Rapid and sensitive point-of-care detection of Orthopoxviruses by ABICAP immunofiltration.

BACKGROUND: The rapid and reliable detection of infectious agents is one of the most challenging tasks in scenarios lacking well-equipped laboratory infrastructure, like diagnostics in rural areas of developing countries. Commercially available point-of-care diagnostic tests for emerging and rare diseases are particularly scarce. RESULTS: In this work we present a point-of-care test for the detection of Orthopoxviruses (OPV). The OPV ABICAP assay detects down to 1 × 104 plaque forming units/mL of OPV particles within 45 min. It can be applied to clinical material like skin crusts and detects all zoonotic OPV infecting humans, including Vaccinia, Cowpox, Monkeypox, and most importantly Variola virus. CONCLUSIONS: Given the high sensitivity and the ease of handling, the novel assay could be highly useful for on-site diagnostics of suspected Monkeypox virus infections in areas lacking proper laboratory infrastructure as well as rapid on-site testing of suspected bioterrorism samples.

Increase of interleukin-18 serum levels after engraftment correlates with acute graft-versus-host disease in allogeneic peripheral blood stem cell transplantation.

PURPOSE: Acute graft-versus-host disease (GvHD) is a constant and severe complication after allogeneic stem cell transplantation regularly involving skin, liver, gut, and lungs. The cytokine interleukin-18 (IL-18) has been shown to increase in patients who develop acute GvHD after bone marrow tranplantation (BMT). MATERIALS AND METHODS: Here, we measured IL-18 serum levels after peripheral blood stem cell transplantation (PBSCT) at several characteristic time points in 24 patients (median age 46 years). Patients received a median of 7.3 x 10(6)/kg bodyweight CD34-positive blood stem cells from HLA-matched family donors (n = 5), matched unrelated donors (n = 18), and one mismatched unrelated donor. GvHD prophylaxis consisted of cyclosporin A alone or combined with methotrexate and/or mycophenolate mofetil. RESULTS: In 14 patients we observed no GvHD or only GvHD grade I whereas ten patients developed GvHD grade II-IV post transplant. Low, intermediate, and high levels of serum IL-18 were found in patients after allogeneic PBSCT independently of GvHD after transplantation. In contrast to GvHD arising after BMT, there was no clear correlation between absolute IL-18 serum levels and GvHD grade after PBSCT. However, the individual time course of IL-18 serum level after engraftment correlates with acute GvHD after PBSCT. In detail, an increase of serum IL-18 of at least 1.6-fold after engraftment is associated with acute GvHD II or higher with a sensitivity of three out of four. Using the 1.6 "cut-off" for IL-18 increase after engraftment, a specificity of up to 100% can be achieved. CONCLUSION: The time course of IL-18 serum levels might be used for GvHD prediction after PBSCT comparable to absolute serum levels after BMT.