Hydralazine use can be associated with IgM-dominated immune complex-mediated glomerulonephritis.

CONTEXT: IgM-dominant immune complex-mediated glomerulonephritis (IgM-dominant ICMGN) is a rare renal entity, characterized by a membranoproliferative pattern by light microscopy, dominant IgM staining by immunofluorescent staining, and subendothelial deposits by electron microscopy. This study was to investigate if some of IgM-ICMGN were associated with autoimmune disorders induced by hydralazine. DESIGN: Seven IgM-dominant ICMGN cases were identified over 8 years. Their pathologic phenotypes and clinical scenarios were analyzed in detail. RESULTS: Patients' ages ranged from 47 to 87 years old with 5 women and two men. Six of seven patients had drug-induced autoimmune phenomenon (hydralazine-induced positive ANCA and ANA). All of them had renal dysfunction and some proteinuria. Most pathologic features showed a membranoproliferative pattern of glomerulonephritis with dominant IgM deposits at subendothelial spaces. IgM nephropathy (a variant of focal segmental glomerulosclerosis), chronic thrombotic microangiopathy, and cryoglobulinemic glomerulopathy were ruled out in the cases. CONCLUSION: The hydralazine-induced autoimmune phenomenon can be seen in IgM-dominant ICMGN, which should be classified as a subtype of membranoproliferative glomerulonephritis.

The Role of Bone Marrow Biopsy Evaluation in the Workup for Monoclonal Gammopathy of Renal Significance: A Diagnosis of Exclusion.

CONTEXT.­: Monoclonal gammopathy of renal significance (MGRS) is a relatively new concept for patients with renal monoclonal protein deposition (RMPD) (except monoclonal cast nephropathy) and has been used as a reason for nephrologists to obtain a bone marrow biopsy (BMB). It takes a team of pathologists and clinicians to determine when RMPD at our institution can be defined as MGRS. OBJECTIVE.­: To identify the proportion of various subtypes of tentative MGRS diagnosed by renal biopsy that can be confirmed as final MGRS after BMB. DESIGN.­: One hundred thirty kidney biopsies with variants of RMPD were identified during the past 10 years. Biopsy cases with known myeloma, B-cell lymphoma, or monoclonal cast nephropathy were separated as a heavy-burden group. The remaining biopsies with RMPD were considered tentative MGRS. Their BMB and clinical indices were further analyzed to determine the final percentage of MGRS diagnoses. RESULTS.­: Among the 130 renal paraprotein deposition cases, 44 (33.8%) were categorized as the heavy-burden group. In the remaining 86 cases, 33 (38.4%) with subsequent identification of myeloma (>10% of monoclonal plasma cells) or lymphoma in BMB were further considered as heavy-burden cases. Eighteen cases (18 of 86; 20.9%) did not receive follow-up BMB; thus, no further analysis was performed. BMBs diagnosed as either nonmalignant (no plasma cells; 8 of 86 cases; 9.3%) or premalignant (<10% plasma cells; 27 of 86 cases; 31.4%) were confirmed to be final MGRS (35 of 86; 40.7%). CONCLUSIONS.­: The data indicate that BMB is an important element in the confirmation of MGRS.

Punctate IgG staining particles localize in the budding ballooning clusters of reactive foot processes in minimal change disease.

The etiology of minimal change disease (MCD) remains a mystery as the only characteristic findings are the diffuse effacement of foot processes seen on electron microscopy (EM). Punctate IgG staining found floating outside glomerular capillary loops in MCD cases was recently identified as autoimmune antibodies against nephrin of podocytes. We hypothesized that the punctate IgG staining is located on budding ballooning clusters (BBC) of reactive foot processes in Bowman's space found on EM. We identified seven patients with MCD cases showing IgG staining that were subsequently evaluated for BBC on EM. We concurrently examined 12 negative controls, either unremarkable cases or tubulointerstitial diseases, by EM. Immunogold labeling was performed to confirm the presence of IgG and determine localization. In seven MCD cases, there were positive punctate IgG staining particles outside of the glomerular basement membranes (GBM) along with concurrent punctate staining for C3, kappa, and lambda. By EM, all seven (100%) MCD cases revealed BBC that was characterized by ballooning foot processes ranging from 1 to 6 µm and was either budding or detached from the GBM in 3-7 clusters; no electron-dense materials were seen in BBC. BBC was also seen in only 1 of 12 (8%) negative controls. Immunogold labeling identified IgG particles within BBC of MCD by EM, but not in the negative control. Our data suggest that BBC are EM structures of reactive foot processes that are most likely correlated with punctate IgG staining seen in cases of MCD, supported by immunogold labeling for IgG.

Langerhans Cell Histiocytosis in the Pediatric Spine Requiring Stabilization: A Literature Review and Report of 3 Cases.

CASE: This report describes 3 cases of Langerhans cell histiocytosis (LCH) of the cervical and thoracic spine in patients aged 4 to 10 years. Each patient had painful lytic spinal lesions with vertebral body collapse and posterior involvement suggesting instability requiring corpectomy, grafting, and fusion. All 3 patients were doing well at their most recent follow-up without pain or recurrence. CONCLUSION: Although LCH of the pediatric spine is usually successfully treated non-operatively, we recommend corpectomy and fusion when there is instability of the spinal column and/or severe stenosis. Posterior element involvement occurred in all 3 cases and may lead to instability.

Differences in activation of intracellular signaling in primary human retinal endothelial cells between isoforms of VEGFA 165.

Purpose: There are reports that a b-isoform of vascular endothelial growth factor-A 165 (VEGFA165b) is predominant in normal human vitreous, switching to the a-isoform (VEGFA165a) in the vitreous of some diseased eyes. Although these isoforms appear to have a different ability to activate the VEGF receptor 2 (VEGFR2) in various endothelial cells, the nature of their ability to activate intracellular signaling pathways is not fully characterized, especially in retinal endothelial cells. We determined their activation potential for two key intracellular signaling pathways (MAPK, AKT) over complete dose-response curves and compared potential effects on the expression of several VEGFA165 target genes in primary human retinal microvascular endothelial cells (HRMECs). Methods: To determine full dose-response curves for the activation of MAPK (ERK1/2), AKT, and VEGFR2, direct in-cell western assays were developed using primary HRMECs. Potential differences in dose-response effects on gene expression markers related to endothelial cell and leukocyte adhesion (ICAM1, VCAM1, and SELE) and tight junctions (CLDN5 and OCLN) were tested with quantitative PCR. Results: Activation dose-response analysis revealed much stronger activation of MAPK, AKT, and VEGFR2 by the a-isoform at lower doses. MAPK activation in primary HRMECs displayed a sigmoidal dose-response to a range of VEGFA 165 a concentrations spanning 10-250 pM, which shifted higher into the 100-5,000 pM range with VEGFA 165 b. Similar maximum activation of MAPK was achieved by both isoforms at high concentrations. Maximum activation of AKT by VEGFA 165 b was only half of the maximum activation from VEGFA 165 a. At a lower intermediate dose, where VEGFA 165 a activated intracellular signaling stronger than VEGFA 165 b, the changes in VEGFA target gene expression were generally greater with VEGFA 165 a. Conclusions: In primary HRMECs, VEGFA 165 a could maximally activate MAPK and AKT at lower concentrations where VEGFA 165 b had relatively little effect. The timing for maximum activation of MAPK was similar for the isoforms, which is different from that reported for non-retinal endothelial cells. Although differences in VEGFA 165 a and VEGFA 165 b are limited to the sequence of their six C-terminal six amino acids, this results in a large difference in their ability to activate at least two key intracellular signaling pathways and VEGF-target gene expression in primary human retinal endothelial cells.

Use of Topical Insulin to Treat Refractory Neurotrophic Corneal Ulcers.

PURPOSE: To report the clinical course of 6 patients with refractory neurotrophic corneal ulcers that were treated with topical insulin drops. METHODS: Retrospective chart review of patients who had neurotrophic corneal ulcers or epithelial defects refractory to standard medical and surgical treatment. Insulin drops, prepared by mixing regular insulin in artificial tears with a polyethylene glycol and propylene glycol base at a concentration of 1 unit per milliliter, were prescribed 2 to 3 times daily. RESULTS: Six patients, aged 2 to 73 years, developed neurotrophic corneal ulcers refractory to a range of medical and surgical treatments, including bandage contact lens, amniotic membrane grafting, and permanent tarsorrhaphy. Each patient was administered topical insulin drops with complete corneal reepithelialization within 7 to 25 days. CONCLUSIONS: Topical insulin may be a simple and effective treatment for refractory neurotrophic corneal ulcers. Further study is required to determine the clinical efficacy and side effect profile of insulin drops.

Different effects of valproic acid on photoreceptor loss in Rd1 and Rd10 retinal degeneration mice.

PURPOSE: The histone-deacetylase inhibitor activity of valproic acid (VPA) was discovered after VPA's adoption as an anticonvulsant. This generated speculation for VPA's potential to increase the expression of neuroprotective genes. Clinical trials for retinitis pigmentosa (RP) are currently active, testing VPA's potential to reduce photoreceptor loss; however, we lack information regarding the effects of VPA on available mammalian models of retinal degeneration, nor do we know if retinal gene expression is perturbed by VPA in a predictable way. Thus, we examined the effects of systemic VPA on neurotrophic factor and Nrl-related gene expression in the mouse retina and compared VPA's effects on the rate of photoreceptor loss in two strains of mice, Pde6b(rd1/rd1) and Pde6b(rd10/rd10) . METHODS: The expression of Bdnf, Gdnf, Cntf, and Fgf2 was measured by quantitative PCR after single and multiple doses of VPA (intraperitoneal) in wild-type and Pde6b(rd1/rd1) mice. Pde6b(rd1/rd1) mice were treated with daily doses of VPA during the period of rapid photoreceptor loss. Pde6b(rd10/rd10) mice were also treated with systemic VPA to compare in a partial loss-of-function model. Retinal morphology was assessed by virtual microscopy or spectral-domain optical coherence tomography (SD-OCT). Full-field and focal electroretinography (ERG) analysis were employed with Pde6b(rd10/rd10) mice to measure retinal function. RESULTS: In wild-type postnatal mice, a single VPA dose increased the expression of Bdnf and Gdnf in the neural retina after 18 h, while the expression of Cntf was reduced by 70%. Daily dosing of wild-type mice from postnatal day P17 to P28 resulted in smaller increases in Bdnf and Gdnf expression, normal Cntf expression, and reduced Fgf2 expression (25%). Nrl gene expression was decreased by 50%, while Crx gene expression was not affected. Rod-specific expression of Mef2c and Nr2e3 was decreased substantially by VPA treatment, while Rhodopsin and Pde6b gene expression was normal at P28. Daily injections with VPA (P9-P21) dramatically slowed the loss of rod photoreceptors in Pde6b(rd1/rd1) mice. At age P21, VPA-treated mice had several extra rows of rod photoreceptor nuclei compared to PBS-injected littermates. Dosing started later (P14) or dosing every second day also rescued photoreceptors. In contrast, systemic VPA treatment of Pde6b(rd10/rd10) mice (P17-P28) reduced visual function that correlated with a slight increase in photoreceptor loss. Treating Pde6b(rd10/rd10) mice earlier (P9-P21) also failed to rescue photoreceptors. Treating wild-type mice earlier (P9-P21) reduced the number of photoreceptors in VPA-treated mice by 20% compared to PBS-treated animals. CONCLUSIONS: A single systemic dose of VPA can change retinal neurotrophic factor and rod-specific gene expression in the immature retina. Daily VPA treatment from P17 to P28 can also alter gene expression in the mature neural retina. While daily treatment with VPA could significantly reduce photoreceptor loss in the rd1 model, VPA treatment slightly accelerated photoreceptor loss in the rd10 model. The apparent rescue of photoreceptors in the rd1 model was not the result of producing more photoreceptors before degeneration. In fact, daily systemic VPA was toxic to wild-type photoreceptors when started at P9. However, the effective treatment period for Pde6b(rd1/rd1) mice (P9-P21) has significant overlap with the photoreceptor maturation period, which complicates the use of the rd1 model for testing of VPA's efficacy. In contrast, VPA treatment started after P17 did not cause photoreceptor loss in wild-type mice. Thus, the acceleration of photoreceptor loss in the rd10 model may be more relevant where both photoreceptor loss and VPA treatment (P17-P28) started when the central retina was mature.