Membranoproliferative glomerulonephritis and circulating cryoglobulins

Relationship between MRI findings and renal histopathology in IgG4-related tubulointerstitial nephritis

OBJECTIVES

Magnetic resonance imaging (MRI) is expected to be a valuable tool for evaluating disease activity in immunoglobulin G4 (IgG4)-related tubulointerstitial nephritis (IgG4-TIN). However, the correlation between MRI findings and renal histopathological findings remains to be elucidated. This study aimed to clarify the correlation.

METHODS

This retrospective cross-sectional study investigated 26 patients with biopsy-proven IgG4-TIN who underwent simultaneous percutaneous kidney biopsies and abdominal MRI examinations. We reviewed kidney biopsy specimens and scored the degree of inflammatory cell infiltration and interstitial fibrosis. We assessed abdominal MRI, specifically examining T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI), for the presence of abnormal signals in the inferior pole of the kidney. Spearman's correlation coefficient test was conducted to examine the relationship between the images and histological findings.

RESULTS

For T1WI, eight cases showed a positive low-intensity signal, and 18 cases were negative. For T2WI, 19 cases were positive for a low-intensity signal, and seven cases were negative. In DWI, 23 cases were positive for a high-intensity signal, and one was negative. T1WI low-intensity signal and T2WI low-intensity signal were significantly correlated with interstitial fibrosis score (correlation coefficients 0.52 and 0.64).

CONCLUSION

Low-intensity signal on T2WI is useful for predicting the degree of fibrosis in IgG4-TIN.

Hepatitis B virus-associated cryoglobulinaemia diffuse endocapillary proliferative glomerulonephritis: a case report and literature review

Cryoglobulinaemia can manifest as fatigue, purpura, and joint pain, and can involve the kidneys and peripheral nervous system. Type II and mixed cryoglobulinemia cases are usually associated with hepatitis C virus infection and autoimmune diseases, and most cases reported outside China have been related to hepatitis C virus. The pathological manifestation of cryoglobulinaemia glomerulonephritis is always membranous proliferative glomerulonephritis or membranous nephropathy; other pathological types are rare. This current case report describes a female patient with hepatitis B virus (HBV)-associated cryoglobulinaemic glomerulonephritis. The patient had hepatitis B complicated with purpura, abnormal urinalysis and renal function. She was positive for rheumatoid factor and had decreased complement, and her blood cryoglobulin level was positive. The pathological findings were consistent with late-stage capillary proliferative glomerulonephritis, which improved after steroid, immunosuppressant and anti-HBV treatment.

Use of biologic agents and methotrexate improves renal manifestation and outcome in patients with rheumatoid arthritis: a retrospective analysis

Background and purpose

We examined whether advances in treatment strategies from older disease-modifying antirheumatic drugs (DMARDs) to new biologic agents and methotrexate improved renal complications and outcome in patients with rheumatoid arthritis (RA).

Methods

We reviewed records of 156 patients with RA who underwent kidney biopsy at our institute between January 1990 and December 2019. All patients were assigned to one of three periods: period 1, 1990–1999 (n = 48); period 2, 2000–2009(n = 57); period 3, 2010–2019 (n = 51).

Results

Membranous nephropathy, nephrosclerosis, AA-amyloidosis, and IgA nephropathy were the four major renal manifestations of RA. AA-amyloidosis was diagnosed by kidney biopsy in 21 patients: period 1, 7 patients (15%); period 2, 10 patients (18%); and period 3, 4 patients (8%). The 4 patients in period 3 were in the years 2010–2014, and no new case of AA-amyloidosis was recorded from 2015 to 2019. In all 21 of the patients with AA-amyloidosis, neither a biologic agent nor methotrexate was administered. Fifteen of the 21 patients required dialysis, and 13 died in periods 1–3 because of amyloid-related cardiac dysfunction less than 2 years after the initiation of dialysis. Two of them are doing well using biologic agent despite dialysis. The remaining three patients who received a biologic agent or methotrexate does not progress to end-stage renal failure. In addition, the other renal complications showing progression to dialysis also decreased over time.

Conclusion

Advances in treatment strategies have improved renal outcome and reduced mortality in patients with RA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02160-2.

Development of osmotic vacuolization of proximal tubular epithelial cells following treatment with sodium-glucose transport protein 2 inhibitors in type II diabetes mellitus patients-3 case reports

We encountered 3 cases of acute kidney injury that occurred after treatment with a SGLT2 inhibitor. In case 1, serum creatinine increased from 1.65 to 3.0 mg/dL, in case 2, serum creatinine increased from 1.03 to 1.21 mg/dL, and in case 3, serum creatinine increased from 0.8 to 1.1 mg/dL. Renal biopsy showed isometric vacuolization on tubules, that was completely negative for Periodic acid-Schiff (PAS) stain in case 1, and was partially negative for PAS stain in case 2 and 3, consistent with osmotic vacuolization. Immunohistochemical analysis showed positive staining for CD138 and CD10 indicating the proximal tubules in the vacuolar lesions. 3 patients were obese with body mass index of more than 30, and showed an increase in serum renin. In conclusion, in type II diabetes mellitus (T2DM), individuals that remain within their standard weight range, SGLT2 inhibitor treatment does not result in osmotic vacuolization of proximal tubular epithelial cells and AKI. However, treatment with a SGLT2 inhibitor may cause damage of the proximal tubules resulting in AKI in T2DM individuals who do not remain within their standard weight range, due to an overdose lavage of sugar in the urine and dehydration.

The Clinical and Histopathological Feature of Renal Manifestation of TAFRO Syndrome

Introduction

Thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome is a severe subtype of idiopathic multicentric Castleman’s disease, characterized by thrombocytopenia, anasarca, fever, reticulin myelofibrosis, and organomegaly. Renal complication of this disease can be life-threatening and sometimes requires hemodialysis, but it has not been elucidated in detail.

Methods

Case-series was designed to evaluate the renal histology of patients with TAFRO syndrome treated at our hospital.

Results

Seven patients were eligible to the criteria. All of them had severe diuretic-resistant anasarca and 6 of 7 had mild proteinuria (<1 g daily). On light microscopy, all patients showed glomerular endotheliopathy characterized by endothelial cell swelling and a double contour of the glomerular basement membrane with mesangiolysis or mesangial loosening. Immunofluorescent staining and electron microscopy did not detect immune deposits in any patient. Electron microscopy revealed endothelial cell swelling with diffuse expansion of the subendothelial space, loss of mesangial architecture, and loss of endothelial cell fenestrations. Treatment with glucocorticoids and molecular-targeting agents, including tocilizumab and rituximab, improved renal dysfunction and anasarca. In 4 of 7 patients with persistent thrombocytopenia, hemorrhagic events occurred despite platelet transfusion or thrombopoietin receptor antagonist therapy.

Conclusion

Severe diuretic-resistant anasarca with mild proteinuria and severe glomerular endotheliopathy were common characteristics of renal dysfunction due to TAFRO syndrome. In addition, endothelial changes mediated via interleukin (IL)-6 and vascular endothelial growth factor (VEGF) that lead to vascular hyperpermeability and water leakage might contribute to anasarca, because molecular-targeting therapy directed against IL-6 or VEGF improved renal dysfunction and severe endothelial damage.

Increase of 1,25 dihydroxyvitamin D in sarcoidosis patients with renal dysfunction

INTRODUCTION

In sarcoidosis, renal involvement includes hypercalcemia-related nephrocalcinosis and granulomatous tubulointerstitial nephritis. Hypercalcemia is thought to be due to increased production of 1,25 dihydroxyvitamin D (1-25D), but 1-25D levels have not been evaluated in sarcoidosis patients with renal dysfunction.

MATERIALS AND METHODS

We enrolled 9 sarcoidosis patients who underwent renal biopsy, and compared the serum 1-25D concentration and eGFR with those in 428 non-sarcoidosis patients who had renal dysfunction (stage 2 or higher CKD with an estimated glomerular filtration rate < 90).

RESULTS

Serum calcium and 1-25D levels were significantly higher in the sarcoidosis patients than in the non-sarcoidosis patients (p < 0.01 and p = 0.01, respectively). There was a positive correlation between 1-25D and eGFR in the patients without sarcoidosis (r = 0.693; p < 0.01). As the renal function of sarcoidosis patients was improved by steroid therapy, the serum 1-25D and adjusted serum calcium levels decreased to near the median values in non-sarcoidosis patients. On renal biopsy, CD68 staining was positive for tissue macrophages in all 8 patients who had tubulointerstitial nephritis (with or without typical granulomas), while Von Kossa staining showed calcification of tubules near or inside granulomas in 6 of these 8 patients.

CONCLUSION

While tissue macrophages promote development of tubulointerstitial nephritis and 1-25D overproduction in renal sarcoidosis, hypercalcemia secondary to elevation of 1-25D may be related to renal calcification and granuloma formation.

Significance of urinary albumin excretion in patients with cast nephropathy

Background: This study was performed to determine whether the urinary albumin excretion rate (%UAE) could distinguish myeloma cast nephropathy (MCN) without glomerular amyloid deposition from MCN with glomerular amyloid deposition. Materials and methods: We retrospectively reviewed clinicopathological data on 16 patients with MCN diagnosed by renal biopsy at Toranomon Hospital from 2004 to 2014. Results: A total of 10 patients had pure MCN without glomerular amyloid deposition (group 1), and 6 patients had MCN with glomerular amyloid deposition (group 2). In all 10 patients from group 1, the underlying disease was multiple myeloma (MM), while 4 patients had MM, and 2 patients had lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) in group 2. Total protein did not show a significant difference between the two groups, but serum albumin was significantly higher in group 1 than group 2 (p = 0.0101). Serum-adjusted calcium did not show a significant difference between the groups, while serum creatinine (Cre) was significantly higher in group 1 than group 2 (p = 0.0343). Although urinary protein excretion did not differ significantly between the groups, the %UAE was significantly lower in group 1 than group 2 (p = 0.00198). In group 2, 3 of the 4 patients with MM died within 15 months of diagnosis, but the 2 patients with LPL/WM are alive after 32 months. In group 1, only 1 patient died (of unknown causes) within 15 months after diagnosis. Conclusion: In patients with MCN, %UAE may be a useful marker for the detection of coexistence of glomerular lesions, such as amyloidosis, which are associated with a poor outcome.

Effectiveness of cryofiltration and mizoribine combination with oral steroid therapy in a patient with membranoproliferative glomerulonephritis due to essential cryoglobulinemia

A 65-year-old male patient with nephrotic syndrome was admitted to our hospital due to worsening systemic edema and purpura on the limbs. He had an impaired renal function, low serum complement level, and elevated rheumatoid factor level. He was positive for cryoglobulin (monoclonal IgM-κ and polyclonal mixed-type IgG), and the results of his kidney biopsy showed a tissue profile of membranoproliferative glomerulonephritis (MPGN). Due to the fact that the secondary cause was unclear, he was diagnosed with MPGN due to essential mixed cryoglobulinemia. On hospital day 20, he was initiated on 50 mg/day prednisolone (PSL). On hospital day 43, oral mizoribine (MZR) at a dose of 150 mg/day was prescribed. On hospital day 49, cryofiltration was performed because the disease was steroid resistant. The treatment promptly decreased urine protein levels. Serum albumin and serum complement levels increased, and complete remission was achieved approximately three months after the initiation of treatment. The PSL and MZR doses were gradually reduced to 2 mg/day and 100 mg/day, respectively, without any reemergence of the symptoms of cryoglobulinemia or relapse of the nephrotic syndrome for three years. Here, we report this case with essential mixed cryoglobulinemia in whom we could achieve complete remission of the disease by adding cryofiltration to the oral corticosteroid and immunosuppressant therapy with mizoribine and could maintain for a long time.

Renal-limited Cryoglobulinemic Vasculitis: Two Case Reports

Cryoglobulinemic vasculitis (CV) presents with systemic manifestations, including renal disease, arthritis, peripheral neuropathy, and muscle weakness. We encountered two patients who developed severe nephrotic range proteinuria; however, extrarenal manifestations were not noted during the clinical course. A renal biopsy revealed typical membranoproliferative glomerulonephritis (MPGN) with huge thrombus-like endothelial deposits and predominant IgM positivity, but electron microscopy did not reveal any definite microtubules. Immunosuppressive therapy and plasmapheresis were only partially effective, and the improvement was not durable. Biological therapy with rituximab (RTX) had no effect. Renal-limited CV should be recognized as a subset of essential CV.

IgA nephropathy featuring massive wire loop-like deposits in two patients with alcoholic cirrhosis

Background

Various renal manifestations are known to develop in patients with liver disease, including chronic hepatitis and cirrhosis.

Case presentation

We evaluated renal disease in two 47-year-old Japanese men with liver cirrhosis and chronic alcoholism for 34 years and 27 years, respectively. Renal biopsy demonstrated massive wire loop-like deposits in the subendothelial space of the glomerular basement membrane and in the mesangium. However, immunofluorescence was only positive for IgA and C3, and electron microscopy did not reveal any organized structures in the electron-dense deposits. IgA nephropathy was diagnosed, although the features were different from primary IgA nephropathy. Both patients had portosystemic shunts associated with liver cirrhosis. Their renal deposits and proteinuria resolved completely after 1 year of steroid therapy.

Conclusion

Alcohol abuse may have contributed to development of secondary IgA nephropathy in these two patients, probably via their portosystemic shunts.

Cryoglobulinaemic glomerulonephritis: artefacts associated with laboratory diagnosis and need for renal biopsy

Cryoglobulinemia as a cause of renal impairment is uncommon but needs to be considered in viral hepatitis and haematological malignancies. Often detection and estimation of cryoglobulins are confounded by collection and processing errors. This report highlights the need for stringent processing measures if the clinical suspicion is high.

Unique Renal Manifestation of Type I Cryoglobulinemia, With Massive Crystalloid Deposits in Glomerular Histiocytes, Podocytes, and Endothelial Cells

OBJECTIVES

We describe a 62-year-old woman with a 15-year history of a plasma cell dyscrasia (monoclonal IgGκ), manifested by type I cryoglobulinemia and dermal vasculitis.

METHODS

In addition to the clinical examinations, light microscopy with immunohistochemistry, sequential multicolor immunohistochemistry, and electron microscopy were used to characterize the crystalline deposits.

RESULTS

At initial presentation and for a later flare, she was treated with cyclophosphamide and prednisolone with good clinical response. She had renal function decline, microscopic hematuria, and proteinuria. A renal biopsy specimen revealed the presence of glomerular macrophages and duplication of the capillary walls with cellular interposition. Glomerular cells contained abundant needle-shaped eosinophilic crystalline inclusions positive for κ light chain. Electron microscopy confirmed the presence of intracytoplasmatic crystalline structures in endothelial cells, podocytes, and macrophages but not in the tubular epithelium. Rituximab treatment was started. At follow-up (now up to 6 months), renal function remained stable.

CONCLUSIONS

This patient displays a unique renal manifestation of type I cryoglobulinemia related to a plasma cell dyscrasia.

Rheumatic manifestations of hepatitis C virus chronic infection: Indications for a correct diagnosis

Hepatitis C virus (HCV) is a hepato- and lymphotropic agent that is able to induce several autoimmune rheumatic disorders: vasculitis, sicca syndrome, arthralgias/arthritis and fibromyalgia. The severity of clinical manifestations is variable and sometimes life-threatening. HCV infection can mimic many primitive rheumatic diseases, therefore, it is mandatory to distinguish HCV-related manifestations from primitive ones because the prognosis and therapeutic strategies can be fairly dissimilar. The new direct-acting antivirals drugs can help to avoid the well-known risks of worsening or new onset of autoimmune diseases during the traditional interferon-based therapies.

The incidence of possible causes of membranoproliferative glomerulonephritis: a single-center experience

BACKGROUND

Diagnosis of membranoproliferative glomerulonephritis (MPGN) is based on kidney biopsy findings: unique glomerular injury pattern and characteristic changes on light, electron microscopy and immunohistochemical analysis. The purpose of this study was to identify possible etiology and incidence of glomerular injury among patients with a diagnosed MPGN.

MATERIALS AND METHODS

A retrospective analysis (years 2000-2014) of 81 clinical cases with a diagnosis of MPGN based on biopsy results was performed. Records were examined, and data about viral, bacterial infections, autoimmune and hematological diseases was collected. Test results of blood C3 and C4 factors of the complement system, and results of kidney biopsy immunohistochemical analysis were investigated. Statistical analysis was performed using Statistical Package for the Social Sciences and p-value less than 0.05 was considered statistically significant.

RESULTS

Study population consisted of 55 males (67.9%) and 26 females (32.1%). The average patients' age was 48.53 (standard deviation ± 16.67) years. The identified etiology of MPGN was: idiopathic in 26 cases (32.10%), bacterial infections in 20 cases (24.69%), viral hepatitis in 16 cases (19.75%), autoimmune diseases in 11 cases (13.58%), and hematological diseases in eight cases (9.88%). Changes of the concentration of complement component C3 as well as component C4 were found; their concentration was decreased in 26 (32.1%) and 17 (20.99%) patients' respectively while concentration was within the normal range in 11 (13.58%) and 19 (23.46%) patients respectively. Immunohistochemistry results revealed immunoglobulin (Ig) deposits: C3+/Ig+ was found in 47 (58.02%) cases, C3-/Ig+ was found in 16 (19.75%) cases and in six (7.41%) cases test was not performed. The total number of immunoglobulin positive biopsies (C3+/Ig+ and C3-/Ig+, also called immune-complex mediated MPGN) was 63 (77.78%). Complement-mediated MPGN (C3+/Ig-) was less common and was diagnosed only in seven cases (8.64%). C3-/Ig- was found in five cases (6.17%).

CONCLUSIONS

The leading cause of MPGN was idiopathic as well as bacterial infections. Complement component C3 concentration was mostly decreased. The incidence of normal and decreased concentration of the complement component C4 was almost equal. Most immunohistochemical deposits in kidney biopsy appeared to be C3/Ig positive, and it was observed in more than half of the cases of each MPGN etiological group. Hippokratia 2015; 19 (4): 314-318.

Diagnostics and treatment of cryoglobulinaemia: it takes two to tango

Cryoglobulins are immunoglobulins that reversibly precipitate in the cold. They come in different flavours and, as such, are differentially associated with lymphoproliferative diseases (type I), or systemic autoimmune diseases, and/or infectious diseases (type II/III). The clinical manifestations of cryoglobulinaemia result from either hyper-viscosity or small vessel vasculitis. Hepatitis C virus (HCV) is a well-known factor in the aetiology of cryoglobulinaemia, but substantial geographical differences exist in the association between cryoglobulins and HCV. In the absence of any underlying disease, cryoglobulinaemia is referred to as 'idiopathic' or 'essential'. Detection of cryoglobulins in the laboratory is hampered by several pitfalls, in particular in the pre-analytical stage as well as in the quantification. In addition, our personal experience reveals that the detection of rheumatoid factor, most often present in high concentrations in patients with mixed cryoglobulinaemia, relies on the choice of the test system. Hence, interpretation of the laboratory results in relation to the clinical manifestations requires a partnership between the clinician and the laboratory specialist in order to make a correct diagnosis. Treatment options are primarily directed by identification of underlying diseases, i.e. infections or systemic autoimmune diseases. Idiopathic cryoglobulinaemia is treated with corticosteroids and immunosuppression, or B cell depleting anti-CD20 biologicals. In this overview, the recent literature on current laboratory and clinical practice of cryoglobulinaemia is discussed from a personal perspective.

Recent advances in the understanding of immune-mediated nephrotic syndrome: diagnostic and prognostic implications

Glomerular diseases with severe defects in glomerular permeability give rise to heavy proteinuria and can present as nephrotic syndrome. There are many different causes of the nephrotic syndrome and a renal biopsy is nearly always needed to elucidate the underlying disease. During the last decade, substantial advances have occurred in the understanding of the pathophysiological mechanisms involved in immune-mediated glomerular diseases. Here, we review the diagnostic and prognostic implications of recent progress on the understanding of membranous nephropathy, minimal change disease, focal segmental glomerulosclerosis, amyloidosis, IgA nephropathy and membranoproliferative glomerulonephritis.

Extrahepatic immune related manifestations in chronic hepatitis C virus infection

The association of chronic hepatitis C with immune related syndromes has been frequently reported. There is a great range of clinical manifestations affecting various systems and organs such as the skin, the kidneys, the central and peripheral nervous system, the musculoskeletal system and the endocrine glands. Despite the high prevalence of immune related syndromes in patients with chronic hepatitis C, the exact pathogenesis is not always clear. They have been often associated with mixed cryoglobulinemia, a common finding in chronic hepatitis C, cross reaction with viral antigens, or the direct effect of virus on the affected tissues. The aim of this review is to analyze the reported hepatitis C virus immune mediated syndromes, their prevalence and clinical manifestations and to discuss the most supported theories regarding their pathogenesis.