Antigen Excretion Research Articles

Detection of Bk Polyomavirus Antigen in Patients with Acute Lymphoblastic Leukemia

Background: BK polyomavirus that is acquired in early childhood as BKPyV is near ubiquitous in adults with a seroprevalence of >80%, it has been found as the main cause of hemorrhagic cystitis in hematopoietic stem cell transplantation patients, due to immunosuppression regimen that lead to the activation of the virus from the latency status and lead to increased viral shedding in urine (viuria).
 Objective: To investigate the frequency of BK Polyomavirus antigen excretion in urine of children with acute lymphoblastic leukemia with and without chemotherapy and compare it with normal controls. 
 Patients and Methods: A case-control study conducted from December 2021 to May 2022 in Baghdad, Iraq on leukemia patients of Central Pediatrics Hospital (Al-Eskan ). Urine samples and urine sediment smears were collected from 60 acute lymphoblastic leukemia patients. And compared with 60 apparently healthy age and sex-matched children, BK polyomavirus antigen in urine was detected using Enzyme-linked Immunosorbent Assay and urine cytology were Pap stained for the detection of decoy cells (DCs).
 Results: Positive BKPyV antigen in urine was seen in 55 (91.7%) of Acute lymphoblastic leukemia patients and 39 (65.0%) in controls (p=<0.001) and all the patients were decoy negative. There was no significant effect of the positivity of antigenuria on neither leukocytes level nor on the occurance of relapse in leukemia patients. 
 Conclusion: The very high frequency of BKPyV in the urine signifies the importance of reactivation of this virus in ALL patients with and without chemotherapy.

Detection of Bk Polyomavirus Antigen in Patients with Acute Lymphoblastic Leukemia

Background: BK polyomavirus that is acquired in early childhood as BKPyV is near ubiquitous in adults with a seroprevalence of >80%, it has been found as the main cause of hemorrhagic cystitis in hematopoietic stem cell transplantation patients, due to immunosuppression regimen that lead to the activation of the virus from the latency status and lead to increased viral shedding in urine (viuria). Objective: To investigate the frequency of BK Polyomavirus antigen excretion in urine of children with acute lymphoblastic leukemia with and without chemotherapy and compare it with normal controls. Patients and Methods: A case-control study conducted from December 2021 to May 2022 in Baghdad, Iraq on leukemia patients of Central Pediatrics Hospital (Al-Eskan ). Urine samples and urine sediment smears were collected from 60 acute lymphoblastic leukemia patients. And compared with 60 apparently healthy age and sex-matched children, BK polyomavirus antigen in urine was detected using Enzyme-linked Immunosorbent Assay and urine cytology were Pap stained for the detection of decoy cells (DCs). Results: Positive BKPyV antigen in urine was seen in 55 (91.7%) of Acute lymphoblastic leukemia patients and 39 (65.0%) in controls (p=<0.001) and all the patients were decoy negative. There was no significant effect of the positivity of antigenuria on neither leukocytes level nor on the occurance of relapse in leukemia patients. Conclusion: The very high frequency of BKPyV in the urine signifies the importance of reactivation of this virus in ALL patients with and without chemotherapy. Keywords: Acute lymphoblastic leukemia, BK Polyomavirus, Antigenuria

Pattern and repeatability of ascarid-specific antigen excretion through chicken faeces, and the diagnostic accuracy of coproantigen measurements as compared with McMaster egg counts and plasma and egg yolk antibody measurements in laying hens

BackgroundA coproantigen enzyme-linked immunosorbent assay (ELISA) has recently been proposed for detecting ascarid infections in chickens. The excretion pattern of ascarid antigens through chicken faeces and the consistency of measurements over the course of infections are currently unknown. This study evaluates the pattern and repeatability of worm antigen per gram of faeces (APG) and compares the diagnostic performance of the coproantigen ELISA with a plasma and egg yolk antibody ELISA and McMaster faecal egg counts (M-FEC) at different weeks post-infection (wpi).MethodsFaecal, blood and egg yolk samples were collected from laying hens that were orally infected with a mix of Ascaridia galli and Heterakis gallinarum eggs (N = 108) or kept as uninfected controls (N = 71). Measurements including (a) APG using a coproantigen ELISA, (b) eggs per gram of faeces (EPG) using the McMaster technique and (c) ascarid-specific IgY in plasma and in egg yolks using an ascarid-specific antibody ELISA) were performed between wpi 2 and 18.ResultsTime-dependent significant differences in APG between infected and non-infected laying hens were quantified. At wpi 2 (t(164) = 0.66, P = 1.00) and 4 (t(164) = −3.09, P = 0.094) no significant differences were observed between the groups, whereas infected hens had significantly higher levels of APG than controls by wpi 6 (t(164) = −6.74, P < 0.001). As indicated by a high overall repeatability estimate of 0.91 (CI = 0.89–0.93), APG could be measured consistently from the same individual. Compared to McMaster and antibody ELISA, coproantigen ELISA showed the highest overall diagnostic performance (area under curve, AUC = 0.93), although the differences were time-dependent. From wpi 6 to 18 coproantigen ELISA had an AUC > 0.95, while plasma IgY ELISA showed the highest diagnostic performance in wpi 2 (AUC = 0.95). M-FEC had the highest correlation with total worm burden, while APG had highest correlations with weights and lengths of A. galli.ConclusionAscarid antigen excretion through chicken faeces can be measured with high accuracy and repeatability using a coproantigen ELISA. The antigen excretion increases over time, and is associated with worm maturation, particularly with the size of A. galli. Our results suggest the necessity of complementary use of different diagnostic tools for a more accurate diagnosis of infections.Graphical

SARS-CoV-2 N-Antigen Quantification in Respiratory Tract, Plasma and Urine: Kinetics and Association with RT-qPCR Results.

Qualitative SARS-CoV-2 antigen assays based on immunochromatography are useful for mass diagnosis of COVID-19, even though their sensitivity is poor in comparison with RT-PCR assays. In addition, quantitative assays could improve antigenic test performance and allow testing with different specimens. Using quantitative assays, we tested 26 patients for viral RNA and N-antigen in respiratory samples, plasma and urine. This allowed us to compare the kinetics between the three compartments and to compare RNA and antigen concentrations in each. Our results showed the presence of N-antigen in respiratory (15/15, 100%), plasma (26/59, 44%) and urine (14/54, 28.9%) samples, whereas RNA was only detected in respiratory (15/15, 100%) and plasma (12/60, 20%) samples. We detected N-antigen in urine and plasma samples until the day 9 and day 13 post-inclusion, respectively. The antigen concentration was found to correlate with RNA levels in respiratory (p < 0.001) and plasma samples (p < 0.001). Finally, urinary antigen levels correlated with plasma levels (p < 0.001). Urine N-antigen detection could be part of the strategy for the late diagnosis and prognostic evaluation of COVID-19, given the ease and painlessness of sampling and the duration of antigen excretion in this biological compartment.

When secretion turns into excretion - the different roles of IgA.

IgA deficiency is the commonest immunodeficiency affecting up to 1 in 700 individuals. The effects of IgA deficiency are difficult to see in many individuals, are mild in many fewer and severe in fewer still. While monovalent IgA is found in serum, dimeric IgA is secreted through mucosal surfaces where it helps to maintain epithelial homeostasis. Studies with knockout mice have taught us that there are subtle inflammatory consequences of removing secretory IgA (sIgA), and the best explanation for these changes can be related by the loss of the 'excretory' immune system. The excretion of antigens is a logical process in regulating the immune system, given the long half-life of complement fixing antibodies. But the function of IgA as an immune or inflammation regulator may go beyond antigen removal.

Combination of Forced Diuresis with Additional Late Imaging in 68Ga-PSMA-11 PET/CT: Effects on Lesion Visibility and Radiotracer Uptake.

Renal excretion of some prostate-specific membrane antigen (PSMA) ligands and consequently increased bladder activity can obscure locally relapsing prostate cancer lesions in PSMA PET/CT. Furthermore, additional late imaging in PSMA PET/CT provides a useful method to clarify uncertain findings. The aim of this retrospective study was to investigate a modified imaging protocol combining late additional imaging with hydration and forced diuresis in individuals undergoing additional late scanning for uncertain lesions or low prostate-specific antigen. Methods: We compared an older protocol with a newer one. In the old protocol, patients undergoing 68Ga-PSMA-11 PET/CT were examined at 90 min after injection, with 1 L of oral hydration beginning at 30 min after injection and 20 mg of furosemide given intravenously at 1 h after injection, followed by additional late imaging at 2.5 h after injection without further preparation. In the new protocol, a second group received the same procedure as before, with an additional 0.5 L of oral hydration and 10 mg of furosemide intravenously 30 min before the late imaging. We examined 132 patients (76 with the old protocol and 56 with the new one) with respect to urinary bladder activity (SUVmean), prostate cancer lesion uptake (SUVmax), and lesion contrast (ratio of tumor SUVmax to bladder SUVmean for local relapses and ratio of tumor SUVmax to gluteal-muscle SUVmean for nonlocal prostate cancer lesions). Results: Bladder activity was significantly greater for the old protocol in the late scans than for the new protocol (ratio of bladder activity at 2.5 h to bladder activity at 1.5 h, 2.33 ± 1.17 vs. 1.37 ± 0.50, P < 0.0001). Increased tumor SUVmax and contrast were seen at 2.5 h compared with 1.5 h (P < 0.0001 for old protocol; P = 0.02 for new protocol). Increased bladder activity for the old protocol resulted in decreased lesion-to-bladder contrast, which was not the case for the new protocol. Tumor-to-background ratios increased at late imaging for both protocols, but the increase was significantly lower for the new protocol. For the old protocol, comparing the 1.5-h to the 2.5-h acquisitions, 4 lesions in 4 patients (4/76 = 5.2% of the cohort) were visible at the postdiuresis 1.5-h acquisition but not at 2.5 h, having been obscured as a result of the higher bladder activity. In the new protocol, 2 of 56 (3.6%) patients had lesions visible only at late imaging, and 2 patients had lesions that could be better discriminated at late imaging. Conclusion: Although the combination of diuretics and hydration can be a useful method to increase the visualization and detectability of locally recurrent prostate cancer in standard 68Ga-PSMA-11 PET/CT, their effects do not sufficiently continue into additional late imaging. Additional diuresis and hydration are recommended to improve the visibility, detection, and diagnostic certainty of local recurrences.

A non-invasive method to assess environmental contamination with avian pathogens: beak and feather disease virus (BFDV) detection in nest boxes.

Indirect transmission of pathogens can pose major risks to wildlife, yet the presence and persistence of wildlife pathogens in the environment has been little studied. Beak and feather disease virus (BFDV) is of global conservation concern: it can infect all members of the Psittaciformes, one of the most threatened bird orders, with infection often being lethal. Indirect transmission of BFDV through contaminated nest hollows has been proposed as a major infection source. However, data on whether and for how long nest sites in the wild remain contaminated have been absent. We determined the BFDV status of birds (parents and nestlings) for 82 nests of Crimson Rosellas, Platycercus elegans and Eastern Rosellas, Platycercus eximius. In 11 of these nests (13.4%, 95% confidence interval 6.9–22.7), we found an infected parent or nestling. Using nest swabs, we then compared BFDV presence at three points in time (before, during and after breeding) in three groups of nest boxes. These were nest boxes occupied by infected birds, and two control groups (nest boxes occupied by uninfected birds, and unoccupied nest boxes). Detection of BFDV on nest swabs was strongly associated with the infection status of parents in each nest box and with the timing of breeding. During breeding, boxes occupied by BFDV-positive birds were significantly more likely to have BFDV-positive nest swabs than boxes occupied by BFDV-negative birds; nest swabs tested BFDV-positive in 80% (28.4–99.5) of nests with parental antigen excretion, 66.7% (9.4–99.2) of nests occupied by parents with BFDV-positive cloacal swabs and 66.7% (22.3–95.7) of nests occupied by parents with BFDV–positive blood. 0% (0–52.2) of nests with BFDV–positive nestlings had BFDV–positive nest swabs. Across all boxes occupied by BFDV-positive birds (parents or nestlings), no nest swabs were BFDV–positive before breeding, 36.4% (95% CI 10.9–69.2) were positive during breeding and 9.1% (0.2–41.3) remained positive after breeding. BFDV was present on nest swabs for up to 3.7 months. Our study provides novel insights into the potential role of nest cavities and other fomites in indirect transmission of BFDV, and possibly other pathogens, and offers a non-invasive method for surveillance of pathogens in wild bird populations.

PO-442 Ex vivo prostate cancer culture system recapitulates in vivo response to androgen antagonist

IntroductionIn vitro models of prostate cancer (PCa) do not always accurately represent the different stages of PCa nor reliably predict treatment efficacy. Therefore, we have developed an experimental platform in which we cultured tumour slices from patient-derived prostate cancer xenografts (PDX) and tested whether ex vivo PCa culture can recapitulate the in vivo response to the androgen antagonist enzalutamide.Material and methodsIn this ex vivo PDX culture system we used tumours from two PCa models in mice, one androgen receptor (AR) expressing model and one AR-negative model. Tumours were removed from the mice and sliced using a vibratome. We characterised the tumour slices by analysing morphology, cell proliferation, apoptosis, expression levels of AR and excretion of prostate specific antigen (PSA). To test the sensitivity to androgen antagonist, tumour slices from the AD and AI models were treated with enzalutamide.Results and discussionsWe optimised support materials, growth medium and use of a 3D smooth rocking platform to increase oxygen and nutrient exchange. Under optimal condition, the tissue slice cultures maintained morphology, proliferative capacity and viability for at least six days. AR expression was largely maintained and tumour slices continued to secrete PSA in AR expressing tumour slices and responded to enzalutamide with a significant decrease of S-phase cells, increase of apoptotic cells, dramatic reduction of AR expression and inhibition of PSA secretion. As expected, the AR-negative model did not respond to the AR antagonist.ConclusionThis thorough characterisation of PCa PDX tumour slices in an ex vivo culture system showed that the response to enzalutamide recapitulates that observed in vivo. The faithful retention of tissue structure and function in this ex vivo model offers an ideal opportunity for drug screenings, thereby reducing costs and numbers of experimental animals.

Renal health after long-term exposure to tenofovir disoproxil fumarate (TDF) in HIV/HBV positive adults in Ghana

The study assessed markers of renal health in HIV/HBV co-infected patients receiving TDF-containing antiretroviral therapy in Ghana. Urinary protein-to-creatinine ratio (uPCR) and albumin-to-protein ratio (uAPR) were measured cross-sectionally after a median of four years of TDF. At this time, alongside extensive laboratory testing, patients underwent evaluation of liver stiffness and blood pressure. The estimated glomerular filtration rate (eGFR) was measured longitudinally before and during TDF therapy. Among 101 participants (66% women, median age 44 years, median CD4 count 572cells/mm3) 21% and 17% had detectable HIV-1 RNA and HBV DNA, respectively. Overall 35% showed hypertension, 6% diabetes, 7% liver stiffness indicative of cirrhosis, and 18% urinary excretion of Schistosoma antigen. Tubular proteinuria occurred in 16% of patients and was independently predicted by female gender and hypertension. The eGFR declined by median 1.8ml/min/year during TDF exposure (IQR -4.4, -0.0); more pronounced declines (≥ 5ml/min/year) occurred in 22% of patients and were associated with receiving ritonavir-boosted lopinavir rather than efavirenz. HBV DNA, HBeAg, transaminases, and liver stiffness were not predictive of renal function abnormalities. The findings mandate improved diagnosis and management of hypertension and suggest targeted laboratory monitoring of patients receiving TDF alongside a booster in sub-Saharan Africa.

Pneumococcal urinary antigen positivity in healthy colonized children: is it age dependent?

Pneumococcal urinary antigen test is a valuable tool for diagnosing pneumococcal pneumonia and meningitis in adults. Its use in children is generally not accepted because of nonspecificity at this age. It is frequently positive in asymptomatic nasopharyngeal carriers. The aim of our study was to assess the age limit from which the test is no longer positive in asymptomatic healthy carriers. A total of 197 children aged 36-83 months attending 9 day care centers in Prague were enrolled during February and March 2010. Nasopharyngeal swab specimens were collected from each participant and selectively cultivated. The presence of pneumococcal antigen in urine was detected by BinaxNOW® S. pneumoniae kit. Streptococcus pneumoniae was cultivated in 53.3 % of healthy children with the highest colonization rate (59.3 %) in children aged 48-59 months. The most frequently colonizing serotypes were: 19F, 23F, 3, 19A, 6B and 4. The presence of pneumococcal antigen in urine decreased with age from 39.0 % in 36-47 months to 17.9 % in 72-83 months old (p = 0.031). The antigen positivity was serotype-dependent and more frequent in nonvaccinated children. We demonstrated age-dependent linear decrease of pneumococcal antigen excretion into urine in healthy children. The positivity rate of the test in children aged 72-83 months was similar to that referred in healthy adults, irrespective of colonization. To confirm this age limit for use of this test in diagnostics of pneumococcal diseases, further study in school-age children is justified.

Natural infection with peste des petits ruminants virus: A pre and post vaccinal assessment following an outbreak scenario

Peste des petits ruminants virus (PPRV) infection was confirmed in a herd of goats (n=55) at an organised farm in Islamabad, Pakistan. PPRV infection was confirmed using both antigen- and antibody-based detection methods, haemagglutination (HA) tests and molecular methods. Animals that survived natural infection developed a typical serological response and virus antigen was detected in fecal matter. Following determination of serological response to infection animals were grouped and either vaccinated or left unvaccinated: group 1 animals succumbed to infection (n=5) and samples were analysed for PPRV antigen; group 2 animals developed clinical disease (n=10) and were divided into 2 groups, half being vaccinated (group 2a) whilst the remainder were unvaccinated (group 2b); group 3 (n=15) animals included those that developed only very mild clinical disease or no clinical disease; group 4 animals (n=5) were negative for clinical disease and were housed as a negative control group. A variable antibody response was detected following resolution of the initial outbreak. Excretion of virus antigen was assessed at different time points following vaccination. Importantly, animals that were vaccinated (group 2a) excreted antigen in fecal matter for 1 month following vaccination whilst unvaccinated animals (group 2b) continued to shed virus antigen for 2 months. The potential for virus excretion in fecal matter and effects of vaccination upon virus infection are discussed. We postulate that excretion in fecal material may represent a mechanism of virus transmission following natural infection and that this mechanism may demonstrate a potential method by which PPRV outbreaks occur spontaneously in areas not previously known to have circulating virus.

The role of cannabinoids in prostate cancer: Basic science perspective and potential clinical applications

Prostate cancer is a global public health problem, and it is the most common cancer in American men and the second cause for cancer-related death. Experimental evidence shows that prostate tissue possesses cannabinoid receptors and their stimulation results in anti-androgenic effects. To review currently relevant findings related to effects of cannabinoid receptors in prostate cancer. PubMed search utilizing the terms “cannabis,” “cannabinoids,” “prostate cancer,” and “cancer pain management,” giving preference to most recent publications was done. Articles identified were screened for their relevance to the field of prostate cancer and interest to both urologist and pain specialists. Prostate cancer cells possess increased expression of both cannabinoid 1 and 2 receptors, and stimulation of these results in decrease in cell viability, increased apoptosis, and decreased androgen receptor expression and prostate-specific antigen excretion. It would be of interest to conduct clinical studies utilizing cannabinoids for patients with metastatic prostate cancer, taking advantage not only of its beneficial effects on prostate cancer but also of their analgesic properties for bone metastatic cancer pain.

Utility of Stool Sample–based Tests for the Diagnosis of Helicobacter pylori Infection in Children

Helicobacter pylori antigen or DNA in stool are meant to detect the bacteria; however, in children the colonization of the gastric mucosa by H pylori is usually weak and fecal excretion of antigen or DNA varies considerably, challenging the utility of these tests in this age group. The aim of the present study was to carry out a systematic review and meta-analysis to evaluate the performance of stool H pylori DNA and antigen tests for the diagnosis of infection in children. We conducted a systematic review and meta-analysis to assess the accuracy of stool tests for diagnosis of H pylori infection in children. We searched PubMed, EMBASE, and LILACS databases. Selection criteria included participation of at least 30 children and the use of a criterion standard for H pylori diagnosis. In a comprehensive search, we identified 48 studies. Regarding antigen-detection tests, enzyme-linked immunosorbent assay (ELISA) monoclonal antibodies showed the best performance, with sensitivity and specificity of 97%, positive likelihood ratio (LR+) of 29.9, and negative likelihood ratio (LR-) of 0.03. ELISA polyclonal antibodies had sensitivity of 92%, specificity of 93%, LR+ of 16.2, LR- of 0.09, and high heterogeneity (P < 0.0001). One-step monoclonal antibody tests demonstrated sensitivity of 88%, specificity of 93%, LR+ of 10.6, and LR- of 0.11. For DNA detection, polymerase chain reaction-based test showed sensitivity of 80.8%, specificity of 98%, LR+ of 17.1, and LR- of 0.18. Detection of H pylori antigen in stools with ELISA monoclonal antibodies is a noninvasive efficient test for diagnosis of infection in children. One-step tests showed low accuracy and more studies are needed to obtain a useful office-based screening test. The available molecular tests are still unreliable.

Direct Cytopathic Effects of Particular Hepatitis B Virus Genotypes in Severe Combined Immunodeficiency Transgenic With Urokinase-Type Plasminogen Activator Mouse With Human Hepatocytes

Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes. Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera. Histologic analysis of mice infected with HBV/C2 for 22-25 weeks showed abundant ground-glass appearance of the hepatocytes and fibrosis in the humanized part of the murine liver owing to the activation of hepatic stellate cells mediated by oxidative stress through transforming growth factor-beta1 signaling, whereas neither was observed with HBV/A2 and B1. The HBV-DNA level in sera was the highest in mice infected with HBV/C2 compared with those with HBV/A2 and HBV/B1 (10(9), 10(7), and 10(4) log copies/mL, respectively, P < .05) during 6-8 weeks postinoculation. HB core-related antigen excretion had a similar trend among the genotypes, whereas secretion of HB surface antigen was more pronounced for HBV/A2 followed by HBV/C2 and much less for HBV/B1. Introduction of precore stop-codon mutation in the HBV/B1 caused a significant increase in viral replication, antigen expression, and a histopathologic picture similar to HBV/C2. By using a humanized in vivo model, we show that different HBV genotypes and even particular mutations resulted in different virologic and histopathologic outcomes of infection, indicating that particular genetic variants of HBV may be directly cytopathic in immunosuppressive conditions.

Persistence of Streptococcus pneumoniae urinary antigen excretion after pneumococcal pneumonia

The aim of this study was to determine the duration of Streptococcus pneumoniae antigen excretion in urine after pneumococcal pneumonia. Urinary antigen detection remained positive in nonconcentrated urine in 18 (52.9%) of the 34 patients in the first month after pneumonia diagnosis. In 12 of these positive cases, the test was still positive in the second month, in six patients after 4 months, and in two cases 6 months after the diagnosis of pneumonia. Using concentrated urine, antigenuria remained positive in all patients for at least 3 months, with antigen detected in three cases more than one year later. We did not observe a relation between age, gender, immunosuppression, underlying diseases, pneumonia severity, positive blood culture, or X-ray presentation and longer-term antigenuria excretion. However, the small number of patients evaluated is a limitation for statistical analysis. In order to correctly analyse a positive urinary antigen test result in patients with pneumonia, it is necessary to know which patients have recently had a previous episode of pneumonia.

Urinary excretion of CD23 antigen in normal individuals and patients with chronic lymphocytic leukaemia (CLL)

A soluble form of CD23 (sCD23) was found in the urine from 12 normal individuals but was not present in 20 normal sera, suggesting that sCD23 produced by cells in tissues is eliminated in the urine. The sCD23 from urine differed in physicochemical properties from the sCD23 found in supernates from B-lymphoblastoid cell lines (B-LCL) and in the sera of patients with B type chronic lymphocytic leukaemia (B-CLL). On SDS-PAGE analysis under reducing conditions urinary sCD23 showed two bands corresponding to molecular weights of 45-60 kD and 28-35 kD indicating that sCD23 may be excreted in combination with another molecule. When subjected to gel filtration in its native state, sCD23 from urine showed a major peak at approximately 150 kD and a minor peak (probably a breakdown product) at 21 kD. Urinary sCD23 was more strongly held by DEAE-cellulose and required 0.5 M buffer pH 8.0 for elution, suggesting that it is more anionic than sCD23 from culture supernates. Five MoAbs recognizing different epitopes on sCD23 from B-LCL supernates were tested on urinary sCD23. Four of the MoAbs were reactive but one (EBVCS-1) was not. Urinary sCD23 did not bind to IgE. The level of sCD23 found in normal urine (approximately 0.02-0.05 micrograms/ml) was exceeded in 17 of 24 cases of B-CLL. In one case with a high cell count and a serum concentration of 10 micrograms/ml, the urine contained 80 micrograms/ml sCD23. In another case a high serum sCD23 was not matched by a high urinary level. In this case the gel filtration pattern was closer to that found with urine sCD23 rather than the B-LCL pattern found with sera of other B-CLL patients.

Clinical Features of Two Cases of Legionnaires' Disease with Persistence of &lt;i&gt;Legionella&lt;/i&gt; Urinary Antigen Excretion

The advantages of diagnosing legionellosis by urinary antigen detection are widely recognized, and include early detection, rapidity of testing, and ease of specimen collection. However, the persistence of Legionella urinary antigen excretion has been suggested in some selected patients, although the clinical features of these patients have not yet been clearly described. Here, we describe the clinical features of two patients with Legionnaires' disease with persistence of Legionella urinary antigen excretion (117 days and 247 days). One patient had an underlying disease, adult T-cell leukemia, and the other patient had ulcerative colitis and was receiving oral corticosteroids. Unusual clinical and radiological findings as well as a review of the literature are presented.

Examination of the Applicability of a Commercial Human Rotavirus Antigen Detection Kit for Use in Laboratory Rabbits

The applicability of a commercial human rotavirus detection kit for the detection of lapine rotavirus in laboratory rabbits was examined. Rotavirus antigen positive samples determined by the kit were shown to include lapine rotavirus by reverse transcriptional polymerase chain reaction and restriction endonuclease analysis. The kit was confirmed to be adequate for the detection of lapine rotavirus by these results. The kit is suggested to be useful for the management of laboratory rabbits because of its ability to detect rotavirus antigen excretion which occurs in the early stage of the infection. It will contribute to minimizing the loss of rabbits in the event of an outbreak.

Factors related to persistence of Legionella urinary antigen excretion in patients with legionnaires' disease.

The aim of this prospective study was to compare patient characteristics, clinical data, and evolution of Legionella pneumophila pneumonia according to the duration of Legionella urinary antigen excretion. Urine samples from 61 patients with Legionella pneumonia diagnosed by detection of urinary antigen were obtained periodically until urinary antigen could no longer be detected. Cases were divided into two groups based on the duration of urinary antigen excretion: group I (46 patients, <60 days) and group II (15 patients, >or=60 days). Groups were compared for patient characteristics, clinical data, and evolution of pneumonia. Antigen excretion >or=60 days was observed significantly more frequently in immunosuppressed patients ( P=0.001) in whom the time to apyrexia was >72 h ( P=0.002), although only the time to apyrexia remained significant on multivariate analysis ( P=0.006). In conclusion, the duration of Legionella urinary antigen excretion was <60 days in most patients but was longer in immunosuppressed patients with a longer time to defervescence of fever.

Urinary excretion of pneumococcal cell wall polysaccharide in children.

The urinary excretion of the cell wall polysaccharide of Streptococcus pneumoniae was studied in 92 children with the NOW test. Cell wall polysaccharide was detected in 65% of pneumococcal carriers and in 10% of noncarriers. Excretion rates were similar in healthy children and in children with acute otitis media. The high rate of antigen excretion among nonill carriers suggests that colonization is a major source of urinary antigen in children.