Presence Of IgG Antibodies Research Articles

A novel splice variant of FcγRIIa: A risk factor for anaphylaxis in patients with hypogammaglobulinemia

Our index case was a patient with common variable immunodeficiency (CVID). She had anaphylactoid reactions on administration of intravenous immunoglobulin (IVIg) associated with the presence of IgG antibodies against IgA. We sought to determine the role of Fcγ receptor (FcγR) IIa in IVIg-induced anaphylactoid reactions. Neutrophils and PBMCs were isolated from healthy subjects and IVIg-treated patients. FcγRIIa mRNA and DNA were analyzed by using real-time PCR and sequencing. IgG-mediated elastase release and intracellular Ca(2+) mobilization were determined in neutrophils and transfected cell lines, respectively. A novel splice variant of FcγRIIa containing an expressed cryptic exon 6* (FcγRIIa(exon6∗)) was identified in our index patient. This exon is normally spliced out of all FcγRII isoforms, except the inhibitory FcγRIIb1. Compared with healthy control subjects, the heterozygous FCGR2A(c.742+871A>G) mutation was more frequent in patients with CVID (n = 53, P < .013). Expression in patients with CVID was associated with anaphylaxis on IVIg infusion (P = .002). On screening of additional IVIg-treated patient cohorts, we identified 6 FCGR2A(c.742+871A>G) allele-positive patients with Kawasaki disease (n = 208) and 1 patient with idiopathic thrombocytopenia (n = 93). None had adverse reactions to IVIg. Moreover, FcγRIIa(exon6∗) was also demonstrated in asymptomatic family members. Functional studies in primary cells and transfected murine cells demonstrated enhanced cellular activation by FcγRIIa(exon6∗) compared with its native form, as shown by increased elastase release and intracellular calcium mobilization. A novel splice variant, FcγRIIa(exon6∗), was characterized as a low-frequency allele, coding for a gain-of-function receptor for IgG. In the presence of immune complexes, FcγRIIa(exon6∗) can contribute to anaphylaxis in patients with CVID.

Efficacy of Whole Blood Reconstituted (WBR) in Exchange Transfusion (ET) in Hemolytic Disease of New Born (HDN) —A Study of 110 Cases

Aim: This study was aimed to review and establish the practice of exchange transfusion (ET) with whole blood reconstituted (WBR) in hemolytic disease of newborn (HDN). Objectives: To observe fall in indirect serum bilirubin, correction of anemia and comparison with related studies. Background: Hemolytic disease of the Newborn is characterized by presence of IgG antibodies in maternal circulation, which causes hemolysis in the fetus by crossing the placenta and sensitizing red cells for destruction by macrophages in the fetal spleen with consequent hyperbilirubinemia. Exchange transfusion with or without phototherapy is the method of choice for treating the newborn with on going hemolysis Methods/Materials: Sample size consisted of 110 neonates in whom 119 exchange transfusions were carried out with WBR. WBR was prepared by suspending O Rhesus-D (RhD) positive/negative cells (compatible with neonate’s/ mother’s serum) in AB plasma. Double volume exchange transfusion(s) were carried out through umbilical vein by push-pull technique. Results: Out of 110 cases, 61 (55.5%) were of RhD HDN whereas ABO and other group HDN cases were 30 (27.3%) and 19 (17.3%) respectively. An average post-ET fall in indirect serum bilirubin by 54.6% and correction of anemia by3.7 gm/dl were reported in the study. Conclusion: An average post-ET fall in indirect serum bilirubin and correction of anemia was found to be more significant when compared to other studies. Hence we recommend exchange transfusion in HDN with WBR to obtain reasonable fall in indirect serum bilirubin and high average rate of correction of anemia.

Goodpasture’s syndrome associated with thrombotic thrombocytopenic purpura secondary to an ADAMTS-13 deficit

A 27-year-old man was hospitalized for acute kidney injury associated with antiglomerular basement membrane antibodies (anti-GBM). He underwent immunosuppression and plasma exchange therapy, without recovery of renal function. Later on, he was again admitted to the hospital with seizures. Evidence of microangiopathic hemolytic anemia, with schistocytes in peripheral blood, was present, as well as a persistent low platelet count and activity of von Willebrand factor from adherence to protease (ADAMTS-13) less than 1 %. The presence of IgG antibodies against ADAMTS-13 was documented, leading to a diagnosis of thrombotic thrombocytopenic purpura (TTP) in the context of Goodpasture's syndrome. The TTP was treated with rituximab and plasmapheresis with a good response. We conclude that early measurement of ADAMTS-13 activity dictated the most appropriate therapy and achieved excellent results in this patient.

Seroepidemiology of toxoplasmosis in pregnant women since the implementation of the Surveillance Program of Toxoplasmosis Acquired in Pregnancy and Congenital in the western region of Paraná, Brazil

To evaluate the susceptibility to toxoplasmosis in pregnant women in the public health service from two cities in the western region of Paraná, Brazil. Four thousand twenty-two pregnant women were evaluated for anti-Toxoplasma gondii IgG and IgM by ELISA and MEIA. Seronegative pregnant women repeated the serology in the second and third trimester of pregnancy. Neonatal screening of 27 newborns was also performed in one of the cities to detect IgM anti- Toxoplasma gondii by fluorometry. All pregnant women answered an epidemiological questionnaire to analyze the factors associated with the risk of infection by Toxoplasma gondii. For statistical analysis, the presence of IgG anti-Toxoplasma gondii was considered as the dependent variable and the variables contained in the epidemiological questionnaire as the independent ones. The prevalence of anti-Toxoplasma gondii IgG in pregnant women was 59.8 and 60.6%. In one of the cities, the variables associated with the presence of IgG antibodies were low educational level and more than one pregnancy. There was no association with other factors studied such as consumption of raw or undercooked meat, consumption of raw vegetables, consumption of colonial salami, handling soil or sand, the presence of a home vegetable garden and cats in the household. In the other city there was no statistical association with the variables studied. No case of acute infection and no seroconversion were confirmed in either city. None of the infants evaluated were positive for toxoplasmosis. Toxoplasmosis is common in pregnant women attended by the public health service in the region studied and 40% of them are susceptible to the infection. These data reinforce the need to keep the screening program in these cities.

Viral Infections and Diabetes Mellitus

Type-1-diabetes (T1D) is known to be caused by progressive destruction of pancreatic B-cells, genetic factors are believed to play a major role in the disease development, however, environmental factors are also implicated in the pathogenesis, viruses are one of these factors, as well as triggering beta-cells specific autoimmunity, viruses may cause diabetes by directly infecting and destroying beta-cells, 14 different viruses have been reported to be associated with the development of T1D. In this work, the relationship between (T1D) and seropositivity to three viruses (CMV, EBV and HCV) have been studied, the sera of 54 T1D patients and controls under the age of 30 from both sexes have been investigate for the presence of IgG antibodies against CMV, EBV and total anti-HCV antibodies (Abs). Results revealed that 94.4% of the T1D patients were infected with CMV, 61.1% were infected with EBV and 35.1% were infected with HCV. While among the control group it was found that 77% were infected with CMV comparing to 92.5% and 3.7% were infected with EBV and HCV, respectively. Out of the 54 diabetics 8 (14.8%) found to be infected with the three viruses while none of the controls found to have such seropositivity. From those results it may be concluded that neither the CMV nor the EBV has a relation with T1D while the infection with HCV may be contributed to T1D since there is a significant difference (p&lt;0.001) between the number of T1D patients and number of controls who have anti-HCV Abs.

Sero-surveillance of Rift Valley fever in sheep and goat flocks in high risk areas in Kenya

The surveillance of Rift Valley Fever (RVF) was carried out in the risk areas of Kenya by monitoring free range/migratory and sedentary farm sheep and goat herds for antibodies to RVF virus (RVFV). A total of 986 serum samples were collected and analyzed from farms in Molo, (where no outbreaks has ever been previously reported), Naivasha, (an RVF-endemic area and where the first case of RVF was reported in Kenya), Kajiado, (where there had been reports of an RVF-like disease) and Shompole, (a chief transmigratory livestock-route and market on the Kenya/Tanzania border). Of the total sera tested, 16.9% (164/966), 8.4% (81/966) and 4.1% (39/966) were found to be positive by IgG-sandwich enzyme-linked immunosorbent assay (ELISA), IgM-capture ELISA and serum neutralization (SN) tests respectively. On average, the percentages of sera testing positive for antibodies from sedentary farm herds (Molo, Nakuru and Naivasha) were higher than those from the free-range herds (Kajiado, Namanga, Magadi and Shompole). Although no IgM antibodies were detected in sera from Molo, a significant percentage of the sera showed presence of IgG antibodies. This study also confirms that the RVF-like disease that had been informally reported in the pastoralist areas of Namanga and Kajiado was actually RVF.

Investigation of schizophrenic patients from Istanbul, Turkey for the presence of West Nile virus

Association of some neurotropic viruses like Borna Disease virus and Herpes virus with schizophrenia is better explained. However, the role of West Nile virus (WNV) infection in schizophrenia is not well documented. Therefore, this study was performed to investigate possible association between schizophrenia and presence of antibodies and WNV RNA in schizophrenic patients. For this, 200 blood samples from patients with schizophrenia and 200 from control groups were collected in Istanbul, Turkey. WNV RNA was not detected in any of the 200 patients and 200 controls analyzed by real-time RT-PCR. One hundred and twelve sera of schizophrenic patients and 162 of controls were analyzed for the presence of IgG antibodies to WNV by a commercial IgG-ELISA (Euroimmun, Germany). Antibodies to WNV were detected in 6 schizophrenic patients and 5 controls. ELISA positive patients had antipsychotic therapy. The difference between groups in terms of seropositivity to WNV was not statistically significant (p = 0.887, p = 0.148). Known symptoms of schizophrenia were observed in these patients, and interestingly majority had close contact to cats in the past and come from agricultural area of Turkey where potential area of mosquitoes and bird habitat. In conclusion, the results of this study show that antibodies to WNV in people do not seem to be associated with schizophrenia. However, detecting antibodies to WNV in schizophrenic patients suggests that WNV infection should be considered in endemic areas as it may play role in psychiatric diseases.

The impact of donor-specific antibodies on graft outcome in pediatric renal transplantation from deceased donors

Despite prospective crossmatching and modern immunosuppression, early acute rejection is still present in cadaveric renal transplantation. The purpose of this study was to evaluate the incidence of preformed anti-donor antibodies, detected by 2 solid-phase techniques, and to analyze their impact on early renal allograft outcome. Flow crossmatch detecting the presence of anti-donor IgG and IgM antibodies was performed in pre-transplant sera of 279 patients with negative cytotoxic crossmatch. Screening for IgG antibodies detected by bead-based multiplex technique was performed in sera of 69 patients from the FCXM group. The incidence of early biopsy-proven rejection and graft failure within 3 months after transplantation was analyzed. Anti-donor IgG antibodies were detected in 33 patients (11.8%) by flow crossmatch and in 10 patients by multiplex (14.5%). IgM antibodies were detected in 23 patients (8.2%). All multiplex-positive sera were also positive for IgG by flow crossmatch, but in 18 cases no antibodies were found by multiplex technique. Biopsy-proven acute rejection within 3 months after transplantation was observed in 16 patients, and 5 allografts were lost due to immunological reasons. Presence of IgG antibodies was found to have no effect on early outcome, while the presence of IgM antibodies was associated with significantly higher rejection rate and immune-related graft failure. Anti-donor IgG antibodies detected by bead-based and cell-based technique have no impact on biopsy-proven rejection rate or graft failure. Anti-donor IgM detected by flow crossmatch have significant impact on early transplantation outcome.

Manejo obstetrico y perinatal en miastenia gravis

Myasthenia gravis is an autoimmune disorder characterized by the presence of IgG antibodies against human acetylcholine receptors on striated muscle. Presentation during pregnancy is very rare. This disease is characterized clinically by fatigability of voluntary muscles, particularly those of the eyes, face, oropharynx and extremities.We report the case of a patient with a term pregnancy and a history of myasthenia gravis. The clinical course during pregnancy, childbirth and the puerperal period, as well as the therapeutic possibilities, are described. Commentary: Myasthenia gravis has an unpredictable course during pregnancy, since this disease can exacerbate or trigger situations of perinatal risk. Treatment with anticholinesterase agents, immunomodulators, plasmapheresis and human immunoglobulin can be used, if necessary, with satisfactory results. The incidence of neonatal myasthenia gravis is unrelated to the severity of the mother′s clinical picture and to anticholinesterase antibody titers.

Sero-epidemiologic investigation on tick-borne diseases of humans and domestic animals in Zhejiang province

To investigate the seroprevalence of tick-borne diseases in humans and domestic animals from rural areas of Zhejiang province. Anji county, Jindong district and Tiantai county were selected for samples collection according to their geographic locations and historical prevalence of tick-borne diseases. Blood samples of humans and domestic animals were collected in the three sites. An indirect immuno-fluorescent antibody test was used to determine the presence of IgG antibodies of Rickettsiae heilongjiangii, Orientia tsutsugamushi, R. typhi, Anaplasma phagocytosis, Ehrlichia chaffeensis, Bartonella, R. hainan and Coxiella burnetii in these samples. Six hundred and eighty-three blood samples including 579 from humans and 104 from domestic animals (53 from cattles and 51 from sheep) were collected from the three sites. Antibody positive rates of Orientia tsutsugamushi, R. typhi, Ehrlichia chaffeensis and Coxiella burnetii were significantly different between these sites. IgG from all the 8 pathogens were detected in samples from humans. It was found that the sero-prevalence rates of R. typhi, Bartonella and C. burnetii (20.7%, 10.9%, 5.5%) of adults were higher than those of other Rickettsiae under investigation. The seroprevalence of R. typhi increased along with age. IgG from the 7 pathogens were detected in samples from domestic animals except for Anaplasma phagocytosis. The sero-prevalence rates of R. typhi, Bartonella and R. hainan (69.2%, 51.0%, 22.1%) of adults were higher than those of other Rickettsiae investigated. Tick-borne diseases did spread widely in humans and domestic animals from different rural areas of Zhejiang province. The sero-prevalence rates of R. typhi, B. henselae, R. hainan and C. burnetii were higher than that from other pathogens.

Neutrophil Platelet Satellitism Revisited: Sidedness and Domain of Neutrophil Associated Platelet Aggregates.

Abstract 4469Platelet Satellitism surrounding polymorphonuclear neutrophils has been observed almost exclusively in EDTA-treated blood at room temperature. The mechanism underlying this phenomenon is not fully understood. In a PubMed search of the English language medical literature, there are only 44 reported cases involving the phenomenon of Platelet Satellitism.We report a case of platelet rosetting around neutrophils in a 78-year old woman with incidental thrombocytopenia. Her isolated thrombocytopenia was not mediated by any form of immunosuppression, medications, hypersplenism, intravascular consumption, or diminished platelet production. A diagnosis of Pseudothrombocytopenia was made based upon her peripheral blood smear revealing platelet aggregates displaying sidedness in relation to her neutrophils.Platelet Satellitism is postulated to represent an immunologic phenomenon caused by the presence of natural antibodies in which the platelets aggregate around polymorphonuclear neutrophils. The reasons behind why certain individuals possess agglutinating antibodies that lead to platelet clumping, and others have antibodies that cause platelet satellitism is unknown. A proposed mechanism is natural antibodies directed against different epitopes on the platelet GPIIb-IIIa complex. The reported frequency of platelet Satellitism is much lower than that of EDTA platelet clumping (approximately 1:30,000 blood counts) according to the reviewed literature.Platelet Satellitism to polymorphonuclear neutrophils was initially documented by Field and MacLeod in 1963, and has since been reported as an incidental finding in peripheral blood smears when EDTA was used as an anticoagulant. The process by which platelets bind and form rosettes around polymorphonuclear leukocytes is due to activation of EDTA-dependent antiplatelet and antineutrophil IgG autoantibodies directed against the platelet glycoprotein IIb/IIIa complex and Fc receptors of neutrophils. Further, it is theorized that a non-immunologic cause may play in role in which adherence is induced by thrombospondin or the alpha-granule protein of other platelets. In rare instances, platelets may aggregate around monocytes or basophils.Our retrospective review underscores the importance of recognizing the principle of Pseudothrombocytopenia due to EDTA-induced Platelet Satellitism. This entity is in vitro phenomena which has no clinical bearing in terms of a predisposition to increased mucous membrane bleeding. As in other literature cases, a clear correlation between the presence of IgG antibodies and a specific clinical situation, disease, or use of drugs could not be demonstrated. Therefore, these antibodies, which are present in some normal individuals, might occur naturally. Due to the exposure of certain antigenic structures present on EDTA-modified platelets and neutrophils, they may manifest themselves by triggering the Platelet Satellitism phenomenon. Disclosures:No relevant conflicts of interest to declare.

Outbreak of trichinellosis in eastern Slovakia

Abstract Trichinellosis is a zoonosis caused by ingestion of undercooked raw meat from animals that harbour infectious larvae. In most of the Slovak regions there is ongoing life cycle of circulating trichinellosis in wild carnivores and wild boar population. The outbreak of trichinellosis occured in Rožňava district east Slovakia during spring in 2008. Ten members of farmer’s family and their relatives got ill while processing meat from home-made pig-slaughter for meals and meat products intended for wedding dinner. During the meat processing all of them tasted raw meat. Moreover, another 45 persons were exposed to this infection by eating heat-treated meat products. The most common predominant clinical signs were: myalgias, fever, fatigue, exanthema and periorbital oedema. On the 40th day after infection there were intermediate to high titres of trichinella IgG antibodies detected (10 patients), high levels of eosinophilia (10 patients) with maximum of 6.76 × 109/l (55 %) and profound changes in selected laboratory parameters: decreased levels of total proteins, increased levels of alpha 1-globulin and C reactive protein. Presence of IgG antibodies as well as aforementioned laboratory parameters was important markers of trichinellosis in our study, whereas other laboratory changes (leukocytosis, high levels of activity lactate dehydrogenase and creatine kinase) were detected only in few hospitalized patients.

P294 Antibodies to recombinant enzyme in Pompe's disease

Myozyme (alglucosidase alfa) is drug indicated for use in patients with Pompe disease (GAA deficiency). During the drug administration, life-threatening and severe allergic reactions have been observed. These reactions included anaphylactic shock, cardiac arrest, respiratory distress, hypotension, bradycardia, hypoxia, bronchospasm, dyspnea, angioedema, urticaria, etc. Acute cardiorespiratory failure requiring intubation and inotropic support has been observed after infusion with Myozyme in infantile-onset Pompe disease patients. The most common adverse reactions are Infusion reactions – fever, rush, tachycardia, hypertension, pallor, etc. There is also a risk of cardiac arrhythmia and sudden cardiac death during general anesthesia. Usually, before the infusion of Myozyme patients are pre-medicated with antihistamines, antipyretics and steroids. But, infusion reactions may still occur at any time during, or up to 2 hours after, the infusion. Treatment of less severe reactions includes slower infusion rate, and antihistamines, antipyretics and steroids. Clinical investigations of the patients with Pompe disease often reveal the presence of the IgG antibodies to alglucosidase alfa. The patients with significant titers of these antibodies have a poorer response to treatment and have more often infusion reactions. We would like to present a case of a girl with infantile onset Pompe disease. The treatment with Myozyme has been started when she was 4 months old. It was noticed that her infusion reactions gradually became more often and more severe, including anaphylactic shock. At that moment, we ceased further Myozyme infusions and investigated for the presence of IgG antibodies. The titer of IgG antibodies was found to be high. Our aim was to neutralize those antibodies. At the same time, the paper about this was published (N Engl J Med. 2009 ; 360(2):194-5.). Therefore, we started the same treatment protocol: rituximab + intravenous immunoglobulin + methotrexate. The protocol is not over yet, but our patient is receiving the Myozyme treatment again and without allergic reaction.

Coxiella burnetii seroprevalence in the rural part of Bolu, Turkey*

Aim: This study was performed to determine the seroprevalence of Coxiella burnetii in the rural part of Bolu, a city located in the western part of the Black Sea region of Turkey. Materials and Methods: The study population was chosen by cluster sampling to represent the rural population of the city. Serum samples were collected from the 9 rural districts of Bolu. Blood samples were taken to the laboratory while stored at 4 °C in ice-cooled boxes. The sera were then stored at -20 °C until testing. The presence of IgG antibodies against C. burnetii phase-II antigens in the sera was determined using IFA. Results: The study included 293 cases and C. burnetii phase-II IgG was positive in 61 of the subjects (20.8%). The seroprevalence of C. burnetii was 23.8% (59/248) among the participants above 18 years of age and 4.4% (2/45) among those younger than 18 years of age (P < 0.01). There was a significant relationship between C. burnetii seropositivity and direct contact with the birth products of farm animals (P < 0.001); however, there was not a significant difference between genders. Conclusions: Although the seroprevalence rate was high, Q fever was underreported and unrecognized in rural Bolu. We conclude that Q fever must be considered in patients with a suitable clinical course in this region.

Heat Inactivation Can Differentiate Between IgG and IgM Antibodies in the Pretransplant Cross Match

The presence of IgG antibodies in the pretransplant cross-match (XM) test results in hyperacute rejection, but IgM antibodies are inconsequential. The XM should be able to differentiate between IgG and IgM antibodies. This study evaluated 3 methods. This study was based on 500 patients for whom XM were performed between 2004 and 2006 with all 3 techniques. Two patient sera were used: normal serum and heat inactivated serum, which was prepared by incubating patient serum at 63°C for 10 minutes to destroy IgM antibodies. The efficiencies of flow cytometry XM (FC-XM), dithiothreitol complement-dependent microlymphocytotoxicity (DTT/CDC-XM), and heat inactivation (HI-CDC-XM) to differentiate between IgG and IgM were evaluated by using both sera. Patients with positive XM, and negative HI-CDC-XM were reported as negative XM. During the study period, there were 70 patients with positive B-cell XM. Forty-nine became negative after HI-XM, and 21 remained positive. Only 34 cases became negative after DTT-CDC-XM and 36 remained positive. HI-CDC-XM was comparable to FC-XM; all patients testing negative with this technique experienced successful renal transplantations without hyperacute, accelerated, or acute rejection episodes. Our study showed that HI-CDC-XM was effective at exclude donor-specific IgM antibodies, a result which was comparable to FCXM to detect only IgG antibodies. HI is simple and rapid and does not involve any extra equipment or cost.

Development of an ELISA to detect Sin Nombre virus-specific IgM from deer mice ( Peromyscus maniculatus)

Peromyscus maniculatus (deer mouse) is the primary reservoir for Sin Nombre virus (SNV). Although the presence of IgG antibodies is often used as a marker of infection, it provides little information on active infections in a population but usually is an indicator of past infections. The presence of IgM antibodies is a much better marker for determining whether active infections are present in a population. A μ-capture SNV-specific IgM enzyme linked immunosorbent assay (ELISA) was developed. From live-trap and release studies a total of 68 rodent sera were studied for the presence of Sin Nombre virus-specific IgG and IgM antibodies. In these studies, IgM responses were detected in a number of animals. In some cases early SNV infection was determined through the presence of anti-SNV IgM before IgG antibodies could be detected. From the set of animals analyzed, it was concluded that the IgM response against SNV can persist anywhere from 1 to up to over 2 months, with a median of less than 1 month. Most importantly, it was demonstrated that anti-Sin Nombre virus IgM is an important tool for detection of early infections in rodents and should be considered as a key diagnostic tool.

Clinical manifestations and epidemic factors of autumn-winter type scrub typhus in children from northern new endemic area

Scrub typhus is an infectious disease due to Orientia tsutsugamushi transmitted by infected chigger mites. Scrub typhus has long been recognized to occur in southern areas of China, but has recently been increasingly often reported from the north since the first case was reported in Mengyin County, Shandong Province in 1986. The key objectives of the present study were to investigate the clinical manifestations and epidemic factors of scrub typhus in children from the northern new natural foci. The case records of 56 children with scrub typhus who were admitted to the 5 hospitals of Fei County from September 1993 to January 2004 were reviewed. Orientia tsutsugamushi (Ot) was isolated from the cases. Based on ecological observations on the composition, seasonal fluctuation of animal hosts and chigger mites, Ot was isolated from rodents and chiggers. IgG antibodies to Ot was detected by IFA. Genotypes of the Ot isolates were also identified by nested PCR. Among 56 children scrub typhus cases, 46 were male, 10 were female; 96% exhibited typical eschars or ulcers, 100% cases had high fever, skin rashes were observed in 55 cases (98%), and regional lymphadenopathy occurred in 48 cases (86%). All cases came from countryside, and all had histories of exposure to the crop field. fifty-one serum samples of suspected patients with scrub typhus were collected, 48 were positive for antibodies to Ot. The serotypes were Gilliam types. The cases only appeared in September to December with the peak at mid and late October. Leptotrombidium (L.) scutellare was the most important vector causing scrub typhus in the foci. Apodemus (A.) agrarius was the main host animals of Ot in the crop field. Totally 26 strains were isolated from patients, rodents, and chigger mites. The serotypes of 24 out of the 26 isolates were Gilliam types, while the genotypes of these isolates were Kawasaki types. The serotypes of the other 2 isolates were identical and both were Karp types. Children scrub typhus patients were frequently seen in the new natural foci of Shandong province. Exposure history, typical eschars or ulcers, and presence of IgG antibody were the important indexes to diagnose the disease.

Usefulness of enzyme linked immunosorbent assays species specific in the detection of Chlamydia trachomatis and Chlamydophila pneumoniae IgG antibodies in patients with genital infections or respiratory tract infections

Chlamydia trachomatis (Ct) and Chlamydophila pneumoniae (Cpn) are obligate intracellular bacteria causing genital tract infections (GTI) and respiratory tract infections (RTI), respectively. Antigenic cross-reactivity between the two species may complicate serologic diagnosis. In this study, we compared the performance of two ELISA tests in relation to microimmunofluorescence (MIF) for the detection of Ct and Cpn IgG antibodies. We also explored the degree of cross-reactivity by ELISA and MIF. Among 278 positive sera for Cpn and/or Ct IgG antibodies in the MIF, 153 were from patients with GTI and 125 were from patients with RTI. These sera were tested by our in house MIF test and by two commercial ELISA: SeroCP and SeroCT for the detection of anti-Cpn IgG antibodies and anti-Ct IgG antibodies, respectively. In sera from patients with RTI, correlation between MIF and SeroCP was 92%. The specificity of this test was 38.5%. In fact, among the 140 sera from patients with GTI and that cross-reacted in MIF, only six were confirmed by the two ELISA tests as having IgG antibodies to Ct. The correlation between MIF and SeroCT was 80%. The specificity of this test was 100%. Indeed, among the 65 sera from patients with RTI with cross-reactions in MIF, 30 sera showed a negative SeroCT test. SeroCT was highly specific and could diminish considerably the extent of cross-reactions. Whilst, SeroCP test was not specific enough to distinguish between the presence of IgG antibodies and Cpn or Ct.

Presence of IgG antibodies against Chlamydophila felis in cats positive to FIV and/or FeLV

The aim of our study was to confirm the presence of Ig G antibodies against Chlamydophila felis (Cp. felis) in cats infected with feline immunodeficiency virus (FIV) and/or feline leukemia virus (FeLV) and possible higher incidence of any clinical symptoms. A group of 30 cats which had been exposed to FIV and/or FeLV were tested for chlamydial antibodies presence. FIV and FeLV exposure were established by commercial ELISA rapid tests. The results of serological testing to antibodies against Cp. felis in cats with immunofluorescence assay (IFA) are shown. In 16.7% (5/30) of tested cats Ig G antibodies against Cp. felis were found. No correlation with FIV and/or FeLV infection neither with clinical symptoms of upper respiratory tract could be confirmed.

P105 Evaluation of automated immunohematologic system in routine blood group serology testing

Haemolytic disease of the fetus and newborn (HDFN) is characterised by the presence of IgG antibodies in the maternal circulation which cause haemolysis in the fetus by crossing the placenta and sensitising red cells for destruction by macrophages in the fetal spleen. Serological, quantitative and cellular assays have all been developed to predict the severity of HDFN. These assays measure and/or characterise alloantibodies in the maternal circulation. Quantitative assays which accurately measure antibody levels correlate with disease severity better than serological assays which are inherently less precise. Nevertheless, high antibody levels are found in some cases of mild HFDN and relatively low antibody levels are found in some severe cases. This suggests that disease severity is influenced by factors in addition to antibody concentration. These factors remain to be fully elucidated but may include: the subclass and glycosylation of maternal antibodies; the structure, site density, maturational development and tissue distribution of blood group antigens; the efficiency of IgG transport to the fetus; the functional maturity of the fetal spleen; polymorphisms which affect Fc receptor function; and the presence of HLA-related inhibitory antibodies. Cellular assays which are sensitive to factors affecting antibody function have, therefore, been developed in an attempt to improve the prediction of disease severity. Although these assays are cumbersome, there are now sufficient data to suggest that some cellular assays provide clinically useful information to complement serological and quantitative assays.