[Flow-cytometric immunophenotyping in clinical diagnostics]. / Durchflusszytometrische Immunphänotypisierung in der klinischen Diagnostik.

Flow cytometric immunophenotyping represents an indispensable tool in hematological and immunological diagnostics. The most frequent indications include lymphocyte phenotyping and the diagnosis and monitoring of benign and malignant hematologic diseases. The role of immunophenotyping in clinical practice is evolving rapidly. This review provides an overview of its current applications and limitations.

Myeloid-derived suppressor cells in human peripheral blood: Optimized quantification in healthy donors and patients with metastatic renal cell carcinoma.

Induction of myeloid-derived suppressor cells is an important mechanism leading to tolerance against tumors. Phenotypic characterization of MDSC has been established and heterogeneous populations with monocytic or granulocytic features have been characterized. Increased levels of MDSC have been described in metastatic renal cell carcinoma and seem to correlate with an adverse outcome. As MDSC constitute only small populations in peripheral blood of cancer patients, it is highly important to achieve technically optimized conditions for quantification. Different cell preparation techniques--besides freezing and thawing--are potential sources of substantial variation. Our study was focused on an optimized quantification of MDSC in pB of healthy donors and patients with mRCC, in whom major technical sources of variation were analyzed. Whole blood and peripheral blood mononuclear cells were used for the flow cytometric quantification of MDSC in the pB of mRCC patients and healthy donors. We compared (1) analysis in whole blood vs. PBMC after Ficoll gradient centrifugation and (2) immediate analysis after blood drawing vs. analysis one day later. Finally, in order to evaluate our optimized technical approach, pB of 15 patients with histologically confirmed mRCC under treatment with either sunitinib or sorafenib was analyzed. No difference in the number of MDSC was observed after analysis in whole blood vs. PBMC. In contrast, the time point of analysis was a source of substantial variation (one day later vs. immediate analysis after blood drawing). In conclusion, for optimal analysis of MDSC, immediate analysis of whole blood after blood drawing rather than one day later seems to be most appropriate under the aspect of practical feasibility and reliability. Using this method, we were able to confirm both (a) increased numbers of MDSC in patients with mRCC and (b) a decrease of MDSC under sunitinib therapy.

Synchronous tuberculosis, Epstein-Barr virus-associated lymphoproliferative disorder and cytomegalovirus infection in an allogeneic transplant recipient: a case report.

BACKGROUND: Allogeneic stem cell transplant recipients are prone to infections by various organisms. Tuberculosis (TB) represents a rare infectious complication, especially in countries non-endemic for TB. CASE REPORT: Here, we report the case of a German patient with exposure to TB decades before he was diagnosed with disseminated TB as well as synchronous Epstein-Barr virus associated lymphoproliferative disorder and cytomegalovirus infection after allogeneic stem cell transplantation for refractory acute myeloid leukemia. Tuberculostatic and virostatic therapy was administered and the patient could be discharged with no apparent signs of infection two weeks after initiation of therapy. CONCLUSION: This case illustrates the need for awareness of mycobacterial infections in patients from non-endemic regions undergoing stem cell transplantation even if other reasons for fever are present.