrostomy) or is adopted a wait-and-see attitude.

Kidney involvement in a Wegener granulomatosis case

Wegener Granulomatosis is a systemic Anti-Neutrophil Cytoplasmic Autoantibody-associated Vasculitis, affecting small-to-medium vessels. Clinical presentation with simultaneous involvement of kidney and upper and lower respiratory tract is unusual. We report an instructive case of WG, analyzing clinical course, laboratory, and radiological features, kidney, lung, and larynx histological pictures. Besides renal biopsy, nephrology team performed larynx and lung biopsies because of unusual clinical presentation, computed tomography chest examination, and relevant malignancy risk regarding following immunosuppressant therapy.

Does systematic preliminar colour Doppler study reduce kidney biopsy complication incidence?

While ultrasonography is widely performed prior to biopsy, colour Doppler examination is often used only to discover post-biopsy complications. Aim of this paper was to evaluate the usefulness of colour Doppler examination in planning the optimal site of puncture for renal biopsy. Present analysis includes 561 consecutive percutaneous renal biopsies performed from the same operator. Until August 2000 332 biopsies were performed after a preliminary ultrasonography (Group A). From September 2000, 229 patients underwent even a preliminary colour Doppler study (Group B). Postbioptic bleeding were categorized as minor (gross hematuria or subcapsular perinephric hematoma < 4 cmq of greater diameter) or major (hematoma >4 cmq of greater diameter; requiring blood transfusion or invasive procedures; leading to acute renal failure, urine tract obstruction, septicaemia, or death). Major complications were seen in 2.1% in Group A while in Group B only one case was reported (0.43%). Minor clinically significant complications occur in 7.8% in Group A and in 3.4% of cases of Group B. Colour Doppler reduced drastically the incidence of complications observed before the introduction of routine colour Doppler examination prior to biopsy. In our opinion, these data support the use of preliminary colour Doppler study when a biopsy is planned.

Incidence of hepatitis C virus infection in patients with chronic kidney disease on conservative therapy

Hepatitis C virus (HCV) infection is a never-ending public health problem. Many studies have investigated the incidence of HCV infection among dialysis patients, but there have only been a few epidemiological studies in renal conservative therapy. We studied 320 subjects with pre-dialysis chronic kidney disease living in Sicily, Italy. The incidence of HCV infection was 6.25%. In Europe, incidence ranges from 0.2% to 3.5%. It appears that the incidence of HCV infection is higher in the studied patient population than in the population as a whole.

[Treatment of lupus nephritis]

SLE begins with renal symptoms in about 30-50% of the patients and after 10 years over 70% of them has complications. In the last years the medical therapy improved the outcome of SLE and its complications. Presently, the survival for lupus nephritis is 80% after five years. The nephritis treatment is divided into remission-inducing treatment that is followed by remission-maintaining treatment. Moreover, it is considered the therapy for preventing or reducing toxic and side-effects from drugs and the therapy for flare-ups. To initiate the specific therapy is important to consider the histological class (WHO). In the remission-inducing treatment steroids are used alone for 3-6 months in class IIB or in association with cyclophosphamide in classes III-IV and V and for flare-ups. For remission-maintaining treatment steroids are used in association with azathioprine. The drugs improved the outcome of nephritis but produced side-effects that determined the suspension of the drug and/or reduction of dosage and/or the use of other drugs like mycophenolate mofetil or rituximab.