causes of the disturbed development and regula tion of the immune system.” Since immune defects appear early, most of the patients are children. However, there are also long, drawn- out cases extending even into old age, for instance when repeated bouts of pneumonia are not identified as a problem originating in the patient’s immune defense. Ehl sees the advan tage of the CCI as lying in the cooperation between infectiologists, hematologists, internists, transplanters, and pediatricians. “We combine fundamental research with patient care at the clinic and can share our results with each other.” Using their insight into the cellular processes of the immune system, the scientists of the CCI succeeded in implementing the correct therapy for SCID. “As difficult as the disease and its correct diagnosis may be, the therapy is actually relatively simple,” says Ehl. The T cells of the hemopoietic system cannot be activated in SCID patients since the necessary influx of calcium into the cell is disrupted. However, research has shown that the formation of messengers is essential for the activation and the cytotoxicity of the immune response. The scientists found an obvious solution to the problem: counteracting the genetic defect by introducing healthy cells. “In the case of many genetic diseases the doctor can’t do much, but when the hemopoietic system is affected, he can exchange it,” says Ehl. The non-functioning immune cells are killed off by means of chemo Prof. Dr. Stephan Ehl worked as a postdoc under Nobel laureate Prof. Dr. Rolf Zinkernagel in Zurich, Switzerland, after studying medicine in Aachen, Erlan- gen, and Munich. After completing his training as a pediatrician in Freiburg, he earned his habilitation in 2003. Since 2008 Ehl has served as medical director of the Center for Chronic Immunodeficiency (CCI). He has dedicated himself to treating and researching immunodeficiencies for the past 15 years and has made important contributions to the improvement of diag- nostics and the study of the symptoms of immuno- deficiencies. therapy, thus preventing an immune reaction and the rejection of foreign cells. If the patient’s own bone marrow is destroyed, the doctors introduce healthy bone marrow cells from a donor through the veins via blood transfusion, and the cells then find the right place all on their own. “We don’t even have to operate,” says Ehl. Thanks to medical progress it is now possible in some cases to repair the bone marrow cells of a diseased child in a test tube by introducing a healthy gene. The child develops a healthy immune system following the transfusion. The youngest patient at CCI is an eight-month-old child who has just received a bone marrow cell transplant. There had already been a similar case in the patient’s family, so the pediatrician was more alert from the beginning. However, it wasn’t until the baby had undergone several bouts of pneumonia that the severity of the illness was identified. “Now he is doing better again.” “As difficult as the disease and its correct diagnosis may be, the therapy is actually relatively simple” Further Reading Bryceson, Y. T./Pende, D./Maul-Pavicic, A./ Gilmour, K. C./Ufheil, H./Vraetz, T./Chiang, S. C./ Marcenaro, S./Meazza, R./Bondzio, I./Walshe, D./ Janka, G./Lehmberg, K./Beutel, K./zur Stadt, U./ Binder, N./Arico, M./Moretta, L./Henter, J. I./ Ehl, S. (2012): A prospective evaluation of de granulation assays in the rapid diagnosis of fa milial hemophagocytic syndromes. In: Blood 119/12, pp. 2754 – 2763. Maul-Pavicic, A./Chiang, S. C./Rensing-Ehl, A./ Jessen, B./Fauriat, C./Wood, S. M./Sjöqvist, S./ Hufnagel, M./Schulze, I./Bass, T./Schamel, W. W./ Fuchs, S./Pircher, H./McCarl, C. A./Mikoshiba, K./Schwarz, K./Feske, S./Bryceson, Y. T./Ehl, S. (2011): ORAI1-mediated calcium influx is re quired for human cytotoxic lymphocyte degranu lation and target cell lysis. In: Proceedings of the National Academy of Sciences of the United States of America 108/8, pp. 3324 – 3329. 11