Sebastian F. N. Bode

The risk of hemophagocytic lymphohistiocytosis in Hermansky-Pudlak syndrome type 2.

Genetic disorders of lymphocyte cytotoxicity predispose patients to hemophagocytic lymphohistiocytosis (HLH). Reduced lymphocyte cytotoxicity has been demonstrated in Hermansky-Pudlak syndrome type 2 (HPS2), but only a single patient was reported who developed HLH. Because that patient also carried a potentially contributing heterozygous RAB27A mutation, the risk for HLH in HPS2 remains unclear. We analyzed susceptibility to HLH in the pearl mouse model of HPS2. After infection with lymphocytic choriomeningitis virus, pearl mice developed all key features of HLH, linked to impaired virus control caused by a moderate defect in CTL cytotoxicity in vivo. However, in contrast to perforin-deficient mice, the disease was transient, and all mice fully recovered and controlled the infection. An additional heterozygous Rab27a mutation did not aggravate the cytotoxicity defect or disease parameters. In the largest survey of 22 HPS2 patients covering 234 patient years, we identified only 1 additional patient with HLH and 2 with incomplete transient HLH-like episodes, although cytotoxicity or degranulation was impaired in all 16 patients tested. HPS2 confers a risk for HLH that is lower than in Griscelli or Chediak-Higashi syndrome, probably because of a milder defect in cytotoxicity. Preemptive hematopoietic stem cell transplantation does not appear justified in HPS2.

Malignancy‐associated haemophagocytic lymphohistiocytosis in children and adolescents

Haemophagocytic lymphohistiocytosis (HLH) in the context of malignancy is mainly considered a challenge of adult haematology. While this association is also observed in children, little is known regarding inciting factors, appropriate treatment and prognosis. We retrospectively analysed 29 paediatric and adolescent patients for presenting features, type of neoplasm or preceding chemotherapy, treatment and outcome. Haemophagocytic lymphohistiocytosis was considered triggered by the malignancy (M‐HLH) in 21 patients, most of whom had T‐ (n = 12) or B‐cell neoplasms (n = 7), with Epstein–Barr virus as a co‐trigger in five patients. In eight patients, HLH occurred during chemotherapy (Ch‐HLH) for malignancy, mainly acute leukaemias (n = 7); an infectious trigger was found in seven. In M‐ and Ch‐HLH, median overall survival was 1·2 and 0·9 years, and the 6 month survival rates were 67% and 63%, respectively. Seven of 11 deceased M‐HLH patients exhibited active malignancy and HLH at the time of death, while only two out of five deceased Ch‐HLH patients had evidence of active HLH. To overcome HLH, malignancy‐ and HLH‐directed treatments were administered in the M‐HLH cohort; however, it was not possible to determine superiority of one approach over the other. For Ch‐HLH, treatment ranged from postponement of chemotherapy to the use of etoposide‐containing regimens.

Primary and secondary hemophagocytic lymphohistiocytosis have different patterns of T-cell activation, differentiation and repertoire

Hemophagocytic lymphohistiocytosis (HLH) is a life‐threatening inflammatory syndrome characterized by hyperactivation of lymphocytes and histiocytes. T cells play a key role in HLH pathogenesis, but their differentiation pattern is not well characterized in patients with active HLH. We compared T‐cell activation patterns between patients with familial HLH (1°HLH), 2°HLH without apparent infectious trigger (2°HLH) and 2°HLH induced by a viral infection (2°V‐HLH). Polyclonal CD8+ T cells are highly activated in 1°HLH and 2°V‐HLH, but less in 2°HLH as assessed by HLA‐DR expression and marker combination with CD45RA, CCR7, CD127, PD‐1 and CD57. Absence of increased HLA‐DR expression on T cells excluded active 1° HLH with high sensitivity and specificity. A high proportion of polyclonal CD127−CD4+ T cells expressing HLA‐DR, CD57, and perforin is a signature of infants with 1°HLH, much less prominent in virus‐associated 2°HLH. The similar pattern and extent of CD8+ T‐cell activation compared to 2° V‐HLH is compatible with a viral trigger of 1°HLH. However, in most 1°HLH patients no triggering infection was documented and the unique activation of cytotoxic CD4+ T cells indicates that the overall T‐cell response in 1°HLH is different. This may reflect different pathways of pathogenesis of these two HLH variants.

Effective Immunological Guidance of Genetic Analyses Including Exome Sequencing in Patients Evaluated for Hemophagocytic Lymphohistiocytosis

We report our experience in using flow cytometry-based immunological screening prospectively as a decision tool for the use of genetic studies in the diagnostic approach to patients with hemophagocytic lymphohistiocytosis (HLH). We restricted genetic analysis largely to patients with abnormal immunological screening, but included whole exome sequencing (WES) for those with normal findings upon Sanger sequencing. Among 290 children with suspected HLH analyzed between 2010 and 2014 (including 17 affected, but asymptomatic siblings), 87/162 patients with “full” HLH and 79/111 patients with “incomplete/atypical” HLH had normal immunological screening results. In 10 patients, degranulation could not be tested. Among the 166 patients with normal screening, genetic analysis was not performed in 107 (all with uneventful follow-up), while 154 single gene tests by Sanger sequencing in the remaining 59 patients only identified a single atypical CHS patient. Flow cytometry correctly predicted all 29 patients with FHL-2, XLP1 or 2. Among 85 patients with defective NK degranulation (including 13 asymptomatic siblings), 70 were Sanger sequenced resulting in a genetic diagnosis in 55 (79%). Eight patients underwent WES, revealing mutations in two known and one unknown cytotoxicity genes and one metabolic disease. FHL3 was the most frequent genetic diagnosis. Immunological screening provided an excellent decision tool for the need and depth of genetic analysis of HLH patients and provided functionally relevant information for rapid patient classification, contributing to a significant reduction in the time from diagnosis to transplantation in recent years.

Hemophagocytic lymphohistiocytosis as presenting manifestation of profound combined immunodeficiency due to an ORAI1 mutation

Please cite this article as: Klemann C, Ammann S, Heizmann M, Fuchs S, Bode SF, Heeg M, Fuchs H, Lehmberg K, zur Stadt U, Roll C, Vraetz T, Speckmann C, Lorenz MR, Schwarz K, Rohr J, Feske S, Ehl S, Hemophagocytic lymphohistiocytosis as presenting manifestation of profound combined immunodeficiency due to an ORAI1 mutation, Journal of Allergy and Clinical Immunology (2017), doi: 10.1016/j.jaci.2017.05.039.

A roadmap towards personalized immunology

Big data generation and computational processing will enable medicine to evolve from a “one-size-fits-all” approach to precise patient stratification and treatment. Significant achievements using “Omics” data have been made especially in personalized oncology. However, immune cells relative to tumor cells show a much higher degree of complexity in heterogeneity, dynamics, memory-capability, plasticity and “social” interactions. There is still a long way ahead on translating our capability to identify potentially targetable personalized biomarkers into effective personalized therapy in immune-centralized diseases. Here, we discuss the recent advances and successful applications in “Omics” data utilization and network analysis on patients’ samples of clinical trials and studies, as well as the major challenges and strategies towards personalized stratification and treatment for infectious or non-communicable inflammatory diseases such as autoimmune diseases or allergies. We provide a roadmap and highlight experimental, clinical, computational analysis, data management, ethical and regulatory issues to accelerate the implementation of personalized immunology.

A novel disease-causing synonymous exonic mutation in GATA2 affecting RNA splicing

TO THE EDITOR: Inherited and de novo heterozygous germ line mutations in GATA2 cause a pleotropic autosomal dominant genetic disorder characterized by cellular deficiencies with a high propensity for myeloid malignancy.[1][1],[2][2] The clinical syndromes of GATA2 deficiency include monocytopenia

Self-perceived attitudes toward interprofessional collaboration and interprofessional education among different health care professionals in pediatrics.

Interprofessional education (IPE) is the basis for interprofessional collaboration (IPC) in health care systems. It has beneficial effects for both patients and health care professionals. IPC is paramount for adequate care of patients and their families, especially in pediatrics. To determine the attitudes of medical doctors (n=121), nurses (n=15), psychologists (n=14), and social workers (n=19) toward IPE and IPC in a tertiary pediatric university teaching hospital, as well as the inpatient and outpatient settings in pediatrics, we developed a questionnaire with 21 items in four categories based on established questionnaires. All participants worked as part of interprofessional teams, and the overwhelming majority valued IPC highly. Most competencies important for IPC were acquired on the job. There was a substantial lack of interprofessional education, especially for medical doctors and psychologists. IPE still needs to be established as part of the undergraduate curriculum at German universities.

Audience-response systems for evaluation of pediatric lectures--comparison with a classic end-of-term online-based evaluation.

Aim: Course evaluations are often conducted and analyzed well after the course has taken place. By using a digital audience response system (ARS), it is possible to collect, view and discuss feedback during or directly following a course or lecture session. This paper analyzes a student evaluation of a lecture course with ARS to determine if significant differences exist between the results of the ARS lecture evaluation and those of the online evaluation at the end of the semester. In terms of the overall evaluation, consideration is given to the level of students’ prior knowledge, the presentation of the lecture material by the lecturers and the relevance of the lecture topic for students. Method: During the 2011-12 winter semester, the lecture on Pediatrics at the Freiburg Center for Pediatric and Adolescent Medicine (Zentrum für Kinder- und Jugendmedizin (ZKJ) Freiburg) was evaluated using ARS. Thirty-four lectures were evaluated by an average of 22 (range 8-44) students, who responded to four questions each time an evaluation took place. Results: On a 6-point Likert scale (1=very good to 6=deficient), the students rated their level of preparedness with a mean of 3.18, the presentation of the lecture with 2.44, and the relevance of the lecture topic with 2.19. The overall evaluation of the lecture course by means of ARS resulted in 2.31. The online evaluation conducted at the end of the semester yielded a score of 2.45. Highly significant correlations were seen between the results of the ARS for the overall evaluation, assessment of prior knowledge, lecture presentation, and the estimated relevance of the lecture topic. Conclusion: The use of ARS is suitable for immediate evaluation of lectures, in particular regarding timely feedback for the individual lecturerlecturers. In comparison with an end-of-term evaluation, ARS yielded a better assessment.