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Biomedical subjects

A Hornsleth

Publications and source records attributed to A Hornsleth.

At least 19 recordsLinked to original sources

Cytokines and chemokines in respiratory secretion and severity of disease in infants with respiratory syncytial virus (RSV) infection.

BACKGROUND: little is known about inflammatory mediators (IM); like cytokines, chemokines and receptors; in respiratory secretion as possible indicators of the severity of respiratory syncytial virus (RSV) disease. Nor have systematic studies been published on the ratios between IM as such indicators. OBJECTIVE: to define the role of IM ratios as possible indicators of the severity of RSV disease. STUDY DESIGN: about 46 infants aged 0-9 months with acute RSV infections were studied. Prematurity (PM) and/or underlying disease (UD) were present in 11 of them. The concentrations of seven different IM were measured by ELISA in samples of nasopharyngeal secretions (NPS), four cytokines; IL-1, IL-6, IL-10 and TNF-alpha; the cytokine receptor TNF-R1 and the chemokines; IL-8 and RANTES. 21 IM ratios were calculated from these concentrations. The patients were assigned a clinical score (CS) ranging from 0 to 3 according to the severity of disease. RESULTS: when 25 patients with severe disease (CS 2-3) and 21 patients with mild disease (CS 0-1) were compared with respect to different IM ratios, three ratios were related to severity of disease: IL-1/RANTES, IL-8/RANTES and TNF-R1/RANTES. When 12 patients with mild disease were compared with 16 patients with severe disease, omitting patients more than 5 months of age and patients with PM and/or UD, the following IM ratios were related to severity of disease: TNF-R1/RANTES, IL-8/RANTES and RANTES/IL-10. CONCLUSION: of 21 IM ratios studied, TNF-R1/RANTES was related to severity of disease with greatest consistency.

Antigens, CD↗

Role of parvovirus B19 infection in childhood idiopathic thrombocytopenic purpura.

Although parvovirus B19 exhibits a strong tissue-tropism for erythroid progenitor cells leading to anaemia, several case reports indicate that parvovirus B19 infection may also cause the development of thrombocytopenia. Despite recent studies, the frequency and clinical relevance of this association have remained questionable. Consequently, and in view of the paucity of evidence regarding a viral aetiology for idiopathic thrombocytopenic purpura (ITP), we examined the role of parvovirus B19 in 47 children with newly diagnosed ITP. Specific viral DNA indicating a current or recent parvovirus B19 infection was demonstrated in 6 of 47 patients (13%) employing the polymerase chain reaction technique. Our study suggests that children with ITP and associated parvovirus B19 infection are characterized by acute onset of profound thrombocytopenia. Among the parvovirus B19 positive children, duration of disease was brief in three children treated with immunoglobulin but chronic in the remaining three patients given high-dose steroids. Prospective studies are needed to confirm these initial observations. This virus should be considered as a possible aetiologic agent in some children with ITP.

Acute Disease↗

The fluctuating pattern of various genome types of respiratory syncytial virus in Copenhagen and some other locations in Denmark.

A semi-nested RT-PCR method based on a region of the F and G glycoprotein genes was established, allowing the simultaneous detection and differentiation of group A and group B isolates of respiratory syncytial virus (RSV). The PCR products were subjected to digestion with restriction endonucleases to further differentiate the isolates. Using, in addition, previously reported studies the prevalence of various genome types in the Copenhagen region over a period of 6 years was established. Furthermore, the prevalence of genome types was determined in a distant region in Denmark during the winters of 1996/97 and 1997/98, and in yet another distant region during the winter of 1997/98. It was shown that the different regions in Denmark to a large extent share the same pool of genome types of RSV. Yet, while the fluctuating patterns of the two groups and various genome types were almost identical at different hospitals in the Copenhagen region, they varied between the different regions. This suggests that epidemics in local communities primarily rely on region-specific herd immunity parameters and emerge from strains endemically circulating in these local communities. Group B strains in Copenhagen showed an overall predominance, being predominant in three of the six epidemic seasons studied, and of almost equal predominance in one season.

Child↗

Typing of European strains of parvovirus B19 by restriction endonuclease analyses and sequencing: identification of evolutionary lineages and evidence of recombination of markers from different lineages.

European isolates of parvovirus B19 were analyzed by restriction enzyme analysis of PCR products of the VP1/2 coding region and sequencing of the same amplified region, five cloned fragments from each PCR product. Two main groupings were found based on three perfectly linked point deviations. On the assumption that identical point deviations causing the various restriction patterns regardless of time and origin of virus isolation were unlikely to emerge independently in different evolutionary lineages, traits of evolutionary lineages were identified, suggesting a clonal population structure of global circulating B19 strains. However, combinations of markers from different evolutionary lineages were also found, particularly in a strain derived from an individual chronically infected with B19 for more than 7 years. As chronically infected individuals might be subject to superinfections due to contacts or possibly due to blood transfusions or the administration of gamma-globulin, it is suggested that coexistence of, and recombination between variants of B19 of different phylogenetic origin incidentally occur in such individuals.

Capsid↗

Parvovirus B19 infection associated with myocarditis following adult cardiac transplantation.

A 56-year-old woman underwent an uneventful cardiac transplantation due to dilated cardiomyopathy. One week later the patient developed clinical and histological signs of myocarditis. We report for the first time a case of myocarditis in an adult heart transplant recipient, possibly induced by parvovirus B19, as evidenced by the finding of specific IgM in serum and specific DNA in the myocardial cells. Furthermore, this is the first time parvovirus B19 DNA has been observed in the myocardium of an adult. In conclusion, parvovirus B19 should be recognized as a potential pathogen causing myocarditis in heart transplant recipients. In order to establish a definite and rapid diagnosis, a search for specific IgM should be supplemented with PCR investigations of serum and myocardial biopsies when available.

Antibodies, Viral↗

Severity of respiratory syncytial virus disease related to type and genotype of virus and to cytokine values in nasopharyngeal secretions.

BACKGROUND: Investigations concerning the severity of respiratory syncytial virus (RSV) disease as related to (1) RSV type and genotype determined respectively by PCR and restriction enzyme analysis and (2) interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) values in samples of nasopharyngeal secretion (NPS) have not been previously reported. METHODS: We prospectively studied 105 RSV infections in the lower respiratory tract of infants and young children admitted to a pediatric department in Copenhagen during three winter seasons, 1993, 1994 and 1995. RSV strains were typed and genotyped, respectively, by PCR and nucleic acid restriction analysis and correlated to the severity of the disease. The ratio IL-6:TNF-alpha, determined from IL-6- and TNF-alpha values in samples of NPS, was related to the severity of the disease. Concentrations of IL-6 and of TNF-alpha were determined in serum samples taken during 5 weeks after the onset of illness. RESULTS: Type B infections produced more severe disease than did type A infections, as assessed on the length of the hospital stay, use of respiratory support and the presence of an infiltrate on a chest radiograph. This difference was age-related. It was observed in infants 0 to 5 months old, but not in older age groups. Type B genotype B1122 produced more severe disease than type A genotype A2311 in infants 0 to 11 months old. Increased serum concentrations of IL-6 and TNF-alpha were detected in samples taken 1 to 2 days after the onset of illness. Whereas TNF-alpha serum concentrations remained high, IL-6 serum concentrations decreased during the following 3 to 4 weeks. The IL-6:TNF-alpha ratio in samples of NPS was related to the severity of the disease. A high ratio was related to a low severity. CONCLUSIONS: The severity of disease in patients admitted with acute RSV infections can be correlated to the RSV type as determined by PCR, to the RSV genotype as determined by nucleic acid restriction analysis and to the ratio IL-6:TNF-alpha in NPS.

Child, Preschool↗

Restriction pattern variability of respiratory syncytial virus during three consecutive epidemics in Denmark.

A PCR-based assay was used to distinguish between respiratory syncytial virus (RSV) group A and B in order to analyze their prevalence in Denmark in three consecutive epidemics during the winters of 1992/93, 1993/94 and 1994/95. A total of 96 RSV strains isolated from hospitalized children were examined, showing alternation of group prevalence. Furthermore, the genetic variability of the RSV isolates was illustrated by restriction enzyme analysis of PCR products originating from a part of the F and G proteins that has been reported to be highly variable. We found that, in general, different genome types predominated each year, some types being present in consecutive epidemics, indicating a contribution of strains circulating unattended between outbreak seasons, while others seemed to disappear or became undetectable, being replaced by emerging types. Some of the genome types found seemed related to strains isolated up to more than two decades ago in other parts of the world. This indicates that the temporal fluctuation in predominance of genome types presumably caused by selective pressure exerted by host immunity is due to the favoring of strains from a pool of globally circulating, genetically relatively stable genome types, rather than a molecular evolution in strains induced or directed by immunoselective pressure.

Animals↗

Parvovirus B19 infection infrequently involved in children and adults with myelodysplastic syndrome.

Parvovirus B19 infection has occasionally been reported to mimic myelodysplastic syndrome (MDS) or to cause worsening of anemia in MDS. We examined the presence of parvovirus DNA in a series of children (n=19) and adults (n=39) with a diagnosis of MDS. The series of adults included only refractory anemia (RA) and RA with ring sideroblasts (RARS). Investigation for parvovirus B19 DNA in bone marrow cells was performed employing the nested form of the polymerase chain reaction (PCR). Only a 51-year-old male with RA tested positive for parvovirus DNA. Serial examinations demonstrated the disappearance of parvovirus DNA from the bone marrow. We conclude that parvovirus infection may only rarely mimic MDS or be a superimposed infection in childhood MDS or in RA and RARS in adults.

Adolescent↗

High rate of nasopharyngeal carriage of potential pathogens among children in Greenland: results of a clinical survey of middle-ear disease.

Nasopharyngeal and middle-ear colonization with bacteria and viruses, including Mycoplasma pneumoniae and chlamydiae, was investigated in a survey of 54 children with acute otitis media (AOM) and 201 control children without AOM in Greenland. In total, 98% with AOM and 91% without AOM carried potentially pathogenic bacteria in the nasopharynx. Two or more potentially pathogenic species were carried by 78% with AOM and 57% without AOM. Haemophilus influenzae was found in 92% and 77%, respectively, but only Streptococcus pneumoniae was found significantly more often in the nasopharynx of children with AOM than in age-matched controls (P < .03). The two species were found in 22 of 24 ear-discharge specimens. Nine children (three with AOM) had chlamydiae in the nasopharynx, and seven of them reported rhinitis. Enteroviruses or rhinoviruses were detected in 23 nasopharyngeal specimens from 39 children with AOM, in 13 such specimens from 39 children without AOM (P = .040), and in 4 of 14 ear-discharge specimens. The potentially pathogenic load in the nasopharynx was massive, suggesting an association with the high prevalence of otitis media among children in Greenland.

Bacterial Infections↗

Parvovirus B19 infection and Diamond-Blackfan anaemia.

It is the purpose of the study to report the frequency of parvovirus in children with a diagnosis of Diamond-Blackfan anaemia and to discuss the possible aetiological role of parvovirus in Diamond-Blackfan anaemia. We found parvovirus DNA in 3 of 11 bone marrow smears. Giant pronormoblasts showed low sensitivity (33%) and poor specificity (75%). The presence of giant pronormoblasts was associated with a very high myeloid:erythroid ratio, and may not be specific for parvovirus infection, but a feature of severely suppressed erythropoiesis. The three parvovirus-positive patients were the only children who experienced a remission, and who are free of medication. The seven surviving parvovirus-negative patients are all currently on steroid treatment.

Bone Marrow↗

Parvovirus: the expanding spectrum of disease.

Treatment of parvovirus infections among immunocompromised hosts using immunoglobulin has provided the clinician with a useful therapeutic tool but has also highlighted the problems concerning chronic disease states. The discovery of the human parvovirus B19 in 1975 and subsequent studies of its effects in humans have identified this virus as the causative agent of a broad spectrum of diseases. Recent improvements regarding the development of sensitive PCR techniques and methods for cultivation have provided new insight into its pathogenic role, its virology and immunology, and the varied clinical manifestations. The current state of knowledge concerning parvovirus enabled us to divide the long list of diseases caused by this virus into three main categories: (1) disease found among normal hosts (asymptomatic disease, erythema infectiosum, arthropathy, hydrops fetalis), (2) hematologic diseases (aplastic crisis, chronic anemia, idiopathic thrombocytopenic purpura, transient erythroblastopenia of childhood, Diamond-Blackfan anemia) and, finally, (3) a heterogeneous group of diseases, in which the etiologic role of parvovirus is less clear and sometimes putative (neurologic disease, rheumatologic disease, vasculitic and myocarditic syndromes). In particular, arthropathy, hydrops fetalis and the hematologic disorders may be of pediatric concern. Consequently, it is of paramount importance that in all of these cases the clinician includes parvovirus as a differential diagnosis.

Erythema Infectiosum↗

Parvovirus B19 infection associated with encephalitis in a patient suffering from malignant lymphoma.

A parvovirus B19 infection was established in a 58-year-old woman undergoing treatment for malignant lymphoma. Clinically, the patient displayed a variety of neurologic symptoms that could not readily be explained by the mere presence of lymphoblastic cells within the central nervous system. This is the first time parvovirus B19 DNA has been detected in the cerebrospinal fluid of a patient suffering from encephalitis.

Acute Disease↗

Chronic parvovirus infection mimicking myelodysplastic syndrome in a child with subclinical immunodeficiency.

PURPOSE: We present a report of a child with subclinical immunodeficiency who became chronically infected with parvovirus resulting in pancytopenia and morphologic abnormalities in the bone marrow mimicking myelodysplastic syndrome (MDS). PATIENTS: An 8-year-old boy presented with severe anemia, moderate thrombocytopenia and granulocytopenia. The patient showed hyper-immunoglobulin M (IgM) immunodeficiency but no increased susceptibility to infections. The bone marrow was hypercellular with dysplastic granulocytopoiesis and erythroblastopenia. RESULTS: Treatment with cyclosporine and i.v. Ig resulted in temporary normalization of the hemoglobin level. For several years it was assumed that the patient had MDS. A diagnosis of parvovirus infection was initially rejected due to the lack of specific antibodies and the absence of giant pronormoblasts in the bone marrow. When the polymerase chain reaction technique became available, parvovirus DNA was detected from the entire disease course. CONCLUSIONS: This case report expands our conception of the clinical spectrum of parvovirus infection and emphasizes that parvovirus must be considered as a differential diagnosis in MDS. We recommend performing a parvovirus DNA test despite negative serologic findings in patients with MDS, especially when associated with immunologic abnormalities.

Child↗

Recurrent aphthous ulceration: a possible clinical manifestation of reactivation of varicella zoster or cytomegalovirus infection.

The etiology of the most common intraoral mucosal disease, recurrent aphthous ulceration (RAU), remains obscure. Here, attempts were made to diagnose reactivation of varicella zoster (VZV), cytomegalovirus (CMV), Epstein-Barr (EBV) and human hepes virus 6 (HHV-6) infections from paired sera in association with RAU recurrences. The first sample was obtained within 3 days after a new recurrence (1) and the second 10-14 days later (2). The study initially comprised 18 otherwise healthy RAU patients (gr A) and 17 sex- and age-matched healthy non-RAU individuals. Values of specific antibody subclasses (IgM, IgG, IgA) were determined by ELISA (VZV, CMV, EBV) and IFA (HHV-6). Patients and controls exhibited differences in parameters on specific VZV IgM and CMV IgM. In order to substantiate these findings, specific VZV IgM and CMV IgM were subsequently also evaluated in 17 other RAU patients (gr B). Ten patients in gr A and 11 in gr B were IgM seropositive for either VZV and/or CMV in at least one of the serum samples, whereas in the controls only one was VZV IgM positive and none CMV IgM positive. Evaluated as groups, optometric density (OD) antibody levels of VZV IgM were significantly higher in the patients (gr A (1,2) vs controls: p < 0.0001; gr B (1,2) vs controls: p < 0.001). CMV OD IgM antibody values were significantly higher in gr B only (1,2 vs controls: p < 0.01). The study lends support for reactivation of VZV and/or CMV infection associated with RAU recurrences.

Adolescent↗