Direct Immunofluorescence Microscopy Research Articles

Generation of Antibodies of Distinct Subclasses and Specificity Is Linked to H2s in an Active Mouse Model of Epidermolysis Bullosa Acquisita

Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disease, characterized by antibodies to type VII collagen (COL7). EBA can be induced in mice by immunization with a fragment of the non-collagenous 1 domain of murine COL7. Contrary to other autoimmune diseases, e.g., rheumatoid arthritis, little is known about the genetic susceptibility for EBA. We therefore used the EBA mouse model to address the hypothesis that disease induction depends on the major histocompatibility complex (MHC) haplotype. Mice from different inbred strains were immunized with recombinant murine COL7. Five distinct responses were observed: induction of (i) severe disease in SJL/J (H2s) and female MRL/MpJ (H2k), (ii) mild and transient disease in C57Bl/10.s (H2s), (iii) microscopic blistering in DBA/1J (H2q), (iv) only presence of non-pathogenic autoantibodies in C57Bl/6J (H2b), NZM2410/J (H2z), BXD2 (H2b), and male MRL/MpJ, and (v) complete resistance to EBA in NOD/ShiLtJ (H2g7) and C57Bl/10.q (H2q) mice. Overall, susceptibility to EBA was strongly associated with H2s. In addition, the diseased phenotype was associated with autoantibodies to specific regions of COL7. Our findings show that induction of antibodies with a distinct specificity is linked to the MHC haplotype in experimental EBA. Furthermore, our data are the basis for future studies with the goal of identifying non-MHC EBA susceptibility genes.

Glomerulonephritis in schistosomiasis mansoni: a time to reappraise

The current prevalence of glomerulonephritis in patients with hepatosplenic schistosomiasis mansoni in Brazil was evaluated. Sixty three patients (mean age 45.5 ± 11 years) attending the outpatient infectious disease clinic of a University Hospital in Belo Horizonte, Brazil, from 2007 to 2009, were consecutively examined and enrolled in the present investigation. Diagnosis of hepatosplenic schistosomiasis was based on epidemiological, clinical and parasitological data and imaging techniques. Eight patients, who presented >30 mg/day albuminuria, were submitted to percutaneous ultrasound guided renal biopsy. Kidney tissue fragments were examined under light, direct immunofluorescence and electron microscopy. All patients showed mesangial enlargement. In five, mesangial hypercellularity was observed and four presented duplication of the glomerular basement membrane. Areas of glomerular sclerosis were diagnosed in four. Deposits of immunoglobulin M and C3 were present in six samples; deposits of IgG in four, IgA in three and C1q in two samples. In all patients, immunoglobulin A was reported in the lumen of renal tubules. Deposits of kappa and lambda were observed in six samples. Electron microscopy revealed dense deposits in the glomerular tissue of three patients. Arterial hypertension, small esophageal varices, slight increases in serum creatinine and decreases in serum albumin were associated with glomerular disease. Renal disease associated with hepatosplenic schistosomiasis was verified in 12.7% of patients and type I membranoproliferative glomerulonephritis was observed in 50% of them. Schistosomal glomerulopathy still is an important problem in patients with hepatosplenic schistosomiasis in Brazil.

Forced Expression of Methionine Adenosyltransferase 1A in Human Hepatoma Cells Suppresses in Vivo Tumorigenicity in Mice

Methionine adenosyltransferase (MAT) catalyzes the synthesis of S-adenosylmethionine, the principal methyl donor, and is encoded by MAT1A and MAT2A in mammals. Normal liver expresses MAT1A, which is silenced in hepatocellular carcinoma. We have shown that hepatoma cells overexpressing MAT1A grew slower, but whether this is also true in vivo remains unknown. To investigate the effect of overexpressing MAT1A on in vivo tumorigenesis, we generated stable transfectants of Huh7 cells overexpressing either MAT1A or empty vector. Real-time PCR and Western blotting were used to measure expression, and BALB/c nude mice were injected subcutaneously with untransfected or Huh7 cells transfected with empty or MAT1A expression vector to establish tumors. Tumor properties such as proliferation, angiogenesis, and apoptosis were compared, and microarray analysis was performed. Huh7 cells overexpressing MAT1A had higher S-adenosylmethionine levels but lower bromodeoxyuridine incorporation than control cells. Tumor growth rates and weights were lower in MAT1A transfected tumors. In addition, microvessel density and CD31 and Ki-67 staining were lower in MAT1A transfected tumors than control tumors, whereas the apoptosis index was higher in MAT1A-transfected tumors. Forced expression of MAT1A induced genes related to apoptosis and tumor suppression and lowered expression of cell growth and angiogenesis proteins. Our data demonstrate in vivo overexpression of MAT1A in liver cancer cells can suppress tumor growth. They also suggest inducing MAT1A expression might be a strategy to treat hepatocellular carcinoma.

Premonitory Epidermolysis Bullosa Acquisita Mimicking Eyelid Dermatitis

We report a unique case of a 71-year-old female patient with epidermolysis bullosa acquisita. The patient initially presented with the clinical symptoms of bilateral eyelid dermatitis that occurred several months prior to the development of oral and pharyngeal erosions and blisters. While no contact allergy was found by patch testing, direct immunofluorescence microscopy demonstrated linear deposits of IgG at the basement membrane zone. By indirect immunofluorescence microscopy on human salt-split skin, IgG antibodies bound to the dermal side of the split. Immunoblot analysis showed predominant IgG4 reactivity of the patient's serum with the recombinant non-collagenous-1 domain of type VII collagen. Because of treatment resistance to systemic corticosteroids, dapsone, and colchicine, we initiated a combination treatment of protein A immunoapheresis and rituximab. With this treatment, complete remission was achieved within 4 months. Our case highlights that epidermolysis bullosa acquisita may initially mimic an eyelid dermatitis. Consequently, dermatologists should be aware of this rare differential diagnosis of eyelid dermatitis where a contact allergy or atopic dermatitis is absent.

Clinical, histological and immunpathological findings in 32 patients with dermatitis herpetiformis Duhring

Dermatitis herpetiformis is a chronic severely pruritic dermatosis. It is a cutaneous manifestation of celiac disease. The aim of our study was to collect clinical, histological and immunopathological data on patients who were treated in the University Departments of Dermatology in Würzburg and Lübeck from 1996 to 2008. We retrospectively analyzed 32 patients. Only patients with positive findings on direct immunofluorescence microscopy were included in this study. All patients demonstrated skin lesions in the predilection areas of knees, elbows, gluteal region and scalp. The male to female ratio was 1.5 : 1 and the average age was 43 years. The interval between the first symptoms and diagnosis ranged from 6 weeks to 20 years. Direct immunofluorescence microscopy showed that granular IgA deposits were more often found continuously along the dermal-epidermal junction rather than focally in the tips of the dermal papillae. Results of small intestinal biopsies were available from 29 patients and confirmed the presence of celiac disease in all cases. None of the patients reported gastrointestinal symptoms. IgA antibodies against tissue transglutaminase and epidermal transglutaminase were found in 88% and 94% of patient sera, respectively. The detection of IgA autoantibodies against epidermal transglutaminase is the most sensitive serological test in the diagnosis of dermatitis herpetiformis. Our observations confirm that patients with dermatitis herpetiformis usually do not demonstrate apparent gastrointestinal symptoms.

Clearance rates of circulating and tissue-bound autoantibodies to type VII collagen in experimental epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a severe autoimmune skin disease characterized by autoantibodies to type VII collagen, the major component of anchoring fibrils. In this and other autoimmune bullous dermatoses, specific autoantibody detection systems are not only of diagnostic use but also allow monitoring of circulating and skin-bound autoantibodies during the course of the disease. However, little is known about their natural clearance rates in these different compartments. To study clearance rates of circulating and tissue-bound autoantibodies to type VII collagen in experimental EBA. Using offspring from mice with experimentally induced EBA, we examined retention times of diaplacentally transmitted autoantibodies to type VII collagen in serum of neonatal mice by enzyme-linked immunosorbent assay and of immunoreactant deposits in skin by direct immunofluorescence microscopy. Additionally, the pathogenic potential of transmitted autoantibodies was evaluated in descendant mice. Immediately after birth, comparable levels of pathogenic antibody concentrations were observed in maternal and neonatal mice. The clearance time of skin-bound autoantibodies was twice as long as that of circulating autoantibodies (8 and 4 weeks, respectively). Maternofetal transfer of pathogenic autoantibodies produced specific immunopathological (IgG, IgG1, IgG2a/b and complement C3 deposits) but not histological or clinical alterations in skin of offspring mice. Although still to be confirmed in humans, our findings add to the knowledge on turnover rates of circulating and skin-bound autoantibodies in autoimmune bullous dermatoses, which in turn may facilitate a more specific monitoring of these antibodies during the disease course, reduce the need for repeated skin biopsies, and may also be helpful in guiding treatment decisions.

Linear IgA bullous dermatosis: a clinical study of 16 cases at National Taiwan University Hospital

Linear immunoglobulin A bullous dermatosis (LABD) is a rare autoimmune subepidermal bullous disease. It is defined by continuous linear deposition of IgA in the basement membrane zone on direct immunofluorescence microscopy. The clinical presentations of LABD may mimic other diseases, and data in Taiwanese populations are still lacking. The current study aims to examine LABD status in Taiwan. We reviewed the database at our institute from 1995 to 2008. The gold standard for the diagnosis of LABD is based on continuous linear depositions of IgA in the basement membrane zone on direct immunofluorescence. A total of 16 LABD patients were identified. Mean age at diagnosis was 55 years, and most (> 80%) occurred after the fourth decade. The trunk was most commonly involved (76%). However, in contrast to previous reports, the mucosal involvement was rare in our series (18%). Initial impressions were dermatitis herpetiformis in 8 patients (50%), bullous pemphigoid in 4 patients (25%), and vasculitis, varicella, and pemphigus vulgaris in the remaining 4 patients (25%). Four patients reported a history of drug ingestion shortly before the onset of the disease, and all recovered after discontinuing the offending drugs. One of them had griseofulvin-associated LABD, a case not reported previously. The other three drugs were rifampin, vancomycin and gemcitabine. Among the various regimens, dapsone (100 mg) twice a day achieved the best treatment response in the five treated patients. The rare and diverse presentations of LABD highlight the importance of our study results in aiding clinical diagnosis and planning treatment strategies.

Fibrillar IgA deposition in dermatitis herpetiformis – an underreported pattern with potential clinical significance

Dermatitis herpetiformis has characteristic clinical and histopathologic findings. A fibrillar pattern of IgA deposition on direct immunofluorescence in dermatitis herpetiformis is underreported. Here, we describe three patients with the fibrillar pattern of IgA deposition on direct immunofluorescence examination that initially misled diagnosis in one of the three. Interestingly, two of the three patients lacked anti-transglutaminase and anti-endomysial antibodies but had a clinical course typical of dermatitis herpetiformis. Dermatitis herpetiformis may have a fibrillar rather than granular pattern of IgA deposition on direct immunofluorescent microscopy, and patients with this pattern of immunoglobulin deposition may lack circulating autoantibodies.

Spectrum of Biopsy Proven Glomerular Disease: An Experience Based on Light Microscopy and Direct Immuno tluorescence Microscopy

Glomerular diseases continue to be the leading cause of end-stage renal disease globally. In this study, 80 adequate renal biopsy specimens were subjected to histopathology and direct immunofluorescence (DIF) microscopy in the Department of Pathology, Rajshahi Medical College, from July 2008 to June 2009, to evaluate the spectrum of glomerular disease. Of them 42.5% were male and 57.5% were female with ratio 1: 1.35. The most frequent clinical presentation was nephrotic syndrome (62.5%). Primary glomerular diseases was accounting for 91.25 % of all glomerular disease and of them; FSPGN was the most common histological lesion (27.4%). DMesPGN was the second most common lesion {17.8%) followed by MCD (15.07%), MGN (10.96%), FSGS (10.96%), lgA nephropathy (6.85%), CSG (2.74%) and Cres. GN (2.74%). Lupus nephritis was the most prevalent (71.43%) among secondary glomerulonephritis cases. Among 73 adequate cases for DIF, 63.01% were found to be DIF positive and lgG alone and in various combinations were found in 82.60 % cases (highest deposits).TAJ 2009; 22(1): 239-244

Subcorneal Pustular Dermatosis–Type IgA Pemphigus With Autoantibodies to Desmocollins 1, 2, and 3

IgA pemphigus is a rare neutrophilic acantholytic autoimmune disease that is characterized by IgA deposits on keratinocyte cell surfaces. Clinically and histologically, IgA pemphigus is divided into 2 major subtypes: subcorneal pustular dermatosis and intraepidermal neutrophilic IgA dermatosis. We report the first case of subcorneal pustular dermatosis-type IgA pemphigus that showed reactivity to all 3 isoforms of the desmocollin family by indirect immunofluorescence microscopy of COS7 cells transfected with desmocollin 1, 2, or 3. We describe a 94-year-old woman with IgA pemphigus with a unique immunopathologic pattern. Direct immunofluorescence microscopy revealed IgA deposits throughout the entire epidermis, with stronger staining in the upper epidermis. The autoantibodies from this patient did not show IgA or IgG reactivity with desmogleins via immunoblotting or enzyme-linked immunosorbent assay. By indirect immunofluorescence by the use of COS7 cells transfected with desmocollin 1, 2, or 3, IgA autoantibodies in a serum sample from our patient clearly reacted with all of them. The pathophysiology and autoantigen profile of bullous autoimmune diseases, especially pemphigus and its subforms, are more complex than previously believed. Because pemphigus seems to be a heterogeneous disorder, further studies are needed to evaluate the complexity of the disease.

A case of linear immunoglobulin A bullous dermatosis in a patient exposed to sun and an analgesic

Background: Medications are the most common triggers of linear immunoglobulin A bullous dermatosis (LABD). LABD induced by ultraviolet (UV) radiation has rarely been described. This article reports a case of LABD in a patient exposed simultaneously to an analgesic and UV radiation. Case summary: A 45-year-old woman developed LABD lesions on sun-exposed skin after 3 days of sunbathing and consumption of a medication for headache containing propyphenazone, butalbital, and caffeine. The lesions spread to unexposed skin and, by day 5, the patient had vesicles and bullae on the palms and soles, face, trunk, and extremities. LABD was diagnosed with direct and indirect immunofluorescence microscopy and Western blot analysis. Treatment was successful with prednisone, started at a dosage of 1 mg/kg/d, for 5 months. Lesions located on sunexposed areas, the absence of relapse for 5 years despite continuing sun exposure against medical advice, and subsequent avoidance of the suspected medication suggest that the bullous flare may have been due to the concomitant action of 2 triggers. That the analgesic had a role in this cutaneous manifestation is possible according to the Naranjo algorithm for adverse drug reactions. Conclusions: A case of LABD possibly associated with sun exposure and an analgesic is described. Treatment with prednisone successfully resolved the lesions in this patient.

Risk Factors for Relapse in Patients With Bullous Pemphigoid in Clinical Remission

To identify prognostic factors for relapse in the first year after cessation of therapy in bullous pemphigoid (BP). Prospective, multicenter, cohort study (January 1, 2000, through December 31, 2006). Fifteen French dermatology departments. Patients Patients with BP in remission under low doses of topical or systemic corticosteroids. Interventions Cessation of corticosteroid treatment (day 0) followed by a systematic clinical and immunologic follow-up. The end point was clinical relapse within the first year after cessation of therapy. Associations of clinical, biological, and immunologic (including direct immunofluorescence, serum anti-basement membrane zone autoantibodies, and serum BP180 autoantibodies by enzyme-linked immunosorbent assay [ELISA] on day 0) variables with clinical relapse were assessed by means of univariate and multivariate analyses. On day 0, 30 of 114 patients (26.3%) still had a positive result of direct immunofluorescence, 63 of 112 (56.3%) had circulating anti-basement membrane zone autoantibodies, and 34 of 57 (60%) had anti-BP180 antibodies by ELISA. At month 12, 22 patients were dead (n = 11) or lost to follow-up (n = 11), 51 were in remission, and 45 had had relapses (mean interval to relapse, 3.2 months). Factors predictive of relapse within 12 months after cessation of therapy were a positive result of direct immunofluorescence microscopy (P = .02), a greater age (P = .01), and high-titer ELISA scores (P = .02) on day 0. In multivariate analysis, the only factor independently predictive of relapse was a high-titer ELISA score on day 0 (odds ratio, 11.00; 95% confidence interval, 1.29-93.76). High-titer anti-BP180 ELISA score and, to a lesser degree, a positive direct immunofluorescence finding are good indicators of further relapse of BP. At least 1 of these tests should be performed before therapy is discontinued.

Cutaneous histopathology of lupus erythematosus

Lupus erythematosus (LE) is an autoimmune connective tissue disease whose precise aetiological basis is at present uncertain, in which the clinical presentations range from a skin rash unaccompanied by extracutaneous stigmata to one comprising progressive multisystem disease. Recent advances in our understanding of the pathophysiological basis of LE bring hope for novel therapeutic approaches. Essential to a logical therapeutic strategy is accurate diagnosis and subclassification. With respect to the foregoing, a thorough knowledge of clinical manifestations and serology is essential. A skin biopsy for routine histology, as well as the application of direct immunofluorescence microscopy to lesional and/or non-lesional skin, can be a powerful adjunct both to diagnosis and subclassification. From a clinical standpoint, the disease may be classified into systemic (acute), subacute cutaneous and discoid (chronic) forms, all of which have specific correlative cutaneous histopathology which calls to mind a distinct set of histological mimics. There are other, less common, variants of LE, each with its own specific histological differential diagnoses. The cutaneous histopathology that correlates with the traditional forms of LE, along with certain of the novel subtypes, are the subject of this review.

In vivo confocal laser scanning microscopy for non‐invasive diagnosis of pemphigus foliaceus

In vivo confocal laser scanning microscopy (CLSM) is a modern non-invasive method for investigation of the skin that allows real-time visualization of individual cells and sub-cellular structures at resolution similar to the one provided by routine histopathology. Our aim was to investigate the potential of CLSM for non-invasive diagnosis of pemphigus foliaceus (PF). Pre-existing and mechanically induced lesions in two cases of PF were examined by means of CLSM, parallel to routine histology, direct immunofluorescence microscopy and enzyme-linked immunosorbent assay performed in the same patients. The morphological features characteristic for PF, namely an intraepidermal blister with acantholytic cells in the blister cavity, were readily detectable by means of CLSM. The findings were consistent in both patients and across the investigated lesions. The confocal images were consistent with the routine histology of the pre-existing lesions. No differences in the confocal images of pre-existing lesions compared with mechanically induced ones were observed. Our findings suggest the potential of CLSM as a non-invasive tool for the diagnosis of pemphigus and differentiation of its subtype. Although at present the method cannot replace the current diagnostic standards for pemphigus, it may be successfully used as in vivo non-invasive screening tool to facilitate the diagnosis and point to the need for further investigation of the patient.

Giardia duodenalis in feedlot cattle from the central and western United States

BackgroundGiardia duodenalis is a ubiquitous protozoan parasite that has emerged as a significant opportunistic human pathogen. G. duodenalis may have a deleterious effect on animal growth and performance, therefore its potential as a production limiting organism should not be discounted. We therefore undertook this study to determine management and environmental factors in feedlots that influence the prevalence and environmental load of G. duodenalis cysts in fecal material deposited by feedlot cattle in the central and western United States.ResultsTwenty two feedlots from 7 states were included in the study, and up to 240 fecal samples were collected from pen floors of up to 6 pens per feedlot. Giardia duodenalis cysts were identified and counted using direct immunofluorescent microscopy. The estimated overall point prevalence of G. duodenalis was 19.1%, representing feedlots from a wide range of climates and management systems. Pen-level prevalence varied from 0 to 63.3%, with pen-level shedding estimates ranging from 0 to 261,000 cysts/g feces. Higher environmental temperatures, increased animal density, and increased time in the feedlot were associated with a lower prevalence of G. duodenalis. Removing manure before placing a new group of cattle in a pen was associated with a decreased prevalence of G. duodenalis in fecal pats. Using coccidiostats as a feed additive was associated with a higher prevalence of Giardia.ConclusionManagement practices could be employed that would limit the probability that feedlot cattle shed G. duodenalis in their feces and therefore potentially limit contamination of their environment.

Complement deposition in renal histopathology of patients with ANCA-associated pauci-immune glomerulonephritis

The pathogenesis of ANCA-associated pauci-immune glomerulonephritis has not been fully elucidated. Several studies had suggested that complement deposition could be detected in renal histopathology. The current study investigated the clinical and pathological significance of complement deposition in renal histopathology of patients with ANCA-associated pauci-immune glomerulonephritis. Renal biopsy specimens from 112 patients with ANCA-associated pauci-immune glomerulonephritis were investigated using direct immunofluorescence, light and electron microscopy. For direct immunofluorescence, IgG, IgA, IgM, C3c and C1q staining on fresh frozen renal tissue were routinely performed immediately after a renal biopsy. Complement deposition was defined as the presence of C3c or C1q for at least 1+ in a 0-4+ scale. Clinical and histopathological data between patients with and without complement deposition were compared. In direct immunofluorescence microscopy, C3c and C1q could be detected in glomerular capillary wall and/or mesangium in the specimens of 37/112 (33.0%), 7/112 (6.3%) patients, respectively. Compared with patients without C3c deposition, patients with C3c deposition had a higher level of urinary protein (P < 0.01) and poorer initial renal function (P < 0.05). Complement deposition was not rare in renal histopathology of human ANCA-associated pauci-immune glomerulonephritis, which was associated with more severe renal injury.

Potential of Fibroblast Cell Therapy for Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited skin-blistering disorder caused by mutations in the COL7A1 gene that lead to reduced type-VII collagen and defective anchoring fibrils at the dermal-epidermal junction (DEJ). Presently there are no effective treatments for this disorder. Recent mouse studies have shown that intradermal injections of normal human fibroblasts can generate new human type-VII collagen and anchoring fibrils at the DEJ. To assess potential clinical benefits in humans, we gave single intradermal injections of allogeneic fibroblasts to five subjects with RDEB. We noted increased type-VII collagen at the DEJ at 2 weeks and at 3 months following injection and increased anchoring fibrils, although none of these had normal morphology. No adverse effects, clinical or immunopathologic, were noted. We believe the major effect of allogeneic fibroblasts is to increase the recipients' own COL7A1 mRNA levels with greater deposition of mutant type-VII collagen at the DEJ and formation of additional rudimentary anchoring fibrils. Nevertheless, this mutant protein may be partially functional and capable of increasing adhesion at the DEJ. This is the first study demonstrating that intradermal injections of allogeneic fibroblasts have therapeutic potential in human subjects with RDEB.

Acute Childhood Encephalitis and Encephalopathy Associated With Influenza

Influenza virus infection has been associated with a variety of neurologic complications. The objective of this study was to evaluate prospectively the role of influenza viruses in acute childhood encephalitis/encephalopathy (ACE). All children admitted to the Hospital for Sick Children, Toronto, during an 11-year period with ACE and evidence of acute influenza virus infection were included. Acute influenza virus infection was defined by detection of the organism in the nasopharynx by direct immunofluorescence microscopy or viral culture and/or by a 4-fold or greater rise in complement fixation titer. A total of 311 children with ACE were evaluated; evidence of influenza infection was detected in 7% (22 of 311). Eight were excluded from the main analysis because of evidence implicating other potential pathogens. Eleven of the 14 included subjects were <5 years of age. A respiratory prodrome was documented in 93% of subjects. In 64% neurologic manifestations developed within 5 days of onset of respiratory symptoms. Neuroimaging abnormalities were more common in children <2 years of age. Neurologic sequelae occurred in more than one-half of subjects. In this prospective registry, influenza virus infection was associated with 5% of ACE cases. The majority of children were <5 years of age and the prevalence of neuroimaging abnormalities was higher in children <2 years of age suggesting that younger children are predisposed to the neurologic complications of influenza. An acute rather than a postinfectious process was suggested by the briefness of the respiratory prodrome in most cases.

Prevalence of Giardia and Cryptosporidium spp in calves from a region in New Zealand experiencing intensifi cation of dairying

AIM: To investigate the prevalence of Giardia and Cryptosporidium spp in calves born during two spring-calving seasons in a rapidly intensifying dairying region in the South Island; to evaluate potential correlations between the prevalence of the organism and age, characteristics of faeces, and animal-housing practices; and to compare the results with those from established dairying regions in the North Island. METHODS: A longitudinal study was conducted in 2005 and 2006 on 10 dairy farms located in the Otago region, South Island, New Zealand. A total of 1,190 faecal samples were collected from calves 1–7 weeks old. Direct immunofluorescent microscopy was used to screen the faecal samples for Giardia cysts and Cryptosporidium oocysts. The prevalence of Giardia and Cryptosporidium spp detected in calves in Otago was compared with that previously measured in calves from dairying regions in the Waikato and Manawatu, in the North Island. RESULTS: On average, Giardia and Cryptosporidium spp were detected in 31% and 2.6% of all samples, respectively. The prevalence of Giardia spp cysts in faeces was higher in calves ≥3 weeks of age in 2005 (p≤0.02) and in calves ≥2 weeks of age in 2006 (p=0.07) than in younger calves. No age-related pattern was observed for Cryptosporidium spp in either year. No correlations were evident between characteristics of faeces or animalhousing practices and the prevalence of either organism, which did not differ between the two dairy farming regions. CONCLUSIONS: Prevalence rates of Giardia and Cryptosporidium spp in calves 1–7 weeks old did not differ between the two geographical regions, nor did the regions' distinct climate conditions appear to influence the prevalence of either pathogen. Considering data from both years together, the presence of Giardia spp cysts in faeces appeared to increase in the first week or two after birth, so that, on average, 30–40% of animals from 3–6 weeks of age were affected. CLINICAL RELEVANCE: This is the first study to report the prevalence of Giardia and Cryptosporidium spp in dairy calves in the South Island of New Zealand.

Non-neoplastic Renal Diseases are Often Unrecognized in Adult Tumor Nephrectomy Specimens

The pathologic evaluation of tumor nephrectomy specimens focuses on the diagnosis, grading, and staging of the neoplasm. The presence of coincidental non-neoplastic diseases in these specimens may have significant implications for patient outcomes. The purpose of this study is to determine the spectrum of non-neoplastic disease processes that may be overlooked in tumor nephrectomies, and to ascertain the extent to which surgical pathologists are trained to recognize these lesions. We reviewed the hematoxylin and eosin-stained slides of 246 adult tumor nephrectomy specimens with an emphasis on the non-neoplastic renal parenchyma. Further analysis of cases with pathologic alterations included special stains and direct immunofluorescence microscopy. The surgical pathology reports were reviewed to determine whether the non-neoplastic lesions were originally identified. We also surveyed United States pathology residency programs to determine how many require training in medical renal pathology. Forty-one cases (16.7%) had alterations, such as diffuse and/or nodular mesangial sclerosis, mesangial hypercellularity, or glomerular basement membrane thickening that warranted further study. After further work-up and clinical correlation, the pathologic changes in 24 cases were categorized as follows: diabetic nephropathy (19 cases) of which one demonstrated atheroembolic disease, thrombotic microangiopathy (3 cases), sickle cell nephropathy (1 case), and focal segmental glomerulosclerosis (1 case). Twenty-one (88%) of these diagnoses were not identified at initial pathologic evaluation. Only 35 of 98 pathology residency programs that responded to our survey require any formal training in medical renal pathology. Although accurate pathologic evaluation of renal neoplasms remains essential, surgical pathologists should be aware that coincidental non-neoplastic renal diseases are common, often not recognized, and may have important implications for patient care. Further consideration should be given to the training requirements of pathology residents and the guidelines for evaluation of nephrectomy specimens to avoid missing non-neoplastic renal lesions.