RESUMEN
Within 8 weeks of primary Clostridioides difficile infection (CDI), as many as 30% of patients develop recurrent disease with the associated risks of multiple relapses, morbidity, and economic burden. There are no clear clinical correlates or validated biomarkers that can predict recurrence during primary infection. This study demonstrated the potential of a simple test for identifying hospitalized CDI patients at low risk for disease recurrence. Forty-six hospitalized CDI patients were enrolled at Emory University Hospitals. Samples of serum and a novel matrix from circulating plasmablasts called "medium-enriched for newly synthesized antibodies" (MENSA) were collected during weeks 1, 2, and 4. Antibodies specific for 10 C. difficile antigens were measured in each sample. Among the 46 C. difficile-infected patients, 9 (19.5%) experienced recurrence within 8 weeks of primary infection. Among the 37 nonrecurrent patients, 23 (62%; 23/37) had anti-C. difficile MENSA antibodies specific for any of the three toxin antigens: TcdB-CROP, TcdBvir-CROP, and/or CDTb. Positive MENSA responses occurred early (within the first 12 days post-symptom onset), including six patients who never seroconverted. A similar trend was observed in serum responses, but they peaked later and identified fewer patients (51%; 19/37). In contrast, none (0%; 0/9) of the patients who subsequently recurred after hospitalization produced antibodies specific for any of the three C. difficile toxin antigens. Thus, patients with a negative early MENSA response against all three C. difficile toxin antigens had a 19-fold greater relative risk of recurrence. MENSA and serum levels of immunoglobulin A (IgA) and/or IgG antibodies for three C. difficile toxins have prognostic potential. These immunoassays measure nascent immune responses that reduce the likelihood of recurrence thereby providing a biomarker of protection from recurrent CDI. Patients who are positive by this immunoassay are unlikely to suffer a recurrence. Early identification of patients at risk for recurrence by negative MENSA creates opportunities for targeted prophylactic strategies that can reduce the incidence, cost, and morbidity due to recurrent CDI.
Asunto(s)
Toxinas Bacterianas , Clostridioides difficile , Infecciones por Clostridium , Biomarcadores , Infecciones por Clostridium/epidemiología , Medios de Cultivo , Humanos , Inmunoglobulina A , Inmunoglobulina G , RecurrenciaRESUMEN
BACKGROUND: Diagnostic immunoassays for Lyme disease have several limitations including: 1) not all patients seroconvert; 2) seroconversion occurs later than symptom onset; and 3) serum antibody levels remain elevated long after resolution of the infection. INTRODUCTION: MENSA (Medium Enriched for Newly Synthesized Antibodies) is a novel diagnostic fluid that contains antibodies produced in vitro by circulating antibody-secreting cells (ASC). It enables measurement of the active humoral immune response. METHODS: In this observational, case-control study, we developed the MicroB-plex Anti-C6/Anti-pepC10 Immunoassay to measure antibodies specific for the Borrelia burgdorferi peptide antigens C6 and pepC10 and validated it using a CDC serum sample collection. Then we examined serum and MENSA samples from 36 uninfected Control subjects and 12 Newly Diagnosed Lyme Disease Patients. RESULTS: Among the CDC samples, antibodies against C6 and/or pepC10 were detected in all seropositive Lyme patients (8/8), but not in sera from seronegative patients or healthy controls (0/24). Serum antibodies against C6 and pepC10 were detected in one of 36 uninfected control subjects (1/36); none were detected in the corresponding MENSA samples (0/36). In samples from newly diagnosed patients, serum antibodies identified 8/12 patients; MENSA antibodies also detected 8/12 patients. The two measures agreed on six positive individuals and differed on four others. In combination, the serum and MENSA tests identified 10/12 early Lyme patients. Typically, serum antibodies persisted 80 days or longer while MENSA antibodies declined to baseline within 40 days of successful treatment. DISCUSSION: MENSA-based immunoassays present a promising complement to serum immunoassays for diagnosis and tracking therapeutic success in Lyme infections.
Asunto(s)
Borrelia burgdorferi , Enfermedad de Lyme , Humanos , Estudios de Casos y Controles , Antígenos Bacterianos , Inmunoglobulina G , Anticuerpos Antibacterianos , Biomarcadores , Células Productoras de Anticuerpos , Diagnóstico PrecozRESUMEN
BACKGROUND: Clostridioides difficile infections (CDI) have been a challenging and increasingly serious concern in recent years. While early and accurate diagnosis is crucial, available assays have frustrating limitations. OBJECTIVE: Develop a simple, blood-based immunoassay to accurately diagnose patients suffering from active CDI. MATERIALS AND METHODS: Uninfected controls (N = 95) and CDI patients (N = 167) were recruited from Atlanta area hospitals. Blood samples were collected from patients within twelve days of a positive CDI test and processed to yield serum and PBMCs cultured to yield medium enriched for newly synthesized antibodies (MENSA). Multiplex immunoassays measured Ig responses to ten recombinant C. difficile antigens. RESULTS: Sixty-six percent of CDI patients produced measurable responses to C. difficile antigens in their serum or MENSA within twelve days of a positive CDI test. Fifty-two of the 167 CDI patients (31%) were detectable in both serum and MENSA, but 32/167 (19%) were detectable only in MENSA, and 27/167 (16%) were detectable only in serum. DISCUSSION: We describe the results of a multiplex immunoassay for the diagnosis of ongoing CDI in hospitalized patients. Our assay resolved patients into four categories: MENSA-positive only, serum-positive only, MENSA- and serum-positive, and MENSA- and serum-negative. The 30% of patients who were MENSA-positive only may be accounted for by nascent antibody secretion prior to seroconversion. Conversely, the serum-positive only subset may have been more advanced in their disease course. Immunocompromise and misdiagnosis may have contributed to the 34% of CDI patients who were not identified using MENSA or serum immunoassays. IMPORTANCE: While there was considerable overlap between patients identified through MENSA and serum, each method detected a distinctive patient group. The combined use of both MENSA and serum to detect CDI patients resulted in the greatest identification of CDI patients. Together, longitudinal analysis of MENSA and serum will provide a more accurate evaluation of successful host humoral immune responses in CDI patients.