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Biomedical subjects

R E Baughn

Publications and source records attributed to R E Baughn.

At least 19 recordsLinked to original sources
PubMed1997

Emergence of antibody to capsular polysaccharides of Streptococcus pneumoniae during outbreaks of pneumonia: association with nasopharyngeal colonization.

Antibody to pneumococcal capsular polysaccharides (PPS) of Streptococcus pneumoniae plays a major role in protecting the host against pneumococcal infection. A variable proportion of healthy adults have antibody to PPS, often in the absence of recognized pneumococcal infection. To determine whether exposure to pneumococci or colonization by pneumococci, or both, stimulates the emergence of antibody to PPS, we studied outbreaks of pneumonia at two military camps. Of the men who were present at a military training camp during an outbreak of pneumonia due to S. pneumoniae serotype 1 but who did not develop pneumonia, 27.8% had IgG antibody to PPS 1, whereas only 3.6% of controls had this antibody. In another outbreak caused by S. pneumoniae serotypes 7F and 8, 35.9% of asymptomatic soldiers who had nasopharyngeal colonization by one of these strains had antibody to the relevant PPS, and another 30.8% who originally did not have antibody developed it within 30 days; thus, 66.7% of these soldiers had antibody to the relevant PPS. These data show that serotype-specific antibody promptly appears following exposure to an outbreak of pneumococcal pneumonia and is probably mediated through acquisition of nasopharyngeal pneumococcal carriage.

Adult↗
PubMed1997

Genetic regulation of the capacity to make immunoglobulin G to pneumococcal capsular polysaccharides.

BACKGROUND: Genetic regulation of immunoglobulin G(IgG) responses to pneumococcal capsular polysaccharides (PPS), has been demonstrated in mice but not in humans. Earlier studies from this laboratory showed that healthy adults have a varying capacity to generate IgG antibody to PPS; this study sought to determine whether this capacity is genetically controlled. METHODS: A 23-valent pneumococcal vaccine was administered to 72 unrelated White adults, 4 nuclear families, and 61 members of an extended Ashkenazic Jewish family. Selected individuals later received one or more doses of the vaccine and/or a single dose of protein-conjugated PPS. Four to six weeks after each vaccination, IgG to PPS was measured by ELISA. Immunoglobulin allotypes and HLA types were determined by standard techniques. RESULTS: After vaccination, 53% of the 72 unrelated White adults had measurable levels of IgG antibody to all of 10 PPS studied (high-level responders), 36% had IgG to 6-9 PPS, and 11% had IgG to < or = 5 of 10 PPS (low-level responders). Persons who did not make IgG to an individual PPS also failed to make IgM or IgA to that antigen. Low-level responders had reduced mean IgG levels to PPS to which they did make IgG; nevertheless, their total serum concentrations of IgG, IgG2, IgA, and IgM were normal, and each made IgG2 to at least one PPS, all indicating that a global defect in Ig production was not responsible. The responder status of offspring was highly associated with that of their parents. Segregation analysis of 61 Ashkenazic family members revealed that the capacity to generate anti-PPS IgG was inherited in a mixed, codominant fashion. Repeated vaccination or administration of protein-conjugated PPS did not elicit measurable IgG in nonresponders. The HLA type was not associated with antibody responses. An association between IgG level and Gm(23)+ allotype was observed in unrelated Whites but not in Ashkenazic Jews. CONCLUSIONS: Thus, humans exhibit a variable capacity to respond to PPS. This response is hereditable in a mixed, codominant fashion. The absence of IgG to a PPS, even after antigen is presented in a protein-conjugate form, may reflect a genetically mediated failure to recognize polysaccharide antigens. Since persons who respond to fewer PPS also have lower levels of IgG to PPS to which they do respond, genetically determined deficiencies in events that involve proliferation of committed B lymphocytes may also play a role.

Adolescent↗
PubMed1996

Molecular mimicry between an immunodominant amino acid motif on the 47-kDa lipoprotein of Treponema pallidum (Tpp47) and multiple repeats of analogous sequences in fibronectin.

Molecular mimicry, resulting from structural similarities between self-determinants on host Ags and an organism's antigenic determinants (epitopes), can incite autoimmune events in certain bacterial and viral diseases. In the course of comprehensively mapping the 47-kDa lipoprotein (Tpp47) of Treponema pallidum subsp. pallidum using an overlapping synthetic peptide strategy, we identified a major immunoreactive epitope (411PGTEYT416) that exhibited considerable motif identity with multiple repeats of analogous linear sequences found in mammalian fibronectins. To further explore the importance of this motif as a probable instigator in the induction of polyspecific cross-reactive Abs, mimetic variants were synthesized for immunologic studies. Mimetics with ala (A) replacements in each amino acid position were used to determine which residues were critical for Ab binding. Animals immunized with two mimetics (PGTEYT or PGSEYT) coupled to tetanus toxoid exhibited: 1) modified responses when challenged with viable T. pallidum; and 2) classical Arthus reactions when challenged intradermally with either motif linked to a different carrier. The cross-reactive nature of the Ab responses to both mimetics was confirmed in a variety of ELISAs using mimetics, fibronectins, and collagens. Inhibition-ELISA studies with both fibronectin and an unrelated mimetic of the RGD motif suggest that intra- and intermolecular epitope spreading occurs following mimetic immunization and involves additional self-epitopes. These observations suggest that although molecular mimicry plays a pivotal role in initially triggering the anti-fibronectin and anti-collagen responses associated with disseminated syphilis, expansion of those autoimmune responses may be due to other self-epitopes once tolerance is abrogated.

Amino Acid Sequence↗
PubMed1996

The lack of association between aging and postvaccination levels of IgG antibody to capsular polysaccharides of Streptococcus pneumoniae.

One possible explanation for the apparently reduced efficacy of pneumococcal vaccine in elderly subjects is that IgG responses to pneumococcal capsular polysaccharides (PPSs) decline with aging. We administered pneumococcal vaccine to 118 adults who ranged in age from 20 to 93 years; 33 were > or = 70 years old. Four to 6 weeks later, we measured IgG reactive with PPSs from 10 commonly infecting serotypes of Streptococcus pneumoniae. By regression analysis, a slight but nonsignificant increase in anti-PPS IgG was observed with increased age for six serotypes and a nonsignificant decrease was observed for four. Mean IgG levels and the percentage of subjects with IgG levels > or = 1 microgram/mL were no different among persons > or = 70 years of age than among those < or = 69 years of age. These results show no consistent effect of aging on anti-PPS IgG levels 4-6 weeks after pneumococcal vaccination.

Adult↗
PubMed1996

Epitope mapping of B-cell determinants on the 15-kilodalton lipoprotein of Treponema pallidum (Tpp15) with synthetic peptides.

The antigenicity of the 15-kDa lipoprotein of Treponema pallidum (Tpp15 or TpN15) was comprehensively evaluated in epitope-scanning studies with overlapping deca- and octapeptides and polygonal rabbit and human infant immunoglobulins (Igs) and antisera. This approach enabled us to identify potentially important regions and to determine the optimal dilutions of Igs or antisera for use in further studies. IgM and IgG from both species were capable of recognizing multiple, continuous epitopes. A total of 13 peptides, principally clustered in the central regions of the protein, were recognized by all syphilitic sera and Ig fractions. On the basis of window analyses, frequency profiles, and alanine substitution studies, five heptapeptides were selected for mimetic studies. Two of these five immunodominant, continuous epitopes initially appeared to be species specific; however, antisera elicited against mimetics of all five epitopes were polyspecific, recognizing similar motifs on several other treponemal proteins, including those of avirulent organisms. The only mimetic which yielded positive reactions with infant IgM and syphilitic sera in the absence of cross-reactions with rabbit antisera to avirulent treponemes was the variant of the VMYASSG motif. These findings are relevant to the development of simple, inexpensive assays for the serodiagnosis of active syphilis.

Amino Acid Sequence↗
PubMed1995

In vitro evaluation of the role of humoral immunity against Bartonella henselae.

The contribution of humoral immunity against Bartonella henselae was evaluated by examining the in vitro bactericidal activity of sera and the ability of these microorganisms to activate complement and stimulate phagocytosis and an oxidative burst in polymorphonuclear leukocytes. The organism was killed by complement-mediated cytolysis. Complement activation preferentially proceeded by the alternative pathway. The presence of specific antibodies did not increase the serum bactericidal activity or complement activation. However, phagocytosis and the subsequent production of oxygen radicals, evaluated by flow cytometry, were significantly enhanced in the presence of bacteria previously opsonized with immune sera.

Adult↗
PubMed1994

Analysis of western blotting (immunoblotting) technique in diagnosis of congenital syphilis.

The diagnosis of congenital syphilis in apparently healthy infants continues to be problematic. Immunoglobulin M antibodies specific for a subset of Treponema pallidum antigens have been detected by Western blotting (immunoblotting). In the present study we investigated the sensitivity and specificity of this method. We tested 26 infants aged 0 to 4 months who fulfilled the accepted criteria for the diagnosis of congenital syphilis. There were 14 symptomatic infants. Sera from 13 of these infants were positive for the 47-kDa treponemal antigen (92% sensitivity). The remaining 12 infants were clinically asymptomatic when tested at birth but subsequently displayed features consistent with the disease. Reactive blots (antibodies to the 47- and/or the 15-kDa antigens) were noted in 10 of the 12 infants (83% sensitivity). Thirty infants whose mothers had syphilis were monitored and shown to be uninfected. Nonreactive blots were seen in sera from 27 infants, while sera from 3 older infants had false-positive tests (90% specificity). The Western blotting technique is sensitive (even in the diagnosis of clinically inapparent cases) and, in the absence of immunoglobulin M rheumatoid factor, is a useful confirmatory test for congenital syphilis.

Antibodies, Bacterial↗
PubMed1994

Cardiolipin-protein complexes and initiation of complement activation after coronary artery occlusion.

Specific rabbit anti-cardiolipin (anti-CL) antibodies were used to investigate the hypothesis that cardiolipin, associated with mitochondrial membrane proteins, binds C1 and facilitates activation of the complement cascade following reperfusion of ischemic myocardium. By immunoelectron microscopy, anti-CL localized to subsarcolemmal mitochondria, emerging through breaks in membranes of damaged cardiac myocytes. Anti-CL reacted with > 15 mitochondrial constituents, most of which comigrated with the proteins that bind C1q in transblots of subsarcolemmal mitochondria, fractionated by polyacrylamide gel electrophoresis under reducing conditions in the presence of sodium dodecyl sulfate. A subset of the C1q-binding proteins > 24 to 37 kDa served as stable sites for assembly of C3, C5, and C9. Cardiac lymph, collected during the first hour after reperfusion of ischemic myocardium, contained proteins of diverse size that reacted with both anti-CL and C1q. Cardiac lymph, collected before occlusion and 4 to 5 hours after reperfusion, in comparison, had few if any C1q or anti-CL reactive proteins. Treatment with phospholipase suppressed the C1q-binding activity and anti-CL reactivity of the proteins in reperfusion lymph and those with similar properties in mitochondrial extracts. Our data suggest that during ischemia, mitochondria, extruded through breaks in the sarcolemma, unfold and release membrane fragments in which cardiolipin and protein are intimately associated. By binding C1 and supplying sites for the assembly of later-acting complement components, these fragments provide the means to disseminate the complement-mediated inflammatory response to ischemic injury.

Animals↗
PubMed1994

Congenital and neonatal syphilis in guinea-pigs show a different pattern of immune response.

C4-deficient (C4D) and Albany strains of guinea-pigs transplacentally and neonatally infected with Treponema pallidum showed distinctive patterns of humoral immune responses. Congenitally infected progeny of both strains originated from dams intradermally (i.d.) infected at mid-pregnancy with virulent T. pallidum. In the neonatal groups families of C4D and Albany strains consisting of 1-3-day-old offspring and their mothers were i.d. infected with a similar dose of T. pallidum. Regardless of the strain, asymptomatic congenitally infected guinea-pigs (n = 16) responded from the first day of life with high levels of IgM [T. pallidum (TP) ELISA] antitreponemal antibodies and up to 85% presented with IgM CIC (circulating immune complexes) and IgM RF (rheumatoid factor). Although relatively high levels of IgM antitreponemal antibodies persisted in these animals throughout the 4-month experimental period, significant levels of host IgG antitreponemal antibodies were detectable after 2-3 months of age. Neonatally infected guinea-pigs of both strains (n = 27) responded similar to the infected sow but with relatively lower levels of IgM and IgG antitreponemal antibodies at 1 and 4 weeks, respectively, both of which increased with the time of infection. Antibodies were also detected in these animals by fluorescent treponemal antibody adsorption test (FTA-ABS). Unlike congenital syphilis, neonatally infected animals developed IgG-CIC after 2-3 months of infection and none of them showed any RF. In neonatal syphilis, FTA-ABS antibody levels were closely associated with the onset of lesions, whereas those of TP ELISA were not. The distinctive immune responses observed in these experimental models have the potential to differentiate between congenitally and neonatally infected human infants, even though the current clinical management is the same.

Animals↗
PubMed1993

Antibody to capsular polysaccharides of Streptococcus pneumoniae: prevalence, persistence, and response to revaccination.

The prevalence of immunity to Streptococcus pneumoniae in the adult population of the United States is unknown. In the study described herein, military recruits had anticapsular IgG antibody to only 15% of common pneumococcal serotypes, whereas working men and elderly men had IgG antibody to 33% and 34% of the common serotypes, respectively (P < .001). Among eight elderly subjects, the prevalence of IgG antibody to capsular polysaccharides increased from 30% to 78% after pneumococcal vaccination; 6 years thereafter, the rate of positive reactions had declined to 58% and IgG levels had declined substantially. With revaccination, IgG levels returned to within (+/-) 40% of the original postvaccination levels. IgM and IgG antibody appeared or began to increase in titer 6 days after vaccination; the rate and degree of response were the same after the first and second exposures. Since most individuals rapidly develop IgG antibody after colonization by S. pneumoniae and since IgG confers immunity, these data suggest that pneumonia is infrequent among healthy adults not because preexisting immunity is widespread but because--with colonization--an immune response develops rapidly, preceding specific events that might lead to infection. Our findings support recommended vaccination procedures and suggest that wider application in subsets of healthy younger adults should be considered.

Adolescent↗
PubMed1992

Response of latent syphilis or neurosyphilis to ceftriaxone therapy in persons infected with human immunodeficiency virus.

OBJECTIVE: To evaluate the effect of ceftriaxone in treating latent syphilis or asymptomatic neurosyphilis in patients infected with the human immunodeficiency virus (HIV). DESIGN: Follow-up study of patients treated at two HIV-based clinics during 16 months from 1989 to 1991. PATIENTS: Patients were those in whom a clinical diagnosis of latent syphilis or asymptomatic neurosyphilis was made, who received all recommended doses of antimicrobial therapy, and who returned for follow-up visits for 6 or more months. RESULTS: Forty-three patients were treated with ceftriaxone, 1 to 2 g daily for 10 to 14 days. Thirteen underwent lumbar puncture before treatment; 7 (58%) had documented neurosyphilis (pleocytosis in 5, elevated protein levels in 6, VDRL reactive in cerebrospinal fluid [CSF] in 7), and 6 had documented latent syphilis (entirely normal CSF). The remaining 30 were said to have presumed latent syphilis. There was no relation between the diagnosis and the selected dosage of ceftriaxone. Response rates were similar in those who had documented neurosyphilis and documented or presumed latent syphilis. Overall, 28 patients (65%) responded to therapy, 5 (12%) were serofast, 9 (21%) had a serologic relapse, and 1 (2%) who experienced progression to symptomatic neurosyphilis was a therapeutic failure. Thirteen patients received benzathine penicillin for presumed latent syphilis; results were similar to those observed after ceftriaxone therapy, with 8 (62%) responders, 1 (8%) serofast, 2 (15%) relapses, and 2 (15%) failures. CD4 cell counts in responders were not different from those who failed to respond. CONCLUSIONS: Even in the absence of neurologic symptoms, half of the HIV-infected persons who have serologic evidence of syphilis may have neurosyphilis. Although ceftriaxone achieves high serum and CSF levels, 10 to 14 days of treatment with this drug were associated with a 23% failure rate in HIV-infected patients who had latent syphilis or asymptomatic neurosyphilis. Three doses of benzathine penicillin did not have a significantly higher relapse rate and may provide appropriate therapy, at least for documented latent syphilis in persons co-infected with HIV. Studies comparing ceftriaxone with 10 to 14 doses of procaine penicillin are needed to determine the most cost-effective treatment for asymptomatic neurosyphilis or presumed latent syphilis in this group of patients.

Adult↗
PubMed1992

Experimental congenital syphilis: guinea pig model.

Neonates born to female guinea pigs of either a highly susceptible (C4D) or a resistant (Albany) strain, infected prior to or during pregnancy with a single dose of Treponema pallidum, showed in their sera from the first day of life immunoglobulin M (IgM) antibodies to T. pallidum, circulating immune complexes consisting of IgM antibodies and treponemal antigens, and IgM rheumatoid factor. Although the animals were asymptomatic for a 6-month observation period, several lines of evidence indicated that they were infected in utero. Molecular analysis of whole sera, purified serum IgM fraction, or dissociated immune complexes demonstrated IgM reactivity against one (47 kDa) or more of several T. pallidum peptides (15, 17, 37, 42, 45, and 87 kDa) recognized as integral membrane components. Sequential analysis of the neonates' sera by immunoblot and enzyme-linked immunosorbent assay, using alcohol-treated T. pallidum, T. phagedenis biotype Reiter, and T. vincentii, demonstrated early IgM antibodies followed 3 to 4 months later by IgG2- and IgG1-specific antibodies to T. pallidum. Moreover, an infectivity test done in five rabbits with pooled tissue extracts prepared from liveborn or stillborn animals evoked a seroconversion in two rabbits (reactive Venereal Disease Research Laboratory and fluorescent treponemal antibody tests), suggesting the presence of T. pallidum in the organs. Sera from neonates born to either T. phagedenis biotype Reiter-injected mothers or three normal pregnant females were all serologically negative. The model offers new possibilities for exploration of factors responsible for asymptomatic infection often observed in human congenital syphilis.

Animals↗
PubMed1992

Evidence that autologous idiotypic regulation of anti-arginine-glycine-aspartic acid autoantibodies may influence development and progression of syphilitic lesions in infected rabbits.

The 83-kDa receptor protein of Treponema pallidum (TpN83) recognizes and binds fibronectin (Fn) at the amino acid sequence RGD site. By using experimentally infected animals, we have demonstrated that immunoglobulin G antibodies to this antigen and autoantibodies to the RGD site of Fn are putative components of immune complexes. This, and other findings, led us to initially hypothesize that anti-idiotypes (anti-Id) of an anti-TpN83 response are autoantibodies to RGD. Alternatively, we reasoned that if anti-Fn autoantibodies played a role in the pathogenesis of syphilis, then down-regulation of such a response by the Id network might directly affect progression of the disease. To test the hypothesis, rabbits were immunized with either affinity-purified TpN83 antigen or the synthetic Fn-7 peptide, KYGRGDS, and subsequently challenged with T. pallidum. Compared with results obtained with unimmunized, control rabbits, accelerated lesion development was noted in the rabbits immunized with TpN83. Pronounced, though unexpected, differences with respect to lesion development and progression were noted in the animals immunized with Fn-7 and then challenged intravenously; a minimal number of lesions appeared with a delayed onset. These lesions, like the localized chancres seen following intradermal challenge, were smaller and minimally ulcerated, and they healed rapidly. The Fn-7-immunized rabbits all differed from the controls in that anti-Id to anti-RGD F(ab')2 were demonstrable within 4 weeks following infection; decreases in anti-Fn autoantibody levels were associated with concomitant increases in anti-Id levels. Immunoglobulin Gs (anti-Id) from these animals following elution from anti-RGD F(ab')2 immunoaffinity columns also reacted with affinity-purified TpN83 antigen in immunoassays. These results suggest that down-regulation of autoreactive clones by manipulation of the idiotypic network in experimental syphilis warrants further investigation.

Amino Acid Sequence↗
PubMed1992

Production of rheumatoid factor in adoptively immune guinea-pigs after challenge with Treponema pallidum.

Guinea-pigs of inbred strains 2 and C4D were infused with various concentrations (1 x 10(8) to 4 x 10(8) of syngeneic nylon wool-purified Treponema pallidum-immune T lymphocytes (TPI-T) and challenged 24 hr later with virulent T. pallidum (10(8) organisms). The degree of protection depended on the number of infused T cells and was associated with an accelerated production of IgM rheumatoid factor (RF). Fully protected animals (4 x 10(8) TPI-T) did not produce treponemal antibodies or circulating immune complexes (CIC) but produced IgM RF detectable 10 days after infection. Partially protected animals (< or = 2 x 10(8) TPI-T) produced, 30 days post-infection, relatively low levels of treponemal antibodies but high levels of CIC and RF. Control animals infused with 2 x 10(8) TPI-T lymphocytes but not infected with T. pallidum, when monitored for a period of 6 weeks, did not produce treponemal antibodies, CIC, or RF, excluding the possibility that IgM RF could be generated by the donor's B cells contaminating (circa 3%) the TPI-T lymphocytes. Moreover, unprotected syngeneic control animals infused, prior to infection, with T. phagedenis biotype Reiter-immune T cells or with T. pallidum-free testicular inflammatory fluid-immune T cells responded with increasing levels of treponemal antibodies; only a few animals produced RF and CIC 5 months after infection similarly to control guinea-pigs infected only. The production of RF in partially protected animals responding to infection with treponemal antibodies and CIC was apparently associated with the presence of the CIC; but the mechanism of RF production in fully protected animals in which no antibodies or CIC were detected is currently unknown.

Animals↗
PubMed1991

Enteric infection with an obligate intracellular parasite, Encephalitozoon cuniculi, in an experimental model.

Rabbits were intrarectally infected with 3 doses (5 x 10(3), 5 x 10(5), and 5 x 10(7] of an obligate intracellular parasite, Encephalitozoon cuniculi, with or without prior colonic lavages. Although chronic administration of enemas seems to interfere to some degree with the intestinal translocation of the parasite, systemic infection was observed in both manipulated and nonmanipulated animals. The animals responded with antibodies of immunoglobulin A (IgA) and IgG isotypes, reflecting the route of infection. They also produced significant amounts of circulating immune complexes composed of IgA and IgG antibodies and E. cuniculi antigens. Lesions compatible with encephalitozoonosis were seen in the liver, kidney, lung, and brain. In all instances, nonmanipulated animals had more severe lesions than manipulated rabbits given the same dose of parasites. Levels of serum antibodies, circulating immune complexes, and histopathologic changes were associated with the infection dose. The presented data suggest that human microsporidiosis may also be transmitted via the rectal route. It is, therefore, of clinical relevance in view of several reports of microsporidian infections in patients with acquired immunodeficiency.

Administration, Rectal↗
PubMed1990

Effect of human immunodeficiency virus (HIV) infection on the course of syphilis and on the response to treatment.

PURPOSE: To evaluate evidence that concurrent infection with human immunodeficiency virus (HIV) alters both the natural history of syphilis (by increasing the frequency of early neurosyphilis) and the response to penicillin. DATA IDENTIFICATION: Review of major works on syphilis in the English language and files maintained since 1971, supplemented by a systematic search using Index Medicus and MEDLARS. DATA EXTRACTION: The works mentioned above were critically reviewed for information on early neurosyphilis and, where relevant, HIV infection. RESULTS OF DATA ANALYSIS: The central nervous system is regularly involved in early syphilis. Standard recommended doses of benzathine penicillin provide cerebrospinal fluid levels that are probably at the borderline of efficacy, and cure relies on treatment and an adequate host immune response. Early neurosyphilis, appearing within 2 years of onset of infection with Treponema pallidum, was uncommon in the prepenicillin era and usually occurred after inadequate therapy. This complication was exceedingly rare in the first three decades of penicillin use. In contrast, in the past decade, 40 patients with HIV infection have been reported to have asymptomatic neurosyphilis, or syphilitic meningitis, cranial nerve abnormalities (predominantly in cranial nerves II and VIII), or cerebrovascular accidents, singly or together. In 40% of cases, HIV infection was first diagnosed when neurologic symptoms appeared. Of the 38 patients for whom information was available, 18 had the acquired immunodeficiency syndrome (AIDS), 7 had AIDS-related complex, and 13 had antibody to HIV. Sixteen had previously been treated for syphilis, of whom 5 (31%) had received benzathine penicillin within the previous 6 months. Preliminary data also suggest that skin lesions and VDRL (Venereal Disease Research Laboratory) antibody in HIV-infected patients with secondary syphilis respond more slowly to conventional penicillin therapy. CONCLUSION: Intensive therapy and follow-up observation is indicated for early syphilis in HIV-infected subjects. Novel approaches to treatment deserve systematic evaluation.

HIV Infections↗
PubMed1990

The diagnostic dilemma of otosyphilis. A new western blot assay.

Currently, the diagnosis of otosyphilis applies to any patient with otologic symptoms of unknown cause and a positive fluorescent treponemal antibody-absorption (FTA-ABS) test result. However, the FTA-ABS assay can have false-positive results and does not distinguish between active and treated disease. The VDRL test, which has been used to distinguish inactive disease, frequently yields negative results in patients who are nonetheless given the diagnosis of otosyphilis. A new Western blot assay can eliminate the possibility of a false-positive result and can confirm whether the infection is active. This assay was used to diagnose unsuspected active syphilis in a patient believed to have autoimmune ear disease. In three other cases of suspected otosyphilis, the diagnosis was refuted when the Western blot demonstrated that the FTA-ABS result was false-positive or that the infection was inactive.

Adult↗