Hermann Girschick

Reference values for B cell subpopulations from infancy to adulthood

The composition of the peripheral blood lymphocyte compartment underlies developmental changes during ontogeny. Recently, several new B cell populations have been characterized which were suggested to develop in an age‐dependent manner. However, age‐dependent reference values for distinct B cell populations have rarely been reported. Therefore, we have characterized developmental changes in peripheral B cell populations from infancy to adulthood in order to define age‐dependent reference values. Using a flow cytometric approach we analysed the frequencies as well as the absolute counts of naive, switched and non‐switched memory B cells, CD27‐negative memory B cells, transitional B cells as well as CD21lowCD38low B cells from neonates up to the age of 50 years. Most of the B cell subsets showed age‐dependent developmental changes: while the peripheral B cell pool during infancy is characterized predominantly by transitional and naive B cells, the fraction of switched and non‐switched memory B cells increases gradually with age. CD21lowCD38low B cells as well as plasmablasts do not exhibit developmental changes. In summary, we could demonstrate particular changes in the peripheral blood B cell compartment during ontogeny. This study provides reference values of different B cell subpopulations offering comparability for studies addressing disturbed peripheral B cell development in immunodeficiency, autoimmunity or B cell reconstitution following cell‐depleting therapies.

Chronic recurrent multifocal osteomyelitis in children: Diagnostic value of histopathology and microbial testing

Chronic recurrent, unifocal or multifocal osteomyelitis (CRMO), an inflammatory disorder of unknown origin, involves different osseous sites and may be associated with palmoplantar pustulosis. Bacterial cultures of affected tissue were reported negative in nearly all cases. Radiological and magnetic resonance imaging features of CRMO have been described, but differential diagnosis remains difficult, including rheumatic diseases, bacterial osteomyelitis, and malignancy. Although definite diagnosis relies on histopathologic confirmation by biopsy, histopathologic criteria have not been defined. Because CRMO may be treated with nonsteroidal antiinflammatory drugs, but not antibiotics, distinguishing CRMO from bacterial osteomyelitis is of major importance. Histopathologic analysis of 12 patients with CRMO indicated a wide variation of reparative changes of bone, but chronic inflammation could not be found at all sites in the same biopsy. The inflammatory infiltrate was mostly scattered, consisting mainly of lymphocytes, plasma cells, histiocytes, and also few neutrophil granulocytes. Immunohistochemistry showed a predominance of CD3(+), CD45RO(+) T-cells, which were mainly CD8(+). In addition, CD20(+) B cells and CD68(+) macrophages were abundant in each biopsy specimen. Mild lymphocytic and granulocytic infiltrates were also detected in three synovial biopsy specimens obtained from adjacent joints. All bacterial and fungal cultures from native biopsy tissues were negative. Amplification of partial-length 16S ribosomal DNA by polymerase chain reaction (PCR) using broad-range eubacterial primers was below the detection limit in all patients. Because histopathologic features alone may not provide conclusive evidence, CRMO should be included in the differential diagnosis of chronic inflammatory bone lesions in children, and the definite diagnosis should be made by the clinical picture, x-ray studies, bone scan, bacterial culture, and histopathologic analysis in a multidisciplinary approach.

MicroRNAs – micro in size but macro in function

MicroRNAs (miRNAs) are endogenous small RNAs that can regulate target mRNAs by binding to their 3′‐UTRs. A single miRNA can regulate many mRNA targets, and several miRNAs can regulate a single mRNA. These have been reported to be involved in a variety of functions, including developmental transitions, neuronal patterning, apoptosis, adipogenesis metabolism and hematopoiesis in different organisms. Many oncogenes and tumor suppressor genes are regulated by miRNAs. Studies conducted in the past few years have demonstrated the possible association between miRNAs and several human malignancies and infectious diseases. In this article, we have focused on the mechanism of miRNA biogenesis and the role of miRNAs in human health and disease.

Chronic recurrent osteomyelitis with clavicular involvement in children: diagnostic value of different imaging techniques and therapy with non-steroidal anti-inflammatory drugs

Abstract Chronic recurrent, uni- or multifocal osteomyelitis (CRMO), an inflammatory disorder of unknown origin, involves mk:/night/arul/4310946m.3dultiple osseous sites and may affect the clavicle. We report on 6 children with clavicular involvement out of 11 children suffering from CRMO. The major clinical symptoms were local swelling and pain. Five children had hyperostosis of the clavicle and synovitis of adjacent joints. Histology showed chronic osteomyelitis with a predominance of lymphocytes in the inflammatory infiltrates. Cultures of biopsy tissue specimens were sterile. The patients were followed for at least 3.5 years. Three patients had up to six relapses. The most effective diagnostic tools to define CRMO were standard X-ray and bone scan in combination with biopsy and cultures. In our patients CT and MRI were misleading as they suggested the presence of malignancy. However, the sensitivity of MRI to detect involvement of bone, adjacent joints and soft tissues were better in comparison to X-ray or bone scan. Non-steroidal anti-inflammatory drugs were effective in reducing pain, swelling and limitation of motion. Reconstructive surgery was not indicated in any case. The long-term outcome of growth and function of affected bones was excellent. Conclusion Diagnosis of chronic osteomyelitis of the clavicle should be made by history and physical examination and be confirmed by standard X-ray, bone scan and open biopsy. In contrast MRI and CT can provide data on the involvement of adjacent joints, soft tissue and muscles especially in the early process of disease, but do not add information relevant to the patients management. Treatment with non-steroidal anti-inflammatory drugs is rapidly beneficial in most patients.

Chronic recurrent multifocal osteomyelitis: what is it and how should it be treated?

Background Chronic recurrent multifocal osteomyelitis (CRMO) is the most severe form of chronic nonbacterial osteomyelitis. In children and adolescents, chronic nonbacterial osteomyelitis predominantly affects the metaphyses of the long bones, but lesions can occur at any site in the skeleton. Other organs (the skin, eyes, gastrointestinal tract and lungs) can also be affected. Clinical diagnosis is often difficult because the symptoms and course of disease vary significantly. We present a 10-year-old girl diagnosed with CRMO involving several vertebrae, the femur and the metatarsus.Investigations Physical examination, abdominal ultra sonography, conventional X-ray, MRI, technetium bone scan, esophagogastroduodenoscopy, colonoscopy, tests for HLA-B27 and thiopurine methyltransferase, polymerase chain reaction and thoracic vertebral bone biopsies.Diagnosis CRMO and Crohns disease.Management The patients condition improved whilst being treated with NSAIDs for 3 months; however, the patient had an allergic skin reaction to this therapy. Treatment was switched to sulfasalazine, accompanied by 3 weeks of therapy using oral prednisone, but sulfasalazine was discontinued 2 months later because the patient exhibited a minor elevation in the levels of liver enzymes. The patient was free of musculoskeletal symptoms for 6 months, at which time she started to complain again about pain in her back and bowel. Multimodal therapy, consisting of mesasalazine, corticosteroids (budesonide) and azathioprine, induced clinical remission of Crohns disease.

Chronic nonbacterial osteomyelitis in childhood: prospective follow-up during the first year of anti-inflammatory treatment

IntroductionChronic nonbacterial osteomyelitis (CNO) is an inflammatory disorder of unknown etiology. In children and adolescents CNO predominantly affects the metaphyses of the long bones, but lesions can occur at any site of the skeleton. Prospectively followed cohorts using a standardized protocol in diagnosis and treatment have rarely been reported.MethodsThirty-seven children diagnosed with CNO were treated with naproxen continuously for the first 6 months. If assessment at that time revealed progressive disease or no further improvement, sulfasalazine and short-term corticosteroids were added. The aims of our short-term follow-up study were to describe treatment response in detail and to identify potential risk factors for an unfavorable outcome.ResultsNaproxen treatment was highly effective in general, inducing a symptom-free status in 43% of our patients after 6 months. However, four nonsteroidal anti-inflammatory drug (NSAID) partial-responders were additionally treated with sulfasalazine and short-term corticosteroids. The total number of clinical detectable lesions was significantly reduced. Mean disease activity estimated by the patient/physician and the physical aspect of health-related quality of life including functional ability (global assessment/childhood health assessment questionnaire and childhood health assessment questionnaire) and pain improved significantly. Forty-one percent of our patients showed radiological relapses, but 67% of them were clinically silent.ConclusionsMost children show a favorable clinical course in the first year of anti-inflammatory treatment with NSAIDs. Relapses and new radiological lesions can occur at any time and at any site in the skeleton but may not be clinically symptomatic. Whole-body magnetic resonance imaging proved to be very sensitive for initial and follow-up diagnostics.

Molecualar survival strategies of the Lyme disease spirochete Borrelia burgdorferi

Lyme disease is a tick-transmitted disease caused by the spirochete Borrelia burgdorferi. The bacterium adopts different strategies for its survival inside the immunocompetent host from the time of infection until dissemination in different parts of body tissues. The success of this spirochete depends on its ability to colonise the host tissues and counteract the hosts defence mechanisms. During this process borrelia seems to maintain its vitality to ensure long-term survival in the host. Borrelias proteins are encoded by plasmid and chromosomal genes. These genes are differentially regulated and expressed by different environmental factors in ticks as well as in the mammalian host during infection. In addition, antigenic diversity enables the spirochete to escape host defence mechanisms and maintain infection. In this review we focus on the differential expression of proteins and genes, and further molecular mechanisms used by borrelia to maintain its survival in the host. In light of these pathogenetic mechanisms, further studies on spirochete host interaction are needed to understand the complex interplay that finally lead to host autoimmunity.

Autoinflammatory bone disorders with special focus on chronic recurrent multifocal osteomyelitis (CRMO)

Sterile bone inflammation is the hallmark of autoinflammatory bone disorders, including chronic nonbacterial osteomyelitis (CNO) with its most severe form chronic recurrent multifocal osteomyelitis (CRMO). Autoinflammatory osteopathies are the result of a dysregulated innate immune system, resulting in immune cell infiltration of the bone and subsequent osteoclast differentiation and activation. Interestingly, autoinflammatory bone disorders are associated with inflammation of the skin and/or the intestine. In several monogenic autoinflammatory bone disorders mutations in disease-causing genes have been reported. However, regardless of recent developments, the molecular pathogenesis of CNO/CRMO remains unclear.Here, we discuss the clinical presentation and molecular pathophysiology of human autoinflammatory osteopathies and animal models with special focus on CNO/CRMO. Treatment options in monogenic autoinflammatory bone disorders and CRMO will be illustrated.

Gastroenteritis in childhood: a retrospective study of 650 hospitalized pediatric patients

BACKGROUND Acute diarrhea continues to be an important cause of hospitalization in young children, and deaths still occur as a result. We reviewed a large cohort of hospitalized children affected by gastroenteritis. The hypothesis of our study was that clinical characteristics and a limited set of laboratory data can differentiate between the different causative pathogens of diarrhea. METHODS A chart review was performed of 650 patients with pathogen-proven diarrhea treated between April 2005 and May 2008 in the childrens hospital of the University of Würzburg. Clinical presentation at the time of admission and during hospital stay, laboratory findings, stool pathogen results, and epidemiological data were collected and compared. A severity score was generated. RESULTS Rotavirus was the most common gastroenteritis pathogen identified, followed by norovirus, adenovirus and Salmonella spp. Nosocomial infections were caused most commonly by norovirus. Rotavirus was the most common agent when there was simultaneous detection of two or more viruses. Rotavirus infections were significantly more severe, with a higher frequency of diarrhea and elevated liver enzymes. Infections due to Salmonella spp showed significantly higher values for C-reactive protein, erythrocyte sedimentation rate, and body temperature. A seasonal distribution was noted, with the peak for rotaviruses/noroviruses in winter/spring, the peak for adenoviruses in November/December, and the peak for Salmonella spp in the summer months. Younger children and toddlers had significantly higher gastroenteritis and airway inflammation scores. Of note, respiratory symptoms and parameters of systemic inflammation differed between the different pathogens. CONCLUSIONS Gastroenteritis is a common reason for hospital admission in previously healthy children during the first years of life. Rotaviruses were found to be the most common pathogens in our cohort. On the basis of clinical and laboratory parameters it appears possible to distinguish between the different causative agents. This may have implications for hospital hygiene management and for the identification of predictive markers of a severe course.

Chronic non-bacterial osteomyelitis is associated with impaired Sp1 signaling, reduced IL10 promoter phosphorylation, and reduced myeloid IL-10 expression

Chronic non-bacterial osteomyelitis (CNO) is an auto-inflammatory disorder that affects the skeletal system. Interleukin (IL-)10 is an immune-modulatory cytokine that controls inflammation, and limits inflammatory cytokine responses. Dysregulation of IL-10 expression has been shown to result in autoimmune and infectious diseases. We investigated IL-10 expression by monocytic cells from CNO patients and controls. In response to stimulation with LPS, IL-10 expression from CNO monocytes was reduced (p<0.001). This was independent of IL10 promoter polymorphisms. Thus, we investigated Sp1 recruitment to the IL10 promoter and saw markedly reduced binding in CNO monocytes. This was accompanied with reduced phosphorylation of histone H3 serine 10 (H3S10), an activating epigenetic mark. Impaired recruitment of Sp1 to the IL10 promoter, and reduced H3S10 phosphorylation, may be a reflection of deficient MAPK signaling in CNO monocytes in response to LPS stimulation. Thus, we have discovered a mechanism that may be central in the pathophysiology of CNO.