Alenka Vizjak

Zika Virus Associated with Microcephaly

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 in South and Central America and the Caribbean. A major concern associated with this infection is the apparent increased incidence of microcephaly in fetuses born to mothers infected with ZIKV. In this report, we describe the case of an expectant mother who had a febrile illness with rash at the end of the first trimester of pregnancy while she was living in Brazil. Ultrasonography performed at 29 weeks of gestation revealed microcephaly with calcifications in the fetal brain and placenta. After the mother requested termination of the pregnancy, a fetal autopsy was performed. Micrencephaly (an abnormally small brain) was observed, with almost complete agyria, hydrocephalus, and multifocal dystrophic calcifications in the cortex and subcortical white matter, with associated cortical displacement and mild focal inflammation. ZIKV was found in the fetal brain tissue on reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay, with consistent findings on electron microscopy. The complete genome of ZIKV was recovered from the fetal brain.

Pathology, Clinical Presentations, and Outcomes of C1q Nephropathy

C1q nephropathy is an uncommon glomerular disease with characteristic features on immunofluorescence microscopy. In this report, clinicopathologic correlations and outcomes are presented for 72 patients with C1q nephropathy. The study comprised 82 kidney biopsies from 28 children and 54 adults with male preponderance (68%). Immunofluorescence microscopy showed dominant or co-dominant staining for C1q in the mesangium and occasional glomerular capillary walls. Electron-dense deposits were observed in 48 of 53 cases. Light microscopy revealed no lesions (n = 27), focal segmental glomerulosclerosis (FSGS; n = 11), proliferative glomerulonephritis (n = 20), or various other lesions (n = 14). Clinical presentations in the patients who had no lesions histology were normal urine examination (7%), asymptomatic hematuria and/or proteinuria (22%), and nephrotic syndrome (minimal change-like lesion; 63%), which frequently relapsed. All patients with FSGS presented with nephrotic syndrome. Those with proliferative glomerulonephritis usually presented with chronic kidney disease (75%) or asymptomatic urine abnormalities (20%). Of the patients with sufficient follow-up data, complete remission of the nephrotic syndrome occurred in 77% of those with a minimal change-like lesion, progression to end-stage renal disease occurred in 33% of those with FSGS, and renal disease remained stable in 57% of those with proliferative glomerulonephritis. In conclusion, this study identified two predominant clinicopathologic subsets of C1q nephropathy: (1) Podocytopathy with a minimal change-like lesion or FSGS, which typically presents with nephrotic syndrome, and (2) a typical immune complex-mediated glomerular disease that varies from no glomerular lesions to diverse forms of glomerular proliferation, which typically presents as chronic kidney disease. Clinical presentation, histology, outcomes, and presumably pathogenesis of C1q nephropathy are heterogeneous.

C1Q nephropathy in children

C1q nephropathy (C1qNP) is a peculiar form of glomerulonephritis characterized by mesangial immunoglobulin and complement deposits, predominantly C1q, with no evidence of systemic lupus erythematosus. We describe the incidence, manifestation, histopathologic findings, follow-up, treatment and outcome of C1qNP. Twelve C1qNP patients were identified among 131 children who had undergone renal biopsy, accounting for a 9.16% incidence of C1qNP. Light microscopy examination showed focal segmental glomerulosclerosis (FSGS) with or without diffuse mesangial proliferation (n=6), minimal change disease (MCD) (n=4) or focal glomerulonephritis (n=2). C1q deposits were found in all, while electron microscopy revealed visible deposits in nine cases. Eight children presented with nephrotic syndrome, while one had nephrotic proteinuria and renal insufficiency that progressed to end-stage renal failure. The remaining three patients presented with nonnephrotic proteinuria associated with microhematuria, hypertension or renal insufficiency. Only one nephrotic syndrome patient responded excellently to corticosteroids, while four became corticosteroid dependent, and three were corticosteroid resistant, showing a very poor response to other immunosuppressive therapy as well. Patients with non-nephrotic proteinuria demonstrated fixed laboratory findings. Most C1qNP patients had FSGS or MCD, the majority of them presenting with corticosteroid-dependent or corticosteroid-resistant nephrotic syndrome. The latter showed a very poor response to any immunosuppressive therapy and high risk for progressive renal insufficiency.

Zika Virus-Associated Micrencephaly: A Thorough Description of Neuropathologic Findings in the Fetal Central Nervous System.

CONTEXT -The 2015 outbreak of Zika virus in Brazil resulted in a 20-times increased prevalence of congenital microcephaly in stillborns and neonates and was instrumental in raising the suspicion of a causal association between Zika virus and microcephaly. OBJECTIVE -To provide a comprehensive description of the neuropathologic features of congenital Zika virus infection. DESIGN -Autopsy evaluation of the brain from a fetus of 32 weeks and 6 days of gestation, with a prenatal diagnosis of microcephaly associated with polymerase chain reaction-confirmed, fetal, Zika virus infection. RESULTS -Multiple severe pathology findings were present. These included lissencephaly, except for the occipital lobes, where some pachygyria was observed. Also present was reduction and thinning of white matter, ventriculomegaly of the lateral ventricles, and coalescent calcifications in the cortical-subcortical white matter border associated with glioneuronal outbursting into the subarachnoid space above and heterotopias below. There were small, scattered calcifications in the basal ganglia, with fewer in the white matter and germinal matrix, and none in the cerebellum and brainstem. The cerebellum and pontine base were atrophic because of Wallerian degeneration or maldevelopment of descending tracts and pontocerebellar connections. CONCLUSION -Our findings are in agreement with neuroimaging of Zika virus-associated fetal and infant micrencephalic brains and, to some extent, with neuroimaging of other intrauterine infections causing microcephaly.

Microthrombotic/Microangiopathic Manifestations of the Antiphospholipid Syndrome

The paper presents an overview of clinical manifestations and histopathologic findings in different organs in microvascular thrombotic and microangiopathic antiphospholipid syndrome (MAPS). Subsets of antiphospholipid syndrome (APS) are presented and defined. Clinico-pathologic correlations seem insufficient so far, because of a lack of detailed systematic studies of the histopathology in different organs. Based on their own autopsy and biopsy studies, the authors propose a novel categorization of histopathologic lesions that occur in patients with classic and catastrophic APS. In addition to the already accepted category of a microvascular thrombotic type of lesions, microangiopathic lesions consistent with thrombotic microangiopathy are proposed to be included in new revised classification criteria for definite APS. Microvascular thrombotic and so far underestimated microangiopathic histopathologic lesions have been shown to appear in various combinations and of different ages in patients with both classic and catastrophic APS, which fits into the concept of MAPS. These preliminary findings of our studies are also in line with the most recent hypothesis of two main mechanisms in the pathogenesis of APS, emphasizing a key role of endothelial cell affection induced by aPL on the one hand and interference with coagulation cascade on the other side.

Performance evaluation of a novel chemiluminescence assay for detection of anti-GBM antibodies: an international multicenter study

BACKGROUND Autoantibodies to the non-collagen region (NC1) of the alpha-3 subunit of collagen IV represent a serological hallmark in the diagnosis of Goodpastures syndrome (GPS). The objective of our study was to carefully analyze the performance characteristics of a novel anti-glomerular basement membrane (GBM) chemiluminescence immunoassay (CIA). METHODS Sera from patients with GPS (n = 90) were collected from four clinical centers. Samples from different disease groups (n = 397) and healthy individuals (n = 400) were used as controls. All samples were tested for anti-GBM antibodies by a rapid, random access CIA (QUANTA Flash™ GBM). Most of the samples were also tested using other methods including different commercial anti-GBM IgG assays and research assays for anti-GBM IgA and IgM. RESULTS The sensitivity and specificity of the novel CIA was 95.6% [95% confidence interval (CI) 89.0-98.8%] and 99.6% (95% CI 98.9-99.9%), respectively. Receiver operating characteristic analysis showed good discrimination between GPS patients and controls. The area under the curve was 0.98 (CI 0.96-1.0). The three anti-GBM antibody-positive samples from the control group were from two healthy individuals and one human immunodeficiency virus (HIV)-infected patient. All three individuals had low levels of anti-GBM antibodies [20, 24 and 25 chemiluminescent unit (CU), cutoff 20 CU]. When the results of the new CIA were compared to other methods, good agreement was observed: 95.8% (kappa = 0.92) versus EliA™ GBM, 97.4% (kappa = 0.95) versus both BINDAZYME™ Anti-GBM and QUANTA Lite® GBM. Anti-GBM IgA was detectable in low concentrations in patients with GPS and was associated with anti-GBM IgG but was less useful in discriminating GPS patients and controls. No discrimination was found for anti-GBM IgM. CONCLUSION The novel QUANTA Flash™ GBM CIA demonstrated good sensitivity and specificity and had good agreement with other methods. Our data confirm that ∼5% of patients with GPS do not have detectable levels of anti-GBM antibodies.

Fibrillary noncongophilic renal and extrarenal deposits: a report on 10 cases.

Cases in which glomerular deposits of Congo red negative amyloid-like fibrils were demonstrated by electron microscopic identification are included in this study. In the 1,266 kidney biopsies studied, there were 9 biopsies from 8 patients with fibrillary glomerulonephritis and 2 biopsies from 2 patients with systemic lupus. In 1 case of fibrillary glomerulonephritis (FGN), autopsy was performed. Electron microscopic examination showed glomerular (100%) and extraglomerular (60%) fibrillary deposits in the biopsy samples of patients with FGN and also in patients with systemic lupus. In the autopsy case, similar fibrillary deposits were demonstrated in the kidney, pancreas, spleen, lungs, and liver. The diameter of the fibrils, which were arranged similarly in all cases, varied from 8 to 27 nm individually, the length being about 1.5 w m. The authors speculate that extraglomerular kidney fibrillary deposits concurrent with the same type of deposits in other organs suggests systemic manifestation of FGN.

The Dissociation of Arterial Hypertension and Lupus Glomerulonephritis in Systemic Lupus Erythematosus

In spite of several articles questioning the general opinion that arterial hypertension in patients with systemic lupus erythematosus (SLE) is only the consequence of lupus glomerulonephritis (LGN), this still remains the usual pathophysiologic explanation. The purpose of this study was to explore the correlations between hypertension and LGN and to assess the importance of hypertension control for the prognosis of patients. A retrospective analysis of 173 patients with SLE over a period of 14 years was performed. For most of the patients, data were available from regular follow-up visits over an average of 6 years. Our results show a dissociation of hypertension and LGN and an association of hypertension and renal dysfunction. Severe hypertensive renal vascular lesions correlated well with a decrease of renal function. Successful treatment of hypertension is therefore essential in order to prevent deterioration of renal function in patients with LGN.

Acute kidney injury in immunoglobulin A nephropathy: potential role of macroscopic hematuria and acute tubulointerstitial injury.

The aim of our retrospective study was to analyze the clinical course and outcome of patients with immunoglobulin A (IgA) nephropathy who presented with macroscopic hematuria and acute kidney injury (AKI). During the period from 1990 to 2005, seven out of 584 adult patients with IgA nephropathy (1.2%) fulfilled the criteria for macroscopic hematuria‐induced AKI. There was an equal gender distribution among our patients, and a rather high average age at presentation (55.7 ± 10.9 years). Four patients who were oliguric upon admission to hospital needed hemodialysis treatment. The average serum creatinine at the time of kidney biopsy was 429.8 ± 377 µmol/L (median value 378). The percutaneous kidney needle biopsies showed focal proliferative crescentic glomerulonephritis of subclass III, according to the Haas scheme, associated with prominent red blood cell tubular casts and acute tubulointerstitial nephritis. Four patients with the most prominent crescents and tubulointerstitial involvement were treated with methylprednisolone. All patients, treated and untreated, recovered their kidney function (the serum creatinine at a median follow‐up of 15 months was 111.7 ± 38 µmol/L). In conclusion, AKI in IgA nephropathy accompanied by macroscopic hematuria appears to have been a reversible condition in our series of patients. Regarding pathogenesis, the kidney biopsy study points to the important role of glomerular bleeding with consequent, widespread obstructive red blood cell tubular casts accompanied by tubular injury and interstitial nephritis.

IMMUNOTACTOID GLOMERULOPATHY WITH UNUSUALLY THICK EXTRACELLULAR MICROTUBULES AND NODULAR GLOMERULOSCLEROSIS IN A DIABETIC PATIENT

It has recently been suggested that immunotactoid glomerulopathy be separated from much more common fibrillary glomerulonephritis by ultrastructural features of highly organized immune deposits containing tubules of more than 30 nm in diameter. We report and discuss the results of a light, immunofluorescence and electron microscopic study of a needle renal biopsy from a 75-year-old, non-insulin dependant diabetic female presented with nephrotic syndrome, hypertension and a progressive renal failure. A unique coexistence of nodular glomerulosclerosis, as traditionally ascribed to diabetes with a peculiar type of immunotactoid glomerulopathy was confirmed by the exclusion of amyloidosis, monoclonal gammopathies, systemic autoimmune diseases and cryoglobulinemia. Mesangial, scattered subepithelial and segmentally prominent subendothelial immune deposits were found highly organized in mostly parallel arrays of 40 to 91 nm thick tubules. The average thickness of 67 nm exceeds the average diameter of tubules in all other 11 published cases of immunotactoid glomerulopathy to date. By immunofluorescence, predominantly capillary wall, thick, ribbon-like glomerular deposits contained IgG, IgM, kappa and lambda light chains of equal intensity, C3, C4 and fibrin related antigens. Mild to moderate glomerular cell proliferation associated with nodular sclerosis has been assumed to be causally related to immunotactoid deposits.