Detection of Human Anti-Trypanosoma cruzi Antibody with Recombinant Fragmented Ribosomal P Protein

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and is endemic in many Latin American countries. Diagnosis is based on serologic testing and the WHO recommends two or more serological tests for confirmation. Acidic ribosomal P protein of T. cruzi showed strong reactivity against positive sera of patients, and we cloned the protein after fragmenting it to enhance its antigenicity and solubility. Twelve positive sera of Chagas disease patients were reacted with the fragmented ribosomal P protein using western blot. Detection rate and density for each fragment were determined. Fragments F1R1, F1R2, and F2R1 showed 100% rate of detection, and average density scoring of 2.00, 1.67, and 2.42 from a maximum of 3.0, respectively. Therefore, the F2R1 fragment of the ribosomal P protein of T. cruzi could be a promising antigen to use in the diagnosis of Chagas disease in endemic regions with high specificity and sensitivity.

Olfactory function and related factors in systemic lupus erythematosus / 中华风湿病学杂志

Objective To investigate the olfactory function in patients with systemic lupus erythematosus (SLE) and to explore factors that may influence it.Methods The Connecticut Chemosensory Clinical Research Center (CCCRC) test was carried out in SLE patients and healthy controls for olfactory function testing.ELISA method was used to detect anti-ribosomal P protein antibody in the serum.The statistical methods used in this study including t test,ANOVA,LSD-t test,Pearson correlation analysis,multiple linear regression analysis,andx2 test.Results ① The CCCRC scores of the active,inactive group and healthy controls were compared,the difference was statistical significant (F=26.52,P=0.01).CCCRC score in active SLE group (62±16) was lower than that of the inactive group (80±13) the and the normal control group (83±12) (P＜0.01),while there was no statistical significant difference between the inactive group and the normal controls (P=0.226).② CCCRC score was lower in 16 ARPA positive SLE patients (61±17) than 49 negative patients (74±16) (t=2.681,P=0.009).③ In addition,CCCRC score showed a negative correlation with ARPA serum concentration (r=-0.327,P=0.008).There was no significant correlation between CCCRC score and disease course (r=0.141,P＞0.05).④ Multiple linear regression analysis indicated that CCCRC score was associated with age and ARPA.Conclusion SLE patients have olfactory dysfunction and the dys-function is associated with age and ARPA.

Manifestaciones renales y neuropsiquiátricas en pacientes con lupus eritematoso sistémico y anticuerpos anti-P ribosomal / Renal and neuropsychiatric manifestations in patients with systemic lupus erythematosus and ribosomal P protein autoantibodies

Los auto anticuerpos contra la proteína P ribosomal (anti-P ribosomales) se presentan en aproximadamente el 15% de los pacientes con lupus eritematoso sistémico (LES). Estos anticuerpos fueron inicialmente asociados con psicosis lúpica y enfermedad neuropsiquiátrica. Posteriormente se reconoció su asociación con alto riesgo de compromiso renal y hepático. Objetivos: evaluar la coexistencia serológica y clínica de anticuerpos anti-P ribosomal y anti-DNA en pacientes con LES con compromiso renal y neuropsiquiátrico. Materiales y métodos: casos: 12 pacientes con lupus neuropsiquiátrico (cambios conductuales 6, depresión 4, alucinaciones 3, alteración cognitiva 2, convulsiones 2 y psicosis 2). Controles: 13 pacientes con actividad por LES sin evidencia de manifestaciones neuropsiquiátricas. Todos los pacientes estuvieron activos para el tiempo de la evaluación. Los anticuerpos anti-P ribosomal fueron determinados por ELISA y los anti-dcDNA por el método de Crithidia luciliae. La función renal fue valorada por medición de creatinina y el compromiso renal con uroanálisis. Resultados: la edad media fue de 39 años, 2 hombres / 23 mujeres. Ocho casos (66,6%) y seis (46,1%) controles tenían compromiso renal. El 20% de los pacientes fueron positivos para anti-P ribosomal (5/25 pacientes: 2 controles y 3 casos). El 36% de los pacientes tenían anticuerpos anti-dsDNA (30,7% controles y 41,6% casos). La presencia de anticuerpo P ribosomal estuvo asociada con anti-dcDNA (p = 0,002) y con nefritis lúpica (p = 0,046), pero no hubo asociación entre el anti-P ribosomal y las manifestaciones neuropsiquiátricas (p = 0,645). Conclusiones: la presencia de anticuerpos anti-P ribosomal está asociada con anti-dcDNA y nefritis lúpica. Este estudio no encontró asociación estadísticamente significante entre anti-P ribosomal y manifestaciones neuropsiquiátricas del LES.

Summary The ribosomal P protein autoantibodies are present in approximately 15% of patients with Systemic Lupus Erythematosus (SLE). These antibodies were initially associated with lupus psychosis and neuropsychiatric diseases. Posteriorly, they were associated to a higher risk of renal and liver involvement in patients with SLE. Objective: to evaluate the serologic and clinic coexistence of ribosomal P protein autoantibodies and anti-dsDNA in patients with SLE with renal and neuropsychiatric manifestations. Materials and Methods: cases: 12 patients with neuropsychiatric and renal involvement (behavior changes 6, depression 4, hallucinations 3, cognitive impairment 2, seizures 2 and psychosis 2). Controls: 13 patients with active SLE, without evidence of neuropsychiatric manifestations. SLE was active in all patients during the process of evaluations. The anti-ribosomal P protein antibodies were determined by ELISA and the dsDNA antibodies by Crithidia luciliae´s immunofluorescence test. The renal function was evaluated by serum creatinin and urinalyses. Results: the median age was 39 years, 2 men/23 women. 8 cases (66.6%) and 7 controls (53.8 %) have renal involvement. 20% of patients were positive for anti P-ribosomal antibodies (5/25 patients: 2 controls and 3 cases). 36% of patients have anti dsDNA antibodies (30.7% controls and 41.6% cases). The presence of anti-ribosomal P protein antibodies was associated with anti dsDNA antibodies (p = 0.002) and with lupus nephritis (p = 0.046), but no association between ribosomal P protein autoantibodies and neuropsychiatric manifestations was found (p = 0.645). Conclusions: the P-ribosomal antibodies are associated with anti-dsDNA and lupus nephritis. This study did not show statistically significant associations between ribosomal P protein autoantibodies and neuropsychiatric manifestations in patients with SLE.

Molecular cloning of ribosomal P protein in Toxoplasma gondii and the availability to detect antibody against recombinant protein in toxoplasmosis patients

Among the panel of monoclonal antibodies (mAb) against Toxoplasma gondii, mAb of Tg621 (Tg621) clone blotted 38 kDa protein which localized in the cytoplasm of tachyzoites by immunofluorescence microscopy. The protein was not released into the parasitophorous vacuole during or after invasion. The cDNA fragment encoding the protein was obtained by screening a T. gondii cDNA expression library with Tg621. The full length cDNA sequence was completed with 5'-RACE as 1, 592 bp, which contained open reading frame of 942 bp. The deduced amino acid sequence of Tg621 consisted of a polypeptide of 313 amino acids, with significant homology to ribosomal P proteins (RPP) of other organisms especially high to those of apicomplexan species. The expressed and purified TgRPP was assayed in western blot with the sera of toxoplasmosis patients and normal sera, which resulted in the 74.0% of positive reactions in toxoplasmosis patients whereas 8.3% in normal group. Therefore, the antibody formation against TgRPP in toxoplasmosis patients was regarded as specific for T. gondii infection and suggested a potential autoantibody.