Focal segmental glomerulosclerosis and mesangial sclerosis associated with myeloproliferative disorders

Paraneoplastic Syndrome After Kidney Transplantation: Frequency, Risk Factors, Differences to Paraneoplastic Occurrence of Glomerulonephritis in the Native Kidney, and Implications on Long-Term Kidney Graft Function

Posttransplant malignancies are an important complication of solid organ transplantation. Kidney transplant recipients are at particularly high risk of cancer development. The most relevant risk factors of carcinogenesis are the use of immunosuppressive agents and oncogenic viral infections. Additionally, immune dysregulation caused by these factors may predispose to various types of organ damage. Paraneoplastic glomerular diseases are one of the most interesting and understudied cancer manifestations. The appropriate diagnosis of paraneoplastic glomerular damage can be challenging in kidney transplant recipients, due to factors inherent to concomitant medication and common comorbidities. Recent advances in the field of molecular and clinical nephrology led to a significant improvement in our understanding of glomerular diseases and their more targeted treatment. On the other hand, introduction of novel anticancer drugs tremendously increased patients' survival, at the cost of kidney-related side effects. Our review aims to provide insights into diagnosis and treatment of paraneoplastic glomerular diseases, with a special attention to kidney transplant recipients.

Renal tubular necrosis associated with anagrelide administration: a case report

A 62-year-old female patient with essential thrombocythemia experienced rapid renal dysfunction and was subsequently referred to our hospital. Further investigations did not reveal any significant abnormalities except for a slight increase in urinary β2-microglobulin levels. A renal biopsy was performed to investigate the cause of her renal dysfunction, revealing acute tubular necrosis, interstitial edema, and arteriosclerosis. No significant glomerular lesions were observed. Immunofluorescence staining and electron microscopy showed no abnormalities. She had been using anagrelide for 4 years, and her dosage was increased from 2.0 to 3.0 mg/day 10 months before her initial admission. Her renal function began to deteriorate 2 months after the anagrelide dosage increase. Although 0.625 mg of bisoprolol was initiated for tachycardia 3 months after the anagrelide dosage adjustment, we suspected that the acute tubular necrosis was associated with anagrelide administration. After transitioning from anagrelide to hydroxyurea and discontinuing bisoprolol, her renal function improved. This case suggests the importance of considering anagrelide as a potential cause of renal dysfunction in patients using this medication. Therefore, renal biopsy, combined with a comprehensive medical history, is crucial for evaluating the etiology of renal injury in such cases.

Kidney and Urinary Tract Involvement in Chronic Myelomonocytic Leukemia

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy affecting the bone marrow and resulting in peripheral blood monocytosis. Kidney and urinary tract involvement is common and can present dramatically with life-threatening consequences. Kidney involvement can be the result of direct or indirect mechanisms, including prerenal azotemia, glomerular disease, tubulointerstitial involvement, and renovascular disorders. Urinary tract involvement, electrolyte and acid-base disorders, as well as nephrotoxicity from treatment of the disorder can also occur. Given this multifactorial pathogenesis involving several mechanisms concomitantly, nephrologists must exercise heightened awareness and maintain a low threshold for kidney biopsy. There is a pressing need for future research endeavors to elucidate and target the manifestations of CMML that involve the kidneys with the ultimate goal of augmenting overall prognosis and therapeutic outcomes.

Focal Crescentic Glomerulonephritis Superimposed on Myeloproliferative Disease-Related Glomerulopathy in a Case of Myelofibrosis

Proliferative glomerulonephritis in myelofibrosis is a very rare. Mesangial proliferation and sclerosis with changes of chronic thrombotic microangiopathy have been reported, but pauci-immune focal crescentic glomerulonephritis has not been described so far. Herein, we present a 68-year-old male who was a known case of myelofibrosis and presented with rapidly progressive glomerulonephritis and nephrotic range proteinuria. He was diagnosed as anti-neutrophil cytoplasmic antibody (ANCA)-negative focal crescentic glomerulonephritis, and he responded well to a course of intravenous methylprednisolone and cyclophosphamide. Pauci-immune focal crescentic glomerulonephritis may occur in myelofibrosis without ANCA and may be related to unknown pathogenetic mechanisms in myeloproliferative disorders or suggest any superimposed pathology that might respond well to immunosuppressants.

The spectrum of glomerular and vascular kidney pathology associated with myeloproliferative neoplasms

A high prevalence of chronic kidney disease (CKD) occurs in patients with myeloproliferative neoplasms (MPN). However, MPN-related glomerulopathy (MPN-RG) may not account for the entirety of CKD risk in this population. The systemic vasculopathy encountered in these patients raises the hypothesis that vascular nephrosclerosis may be a common pattern of injury in patients with MPN and with CKD. In an exhaustive, retrospective, multicenter study of MPN kidney biopsies in four different pathology departments, we now describe glomerular and vascular lesions and establish clinicopathologic correlations. Our study encompassed 47 patients with MPN who underwent a kidney biopsy that included 16 patients with chronic myeloid leukemia (CML) and 31 patients with non-CML MPN. Fourteen cases met a proposed definition of MPN-RG based on mesangial sclerosis and hypercellularity, as well as glomerular thrombotic microangiopathy. MPN-RG was significantly associated with both myelofibrosis and poorer kidney survival. Thirty-three patients had moderate-to-severe arteriosclerosis while 39 patients had moderate-to-severe arteriolar hyalinosis. Multivariable models that included 188 adult native kidney biopsies as controls revealed an association between MPN and chronic kidney vascular damage, which was independent of established risk factors such as age, diabetes mellitus and hypertension. Therefore, MPN-RG is associated with myelofibrosis and has a poor kidney prognosis. Thus, our findings suggest that the kidney vasculature is a target during MPN-associated vasculopathy and establish a new link between MPN and CKD. Hence, these results may raise new hypotheses regarding the pathophysiology of vascular nephrosclerosis in the general population.

Myeloproliferative Neoplasm and Myelodysplastic Syndrome-Associated Renal Disease: A Histopathological Report of Two Cases

Myeloproliferative neoplasms (MPN) are clonal disorders of hematopoietic stem cells with a proliferation of one or more myeloid lineage and mature cell overproduction, while myelodysplastic syndrome (MDS)/MPN simultaneously show aspects of MDS and MPN, leading to partially ineffective hematopoiesis with associated dysplastic changes. This spectrum of disorders includes chronic myeloid leukemia, polycythemia vera, primary myelofibrosis, and essential thrombocythemia. MDS/MPN are classically not associated with renal complications; however, an accumulating body of evidence suggests that multiple growth factors, cytokines, endothelial damage, and an activated complement system in these patients can induce glomerulopathy, as nearly a third of these patients present with advanced renal disease on diagnosis, which is unlikely to be age or hypertension-related. In this report, we present two cases of patients with MPN/MDS, a 45-year-old male with essential thrombocythemia and a 73-year-old male with polycythemia vera, both of whom developed generalized edema and were referred to our institution from their outpatient nephrologists due to accompanying proteinuria. Renal biopsy of the first patient revealed mesangiocapillary and mesangioproliferative MPN-associated glomerulopathy. In contrast, the second patient was diagnosed with MPN/MDS-associated segmental mesangial proliferative glomerulonephritis and renal vasculature drug toxicity. Both patients were started on treatment - corticosteroid as per consensus.

A Case of Focal Segmental Glomerulosclerosis Associated With Essential Thrombocythemia

A 72-year-old man was admitted for examination of proteinuria (9.14 g/day) and leg edema. Essential thrombocythemia (ET) was diagnosed because of thrombocytosis (platelet count, 57.9×10⁴/μL), elevated megakaryocytes in bone marrow biopsy, and JAK2 V617 mutation. Kidney biopsy led to a diagnosis of focal segmental glomerulosclerosis (FSGS) cellular variant (characterized by glomerular capillaries filled with swollen endothelial cells containing foam cells) in 6 glomeruli, FSGS tip variant in 5 glomeruli, and additional FSGS variants in other glomeruli. Affected glomeruli had anti-CD61 antibody staining-positive megakaryocyte infiltrations. ET mayinduce FSGS because megakaryocyte infiltration increases intraglomerular pressure, resulting in hypertension and proteinuria.

TRP channel function in platelets and megakaryocytes: basic mechanisms and pathophysiological impact

Transient receptor potential (TRP) proteins form a superfamily of cation channels that are expressed in a wide range of tissues and cell types. During the last years, great progress has been made in understanding the molecular complexity and the functions of TRP channels in diverse cellular processes, including cell proliferation, migration, adhesion and activation. The diversity of functions depends on multiple regulatory mechanisms by which TRP channels regulate Ca²⁺ entry mechanisms and intracellular Ca²⁺ dynamics, either through membrane depolarization involving cation influx or store- and receptor-operated mechanisms. Abnormal function or expression of TRP channels results in vascular pathologies, including hypertension, ischemic stroke and inflammatory disorders through effects on vascular cells, including the components of blood vessels and platelets. Moreover, some TRP family members also regulate megakaryopoiesis and platelet production, indicating a complex role of TRP channels in pathophysiological conditions. In this review, we describe potential roles of TRP channels in megakaryocytes and platelets, as well as their contribution to diseases such as thrombocytopenia, thrombosis and stroke. We also critically discuss the potential of TRP channels as possible targets for disease prevention and treatment.

Hematological Malignancies and the Kidney

The incidence of hematologic malignancies is on the rise worldwide. Kidney disease is ubiquitous in patients with hematologic malignancies, encompassing a wide spectrum of disorders involving each kidney compartment, including the vasculature, tubules, interstitium, and glomerulus, and there is significant overlap of kidney involvement with each hematologic malignancy. Vascular disorders include both microvascular and macrovascular damage, via thrombotic microangiopathy, hyperleukocytosis, hyperviscosity, and cryoglobulinemia. The tubulointerstitial compartment may be affected by prerenal azotemia and acute tubular injury, but malignant infiltration, tumor lysis syndrome, extramedullary hematopoiesis, cast nephropathy, granulomatous interstitial nephritis, and lysozymuria should be considered in certain populations. Obstructive uropathy may occur due to nephrolithiasis or retroperitoneal fibrosis. Glomerular disorders, including membranoproliferative, membranous, minimal change, and focal segmental glomerulosclerosis, can rarely occur. By understanding how each compartment may be affected, care can best be optimized for these patients. In this review, we summarize the widely varied etiologies of kidney diseases stratified by kidney compartment and hematologic malignancy, focusing on demographics, pathology, pathophysiology, mechanism, and outcomes. We conclude with common electrolyte abnormalities associated with hematologic malignancies.

Crescentic glomerulonephritis associated with polycythaemia vera: A rare occurrence

Glomerular diseases are one of the most challenging entities in terms of diagnosis and management, especially when associated with systemic illnesses such as malignant disorders. Herein, a case of crescentic glomerulonephritis (CrGN) associated with polycythaemia vera (PV) in a 50-year-old female is described. She presented with bilateral pedal oedema, splenomegaly, renal dysfunction and severe proteinuria. On evaluation, we found PV and CrGN. Renal involvement in PV is rare and generally considered as a manifestation of hypervolemia or high-viscosity-induced renal hyper-perfusion and hyper-filtration. This is a unique case of immunologically-mediated renal disease in PV.

Clinical and Pathological Features of Renal Presentations in Polycythemia Vera

BACKGROUND

Polycythemia vera (PV) is a common type of Philadelphia chromosome-negative chronic myeloproliferative disorder. PV-associated kidney disease is rarely reported and remains poorly understood. It has been observed that chronic kidney disease could be a risk factor for poor prognosis in PV.

METHODS

We retrospectively analyzed the clinicopathological features of renal presentations in eight patients with confirmed PV-associated kidney disease.

RESULTS

The eight patients were 6 males and 2 females, with a mean age of 46.4±16.8 years. Six patients had a history of PV, with a duration range 0.5-16 years. The other two patients were newly diagnosed with PV simultaneously with glomerular disease. Seven patients conducted a JAK2 V617F mutation test, with a positive result in five. Proteinuria and renal dysfunction were the patients' main complaints, with only one having nephrotic syndrome and three having microscopic hematuria. The level of proteinuria ranged from 0.52-10.96 g/day. Three patients had advanced chronic kidney disease (CKD), two in stage 3b and one in stage 4, but only one patient had anemia. Three patients had monoclonal immunoglobulinemia, one patient with immunoglobulin (Ig) G kappa plus light chain lambda, one patient with IgG kappa, and one patient with IgG lambda. Five patients underwent a renal biopsy. The pathological diagnosis was IgA nephropathy in three, non-IgA mesangial proliferative glomerulopathy in one, and glomerular hypertrophy with ischemic renal injury in one patient. Glomerular ischemia, ischemic shrinkage, focal segmental sclerosis, and glomerulomegaly were common pathological features. Glomerular crescents and endocapillary proliferation were also observed. All patients were administered hydroxyurea, and seven were administered renin-angiotensin system inhibitors. During follow-up, one patient with uncontrolled PV developed secondary myelofibrosis and died, three patients were lost to follow-up, and four patients remained alive with CKD.

CONCLUSIONS

Patients with untreated or uncontrolled PV could have massive proteinuria and advanced CKD, pathologically showing ischemic, sclerosing glomerular lesions with hypercellurity, glomerular crescents and endocapillary proliferation. IgA nephropathy was most commonly diagnosed. These findings deserve attention because early screening and effective control of PV may benefit the long-term kidney prognosis.

Renal Diseases Associated with Hematologic Malignancies and Thymoma in the Absence of Renal Monoclonal Immunoglobulin Deposits

In addition to kidney diseases characterized by the precipitation and deposition of overproduced monoclonal immunoglobulin and kidney damage due to chemotherapy agents, a broad spectrum of renal lesions may be found in patients with hematologic malignancies. Glomerular diseases, in the form of paraneoplastic glomerulopathies and acute kidney injury with various degrees of proteinuria due to specific lymphomatous interstitial and/or glomerular infiltration, are two major renal complications observed in the lymphoid disorder setting. However, other hematologic neoplasms, including chronic lymphocytic leukemia, thymoma, myeloproliferative disorders, Castleman disease and hemophagocytic syndrome, have also been associated with the development of kidney lesions. These renal disorders require prompt recognition by the clinician, due to the need to implement specific treatment, depending on the chemotherapy regimen, to decrease the risk of subsequent chronic kidney disease. In the context of renal disease related to hematologic malignancies, renal biopsy remains crucial for accurate pathological diagnosis, with the aim of optimizing medical care for these patients. In this review, we provide an update on the epidemiology, clinical presentation, pathophysiological processes and diagnostic strategy for kidney diseases associated with hematologic malignancies outside the spectrum of monoclonal gammopathy of renal significance.

Treatment of Essential Thrombocythemia with Anagrelide Is Associated with an Increased Risk of Worsened Kidney Function

BACKGROUND AND PURPOSE

When choosing a cytoreduction method for patients suffering from essential thrombocythemia (ET), it is important to know the safety profile of the medicine used. Few articles have been published about the effects of hydroxycarbamide (hydroxyurea, HU) and anagrelide (ANA) on renal function in ET patients. This study is the largest analysis of nephrotoxicity of cytoreductive drugs used in ET therapy so far, which additionally includes risk factors for the progression of kidney disease and coexisting genetic mutation.

EXPERIMENTAL APPROACH

The retrospective study included 310 patients diagnosed with ET. Demographic data, comorbidities, Cr, and estimated glomerular filtration rate (eGFR) were all taken into account prior to diagnosis and after 6 months of HU and ANA treatment.

KEY RESULTS

A statistically significant difference was found between Cr and eGFR levels at baseline and after 6 months of treatment (p < 0.001). The applied treatment (HU and ANA) had the greatest impact on kidney function. ANA significantly increased the risk of worsening renal function in contrary to hydroxycarbamide after 6 months of treatment (eGFR change: median +1 mL/min/1.73 m2 [interquartile range (IQR) (-4)-(+7)] in the HU group vss. median -13 mL/min/1.73 m2 [IQR (-18)-(-6)] in the ANA group, odds ratio [OR] 7.92 95% confidence interval [95% CI] [4.17-15.08], p < 0.001). Lowering of eGFR <60 mL/min/1.73 m2 occurred in 31 patients (31.0%) from the ANA group and 10 people (4.8%) treated with HU (p = 0.000). In 1 patient from the ANA group, >50% decrease in eGFR was observed. The chance for an increase in Cr levels was higher in people with pre-existing arterial hypertension (OR 1.92 CI = 95% [1.21-3.05], p = 0.006). Sex, type of mutation found (JAK2 V617F or CALR), and previous renal impairment did not affect renal function after 6 months of treatment. In addition, there was no difference in the efficacy of ET treatment between HU and ANA (p = 0.998).

CONCLUSIONS AND IMPLICATIONS

The observations indicate that ANA should be used in patients with ET with great caution and taking into account the risk of worsened kidney function.

Onconephrology: The intersections between the kidney and cancer

Onconephrology is a new subspecialty of nephrology that recognizes the important intersections of kidney disease with cancer. This intersection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, paraneoplastic glomerulonephritis, and the interactions of chronic kidney disease with cancer. Data clearly demonstrate that, when patients with cancer develop acute or chronic kidney disease, outcomes are inferior, and the promise of curative therapeutic regimens is lessened. This highlights the imperative for collaborative care between oncologists and nephrologists in recognizing and treating kidney disease in patients with cancer. In response to this need, specific training programs in onconephrology as well as dedicated onconephrology clinics have appeared. This comprehensive review covers many of the critical topics in onconephrology, with a focus on acute kidney injury, chronic kidney disease, drug-induced nephrotoxicity, kidney disease in stem cell transplantation, and electrolyte disorders in patients with cancer.

Renal disease associated with myeloproliferative neoplasms and myelodysplastic syndrome/myeloproliferative neoplasms

AIMS

Renal changes in patients with myeloproliferative neoplasms (MPNs) or myelodysplastic syndrome (MDS)/MPNs have been addressed by few, respectively no, reports. The aim of this study was to focus on a systematic evaluation of renal biopsies in patients with MPNs or MDS/MPNs.

METHODS AND RESULTS

The cohort comprised 29 patients (23 men) aged 67 ± 11 years (mean ± standard deviation), diagnosed with chronic myeloid leukaemia (n = 5), polycythaemia vera (n = 9), primary myelofibrosis (n = 5), essential thrombocythaemia (n = 2), or chronic myelomonocytic leukaemia (n = 4), as well as MPNs or MDS/MPNs not otherwise specified (n = 4). Patients manifested with proteinuria (93%), partially in the nephrotic range (46%), haematuria (72%), and impaired kidney function (93%). The most prominent histological findings included double-contoured glomerular basement membranes (71%), acute endothelial damage (68%), intracapillary platelet aggregation (62%), mesangiolysis (21%), thrombotic microangiopathy (24%), segmental glomerulosclerosis (66%), mesangial hypercellularity and sclerosis, extramedullary haematopoiesis (17%), and also IgA nephropathy (21%) and glomerulonephritis (GN) with features of infection-related GN (21%). MPN and MDS/MPN patients showed significantly more chronic changes than age-matched and sex-matched controls, including global and segmental glomerulosclerosis, mesangial sclerosis, and hypercellularity, whereas the extent of arteriosclerosis was comparable.

CONCLUSIONS

MPN and MDS/MPN patients show glomerular scarring that exceeds age-related phenomena. Ongoing endothelial damage, growth factors released by platelets and deposition of immune complexes are probably the causative mechanisms. Early recognition of renal failure heralded by proteinuria and haematuria, and consequent control of risk factors for kidney failure, should be recommended for MPN and MDS/MPN patients.

A Case of Essential Thrombocythemia and IgA Nephropathy with Literature Review of the Concurrence

Myeloproliferative neoplasms such as essential thrombocythemia (ET) have been associated with glomerular disease on rare instances. A case of ET associated with immunoglobulin A nephropathy (IgAN) is described in a 57-year-old man with a history of hypertension. Progressively worsening renal function was noted in the patient along with unexplained mild thrombocytosis. Pathological review of renal biopsy identified IgAN concurrently with newly diagnosed JAK2-mutated ET. The patient was started on aspirin therapy and closely monitored for his renal function. A literature review of the association of ET and renal disease revealed nine cases of ET associated with IgAN, focal segmental glomerulosclerosis, and fibrillary glomerulonephritis. Comparison of the pathological features of the renal biopsies within the cases noted mesangial proliferation as a common finding, which has been described to be potentiated by platelet-derived growth factor (PDGF). This commonality may represent a link between ET and glomerular disease which deserves further attention in future cases. Improved management of such cases depends on the recognition of the combined occurrence of ET and glomerular diseases and uncovering the shared pathogenesis between platelets and glomeruli.

Myeloid disorders after autoimmune disease

Autoimmune diseases (ADs) are associated with an increased risk not only of lymphoproliferative disorders but also of myeloid malignancies. The excess risk of myelodysplastic syndromes and/or acute myeloid leukemia is observed across several AD types, including systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disorders, multiple sclerosis, among others. The risk of developing myeloid neoplasms (MNs) is dependent on several variables, including the specific AD type, chronicity and severity of the AD, type and duration of exposure of disease modifying anti-rheumatic drugs or cytotoxics/immunosuppressives, and genetic predisposition risk. Putative triggering factors linking AD to elevated MN risk include AD-directed medications, shared genetic susceptibilities between the two disease entities, and chronic immune stimulation or bone marrow infiltration by the AD. Molecular mechanisms underpinning leukemogenesis remain largely speculative and warrant further investigation. Leukemias arising in patients with AD are not always 'therapy-related' in that MNs may develop in certain AD subtypes even among patients with no prior therapy exposure. Only a few studies have attempted to determine factors associated with MN development in AD but failed to demonstrate consistent characteristic clinical or paraclinical features. These reports have failed to demonstrate a clear correlation between individual agent exposure and subsequent leukemia development due to the low rates of therapy exposure compounded by the rarity of MN occurrence. Notwithstanding, the leukemogenic potential is best documented with agents such as azathioprine, cyclophosphamide, and mitoxantrone; this risk of MN development does not appear to be shared by biologic approaches such as anti-tumor necrosis factors-alpha inhibitors. In this article, we discuss plausible biologic mechanisms underlying MN pathogenesis in AD and review the data available on the development of MNs in patients with AD.

WITHDRAWN: Nephrotic syndrome in primary myelofibrosis with renal extramedullary hematopoiesis and glomerulopathy in the JAK inhibitor era

Ahead of Print article withdrawn by publisher. The publisher apologizes for any inconvenience this has caused. The article was scheduled for the journal "Clinical Nephrology. Case Studies" (issn 2196-5293). The article is available in PubmedCentral: https://www.ncbi.nlm.nih.gov/pubmed/29350220 
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Hydroxyurea for Treatment of Nephrotic Syndrome Associated With Polycythemia Vera

Myeloproliferative disorders are a rare cause of focal segmental glomerulosclerosis (FSGS), although the mechanism is unclear. Hydroxyurea is commonly used in these disorders for its cytoreductive properties; however, the effect of this treatment on proteinuria or kidney function remains unclear in cases of myeloproliferative disorder-associated FSGS. We describe the clinical course of a patient with polycythemia vera and nephrotic-range proteinuria, demonstrated to have FSGS on biopsy. The patient had a distant history of granulomatosis with polyangiitis (Wegener's), for which he routinely had his kidney function and proteinuria measured, allowing for early detection of nephrotic syndrome soon after being diagnosed with polycythemia vera. Treatment with hydroxyurea resulted in rapid improvement in proteinuria that correlated with a decrease in hematocrit. This response was replicated 2 additional times when the patient was taken off and then restarted on hydroxyurea therapy. He now maintains a steady dose of hydroxyurea with favorable kidney measures (proteinuria with <1g/d of protein excretion and serum creatinine of 1.27mg/dL [corresponding to estimated glomerular filtration rate of 56mL/min/1.73 m(2)]). This case suggests that early screening and treatment for myeloproliferative disorder-associated FSGS may lead to improved long-standing kidney function.

Polycythemia vera associated with IgA nephropathy: A case report and literature review

A case of polycythemia vera (PV) associated with immunoglobulin A nephropathy (IgAN) in a 57-year-old man is described. The patient had a mild enlargement of the kidneys and elevated serum creatinine level, whereas the glomerular filtration rate was normal. Pathological observation under a light microscope showed mild mesangial hyperplasia. The urinary protein level was found to be positively correlated with changes in blood cell counts. After controlling blood pressure, anti-platelet, hydroxyurea treatment, the patient's proteinuria decreased and renal function remained in the normal range. PV associated with renal disease is rare and generally considered to be associated with hypervolemia or high-viscosity-induced renal hyperperfusion and hyperfiltration. This is a rare case of PV associated with IgAN without a high filtration rate. A review of the clinical features of PV associated with renal disease from previous literature was also conducted. The histological results of the cases varied and included IgAN, focal segmental glomerulosclerosis and membranoproliferative glomerulonephritis.

Poststreptococcal glomerulonephritis in a patient with essential thrombocytosis

In addition to being the main cause of glomerulonephritis in children, poststreptococcal glomerulonephritis (PSGN) has recently been shown in older patients, especially those with malignancy or diabetes mellitus. The pathogenesis of PSGN has been ascribed to activation of complement 3 (C3) of the alternative complement cascade which, along with immunoglobulin (Ig) G and IgM deposits, is observed in renal tissue. Our aim here is to discuss the probable causes of PSGN developing with isolated IgM deposition in a 52-year-old patient with essential thrombocytosis followed-up over the previous 3.5 years. These characteristics make our case the first to be reported in the literature.

Chronic kidney disease in patients with the Philadelphia-negative chronic myeloproliferative neoplasms

BACKGROUND

The progression of kidney function and frequency of chronic kidney disease (CKD) in patients with the Philadelphia-negative myeloproliferative neoplasms (MPN) is unknown, although CKD is linked to increased mortality.

METHODS

This longitudinal retrospective study evaluates the estimated glomerular filtration rate (eGFR) in 143 MPN patients over a period of 9 years.

RESULTS

29% of patients had CKD stage 3 or 4 at time of diagnosis. 20% of patients had a rapid annual loss of eGFR (>3mL/min/1.73m(2)) and eGFR was negatively correlated to monocyte and neutrophil counts.

CONCLUSION

Kidney impairment might contribute to the increased mortality observed in MPN patients.

Glomerular diseases associated with cancer, chemotherapy, and hematopoietic stem cell transplantation

Many solid and hematological malignancies have been associated with different glomerular diseases. Several case reports and case series of cancer-associated glomerular diseases have shown that treating the cancer may lead to resolution of the glomerular process. Hence, knowledge and approach to cancer-associated glomerular diseases is important for both the caring nephrologists and the cancer specialists. While membranous nephropathy has been classically associated with solid malignancies, minimal change disease has been commonly described with hematologic malignancies, especially non-Hodgkin's lymphoma. Membranoproliferative glomerulonephritis is increasingly being recognized to be associated with chronic hematologic malignancies such as chronic lymphocytic leukemia. In this article, we review various cancer-associated glomerular diseases and their pathogenesis as well as principles of treatment. In addition, we also review glomerular diseases seen after chemotherapy and hematopoietic stem cell transplantation.

Kidney involvement in leukemia and lymphoma

Leukemia and lymphoma are hematologic malignancies that can affect any age group. Disease can be aggressive or indolent, often with multiorgan system involvement. Kidney involvement in leukemia and lymphoma can be quite extensive. Acute kidney injury (AKI) is quite prevalent in these patients, with prerenal and acute tubular necrosis being the most common etiologies. However other prerenal, intrinsic, and obstructive etiologies are possible. AKI can be a direct effect of the malignancy, a complication of the malignancy, or the consequence or side effect of chemotherapy. Nephrotic syndrome and glomerulonephritis, often presenting without overt kidney failure, have also been seen in all forms of leukemia and lymphoma. Lastly, the direct effects of the malignancy and complications from the tumor often result in numerous electrolyte disturbances and acid-base disorders, with life-threatening consequences if left untreated.

Renal biopsy cases in myeloproliferative neoplasms (MPN)

We performed renal biopsy in three cases complicated by myeloproliferative neoplasms (MPN). Although several cases of glomerulonephritis associated with MPN have been reported, the etiologies of the renal disorders were not established (Plomley et al., Aust NZ J Med, 13:125–129, 1983; Sharma et al., Nephron, 69:361, 1995; Kanauchi et al., Intern Med, 33:36–40, 1994; Kasuno et al., Nephrol Dial Transplant, 12:212–215, 1997; Au et al., Am J Kid Dis, 34:889–893, 1999; Kosch et al., Nephrol Dial Transplant, 15:1710–1711, 2000; Oymak et al., Nephron, 86:346–347, 2000; Chun et al., Am J Nephrol, 20:344–346, 2000; Chung et al., Am J Nephrol, 22:397–401, 2002; Asaba et al., Clin Exp Nephrol, 7:296–300, 2003; Haraguchi et al., Clin Exp Nephrol, 10:74–77, 2006; Saigusa et al., J Nephrol, 19:656–658, 2006; Okuyama et al., Clin Nephrol, 6:412–415, 2007; Nishi et al., Clin Nephrol, 5:393–398, 2010; Ulusoy et al., Intern Med, 49:2477, 2010). A review of previous reports of renal biopsy cases with MPN in the English literature suggested that circulation control is important for the treatment of renal disorders that mimic glomerulonephritis in MPN.

Myeloproliferative neoplasms cause glomerulopathy

Myeloproliferative neoplasms are clonal hematopoietic stem cell disorders that can produce an undefined glomerulopathy. To better characterize the glomerular disease associated with myeloproliferative neoplasms, we evaluated features of 11 patients with myeloproliferative neoplasm-related glomerulopathy that included 8 patients with primary myelofibrosis, and 1 each with chronic myelogenous leukemia, polycythemia vera, and essential thrombocythemia. Indications for biopsy were nephrotic-range proteinuria (nephrotic syndrome in four) and chronic renal insufficiency. The mean time from diagnosis of the neoplasms to biopsy was 7.2 years. Histologically, mesangial sclerosis and hypercellularity were seen in all 11 cases, segmental sclerosis in 8, features of chronic thrombotic microangiopathy in 9, and intracapillary hematopoietic cells in 4. On follow-up, seven patients had persistent renal dysfunction and four progressed to end-stage renal disease (ESRD). Thus, glomerulopathy appears to be a late complication of myeloproliferative neoplasms, particularly primary myelofibrosis, with guarded prognosis. Greater awareness of this entity and larger studies are needed to define possible therapies.

Pathogenesis, diagnosis and management of paraneoplastic glomerulonephritis

Paraneoplastic glomerulonephritis is a rare complication of malignancy that is frequently mistaken for idiopathic glomerulonephritis. Failure to recognize paraneoplastic glomerulonephritis can subject patients to ineffective and potentially harmful therapy. The pathology of paraneoplastic glomerulonephritis varies between different types of malignancies. This Review discusses the association of glomerulonephritis with both solid tumors and hematological malignancies. The pathogenetic mechanisms of many glomerular lesions seem to relate to altered immune responses in the presence of a malignancy. Studies in the Buffalo/Mna rat model of spontaneous thymoma and nephrotic syndrome indicate that polarization of the immune response toward a T-helper-2 (T(H)2) profile has an important role in the development of thymoma-associated glomerular lesions. Furthermore, overexpression of the T(H)2 cytokine interleukin 13 in rats induces minimal change disease. Such findings from experimental studies might facilitate the identification of biomarkers that can distinguish paraneoplastic glomerulonephritis from idiopathic and other secondary glomerulonephritides. This Review describes potential pathogenetic mechanisms for paraneoplastic glomerulonephritides associated with different malignancies and highlights the need for a multidisciplinary approach to the management of patients with paraneoplastic glomerulonephritis.

Protracted remission of proteinuria after combined therapy with plasmapheresis and anti-CD20 antibodies/cyclophosphamide in a child with oligoclonal IgM and glomerulosclerosis

We describe a child presenting with oligoclonal plasma IgM (1.2 g%) and nephrotic syndrome with focal segmental glomerulosclerosis. Oligoclonality was demonstrated by the analysis of the complementary determining region 3 (CDR 3) on immunoglobulin heavy chains and by two dimensional electrophoresis and Western blot analysis that showed the bulk of isoforms having a cationic muU chain compared with the normal homologue (pI 7.5 vs 6.5). Urinary light chains were absent, and bone marrow aspirate was normal. Usual therapies for nephrotic syndrome with steroids and cyclosporin were useless. At the age of 9 years the patient was treated with plasmapheresis plus cyclophosphamide (2 mg/kg per day for 60 days), which temporarily reduced plasma IgM, and proteinuria was normal for 3 years. After this period, due to new recurrence of nephrotic syndrome, the patient received a cycle with anti-CD20 antibodies (500 mg/m(2) every week for a month) associated with a cycle of plasmapheresis that normalized proteinuria again, and, after 3 years, the proteinuria is still in remission. This is the first case of nephrotic syndrome associated with oligoclonal plasma IgM and mesangial IgM deposits. Both cyclophosphamide and anti-CD20 antibodies associated with plasmapheresis induced, at different stages, stable and protracted remission of proteinuria without evident side effects. Long term efficacy and safety of the association are still to be determined.

Spectrum of renal pathology in hematopoietic cell transplantation: a series of 20 patients and review of the literature

BACKGROUND AND OBJECTIVES

Hematopoietic cell transplantation is a common treatment option for a variety of hematopoietic malignancies. As a result of the use of total body irradiation and/or chemotherapeutic agents, renal dysfunction often ensues. Many pharmacologic agents, such as cyclosporine and high-intensity conditioning regimens, have been linked with thrombotic microangiopathy. In addition, an association between membranous nephropathy and graft-versus-host disease has been reported in this clinical setting.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

A study of autologous and allogeneic hematopoietic cell transplantation patients with renal dysfunction was conducted to document the spectrum of renal manifestations. The pathology files at the University of Washington and University of Chicago Medical Centers were reviewed, and 20 patients with a kidney biopsy after hematopoietic cell transplantation were identified. The histologic findings were correlated with relevant clinical information.

RESULTS

A wide spectrum of renal diseases could be classified into four categories: (1) Complications related to hematopoietic cell transplantation (conditioning regimen, immunosuppression, or posttransplantation complications), (2) podocytopathy, (3) membranous nephropathy, or (4) recurrence or persistence of original hematologic disease. Pathologic diagnoses included thrombotic microangiopathy, polyoma virus nephropathy, acute kidney injury/acute tubular necrosis, acute and chronic interstitial nephritis, minimal-change disease, "tip" variant of focal segmental glomerulosclerosis, membranous nephropathy, amyloidosis, and myeloma cast nephropathy. Membranous nephropathy, minimal-change disease, and amyloidosis were common causes of severe proteinuria. Because of the conditioning regimens, posttransplantation complications, and potential nephrotoxic agents used during hematopoietic cell transplantation, it was difficult to attribute the subsequent renal dysfunction to specific factors.

CONCLUSIONS

The renal biopsy remains essential for diagnosing the underlying injury that can affect one or more compartments of the kidney in this unique clinical setting.

[Lymphoma with initial renal involvement: four cases]

PURPOSE

To present a comprehensive description of the clinical features of patients with renal manifestations during lymphoma.

METHODS

Retrospective review of medical records from all patients diagnosed with lymphoma associated with kidney involvement in our hospital between 1996 to 2004. Four cases were identified and analysed.

RESULTS

Four patients presented a non-Hodgkin's lymphoma. One patient showed intravascular large B-cell lymphoma, revealed by proteinuria. Another patient had a nephrotic syndrome, and two had a renal mass. Renal histology allowed diagnosis of lymphoma in 3 cases.

CONCLUSION

The diagnosis of lymphoma associated with renal involvement is rather difficult, and more specifically in case of intravascular large B-cell lymphoma, or even primary renal lymphoma. We present here a comprehensive review of the literature and we discuss pathogenesis of these conditions.

Focal segmental glomerulosclerosis associated with essential thrombocythemia

Focal segmental glomerulosclerosis (FSGS) is a primary glomerular disease that is characterized by progressive proteinuria and declining renal function. Secondary FSGS is known to be associated with various diseases. However, an association of FSGS with essential thrombocythemia (ET) has been reported in few cases. We report a 76-year-old man who presented with nephrotic syndrome and hepatosplenomegaly. He had thrombocythemia after a splenectomy, which had been carried out at a nearby hospital. A renal biopsy showed that he had focal segmental glomerulosclerosis (FSGS), while assessment of the bone-marrow specimen revealed that he had ET. A possible relationship between FSGS, which occurred in association with a dramatic increase of thrombocytes after a splenectomy in a patient with ET, and increased serum levels of transforming growth factor (TGF)-beta, basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF)-BB was suggested.

Focal segmental glomerulosclerosis in a patient with large bilateral asymptomatic adrenal myelolipomas

Adrenal myelolipomas are rare benign tumors, usually discovered by chance in patients with hypertension, obesity or various endocrine disorders. Focal segmental glomerulosclerosis (FSGS) can occur as a primary disease or in a variety of secondary settings. So far, no association between the two conditions has been described. We report a case of a woman admitted for nephrotic syndrome, in which a coexistence of FSGS and bilateral large adrenal myelolipomas was revealed.

Disseminated hepatosplenic mycobacterial infection masking myeloproliferative diseases as leukemoid reaction: a diagnostic pitfall

The distinction of myeloproliferative disease (MPD) from leukemoid reactions due to reactive causes can be difficult. In the presence of simultaneous occurrence of MPD and an established infection, only the demonstration of a clonal marker or prolonged observation can substantiate the diagnosis. We present three cases of MPD presenting as leukemoid reaction due to disseminated hepatosplenic mycobacterial sepsis. There appeared to be an association between MPD and reduced resistance to mycobacterial infection. Clinicians and hematologist should be aware of such a predisposition and possible dual pathology for proper diagnosis, therapy and monitoring of both the infection and the myeloproliferation.