Adenovirus hepatitis in a patient with severe combined immunodeficiency

An autopsy case of adenovirus hepatitis with severe combined immunodeficiency (SCID) is presented. A 7-month-old female was admitted to the Kitasato University Hospital with chief complaint of persistent fever. A diagnosis of severe combined immunodeficiency (SCID) was made because of defective function in both T and B lymphocytes. Respiratory disturbance and severe hepatic dysfunction were manifested after admission. She died of respiratory failure on the 40th hospital day. Autopsy findings revealed many focal necroses scattered irregularly throughout the liver. Degenerating hepatocytes around the focal necrosis contained nuclear inclusion bodies, and crystalline arrays of adenovirus virions were recognized in these cells by electron microscopy. Adenovirus antigens were brilliantly detected in the nuclear inclusion bodies by indirect immunofluorescence.     

Clinical significance of sequestration in adults with severe malaria

Reduced microcirculatory flow is a fundamental feature in the pathophysiology of severe Plasmodium falciparum malaria and sequestration of red blood cells containing mature parasites is considered a central cause of this. Direct microscopic observation of the microcirculation in the living patient with severe malaria has enabled us to quantify this phenomenon and link it to severity of disease, supporting the findings of pathology studies. Moreover, the sequestered parasite biomass, calculated from parasite derived plasma PfHRP2 concentrations, strongly correlates with disease severity. Artesunate prevents sequestration by killing ring form parasites, aborting their maturation, which can explain the mortality benefit of this drug compared to quinine in the treatment of adult severe malaria. Levamisole is currently tried as adjunctive treatment in severe malaria targeting sequestration.     

Association of a new mannose-binding lectin variant with severe malaria in Gabonese children

Mannose-binding lectin (MBL2) variants that decrease the plasma level of the protein or encode dysfunctional proteins are frequently associated with the severity of a number of infections and autoimmune disorders. The high frequencies of these variants in most populations of the world are probably maintained by some selective advantage against widespread diseases. We found 14 new MBL2 allelic haplotypes, two of them with non-synonymous variants, by screening 136 children with uncomplicated malaria, 131 children with severe malaria and 39 older healthy schoolchildren. We also found a significant association of a novel variant with susceptibility to severe malaria (P=0.010). Increased MBL plasma levels and corresponding MBL2 genotypes were associated with lower concentration of several cytokines and chemokines in plasma of malaria patients. We suggest that malaria could have been one of the evolutionary driving forces shaping the MBL2 polymorphism in the African population.     

Trisomy 1q in a patient with severe aplastic anemia

Aplastic anemia is a rare, serious disease characterized by hypocellular bone marrow and pancytopenia in the peripheral blood. Most cases are acquired, idiopathic, and without gross cytogenetic abnormalities. A few chromosome abnormalities have recurred among a small subset of patients, most commonly trisomy 8 and monosomy 7. Some of these chromosome abnormalities have prognostic and therapeutic significance, although for most the clinical relevance is not known. We present the case of a 40-year-old man with idiopathic severe aplastic anemia in bone marrow cells with trisomy of the whole long arm of chromosome 1 due to an unbalanced translocation between chromosomes 1 and 15 at breakpoints of q10 and 15q10. This clonal abnormality (which, to our knowledge, has not been previously reported in a patient with aplastic anemia) suggests that genes on 1q may be involved in marrow aplasia.     

Artifactually low glycated haemoglobin in a patient with severe hypertriglyceridaemia

This report describes a case of artifactually low glycated haemoglobin (Hb) in a patient with type II diabetes and severe hypertriglyceridaemia. The effect of hypertriglyceridaemia on glycated Hb determination using the Abbott Vision method was investigated in a series of patients with diabetes. The interference of triglycerides in glycated Hb assays was also investigated by two other methods, the Beckman Synchron CX4 delta immunoturbidimetric method, and the Primus affinity chromatography high performance liquid chromatography assay.     

Strongyloides stercoralis infestation in a patient with severe ulcerative colitis

Asymptomatic infestation with Strongyloides stercoralis, common in the tropics, may result in potentially fatal hyperinfection during treatment with immunosuppressive drugs used to treat patients with severe ulcerative colitis (UC). Hence, importance of early recognition and treatment of this nematode in patients with UC before starting immunosuppressive drugs can not be overemphasized. We report a 23-yrs old man with UC who presented with acute severe attack. Since his UC did not respond to intravenous hydrocortisone over 6 days, oral cyclosporine was started on 7th day after repeating stool microscopy, which revealed larvae of Strongyloides stercoralis. Duodenal aspirate also confirmed presence of multiple larvae. He responded to treatment for Strongyloides stercoralis , continuation of hydrocortisone and cyclosporine. Importance of early diagnosis of infestation with Strongyloides stercoralis while on treatment with immunosuppressive drugs for severe UC is emphasized. Difficulties in diagnosis and management of Strongyloides stercoralis infestation in patients with UC are discussed.     

Plasmapheresis in a patient with severe asthma associated with auto-antibodies to platelets

Although the pathogenesis of aspirin-sensitive asthma remains to be specified, it is known that in the presence of acetylsalicylic acid or non-steroidal anti-inflammatory drugs, platelets from aspirin-sensitive asthmatics have been described as generating cytocidal mediators that killed parasite targets such as Schistosoma mansoni larvae. Here we report, in a patient with corticosteroid-dependent asthma associated with aspirin sensitivity, the presence of circulating IgE antibodies against 55 kD and 68 kD platelet antigens. In addition, the serum from this patient was shown to contain a factor able to trigger the release of cytocidal mediators from his platelets as well as from normal individual platelets. This platelet stimulatory activity was presumably supported by IgE antibodies or immune complexes. After informed consent the patient was submitted to plasma exchanges. Plasma removal induced clinical improvement, anti-platelet antibody decrease, and the reduction of the platelet stimulatory activity. All clinical symptoms disappeared within 2 weeks. The disease remained quiescent for 2 months, and daily requirements for prednisone (20-5 mg), and beta-agonist (10-16 to 0-1 inhalations) could be kept at a low level follow-up. The plasma exchanges were delayed by 3 mg kg-1 azathioprine with the maintenance of clinical improvement. A relapse occurred after the arrest of immunosuppressive therapy with the reappearance of both asthma attacks and anti-platelet antibodies, as well as the increase of the platelet stimulatory activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bacteremia caused byLeuconostoc cremoris in a patient with severe burn injuries

A case ofLeuconostoc cremoris bacteremia in a patient with burn wounds over 45% of the body surface is presented.Leuconostoc bacteremia has not previously been reported in burn patients. The predisposing factors in this case were severe burn wounds resulting in immunocompromise, presence of both intravenous and enterai feeding catheters, several surgical interventions and previous treatment with imipenem plus amikacin. The patient was successfully treated with ampicillin 2 g i.v. every 6 hours for 21 days. Infection withLeuconostoc should be suspected when vancomycinresistant organisms resembling streptococci are isolated.     

Monoclonal immunoglobulin-secreting lymphoma in a patient with severe combined immunodeficiency disease

A 3.5 year old boy with X-linked severe combined immunodeficiency disease (SCID), who had been in laminar flow isolation throughout his life, developed a B cell tumour producing up to 3008 mg/dl of an IgM kappa paraprotein 1 month after infusion of both liver and thymus cells from a fetal donor and 6 months after the last of six fetal liver cell infusions given over a 3 year period. Pretransplant studies revealed a high percentage of circulating B lymphocytes. HLA typing suggests that the tumour was of host origin.     

Defective membrane function in a patient with severe combined immunodeficiency disease

We report a girl with severe combined immunodeficiency with functional impairment of both humoral and cellular immunity despite normal numbers of B and T lymphocytes. Immunologic studies revealed hypergammaglobulinaemia, absent migratory response by polymorphonuclear leucocytes to chemoattractants, and diminished lymphocyte proliferative responses to mitogens, antigens and allogeneic leucocytes. However, stimulation of the patient's mononuclear leucocytes with the calcium ionophore, A23187, resulted in a normal proliferative response. We therefore postulate a membrane defect as the basis for immunologic dysfunction in this child.     

Molecular aspects of severe malaria

Human infections with Plasmodium falciparum may result in severe forms of malaria. The widespread and rapid development of drug resistance in P. falciparum and the resistance of the disease-transmitting mosquitoes to insecticides make it urgent to understand the molecular background of the pathogenesis of malaria to enable the development of novel approaches to combat the disease. This review focuses on the molecular mechanisms of severe malaria caused by the P. falciparum parasite. The nature of severe malaria and the deleterious effects of parasite-derived toxins and host-induced cytokines are introduced. Sequestration, brought about by cytoadherence and rosetting, is linked to severe malaria and is mediated by multiple receptors on the endothelium and red blood cells. P. falciparum erythrocyte membrane protein 1 (PfEMP1) is the ligand responsible for a majority of binding interactions, and the multiply adhesive features of this sticky molecule are presented. Antigenic variation is also a major feature of PfEMP1 and of the surface of the P. falciparum-infected erythrocyte. Possible mechanisms of P. falciparum antigenic variation in asexual stages are further discussed. We conclude this review with a perspective and suggestions of important aspects for future investigations.     

Management of severe falciparum malaria

Plasmodium falciparum is the most common cause of severe and life-threatening malaria. Falciparum malaria causes over one million deaths every year. In Africa, a vast majority of these deaths occur in children under five years of age. The presentation of severe malaria varies with age and geographical distribution. The mortality rate is higher in adults than in children but African children develop neuro-cognitive sequelae following severe malaria more frequently. The management of severe malaria includes prompt administration of appropriate parenteral anti-malarial agents and early recognition and treatment of the complications. In children, the complications include metabolic acidosis (often caused by hypovolaemia), hypoglycaemia, hyperlacticacidaemia, severe anaemia, seizures and raised intracranial pressure. In adults, renal failure and pulmonary oedema are more common causes of death. In contrast, concomitant bacterial infections occur more frequently in children and are associated with mortality in children. Admission to critical or intensive care units may help reduce the mortality, and the frequency and severity of sequelae related to severe malaria.     

CD40L association with protection from severe malaria

CD40 ligand (CD40L), a glycoprotein involved in B cell proliferation, antigen presenting cell activation, and Ig class switching, is important in the immune response to infection. Rare coding mutations in CD40L can lead to life-threatening immunodeficiency but the potential for common variants to alter disease susceptibility remains to be explored. To identify polymorphisms in CD40L, we sequenced 2.3 kb of the 5' flanking region and the first exon of the gene in DNA samples from 36 Gambian females and one chimpanzee. Diversity was lower than the average reported for other areas of the X chromosome, and only two polymorphisms were identified. The polymorphisms were genotyped in DNA samples from 957 Gambian individuals, cases and controls from a study of severe malaria. A significant reduction in risk for severe malaria (OR = 0.52, P = 0.002) was associated with males hemizygous for the CD40L-726C. Analysis by transmission disequilibrium test of 371 cases, for whom DNA from both parents was also available, confirmed the result was not due to stratification (P = 0.04). A similar but non-significant trend was found in females. This preliminary association of a common variant in CD40L with a malaria resistance phenotype encourages further genetic characterization of the role of CD40L in infectious disease.     

Analysis of IL10 haplotypic associations with severe malaria

We investigated the association between severe malaria and genetic variation of IL10 in Gambian children, as several lines of evidence indicate that IL10 is protective against severe malaria and that IL10 production is genetically determined. We began by identifying five informative SNPs in the Gambian population that were genotyped in a combined case-control and intrafamilial study including 654 cases of severe malaria, 579 sets of parents and 459 ethnically matched controls. No significant associations were identified with individual SNPs. One haplotype of frequency 0.11 was strongly associated with protection against severe malaria in the case-control analysis (odds ratio 0.52, P=0.00002), but the transmission disequilibrium test in families showed no significant effect. These findings raise the question of whether IL10 associations with severe malaria might be confounded by foetal survival rates or other sources of transmission bias.     

Abnormal lymphocyte capping in a patient with severe combined immunodeficiency disease.

Despite the presence of normal numbers and distribution of T and B lymphocutes and normal levels of serum immunoglobulins, a five-month-old infant failed to show any evidence of T-cell or B-cell immunity. In trying to identify a specific membrane abnormality as a potential cause of the immunologic dysfunction, we examined the lateral mobility of the cell-surface receptor for concanavalin A. In contrast to normal cells, in which the receptor is distributed uniformly over the cell surface, the patient's lymphocytes showed an unusually high accumulation of concanavalin A receptors in surface caps. This capping abnormality appeared in both T and B lymphocytes and was exaggerated by colchicine, an inhibitor of microtubule assembly. These findings support the theory that plasma-membrane-cytoskeleton interactions have a role in the expression of specific immunity; the findings also identify new areas that should be considered in trying to understand the primary immunodeficiency diseases.