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Anales de Pediatria Apr 2021Autoimmune hemolytic anemia (AIHA) is a rare and generally self-limiting disease in children.
INTRODUCTION
Autoimmune hemolytic anemia (AIHA) is a rare and generally self-limiting disease in children.
MATERIAL AND METHODS
A descriptive cross-sectional study was performed in children under 18 years diagnosed with AIHA from January/1997 to July/2019. Clinical variables were collected and AIHA was classified according to the direct antiglobulin test (DAT) in warm AIHA (IgG+/-C3d) and cold AIHA (C3d). Response to treatment and evolution were analyzed.
RESULTS
25 patients were included and 72% were males. The median age at diagnosis was 2 years (range 0.4 to 9). Fever (72%), pallor (68%), jaundice (64%), hepatosplenomegaly and coluria (48%) were the most common presenting symptoms. The median hemoglobin at diagnosis was 5.4 g/dl. DAT was positive in 96%, with detection of IgG antibodies in 76%. A single case presented negative DAT. 20% of the patients associated another cytopenia, one of which was subsequently diagnosed with common variable immunodeficiency. Concomitant viral infection was suspected or documented in 32%. Most of the cases were self-limiting and responded to corticosteroid treatment (72%). Those with partial response (24%), mainly those associated with other cytopenias, required other lines of treatment (rituximab, mycophenolate, immunoglobulins). Complications (32%) and relapses (26%) were detected only in warm AIHA.
CONCLUSIONS
Our case series confirms that AIHA is a very rare disease in childhood. Most cases evolve favorably, although up to a quarter of them require second lines of treatment and, in exceptional cases, they need very aggressive treatments. These latter cases generally correspond to patients who present more than one cytopenia in the course of the disease.
Topics: Anemia, Hemolytic, Autoimmune; Child; Child, Preschool; Coombs Test; Cross-Sectional Studies; Humans; Immunoglobulin G; Infant; Male; Rituximab
PubMed: 32972857
DOI: 10.1016/j.anpedi.2020.07.012 -
Journal of Clinical Laboratory Analysis Mar 2022The laboratory test results and serum-specific antibodies of patients with acute brucellosis initial infection were followed up and analyzed.
BACKGROUND
The laboratory test results and serum-specific antibodies of patients with acute brucellosis initial infection were followed up and analyzed.
METHODS
70 patients in Hohhot City, Inner Mongolia Autonomous Region, with acute brucellosis were followed up for 360 days. Serum samples were collected at 0, 15, 30, 60, 90, 180, and 360 days after diagnosis and analyzed by Rose Bengal plate test (RBPT), colloidal gold test paper (GICA), and test tube agglutination test (SAT). The serum-specific antibodies IgG and IgM were detected.
RESULTS
RBPT results: False negative (-) gradually increased with the extension of the course of disease, with the largest change in 30-60 days after diagnosis, and the constituent ratio increased by 12.9%. GICA results: The false negative increased with the course of disease, and the constituent ratio of false negative was 20.0% after 180 days of diagnosis. SAT results: 1:100 positive showed a ladder like decrease with the increase in the course of disease, and the largest decrease was 90-180 days, with a decrease of 34.3% in the constituent ratio. 360 days after diagnosis, the constituent ratio of positive was only 14.3%. During the follow-up period, the IgG average value fluctuated and the average IgM value decreased.
CONCLUSION
The false-negative results of RBPT, GICA, and SAT increased with the course of disease, and the false-negative rates were higher than 20% after half a year. IgM level is beneficial to the early diagnosis of brucellosis, while IgG level is helpful to the judgment of brucellosis stage.
Topics: Agglutination Tests; Antibodies, Bacterial; Brucellosis; Follow-Up Studies; Humans; Rose Bengal
PubMed: 35137464
DOI: 10.1002/jcla.24205 -
Journal of Feline Medicine and Surgery Mar 2023Leptospirosis is a re-emergent zoonotic bacterial disease associated with renal and hepatic injury. In free-roaming cats in some regions, a high prevalence of...
OBJECTIVES
Leptospirosis is a re-emergent zoonotic bacterial disease associated with renal and hepatic injury. In free-roaming cats in some regions, a high prevalence of antibodies has been identified, and pathogenic leptospires have been detected in renal tissue, indicating that they may play a role in epidemiology. The objective of this study was to determine the prevalence of seroreactivity and urinary shedding of DNA in free-roaming cats from northern California and southern Texas. A secondary objective was to compare the results of a point-of-care (POC) assay, designed to detect antibodies, with the results of the microscopic agglutination test (MAT) when applied to serum samples from feral cats.
METHODS
Specimens were obtained from free-roaming cats from northern California (n = 52; 2020) and southern Texas (n = 75; 2017). quantitative PCR was performed on blood and urine specimens from Californian cats. Serum samples from Californian and Texan cats were subjected to MAT to categorize them as antibody-positive or antibody-negative. The performance of the POC assay was assessed using the MAT as the gold standard.
RESULTS
DNA was not detected in the blood or urine of any cats tested. The results of the MAT were positive in 17.3% (n = 9) of Californian cats and 10.7% (n = 8) of Texan cats ( = 0.3). The median MAT titer was 1:100 (range 1:100-1:200) in Californian cats and 1:200 (range 1:100-1:800) in Texan cats. The POC assay was negative in all specimens.
CONCLUSIONS AND RELEVANCE
Free-roaming cats in California and Texas are exposed to species and may have the potential to act as sentinel hosts. No cats had evidence of current infection, as determined using PCR on blood and urine specimens. The POC test did not reliably detect anti- antibodies in these cats. The role of cats in the maintenance or shedding of pathogenic leptospires requires further investigation.
Topics: Animals; Cats; Texas; Leptospirosis; Leptospira; Kidney; Antibodies, Bacterial; Cat Diseases
PubMed: 36946598
DOI: 10.1177/1098612X231162471 -
PLoS Neglected Tropical Diseases Mar 2023Cryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for...
BACKGROUND
Cryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples.
METHODS
The 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains.
PRINCIPAL FINDINGS
The 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF.
CONCLUSION
Use of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.
Topics: Humans; Cryptococcus neoformans; Meningitis, Cryptococcal; Cryptococcosis; Meningitis; Latex Fixation Tests; Acquired Immunodeficiency Syndrome
PubMed: 36877731
DOI: 10.1371/journal.pntd.0011140 -
MedRxiv : the Preprint Server For... May 2021Serologic, point-of-care tests to detect antibodies against SARS-CoV-2 are an important tool in the COVID-19 pandemic. The majority of current point-of-care antibody...
Serologic, point-of-care tests to detect antibodies against SARS-CoV-2 are an important tool in the COVID-19 pandemic. The majority of current point-of-care antibody tests developed for SARS-CoV-2 rely on lateral flow assays, but these do not offer quantitative information. To address this, we developed a new method of COVID-19 antibody testing employing hemagglutination tested on a dry card, similar to that which is already available for rapid typing of ABO blood groups. A fusion protein linking red blood cells (RBCs) to the receptor-binding domain (RBD) of SARS-CoV-2 spike protein was placed on the card. 200 COVID-19 patient and 200 control plasma samples were reconstituted with O-negative RBCs to form whole blood and added to the dried protein, followed by a stirring step and a tilting step, 3-minute incubation, and a second tilting step. The sensitivity for the hemagglutination test, Euroimmun IgG ELISA test and RBD-based CoronaChek lateral flow assay was 87.0%, 86.5%, and 84.5%, respectively, using samples obtained from recovered COVID-19 individuals. Testing pre-pandemic samples, the hemagglutination test had a specificity of 95.5%, compared to 97.3% and 98.9% for the ELISA and CoronaChek, respectively. A distribution of agglutination strengths was observed in COVID-19 convalescent plasma samples, with the highest agglutination score (4) exhibiting significantly higher neutralizing antibody titers than weak positives (2) (p<0.0001). Strong agglutinations were observed within 1 minute of testing, and this shorter assay time also increased specificity to 98.5%. In conclusion, we developed a novel rapid, point-of-care RBC agglutination test for the detection of SARS-CoV-2 antibodies that can yield semi-quantitative information on neutralizing antibody titer in patients. The five-minute test may find use in determination of serostatus prior to vaccination, post-vaccination surveillance and travel screening.
PubMed: 33972952
DOI: 10.1101/2021.05.01.21256452 -
Epidemiology and Infection Oct 2019Tularaemia is a zoonotic disease, in Europe caused by Francisella tularensis subsp. holarctica. Many lagomorphs and a variety of small rodents are wildlife species prone...
Tularaemia is a zoonotic disease, in Europe caused by Francisella tularensis subsp. holarctica. Many lagomorphs and a variety of small rodents are wildlife species prone to develop clinical disease, while predators and scavengers are relatively resistant and may serve as sentinels. Blood samples from 656 Swedish wild predators and scavengers were serologically investigated using slide agglutination and microagglutination. In the slide agglutination test, 34 seropositive animals were detected, and they were found among all species investigated: brown bear (Ursus arctos), Eurasian lynx (Lynx lynx), raccoon dog (Nyctereutes procyonoides), red fox (Vulpes vulpes), wild boar (Sus scrofa), wolf (Canis lupus) and wolverine (Gulo gulo). Due to haemolysis the microagglutination test was more difficult to read at low titres, and only 12 animals were classified as seropositive. F. tularensis subsp. holarctica was detected by a polymerase chain reaction in lymphatic tissues of the head in one brown bear, one red fox and one wolf. The significance of this finding regarding possible latency of infection is not clear. In conclusion, the results of this study indicate that all predator and scavenger species included in this study may serve as sentinels for tularaemia in Sweden. Their role as reservoirs is unclear.
Topics: Animals; Animals, Wild; Disease Reservoirs; Francisella tularensis; Predatory Behavior; Sentinel Species; Seroepidemiologic Studies; Sweden; Tularemia; Zoonoses
PubMed: 31637994
DOI: 10.1017/S0950268819001808 -
Scientific Reports Jan 2023Typhoid fever continued to be the key cause of morbidity and mortality in developing countries with poor hygienic practices and limited access to safe drinking water....
Typhoid fever continued to be the key cause of morbidity and mortality in developing countries with poor hygienic practices and limited access to safe drinking water. The Widal card agglutination test is the main diagnostic tool in Ethiopia, which is limited in differentiating the overlapping symptoms with other acute febrile illnesses such as malaria and viral enteritis. This eventually leds to unnecessary antibiotic use and eventual drug resistance. Therefore this study wants to assess the burden and associated potential risk factors of typhoid fever among suspected cases using the typhoid rapid stool antigen test in Northeast Ethiopia. A hospital-based cross-sectional study was conducted at Gaint and Meket Shediho primary hospitals from May to July 2021. A total of 255 patients clinically suspected of typhoid fever, and willing to grant informed consent were included systematically. The demographic and hygiene-related variables were collected using a pre-tested structured questionnaire. The rapid stool antigenic test and xylose-lysine-deoxycholate agar (XLD) stool culture were evaluated for the level of agreement. The present study indicated that the prevalence of typhoid fever was 15.3%. This displayed that the human-restricted infectious disease, typhoid fever remained a challenge to Ethiopians. Washing hands with soap, history of typhoid fever, having previous history of hospitalization, and chronic underlying disease was the significant potential factor for typhoid fever. The higher agreement of the rapid stool antigenic test with the stool culture can indicate the factual burden of typhoid fever in the suspected population. This could minimize empiric treatment and the possible emergence of drug resistance. Thus, resource-poor settings may need to look for a rapid and reliable stool antigenic test.
Topics: Humans; Cross-Sectional Studies; Ethiopia; Immunologic Tests; Salmonella typhi; Typhoid Fever; Feces
PubMed: 36635427
DOI: 10.1038/s41598-023-27909-5 -
The Indian Journal of Medical Research Jan 2022Leptospirosis is a zoonotic disease associated with potentially fatal consequences and a grossly underreported disease in Uttar Pradesh. However, only a few studies are...
BACKGROUND & OBJECTIVE
Leptospirosis is a zoonotic disease associated with potentially fatal consequences and a grossly underreported disease in Uttar Pradesh. However, only a few studies are available which report the prevalence of leptospirosis in this State. Hence, this study was undertaken to know the status of the disease in central and eastern Uttar Pradesh.
METHODS
A total of 143 serum and urine samples were collected from patients with acute febrile illness from July 2017 to March 2019. All the serum samples were tested for Leptospira by rapid IgM antibody card and IgM ELISA and urine samples were tested by real-time polymerase chain reaction (RT-PCR) to detect Leptospira DNA. All positive and 10 per cent negative sera from ELISA and RT-PCR (all rapid test positive were also ELISA positive) were sent to the ICMR-Regional Medical Research Centre, Port Blair for microscopic agglutination test (MAT).
RESULTS
Thirty eight (26.6%) out of 143 samples were positive for leptospirosis either by ELISA or RT-PCR. Positive results were eight (6%) by Rapid card, 32 (22%) by IgM ELISA, 10 (7%) by MAT, 10 (7%) by RT-PCR. In MAT, the most common serovar was Lai followed by Hebdomadis, Bangkinang and Pomona.
INTERPRETATION & CONCLUSIONS
Leptospirosis was found to be one of the important causes for acute febrile illness in the central and eastern parts of Uttar Pradesh. The results of the present study suggest that it is necessary to increase diagnostic facility and awareness in clinicians for the screening of leptospirosis in acutely febrile patients to decrease morbidity and mortality associated with this disease.
Topics: Antibodies, Bacterial; Cross-Sectional Studies; Humans; Immunoglobulin M; Leptospirosis; Prospective Studies
PubMed: 35859430
DOI: 10.4103/ijmr.IJMR_1811_19 -
Microorganisms Oct 2020This review describes and appraises a novel protein-based antigen detection test for visceral leishmaniasis (VL). The test detects in patient's urine six proteins from... (Review)
Review
This review describes and appraises a novel protein-based antigen detection test for visceral leishmaniasis (VL). The test detects in patient's urine six proteins from and , the etiological agents of VL. The gold standard test for VL is microscopic observation of the parasites in aspirates from spleen, liver, or bone marrow (and lymph node for dogs). Culture of the parasites or detection of their DNA in these aspirates are also commonly used. Serological tests are available but they cannot distinguish patients with active VL from either healthy subjects exposed to the parasites or from subjects who had a successful VL treatment. An antigen detection test based on the agglutination of anti-leishmania carbohydrates antibody coated latex beads has been described. However, the results obtained with this carbohydrate-based test have been conflicting. Using mass spectrometry, we discovered six / proteins excreted in the urine of VL patients and used them as markers for the development of a robust mAb-based antigen (protein) detection test. The test is assembled in a multiplexed format to simultaneously detect all six markers. Its initial clinical validation showed a sensitivity of 93% and specificity of 100% for VL diagnosis.
PubMed: 33126760
DOI: 10.3390/microorganisms8111676 -
Practical Laboratory Medicine Nov 2022Rapid plasma reagin (RPR) and (TP) antibody test kits are often used to diagnose syphilis, although the relationship between their measured values is unclear. We aimed...
OBJECTIVES
Rapid plasma reagin (RPR) and (TP) antibody test kits are often used to diagnose syphilis, although the relationship between their measured values is unclear. We aimed to reveal the relevance of these kits' results.
DESIGN AND METHODS
In all, 143 sera from 110 patients were tested using 12 TP kits and 5 RPR kits and the results compared.
RESULTS
The specificity and sensitivity of RPR kits were 81-96% and 95-100%, respectively. The correlation coefficients (0.849-0.934) considerably differed between the manual RPR card test and latex agglutination (LA) assay kits. The following sensitivities were obtained: 82-91% for TP fluorescent treponemal antibody absorption assay (FTA-ABS), TP hemagglutination assay (HA), and TP particle agglutination assay (PA); 94-95% for TP LAs; and 92-100% for chemiluminescent immunoassay (CLIA), chemiluminescent enzyme immunoassay (CLEIA), and immunochromatography assay (IC). Correlation coefficients between TP kits were 0.753-0.974, and the measured values varied. Changes in RPR and quantifiable TP kits were the same for patients with reinfected syphilis and with syphilis under treatment.
CONCLUSIONS
RPR tests had lower specificity than TP antibody tests. RPR card test and RPR LAs had similar specificity and sensitivity, but their measured values were different. RPR should be measured using automatic RPR LA without setting the upper limit of the reported value. RPR LA should also be standardized. The sensitivity of TP antibody was better in CLIA, CLEIA, and IC than in FTA-ABS, HA, PA, and LA. Therefore, TP antibody kits should be standardized and quantified.
PubMed: 36217361
DOI: 10.1016/j.plabm.2022.e00302