Adrenal failure and relapse following treatment of systemic histoplasmosis

Histoplasmosis in Australia: report of 16 cases and literature review

We describe 16 previously unreported patients with histoplasmosis from Queensland and northern New South Wales, Australia, and review all previous Australian reports, providing 63 cases in total to study (17 cases of acute pulmonary histoplasmosis, 2 cases of chronic pulmonary disease, and 44 cases of systemic disease, including 17 cases of single-organ infection and 27 instances of disseminated disease). All acute pulmonary disease was acquired in Australia, with 52% of systemic disease definitely autochthonous. Most cases of single-organ disease occurred in immunocompetent patients (76%), and were oropharyngeal (53%) in location. Forty-one percent of disseminated disease occurred in patients with human immunodeficiency virus (HIV). Patients with HIV had high rates of systemic symptoms, pancytopenia, fungemia, and hepatosplenomegaly. Oropharyngeal and adrenal involvement as well as systemic symptoms were prominent in immunocompetent patients with disseminated disease, with 6 of 7 cases of adrenal involvement leading to Addison disease. Most systemic disease was diagnosed by culture of Histoplasma capsulatum. Where serology was assessed in cases other than acute pulmonary disease, it was positive in only 32%.Prognosis for patients with single-organ disease was excellent. Disseminated disease was associated with recurrence in 30% and death in 37%. The results of this study confirm several previously known patterns of disease but also provide new insights into this rare but endemic condition in Australia.

Adrenocortical tumorigenesis, luteinizing hormone receptor and transcription factors GATA-4 and GATA-6

Luteinizing hormone (LH/hCG) responsiveness of normal and pathological human adrenal glands as well as the possibility of constitutive expressions of luteinizing hormone receptor (LHR) in adrenal cortex has been reported. Some recent studies showed a correlation between the LHR and abundant GATA-4 expression in both metastasizing and non-metastasizing human adrenocortical tumors, but not in normal adrenals, implicating the putative relevance of LHR and GATA-4 for adrenocortical pathophysiology. However, the physio- and pathophysiological significance of LHR and GATA-4 in the mechanism of adrenocortical tumorigenesis remains unclear. The paucity of suitable models for adrenal tumorigenesis makes the establishment of proper animal models highly important. LHR expression in the murine adrenal gland is an exception and not found in wild-type (WT) animal. We have previously shown that ectopic LHR expression in the murine adrenal gland can be induced by chronically elevated LH levels. We have generated a gonadotropin-responsive adrenal tumor model in gonadectomized transgenic (TG) mice expressing the inhibin alpha promoter/Simian Virus 40 T antigen transgene (inhalpha/Tag). Given the induction of expression and regulation of GATA-4 and GATA-6 zinc finger transcription factors in the gonads by gonadotropins, this review will explore their relationship to LHR expression and their role in adrenocortical tumorigenesis. A functional link between LHR and GATA-4 actions in the adrenal pathophysiology is proposed.

Histoplasmosis in Australia: A report of a case with a review of the literature

Histoplasmosis is a rare but serious fungal infection commonly presenting as mucosal ulceration of the oral cavity. It is increasingly recognized in Australia but the source of infection remains obscure and it is likely to be under-diagnosed. We report a case of chronic mucosal ulceration which failed to fully respond to periodontal therapy. Histology and culture of a gingival biopsy was consistent with histoplasmosis, and the patient responded favourably to treatment with oral itraconazole. Histoplasmosis may present to general dental practitioners as chronic mucosal ulceration and should be considered in the differential diagnosis of such lesions. Diagnosis is best made by culture and histology of biopsy specimens.