Human immunodeficiency virus infection and the thyroid

Contributions of HIV infection in the hypothalamus and substance abuse/use to HPT dysregulation

Over the last two decades, consequences of HIV infection of the CNS on disease severity and clinical neuropsychiatric manifestations have changed. These changes are due, in part, to improved control of peripheral infection by new anti-retroviral medications and more efficient CNS penetration of combination anti-retroviral therapies (cART). While the life spans of HIV-infected patients have been prolonged with successful cART, the spectrum of cognitive alterations observed in these patients has broadened. Recent studies report that there does not appear to be a single prototypical pattern of neuropsychological impairment associated with HIV, but includes diverse manifestations. Some co-morbidities, such as substance abuse or depression likely play significant roles in the neuropsychiatric profiles of some HIV-infected patients. Newly recognized factors contributing to neurocognitive impairments include aging and unanticipated side effects from cART. Likewise, disturbances in neuroendocrine functioning are emerging as potentially important contributors to HIV-associated neurocognitive alterations. A retrospective review of clinical data from a small cohort of HIV-infected patients admitted to the psychiatric unit of an inner city hospital indicates that thyroid stimulating hormone levels were abnormal in 27% of the patients. Our data from analyses of post-mortem tissues from HIV patients show for the first time HIV infection of the hypothalamus and altered levels of thyroid hormone processing enzymes. Decreased vasopressin and oxytocin immunoreactivity in hypothalamic neurons was also observed. Thus, HIV infection of the CNS may contribute to changes in hypothalamic thyroid hormone signaling, thereby resulting in abnormal hypothalamic-pituitary-thyroid axis feedback and neuropsychiatric dysfunction.

Subclinical hypothyroidism in a patient affected by advanced AIDS and visceral leishmaniasis

Hypothyroidism has been shown to occur in HIV disease. Thyroid function of patients affected by AIDS and leishmaniasis is unknown. Here we report the case of an AIDS advanced patient developing hypothyroidism during leishmaniasis. The thyroid disorder might have been caused by infiltration of the gland by Leishmania. An additive impact of HIV in thyroid function impairment is suggested.

No association between HIV disease and its treatment and thyroid function

OBJECTIVES

The aims of the study were (i) to investigate the prevalence of overt and subclinical thyroid disease in HIV-positive patients in a London teaching hospital; (ii) to determine risk factors associated with the development of thyroid dysfunction, including highly active antiretroviral therapy (HAART) and individual antivirals, and (iii) to determine the occurrence of thyroid dysfunction longitudinally over 3 years.

METHODS

The study consisted of retrospective analyses of thyroid function tests (TFT) in HIV-positive patients. The period prevalence of and factors associated with clinical and subclinical thyroid dysfunction were investigated. Patients with normal TFT but previous thyroid disease were identified from pharmacy records and included in the overt category.

RESULTS

A total of 1565 patients (73% of the clinic population) had at least one TFT taken since 2001. Overall, 3584 samples were analysed. Of the patients included in the study, 1233 (79%) were male, 1043 (66%) were white and 365 (23%) were black African, and in 969 (62%) the main risk for HIV was homosexual sex. Median age at baseline was 37 years. Nine hundred patients (58%) were on HAART at the start of the study. Thirty-nine (2.5%) were found to have overt hypothyroidism, and eight (<1%) had overt hyperthyroidism. Sixty-one (4%) had subclinical hypothyroidism, five (<1%) had subclinical hyperthyroidism and 263 (17%) had a nonthyroidal illness. A normal TFT was obtained for 1118 patients (75.5%). Multivariate analysis suggested that no independent variables were significantly associated with overt hypothyroidism, including HAART and stavudine use specifically. Repeated measurements over 3 years were available for 825 patients and only eight new cases (1%) of overt thyroid disease occurred.

CONCLUSIONS

The prevalence of overt thyroid disease was low in this cohort, suggesting that screening is not warranted.

Assessment of the factors involving in the development of hypothyroidism in HIV-infected patients: a case-control study

OBJECTIVES

Increased prevalence of thyroid dysfunction has been reported in HIV-infected patients, and recent studies have shown hypothyroidism as the most common thyroid function abnormality in this population, especially after treatment with antiretroviral drugs (HAART). The aim of this study is to assess risk factors of hypothyroidism in HIV-infected patients in Iran.

DESIGN

This case-control study was conducted among 15 hypothyroid (cases) and 70 euthyroid (control group) HIV-infected outpatients. Serum Free T4, Free T3, and TSH levels were measured, and data on age, sex, body mass index, opium addiction or injection of illicit drugs, duration of HIV infection and HAART, disease stage, CD4-cell count, opportunistic infection (OI) or malignancy, HCV co-infection, and drug use were collected.

RESULTS

We found no association between hypothyroidism in HIV-infected patients and any parameters measured, and P value was not significant for receipt of HAART (0.141), CD4-cell count (0.094), duration of HIV infection (0.474), duration of HAART (0.418), HCV co-infection (0.146), OI (0.566), or receipt of rifampin (0.816).

CONCLUSION

In this study, age, sex, HAART, mean CD4- cell count, duration of HIV infection, HCV co-infection, and OI were not significant risk factors of hypothyroidism in HIV-infected patients. The occurrence of hypothyroidism may be related to other factors or HIV infection itself. Therefore, hypothyroidism should be considered in all HIV-infected patients.