Mucorales spores induce a proinflammatory cytokine response in human mononuclear phagocytes and harbor no rodlet hydrophobins

Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and Ascomycota. PBMC, monocytes, and monocyte derived dendritic cells (moDCs) from healthy donors were stimulated with resting and germinated stages of Mucorales and Ascomycota. Cytokine response and expression of activation markers were studied. Both inactivated germ tubes and resting spores of Rhizopus arrhizus and other human pathogenic Mucorales species significantly stimulated mRNA synthesis and secretion of proinflammatory cytokines. Moreover, R. arrhizus spores induced the upregulation of co-stimulatory molecules on moDCs and a specific T-helper cell response. Removal of rodlet hydrophobins by hydrofluoric acid treatment of A. fumigatus conidia resulted in enhanced immunogenicity, whereas the cytokine response of PBMCs to dormant R. arrhizus spores was not influenced by hydrofluoric acid. Scanning electron micrographs of Mucorales spores did not exhibit any morphological correlates of rodlet hydrophobins. Taken together, this study revealed striking differences in the response of human mononuclear cells to resting stages of Ascomycota and Mucorales, which may be explained by absence of an immunoprotective hydrophobin layer in Mucorales spores.

[Hereditary hemochromatosis and diabetes mellitus: diagnostic approach and clinical evolution]

We report the characteristics of diabetes mellitus in 10 patients with a suspicion of hereditary hemochromatosis. The results of this personal series were compared to literature's data described in a recent article. Early diagnosis and treatment by phlebotomy can improve blood glucose control in the early stages of the disease. If diagnosis occurs later, when the patient already needs insulin therapy, diabetes will not be improved by phlebotomy anymore.

[Hemochromatosis: the most common of rare diseases]

Familial (hereditary) haemochromatosis (HH) is an iron storage disorder characterized by an increased intestinal absorption of iron and its accumulation in numerous tissues. The disease generates an iron overload with tissue damages also seen in haematologic disturbances (with dyserythropoiesis and haemolysis) and hepatic disorders. Besides typical mutations linked to HH (C282 Y and H63D, HFE locus), three other mutations have been identified and more have to be defined. A complete genetic testing is important to assess the risk of morbidity. Indeed, the clinical picture of HH is dependent upon the specific mutations as well as the individual context (sex, environment, associated hepatic and/or haematologic disorders). Porphyria cutanea tarda (PCT) has for long been found significantly associated with HH. It is now considered that hepatic iron overload related to the combination of heterogeneous genetic traits and environmental factors, including alcoholism and viral hepatitis, precipitates the expression of PCT through the inhibition of uroporphyrinogen decarboxylase (Uro.D).

[Hematochromatosis and diabetes]

Nowadays, haemochromatosis is often diagnosed when the patient is monosymptomatic. Diabetes is frequently the first expression of the disease. So, it is important to know the clinical and biologic characteristics to evoke diagnosis as early as possible. Uncommon presentations request systematic screening.

[Management of hyponatremia]

Hyponatremia is the most commonly encountered ionic disorder and, yet, its management remains uneasy. Inappropriate treatment of severe hyponatremia can nevertheless lead to significant neurological damage. The acute (< 48 h) or chronic (> 72 h) character of the disorder must first be determined. Acute hyponatremia is usually observed during a post-operative period and is generally associated with a neurological symptomatology. This requires prompt treatment to avoid cerebral damage. Chronic hyponatremia, on the other hand, needs a slow correction to avoid the "Osmotic Demyelinating Syndrome". In addition to the intensive care of severe hyponatremia, the actual etiology of the disorder must be sought for and therapy adapted to the underlying pathology.

[Diagnosis and etiology of hyponatremia]

The unexpected finding of hyponatremia should prompt a clinical and biological investigation to find the etiology. Hyponatremia can be the first manifestation of hyperlipemia, unknown paraproteinemia or the Schwartz-Bartter syndrome. Indeed, a quick diagnosis and appropriate treatment are often necessary to reduce morbidity.

[Mucosal immunity in elite athletes]

It is now generally accepted that strenuous exhausting exercise can increase susceptibility to viral infection during the following days or weeks. This review addresses the role of mucosal immunity in respiratory illness and associations with the intensity, volume and duration of exercise. Indeed habitual exercise at an intense level can cause suppression of mucosal immune parameters.