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PubMed1995

Atypical chronic lymphocytic leukaemia with t(11;14)(q13;q32): karyotype evolution and prolymphocytic transformation.

In order to define better the cytological and clinical features of atypical B-cell chronic lymphocytic leukaemia (B-CLL) with t(11:14)(q13;q32), sequential morphologic immunological and cytogenetic studies were performed in seven patients belonging to a series of 72 consecutive cases presenting with a diagnosis of CLL or atypical CLL according to the FAB criteria. Cytologic diagnosis in these seven patients with t(11;14) was typical CLL in two cases presenting with < 10% large lymphocytes (LL) and prolymphocytes (PL) and atypical CLL in five cases in which LL and PL comprised between 10% and 55%. The diagnosis was supported by histologic findings on bone marrow biopsy (five cases) or splenectomy specimens (two cases). A progressive increase of peripheral LL and PL was observed, resulting in a switch of FAB diagnosis over a 6-60-month period from typical CLL into atypical CLL in two cases and from atypical CLL into prolymphocytic leukaemia in five cases. Immunophenotyping showed a mature B-cell phenotype with CD19, CD22, CD24 positivity and CD10 negativity in all patients. A bright-staining pattern for surface immunoglobulins (SIg) was detected in 6/7 cases, CD5 positivity in 6/7 cases, and CD23 positivity in 1/7 cases. The FMC-7 monoclonal antibody was positive in > 40% cells in 5/6 cases. Chromosome changes in addition to t(11;14) were seen in five cases; in two cases unbalanced translocations involving the 3q21 chromosome region, resulting in partial trisomy for the long arm of chromosome 3, were detected early in the course of the disease. Karyotype evolution that was associated with disease progression occurred in 3/6 assessable patients. Comparison of these findings with similar data from 65 B-CLL patients without t(11:14) showed that atypical morphology, switch of FAB diagnosis during the course of the disease, and karyotype evolution were more frequently seen in cases with t(11;14) (5/7 v 15/65 cases, P = 0.015, 7/7 v 7/65 cases, P < 0.0001, and 3/6 v 5/45 assessable cases, P = 0.04, respectively). The frequency of positivity for CD23 and bright SIg staining differed significantly in the two groups. It is concluded that t(11;14) identifies a cytologically atypical subset of B-CLL, characterized by frequent cytologic and cytogenetic evolution and by a distinct immunological profile, sharing some biological features with mantle cell lymphoma.

Antigens, CD↗
PubMed1976

Lymphocyte sensitization to Aspergillus fumigatus antigens in pulmonary diseases in man.

In vitro studies of T-lymphocyte responses using five different batches of Aspergillus fumigatus antigens, were undertaken in twelve patients with A. fumigatus related lung disease and in three normal controls. Using a leucocyte migration method, five of the twelve patients showed significant inhibition of leucocyte migration with a migration index of 0-80 or less to A. fumigatus, but in only three was this demonstrated with more than one batch of antigen (one patient with aspergilloma and two with bronchopulmonary aspergillosis). The same antigens were used in lymphocyte transformation tests. Only two patients, one with aspergilloma and one with bronchopulmonary aspergillosis, showed clearly significant transformation although there were several borderline results. Only three patients had evidence of delayed skin responses to A. fumigatus antigens in vivo, one with aspergilloma, one with bronchopulmonary aspergillosis and one with atypical bronchopulmonary aspergillosis. Two of these three patients also had one or more positive in vitro test results. Thus T-lymphocyte sensitization to A. fumigatus as demonstrated by these in vitro methods, although present in occasional patients, was not clearly related to any one particular clinical syndrome in this small group of patients with aspergillus related pulmonary disease. There was, however, one of the three aspergilloma patients with positive lymphocyte transformation to all five batches of antigens and having higher transformation indices than in any other patient. This suggest that lymphocyte studies should be extended in this group. In contrast to the frequent negative results using A. fumigatus antigens, evidence of T-lymphocyte sensitization to either Candida albicans or Mycobacterium tuberculosis or both, was shown by positive delayed hypersensitivity skin responses and in vitro inhibition of leucocyte migration in the majority of the patients, despite which lymphocyte transformation was often negative. The possibility of impaired capacity to transform is supported by the finding of an impaired response to phytohaemagglutinin (PHA) in four of the twelve cases. This information, together with other data discussed, helps to complete the contrasting immunological profiles seen in different Aspergillus fumigatus related lung diseases.

Antigen-Antibody Reactions↗
PubMed2006

Cytokine production from sputum cells in eosinophilic versus non-eosinophilic asthmatics.

The inflammatory pathways involved in asthma are more complex than the sole Th2-mediated eosinophilic airway inflammation. Different phenotypes of asthma have been recently highlighted and are probably underlied by different immunological profiles. The aim of the study was to assess cytokine production from sputum cells in eosinophilic versus non-eosinophilic asthmatics. Induced sputum was obtained from 48 consecutive stable mild to moderate asthmatics (20 eosinophilic asthmatics, 28 non-eosinophilic asthmatics) and 31 healthy subjects. Cytokine released from sputum cells were measured by a home-made two-step sandwich immunoassay. Cytokines investigated were interleukin (IL)-4, IL-6, IL-10, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma. Sputum cells from eosinophilic asthmatics produced more IL-4 than those from both healthy subjects (P < 0.05) and non-eosinophilic asthmatics (P < 0.05). Conversely, sputum cells from eosinophilic asthma were found to release lower amounts of TNF-alpha than those from healthy subjects (P < 0.05). The group of non-eosinophilic asthmatics did not distinguish from healthy subjects with respect to any cytokines measured. Sputum cells from asthmatics exhibiting eosinophilic airway inflammation release more IL-4 and less TNF-alpha than those of healthy subjects. By contrast, non-eosinophilic asthmatics did not distinguish from healthy subjects by abnormal cytokine release from their sputum cells.

Adult↗
PubMed2007

IL-10 produced by CD4+ and CD8+ T cells emerge as a putative immunoregulatory mechanism to counterbalance the monocyte-derived TNF-alpha and guarantee asymptomatic clinical status during chronic HTLV-I infection.

Although it is believed widely that distinct patterns of the host immune response are associated with the outcome of chronic human T cell lymphotropic virus type 1 (HTLV-I) infection toward asymptomatic or symptomatic neurodegenerative myelopathy (HAM/TSP), the exact mechanism underlying these immunological events still remains unknown. In this study, we have evaluated the cytokine pattern [interleukin (IL)-12, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, IL-4 and IL-10] of innate and adaptive immunity cells present at the peripheral blood from non-infected (NI) and HTLV-I infected individuals [asymptomatic (AS), oligosymptomatic (OL) and HAM/TSP-HT], following in vitro short-term incubation in the absence/presence of phorbol myristate acetate (PMA) pan-leucocyte stimulation. In the absence of PMA stimulation, our data demonstrate that despite the overall immunological profile of AS mimicry that observed for NI, the high frequency of IL-12(+) neutrophils and TNF-alpha(+) monocytes are also a hallmark of this group of individuals. However, the outstanding positive correlation between the high frequency of TNF-alpha(+) monocytes and high levels CD4(+) IL-10(+) and CD8(+) IL-10(+) T cells suggests the establishment of immunoregulatory mechanisms that guarantee their asymptomatic clinical status. On the other hand, OL and HT did not present any association between the high frequency and TNF-alpha(+) neutrophils and monocytes and this immunoregulatory profile at their adaptive immunity cells. Upon PMA-index analysis, high levels of type 1 CD4(+) T cells, as well as higher IFN-gamma/IL-10 and TNF-alpha/IL-10 ratios, were observed in HT, and re-emphasize the role of Th1-cytokines from CD4(+) cells to HTLV-I immunity and disease. Moreover, increasing frequency of CD8(+) IFN-gamma(+) and CD8(+) TNF-alpha(+) cells were observed in the HT, which corroborates the marked inflammatory profile underlying this pathological condition and the role of CD8(+) T cells in the pathogenesis of HAM/TSP.

Adult↗
PubMed1986

Immunoprofile of reactions in leprosy.

The immunologic profile during erythema nodosum leprosum (ENL) revealed increased percentage and absolute count of B-lymphocytes, in addition to considerably lowered levels of complement component C3. Serum immunoglobulins--IgG, IgA, and IgM--were significantly raised after subsidence of ENL, whereas upgrading reaction showed an increase of absolute count of total T lymphocytes and percentage and count of B-lymphocytes. In addition, a raised serum IgM level was noted after regression of ENL. Downgrading reaction demonstrated a decreased percentage of early T-lymphocytes and raised the absolute count of B-lymphocytes. Serum IgA levels were found to be increased after amelioration of ENL.

Complement C3↗
PubMed1999

Is childhood asthma an inflammatory disease?

There is now extensive evidence that asthma results from inflammation in large and small airways, and that the degree of inflammation reflects the clinical severity of the disease. Most of this evidence, however, has come from studies in adult patients. Evidence in children comes largely from indirect studies such as measurements of peripheral blood cells and inflammatory markers, rather than from direct bronchoscopic examination. Studies in adults show that inflammation in asthma is characterized by eosinophilia, epithelial damage, and bronchial hyperresponsiveness, and that activation of allergen-specific T cells plays an important role in orchestrating the inflammatory process. In children, indirect evidence of inflammation comes from the observation that anti-inflammatory agents such as inhaled corticosteroids improve symptoms and bronchial hyperresponsiveness, reduce the number of asthma exacerbations, and limit the progressive decline in lung function. Further evidence comes from measurements of nitric oxide and hydrogen peroxide (potential inflammatory markers) in exhaled air, and of inflammatory mediators in plasma and urine. As in adults, there is evidence that lymphocytes play an important role in orchestrating the inflammatory process. The immunologic profile appears to shift from a Th1-type cytokine profile to an allergen-related Th2-type profile prior to birth. Such a Th2 predominance constitutes a risk factor for the subsequent development of bronchial hyperresponsiveness and asthma in response to allergen.

Asthma↗
PubMed2005

Safety, pharmacokinetics, and immunogenicity of single-dose rFXIII administration to healthy volunteers.

BACKGROUND: Factor XIII (FXIII) is a transglutaminase that cross-links fibrin and other proteins to improve clot strength and resistance to fibrinolysis. Both congenital and acquired FXIII deficiency may result in a bleeding diathesis, and plasma-derived FXIII has been used to treat many of these clinical conditions. OBJECTIVES: A clinical study was designed and performed to evaluate the safety, pharmacokinetics, and immunogenicity of recombinant FXIII (rFXIII) administration to healthy adult volunteers. PATIENTS AND METHOD: Fifty healthy adult volunteers were enrolled in this randomized, double-blinded, placebo-controlled study. A single dose of rFXIII, ranging from 2 U kg(-1) to 50 U kg(-1), or placebo was administered. Safety was evaluated by capturing adverse events, clinical safety laboratory studies, and clinical score for deep venous thrombosis. Blood samples were taken for pharmacokinetic and immunogenicity analysis throughout the 28-day follow-up period. RESULTS: Recombinant FXIII was well tolerated, with no serious adverse events or dose-related toxicities. Following a single i.v. injection of 50 U kg(-1) rFXIII, the estimated terminal half-life was 270-320 h, the volume of distribution ranged from 40 to 75 mL kg(-1), and FXIII activity increased 1.77% per 1 U kg(-1) rFXIII administered. Increase in circulating A2B2 and decrease in free FXIII-B subunit indicate in vivo formation of FXIII heterotetramer. An immunogenic response to rFXIII or yeast, the production host, was not observed. CONCLUSIONS: Recombinant FXIII was well tolerated at doses of up to 50 U kg(-1) in healthy adult volunteers. The safety, pharmacological and immunological profile of rFXIII suggests it should be studied in patients with congenital FXIII deficiency as well as evaluated as a systemic hemostat in patients with acquired FXIII deficiency or hemorrhage.

Adolescent↗
PubMed2000

Effect of Alloiococcus otitidis and three pathogens of otitis media in production of interleukin-12 by human monocyte cell line.

Alloiococcus otitidis is detected in middle ear effusion of otitis media with effusion (OME). Only a limited number of studies are available concerning the immunological profile of A. otitidis. We have studied the ability of A. otitidis and three other representative pathogens of otitis media to stimulate the production of interleukin-12 (IL-12) from a monocytic cell line THP-1. Viable A. otitidis induced the production of IL-12 in THP-1 cells but IL-12 production was reduced if glutaraldehyde-fixed bacteria were used as stimulants. When viable bacteria were physically separated from THP-1 cells during the stimulation period, remarkable reductions of IL-12 secretion were shown after challenge with gram-positive bacteria A. otitidis and S. pneumoniae. When stimulated with soluble extracts of A. otitidis, THP-1 secreted IL-12 in a dose-dependent manner. The subfraction with a molecular mass over 100 kDa showed a strong ability to induce IL-12 production. Our results show that A. otitidis has immunostimulatory capacity with regard to IL-12 production. We also show that soluble antigen(s) of A. otitidis can modulate the immune response in OME.

Antigens, Bacterial↗
PubMed1988

Elastic globes: electron microscopic and immunohistochemical observations.

Specimens from a patient with epidermolysis bullosa contained many elastic globes in the dermis. Ultrastructurally they were composed of (i) medium electron-dense amorphous substances, (ii) electron-dense round structures, and (iii) fine filaments. These various elements were seldom organized into typical normal elastic fiber and, therefore, it was difficult ultrastructurally to recognize them as such or components thereof. Immunohistochemically, elastic globes were strongly reactive with NKH-1, which stains elastic microfibrils, and antibody to serum amyloid P component (anti-SAP), which binds to elastic fiber microfibrils. However, elastic globes were negative with EKH-4 which recognizes 50 kd keratin of amyloid keratin and cytoid bodies. These findings suggested that elastic globes have a close immunologic profile to elastic fiber microfibrils, but not that of epidermal or epithelial keratin.

Adult↗
PubMed1990

Immunohistochemical characterization of palisaded, encapsulated neuroma.

Eleven cases of palisaded, encapsulated neuroma (PEN) were studied by routine light microscopic and immunohistochemical methods. PEN showed the following staining reactions: strong, diffuse for S-100 protein (11/11) and collagen Type IV (Col. IV) (11/11); moderately strong, focal for myelin basic protein (MBP) (9/11) and Leu-7 (9/11); weak, focal for MBP (2/11), Leu-7 (2/11), neuron specific enolase (NSE) (4/11), neural filaments (NF) (5/11), epithelial membrane antigen (EMA) (6/11), and negative for glial fibrillary acidic protein (GFAP). Bielschowsky silver stain was positive in 11/11, but only four cases contained numerous axons. Col. IV and EMA stains showed a complete capsule in 1/11, incomplete capsules in 5/11 and no discernible capsules in the remainder. We concluded that (1) the immunologic profile of PEN is not specific; (2) conventional silver stain remains a suitable method to demonstrate axon-like structures; (3) the ratio of axons to Schwann cells is variable and generally less than 1:1, as previously assumed; (4) MBP and Leu-7 coexpression in Schwann cells suggests myelinization of some of the nerve fibers; (5) the pattern of EMA reaction supports perineurial cell involvement in PEN; and (6) despite the current definition of PEN, they are usually not completely encapsulated as evidenced by Col. IV and EMA strains.

Antigens, Differentiation↗
PubMed1994

B-cell chronic lymphocytic leukaemia stage 0. An immunophenotypic study of 66 cases and comparison with B small cell lymphomas.

The cells of 66 B-CLL stage 0 patients were analyzed using a large panel of monoclonal antibodies in order to better define the immunophenotype of B-CLL. The data were compared with the immunophenotypes of lymph node cells from 51 patients with diffuse B small cell lymphoma or leukaemia with lymph node enlargement. The most frequent immunophenotype of B-CLL stage 0 was SIgM(D)+ EmR+ CD5+ CD9+ CD21+ CD23+ CD35- CD38-. Among the lymphomas, EmR-positive and EmR-negative cases were identified. The vast majority of the EmR-positive cases usually showed the leukaemic pattern, immunophenotype and lymph node histology of B-CLL. The EmR-negative cases usually had immunophenotypes quite different from those of B-CLL and the histology of indented cell lymphoma (centrocytic or intermediate) or features of lymphoplasmacytoid/cytic lymphoma. More than 20% of EmR-positive cells proved to be the most important marker to distinguish B-CLL from other lymphocytic lymphomas. Indeed this was a sign of better prognosis. Lymphoplasmacytoid/cytic lymphomas were EmR-positive with the immunophenotype of B-CLL or EmR-negative with a definitely different immunological profile. This suggests two morphologically similar but biologically different subgroups of these diseases.

Antigens, CD↗
PubMed1989

Increased periodontal bone loss in temporarily B lymphocyte-deficient rats.

In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T-lymphocyte reconstituted), anti-mu treated (temporarily B lymphocyte-deficient), and normal rats. When they were 5 to 9 weeks old, some of the rats were inoculated with Actinomyces viscosus. Bacteroides gingivalis and a strain of oral spirochetes; 90 days later they were killed. A. viscosus and B. gingivalis colonized readily, but the spirochete strain could not be established permanently in the oral cavity of the rats, 95% of the inoculated rats raised serum IgG or IgM antibody against one or more of the microorganisms; nude rats tended to raise less antibody than the three other experimental groups. Inoculated rats had significantly less periodontal bone support than controls. Anti-mu treated inoculated rats had significantly less periodontal bone support than nude and normal rats, whereas no difference was found between normal, nude, and thymus-grafted rats. It is concluded that permanent T-lymphocyte deficiency did not interfere with the development of periodontal disease in this model, whereas a temporary and moderate reduction in B-lymphocyte numbers seemed to predispose for aggravation of periodontal bone loss.

Actinomyces↗
PubMed2004

Clinical and epidemiologic characterization of photosensitivity in HIV-positive individuals.

BACKGROUND: An increased prevalence and severity of cutaneous photosensitivity has been recognized in association with human immunodeficiency virus (HIV) infection. However, this disorder remains poorly characterized in terms of its epidemiology, predisposing factors, clinical, and environmental associations. METHODS: To define the risk factors associated with the presence of photosensitivity among HIV-positive individuals, a cross-sectional study of 631 primary patient visits to an urban HIV Dermatology clinic between January 1997 and August 2001, inclusive, was conducted. A multivariate model was fit to estimate adjusted odds ratios for risk factors associated with photosensitivity diagnosis. Subsequently, a case-series of the patients with photosensitivity was reported. RESULTS: The overall prevalence of photosensitivity was 5.4%, while African-Americans (AA) exhibited a prevalence of 7.3%. In the multivariate model, using highly active anti-retroviral therapy (HAART) (OR=2.82, 95% CI: 1.13, 7.03) and being AA (OR=6.68, 95% CI: 1.56, 28.65) significantly increased the odds of photosensitivity. Patients with photosensitivity were more likely to present during periods of higher ultraviolet (UV) index (P=0.08). Two distinct clinical morphologies were noted: lichenoid and non-lichenoid, eczematous. Sub-morphologies in the non-lichenoid group were suggestive of differences in immunologic profile and estimated UV exposure. CONCLUSION: Photosensitivity associated with HIV infection is an increasingly recognized dermatologic condition with a heterogeneous clinical presentation. AA ethnicity and HAART were independent indicators for the diagnosis of photosensitivity, whereas CD4+ and UV exposure had non-significant associations. The subtleties in these and other clinical variables may directly aid in the recognition and diagnosis of this poorly characterized disorder.

Adult↗
PubMed1986

Patho-anatomical studies in patients dying of AIDS.

The incidence of AIDS in Denmark is the highest reported among the countries of Western Europe. This preliminary account is a report of the autopsy findings in 10 patients, 9 homosexual men and 1 woman. Our aim is to provide a detailed description of the patho-anatomical findings, as well as to compare these with corresponding results reported from the United States, with a view to establishing possible geographical differences in the disease picture. The results of the patho-anatomical studies correspond in all essentials to those from the United States. However, it must be stated that no malignant lymphomas were demonstrated in our patients, although the disease can give rise to very pronounced, possibly transitory, lesions in the lymphatic tissue, easily misinterpreted as malignant. Further features that should be emphasized are the often widespread mycobacterial infection found in the intestinal wall in protracted cases, the occurrence of CMV vasculitis, particularly in the adrenal cortex and medulla, and thromboembolic lesions, often demonstrated in a variety of tissues. The studies made so far emphasize the importance of autopsy in AIDS deaths, as it has extended our detailed knowledge of the patho-anatomical lesions associated with certain opportunistic infections. Further, the autopsy findings have been demonstrably significant either for confirming or for rejecting the clinical diagnosis. On the basis of an analysis of the cellular immunological profile in AIDS, parallels can be drawn to the conditions in certain lymphoproliferative diseases. In autopsied AIDS cases, we recommend a standard scheme covering the tissue specimens to be obtained for histological examination. Strict safety precautions should be observed against infection during autopsy.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Immunosuppression in bitches with pyometra.

The function of the immune system was studied in 34 bitches affected by pyometra. The mean age of the animals was 8.1 +/- 2.8 years. Samples of peripheral blood were examined using a battery of immunological tests. Data obtained from four sets of animals, grouped according to the severity of their disease, were compared. Leucocytosis (neutrophilia and partial monocytosis) and lymphopenia were detected in 62 per cent and 35 per cent of the bitches, respectively. The increase in the number of leucocytes was higher in the severely affected bitches. Inhibition of mitogen-driven lymphocyte proliferation was the characteristic feature of the immunological profile in bitches affected by pyometra, and this corresponded with the impairment of the general state of health. Sera from bitches showing functional inhibition of lymphocytes suppressed the activity of lymphocytes isolated from normal dogs. Sera from bitches affected by pyometra also had higher levels of immunoglobulins, lysozyme and circulating immune complexes. It can be concluded that pyometra is associated with an inflammatory response, but also with a marked suppression of immune system activity.

Animals↗
PubMed1981

Course of coccidioidomycosis in intratracheally infected guinea pigs.

Two hundred Hartley-inbred guinea pigs were infected intratracheally with 50 viable arthrospores of Coccidioides immitis. At weeks 1 through 10 postinfection, groups of 20 guinea pigs were assayed for skin test, macrophage migration inhibitory factor (MIF), and lymphocyte transformation (LT) responses to coccidioidin. Forty-eight hours after skin testing and just before MIF and LT assays, blood was obtained for complement-fixing (CF) antibody titers and the animals were autopsied to assess the extent of fungal dissemination. Immunological assays established that skin tests and MIF responses converted within 3 weeks of infection. LT responses were not demonstrable until week 5. Dissemination of C. immitis to the liver or spleen was an early event, with 21% of guinea pigs positive by week 2 and 70% positive by week 5. CF antibody titers were demonstrable at week 5, increased logarithmically through week 7, then increased at a slower rate thereafter. Concomitant with the decreased rate of antibody production, guinea pigs began to clear C. immitis from their extrapulmonary tissues. Skin test responses peaked at 6 weeks postinfection when CF antibody titers were less than or equal to 1:16 and then plateaued with increased CF titers. Although this overall immunological profile is consistent with the disease in humans, there was not a direct correlation between CF antibody titer and dissemination to the liver or spleen, nor was there an inverse correlation between CF antibody titers and skin test or MIF responses. Rather, CF antibody titers and cell-mediated immune responses were equally demonstrable in guinea pigs with disseminated or nondisseminated disease.

Animals↗
PubMed1987

Transmission of human immunodeficiency virus from parents to only one dizygotic twin.

The acquired immunodeficiency syndrome-related complex was identified in a mother and one of her nonidentical twins. Generalized lymphadenopathy was first noted in the infant at age 17 months, and that of the mother was incidentally discovered 6 months later. The father, who had had homosexual contacts before the conception of the twins, appeared to be in good health. No one in the family had constitutional symptoms or showed signs of opportunistic infection. Both parents and the patient had hypergammaglobulinemia, low T-helper-to-suppressor-cell ratio, and positive serum antibody to human immunodeficiency virus. Attempts to isolate the virus from all family members were unsuccessful. The twin brother was in good health with a normal immunologic profile and negative antibody to human immunodeficiency virus.

AIDS-Related Complex↗
PubMed2001

Prevalence of congenital Toxoplasma gondii infection among newborns from the Poznań region of Poland: validation of a new combined enzyme immunoassay for Toxoplasma gondii-specific immunoglobulin A and immunoglobulin M antibodies.

We determined the value of a new serological assay detecting Toxoplasma-specific immunoglobulin M (IgM) and IgA antibodies at birth for use in mass neonatal screening. The incidence of congenital infection in newborns was compared with data from an epidemiological investigation on the seroprevalence of Toxoplasma in the studied population. Peripheral blood was collected on Guthrie cards during the first 3 days of life and tested for anti-Toxoplasma IgA and IgM using a noncommercial immunocapture enzyme-linked immunosorbent assay (ELISA). When the screening assay was positive, serum samples from the child and the mother were collected for use in Western blotting comparative immunological profile analysis and traditional serological tests for determination of specific IgG, IgM, and IgA antibodies. From December 1998 to April 2000, 17,653 filter paper samples from live-born neonates were successively screened. Congenital T. gondii infection was finally confirmed in 19 newborns. In traditional assays, 13 of 19 infants were IgM and IgA positive using filter paper eluates at birth, 1 child was positive only for IgM, 1 patient was positive for IgM and borderline for IgA, 1 had an equivocal level of IgA, and 3 cases were confirmed only by the Western blot assay. The prevalence of Toxoplasma-specific IgA and/or IgM in filter paper samples at birth was 1 per 929 live-born neonates (1.08/1,000) or about 1 per 523 children (1.9/1,000) born to nonimmune women with a potential risk of primary T. gondii infection during pregnancy, compared to the actual seropositivity rate of 43.7%. The diagnostic sensitivity of the combined IgA-IgM ELISA using neonatal filter paper specimens was not more than 95%, the positive predictive value of the test was 82.6%, and the diagnostic specificity was calculated to be 99.9%. The combined IgA-IgM ELISA is a valuable method for the diagnosis of congenital toxoplasmosis at birth and fulfills criteria for neonatal screening programs. The method showed a good diagnostic sensitivity in neonates untreated prenatally who were born in an area of high seroprevalence of T. gondii infection.

Animals↗