NELL1-Positive HIV-Associated Lupus-Like Membranous Nephropathy with Spontaneous Remission

Introduction: Kidney biopsy findings in patients with human immunodeficiency virus (HIV) are diverse, and optimal therapy for the various immune complex diseases in the setting of HIV is unknown. Case Presentation: A man with well-controlled HIV developed nephrotic range proteinuria, and kidney biopsy revealed lupus-like glomerulonephritis with a predominantly membranous pattern of injury. He opted for conservative therapy and experienced spontaneous and sustained remission. Subsequent testing revealed neural epidermal growth factor-like 1 (NELL1)-positive glomerular immune deposits. NELL1-positive glomerular immune deposits were identified in a total of 2 of 5 tested HIV-associated membranous nephropathy (MN), which were morphologically dissimilar and one of which weakly co-expressed phospholipase A2 receptor (PLA2R). Discussion: This case suggests potentially different outcomes in patients with immune complex diseases in the setting of HIV based on disease etiology and histopathology. HIV-associated MN is occasionally NELL1-positive

The Clone Wars: Diagnosing and Treating Dysproteinemic Kidney Disease in the Modern Era

Dysproteinemic kidney diseases are disorders that occur as the result of lymphoproliferative (B cell or plasma cell) disorders that cause kidney damage via production of nephrotoxic monoclonal immunoglobulins or their components. These monoclonal immunoglobulins have individual physiochemical characteristics that confer specific nephrotoxic properties. There has been increased recognition and revised characterization of these disorders in the last decade, and in some cases, there have been substantial advances in disease understanding and treatments, which has translated to improved patient outcomes. These disorders still present challenges to nephrologists and patients, since they are rare, and the field of hematology is rapidly changing with the introduction of novel testing and treatment strategies. In this review, we will discuss the clinical presentation, kidney biopsy features, hematologic characteristics and treatment of dysproteinemic kidney diseases

Hypocomplementemic interstitial nephritis with long-term follow-up

Prednisone-sensitive hypocomplementemia, renal insufficiency, and kidney biopsy demonstrating severe tubulointerstitial nephritis (TIN), storiform fibrosis, and tubulointerstitial immune deposits are typical of IgG4-related tubulointerstitial nephritis and hypocomplementemic interstitial nephritis. A diagnosis of hypocomplementemic interstitial nephritis requires clinical and pathologic exclusion of IgG4-related tubulointerstitial nephritis. We describe a patient with hypocomplementemic interstitial nephritis who did not develop diagnostic features of IgG4 related disease (RD) over 2-year follow-up. We conclude that hypocomplementemic interstitial nephritis could be on a biologic spectrum with IgG4-related disease, but not all cases will develop the abundance of IgG4-positive plasma cells, systemic manifestations, or elevated immunoglobulin levels characteristic of IgG4-RD

The phenotypes of podocytes and parietal epithelial cells may overlap in diabetic nephropathy

Reversal of diabetic nephropathy (DN) has been achieved in humans and mice, but only rarely and under special circumstances. As progression of DN is related to podocyte loss, reversal of DN requires restoration of podocytes. Here, we identified and quantified potential glomerular progenitor cells that could be a source for restored podocytes. DN was identified in 31 human renal biopsy cases and separated into morphologically early or advanced lesions. Markers of podocytes (WT-1, p57), parietal epithelial cells (PECs) (claudin-1), and cell proliferation (Ki-67) were identified by immunohistochemistry. Podocyte density was progressively reduced with DN. Cells marking as podocytes (p57) were present infrequently on Bowman's capsule in controls, but significantly increased in histologically early DN. Ki-67-expressing cells were identified on the glomerular tuft and Bowman's capsule in DN, but rarely in controls. Cells marking as PECs were present on the glomerular tuft, particularly in morphologically advanced DN. These findings show evidence of phenotypic plasticity in podocyte and PEC populations and are consistent with studies in the BTBR ob/ob murine model in which reversibility of DN occurs with podocytes potentially regenerating from PEC precursors. Thus, our findings support, but do not prove, that podocytes may regenerate from PEC progenitors in human DN. If so, progression of DN may represent a modifiable net balance between podocyte loss and regeneration

Cavernous hemangioma with extensive sclerosis masquerading as intrahepatic cholangiocarcinoma — A pathologist's perspective

A patient presented with an acute episode of bright red blood in her stool. The incidental liver mass seen in segment 4 was suspected to represent a cholangiocarcinoma due to associated mild intrahepatic biliary ductal dilatation and suspicion for capsular retraction. Pathology confirmed that this lesion represented a sclerosing hemangioma. This case report corroborates prior observations that degenerative changes in hemangiomas—sclerosis, narrowing of vascular channels, thrombosis, infarct, hemorrhage—may produce atypical radiographic findings. Since these atypical radiographic features may suggest a primary or metastatic malignancy, the protean appearance of hemangiomas remains an important consideration in the evaluation of hepatic masses

Fetal Renal DNA Methylation and Developmental Programming of Stress-Induced Hypertension in Growth-Restricted Male Mice.

Fetal growth restriction (FGR) is associated with developmental programming of adult onset hypertension, which may be related to differences in nephron development. Prior studies showed that maternal nutrient restriction is associated with reduced nephrogenesis in rodents, especially in male progeny. We hypothesized that maternal genetic risk for FGR may similarly affect fetal kidney development, leading to adult onset hypertension. We employed an angiotensinogen (AGT) gene titration transgenic (TG) construct with 3 copies of the mouse AGT gene that mimics a common human genotype (AGT A[-6]G) associated with FGR. We investigated whether FGR in 2-copy (wild type, [WT]) progeny from 3-copy TG dams leads to developmental programming differences in kidney development and adult blood pressure compared with age- and sex-matched controls. Progeny were tested in the late fetal period (e17.5), neonatal period (2 weeks of age), and as young adults (12 weeks). We measured weights, tested for renal oxidative stress, compared renal DNA methylation profiles, counted the number of glomeruli, and measured adult blood pressure ± stress. Progeny from TG dams were growth restricted with evidence of renal oxidative stress, males showed fetal renal DNA hypermethylation, they had fewer glomeruli, and they developed stress-induced hypertension as adults. Their female siblings did not share this pathology and instead resembled progeny from WT dams. Surprisingly, glomerular counts in the neonatal period were not different between sexes or maternal genotypes. In turn, we suspect that differences in fetal renal DNA methylation may affect the long-term viability of glomeruli, rather than reducing nephrogenesis