Clinical significance of the serum biomarker index detection in children with Henoch-Schonlein purpura.

OBJECTIVE: To explore a panel of serum biomarkers for laboratory diagnosis of pediatric Henoch-Schönlein purpura (HSP). METHODS: The blood white blood cells (WBC) and serum levels of serum amyloid A (SAA), interleukin 6 (IL-6), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin E (IgE), C-reactive protein (CRP), complement component 3 (C3), complement component 4 (C4), and ASO (anti-streptolysin O) were detected in 127 patients with Henoch-Schonlein purpura (HSP), 110 cases of septicemia patients, and 121 healthy volunteers. The diagnostic ability of biomarkers selected from HSP and septicemia patients was analyzed by ROC curve. By designing the calculation model, the biomarker index was calculated for laboratory diagnosis of HSP and differential diagnosis between HSP and septicemia. RESULTS: The levels of serum WBC, CRP, IL-6 and SAA in the septicemia patients were significantly higher than those in the control group (p<0.05). Compared with the healthy individuals, serum levels of WBC, CRP, IL-6, SAA, IgA and IgM were significantly increased in patients with HSP (p<0.05). The area under the curve (AUC) of SAA, IgA, IgM, WBC, IL-6, and CRP in the patients with HSP was 0.964, 0.855, 0.849, 0.787, 0.765, and 0.622, respectively. The values of SAA, IgA, IgM, WBC, IL-6, and CRP in septicemia patients were 0.700, 0.428, 0.689, 0.682, 0.891, and 0.853, respectively. Biomarker index=SAA+IgA/4000+IgM/4000×0.4CRPmean valueCRPi. The biomarker index in HSP patients was significantly higher than that of the healthy controls. However, the biomarker index in septicemia patients was significantly lower than the control. CONCLUSION: The biomarker index of HSP patients is higher than that of the control group. While in the infectious disease represented by septicemia, it is decreased. The detection of biomarker index could exclude the interference of infection as the auxiliary examination to HSP patients.

Comparative diagnostic efficacy of recombinant LLO and PI-PLC-based ELISAs for detection of listeriosis in animals.

The present study for the first time evaluates the serodiagnostic efficacy of two recombinant antigens namely, listeriolysin O (rLLO) and phosphatidyl-inositol phospholipase C (rPI-PLC). Indirect ELISA with the above recombinant antigens was used on samples collected from bovines (n=106), goats (n=138) and pigs (n=92) having either a history of abortion, emaciation and/or apparently healthy animals. Isolation of Listeria was attempted from the blood samples using USDA-FSIS method. On screening of test sera by rLLO-based ELISA, antibodies against anti-listeriolysin O (ALLO) were observed in goats (22.46%), bovines (15.10%) and pigs (16.31%). As advocated, after adsorption of positive serum samples with streptolysin O (SLO), the seropositivity for ALLO was marginally reduced (p>0.05) in goats (21.73%) and bovines (10.38%), whereas, in pigs the reduction (5.43%) was significant (p<0.05). On the contrary, rPI-PLC-based ELISA revealed higher non-specific seropositivity for antilisterial antibodies in goats (45.65%), bovines (31.13%) and pigs (8.69%). Further, on comparing the seropositivity with isolation rate, of the 16 animals that were culturally-positive for L. monocytogenes, 15 showed ALLO positivity in unadsorbed as well as SLO-adsorbed sera by rLLO-based ELISA, however, rPI-PLC-based ELISA could detect seropositivity in only 5 animals. Moreover, rPI-PLC-based ELISA also showed seropositivity in those animals (7/30) that were culturally positive for other Listeria spp. In conclusion, rLLO can serve as a better antigen than rPI-PLC in ELISA for the serodiagnosis of listeriosis in animals; however, prior adsorption of test sera with SLO is required to avoid false positive results.

Co-occurrence of poststreptococcal reactive arthritis and acute glomerulonephritis.

We report a 16-year-old patient who developed concurrent poststreptococcal reactive arthritis and acute glomerulonephritis. A high titer of antistreptolysin O antibody confirmed the preceding streptococcal infection. The patient presented with symmetric persistent tenosynovitis of hands and feet. Renal biopsy showed typical findings of acute glomerulonephritis with crescent formation. Physicians who treat patients with arthritis of acute onset, especially after throat infection, should be aware of possible urinary abnormalities or renal dysfunction.

Protein sorting in Plasmodium falciparum-infected red blood cells permeabilized with the pore-forming protein streptolysin O.

Plasmodium falciparum is an intracellular parasite of human red blood cells (RBCs). Like many other intracellular parasites, P. falciparum resides and develops within a parasitophorous vacuole which is bound by a membrane that separates the host cell cytoplasm from the parasite surface. Some parasite proteins are secreted into the vacuolar space and others are secreted, by an as yet poorly defined pathway, into the RBC cytosol. The transport of proteins from the parasite has been followed mainly using morphological methods. In search of an experimental system that would allow (i) dissection of the individual steps involved in transport from the parasite surface into the RBC cytosol, and (ii) an assessment of the molecular requirements for the process at the erythrocytic side of the vacuolar membrane, we permeabilized infected RBCs with the pore-forming protein streptolysin O using conditions which left the vacuole intact. The distribution of two parasite proteins which served as markers for the vacuolar space and the RBC cytosol respectively was analysed morphologically and biochemically. In permeabilized RBCs the two marker proteins were sorted to the same compartments as in intact RBCs. The protein which was destined for the RBC cytosol traversed the vacuolar space before it was translocated across the vacuolar membrane. Protein transport could be arrested in the vacuole by removing the RBC cytosol. Translocation across the vacuolar membrane required ATP and a protein source at the erythrocytic face of the membrane, but it was independent of the intracellular ionic milieu of the RBC.

Estreptococos Beta-hemolíticos e níveis séricos de antiestreptolisina "O" em comunidade rural, Américo Brasiliense SP, 1981 / Beta hemolytic Streptococcus and serum levels of antistreptolysine \"O\" in a rural community, Américo Brasiliense, 1981

Investigou-se a presença de estreptococos beta-hemolíticos e os níveis séricos de antiestreptolisina "O" (ASO) em comunidade rural dividida em duas populaçöes; escolar e familial. O estudo da populaçäo escolar revelou a presença de 61,8% portadores de estreptococos beta-hemolíticos, com predominância do grupo A e do padräo T11/14 seguido do T4 e do T8/25/Imp.19. A dosagem da ASO revelou 64,6% escolares com títulos abaixo de 250UT; 27,7% com títulos entre 250 e 333UT e 17% acima de 500UT. A média encontrada foi de 262UT. A populaçäo familial revelou 47% de portadores de estreptococos com predominância do grupo G. Entre os protadores do grupo A houve predominância do padräo T8/25/Imp.19, seguido do T4 e T11/14. Nesta populaçäo 79,3% tiveram níveis de ASO abaixo de 250UT; 14,6% resultados entre 250 e 333UT e 6,1% de 500UT. A média encontrada foi de 187UT. Nas populaçöes em estudo houve simultaneidade de 60,8% entre grupos sorológicos de estreptococos e 43,2% entre sorotipos do grupo A. Verificou-se uma correlaçäo significativa entre os dados clínicos, respostas afirmativas ao questionário proposto, presença de estreptococos beta-hemolíticos e níveis séricos de ASO acima da anormalidade