Subclinical Hypothyroidism in HIV-Infected Patients Is Not an Autoimmune Disease

Histopathological changes in Oreochromis mossambicus (Peters, 1852) ovaries after a chronic exposure to a mixture of the HIV drug nevirapine and the antibiotics sulfamethoxazole and trimethoprim

The burden of the human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) infection has transformed the African continent into a major consumer of antiretrovirals (ARVs) drugs. In addition to HIV burden, the African continent has also a high incidence of tuberculosis (TB) and has been experiencing recurring outbreaks of several other viral, bacterial, and parasitic epidemic diseases. The novel severe acute respiratory syndrome coronavirus 2 (SARS-COV-2 or Covid-19) pandemic outbreak is adding to the continent's infectious diseases burden as experts are predicting that it will be here for a long time. One of the consequences of these infectious diseases is that antiviral and antibiotic compounds have become some of the most consumed pharmaceuticals on the continent. Many of these drugs have been frequently detected in surface waters across Africa. There is limited information available on the adverse effects of the mixtures of different types of pharmaceuticals in African aquatic environments on fish reproduction. The present study investigated the effects of the ARV drug nevirapine (NVP - 1.48 and 3.74 μg/L) and its mixture with the antibiotic sulfamethoxazole (3.68 μg/L) and trimethoprim (0.87 μg/L) on O. mossambicus gonads using histopathological endpoints as biomarkers. The fish (n = 52) were exposed for 30 days in a static renewal system. Female O. mossambicus exposed to nevirapine (3.74 μg/L) and to NVP - antibiotic mixture recorded higher ovary indices. Statistically significant differences were found in female ovary indices between the fish exposed to NVP (3.74 μg/L) and the control fish (p = 0.002) as well as between the fish exposed to the NVP - antibiotic mixture and the control fish (p = 0.009). The main observed histopathological changes in the ovaries were increased vitellogenic oocyte atresia and vacuolation of the interstitial tissue in the fish exposed to NVP - antibiotic mixture. It is evident that the presence of NVP - antibiotics mixture in water triggered the observed histopathology in female fish ovaries. The detected abnormal high rate of atretic oocytes could result in impaired fish reproduction.

Low prevalence of symptomatic thyroid diseases and thyroid cancers in HIV-infected patients

Thyroid diseases (TDs) have been widely associated with HIV infection. However, data about TDs prevalence and distribution are controversial, and few published studies are available. The aim of our study was to assess prevalence and risk factors of symptomatic thyroid disturbances, including thyroid cancers, in a large cohort of HIV-infected patients. A retrospective cohort study was performed at the Department of Infectious and Tropical Diseases of the University of Brescia, Italy, in the period 2005–2017. We identified all HIV-positive patients with a diagnosis of symptomatic TD in the electronic database of our Department (HIVeDB); we also operated a record-linkage between our data and the Health Protection Agency database (HPADB) of Brescia Province. Multivariate logistic regression analysis was used to determine risk factors associated with TDs onset; an incidence rate analysis was also performed. During the study period, 6343 HIV-infected patients have been followed at our Department; 123 received a diagnosis of symptomatic TD (1.94% of the entire cohort). In the TDs group, almost half of patients were females (n = 59, 48%), mean age was 47.15 years (SD: 11.56). At TD diagnosis, mean T CD4+ cell count was 491 cell/uL and most patients showed undetectable HIV-RNA (n = 117, 95.12%). Among them, 81 patients were found to have hypothyroidism (63 with Hashimoto’s thyroiditis), 21 hyperthyroidism (17 suffered from Graves’ disease), while 11 subjects were diagnosed with a primitive thyroid cancer. Papillary thyroid cancer was the most frequent histotype (n = 7, 63.63%), followed by medullary (n = 2, 18.18%) and follicular thyroid cancer (n = 1, 9.1%). Male gender was a protective factor for TDs development, especially for hypothyroidism (p < 0.001); age emerged as a variable associated with both hypothyroidism (p = 0.03) and thyroid cancer (p = 0.03), while CD4+ cell nadir <200 cell/mm³ was associated with symptomatic hyperthyroidism (p = 0.005). To conclude, symptomatic thyroid dysfunctions rate in well-treated HIV-infected patients is low. Age and gender are crucial elements in the onset of thyroid abnormalities, together with T CD4+ cell nadir. Interestingly, medullary thyroid cancer seems to be much more frequent in HIV-infected patients compared to the general population.

Asymptomatic thyroid dysfunction in human immunodeficiency virus-1-infected subjects

BACKGROUND:

Thyroid hormone abnormalities have been reported elsewhere in human immunodeficiency virus-1 (HIV-1)-infected individuals, but such studies in Nigerians are scarce in literature.

OBJECTIVE:

To evaluate thyroid function in HIV-1-infected individuals and to correlate thyroid function parameters with cluster of differentiation (CD4⁺) cell count.

MATERIALS AND METHODS:

Total thyroxine (T4), total triiodothyronine (T3), thyroid-stimulating hormone (TSH), and CD4⁺ were estimated in 100 HIV-1-positive individuals on highly active antiretroviral therapy (HAART), 100 HIV-1-positive HAART naïve, and 100 HIV-1-negative controls. The mean values were compared between the groups, and CD4⁺ cell count was correlated with measured thyroid hormones.

RESULTS:

Thyroid function abnormalities were seen in 52 HIV-1-positive individuals on HAART and 56 individuals without HAART treatment. The pattern of thyroid hormone abnormalities is similar in both groups. Among the individuals on HAART, 10 had subclinical hypothyroid, 42 sick euthyroid, and 48 had normal thyroid hormones levels. Similarly, among those without HAART therapy, seven had subclinical hypothyroid, 49 sick euthyroid, and 44 had normal thyroid hormones levels. The HIV-1-positive individuals had significantly lower (P < 0.001) CD4⁺ cell count, TSH (P < 0.05), T3 (P < 0.01), and T4 (P < 0.001) when compared with controls. On the other hand, HIV-1-positive individuals on HAART had significantly higher (P < 0.01) CD4⁺ cell count and lower (P < 0.05) T4 levels than the HAART naïve group. CD4⁺ correlated positively with T4 in HIV-1-positive individuals on HAART (r = 0.26; P = 0.016) and HAART naïve (r = 0.218; P = 0.038). There was no significant correlation between CD4⁺ and measured thyroid hormones in the control individuals.

CONCLUSION:

Asymptomatic thyroid hormone abnormalities are common in HIV-infected individuals, and these abnormalities are independent of whether the individuals were on HAART or without HAART treatment.

Prevalence and Influencing Factors of Thyroid Dysfunction in HIV-Infected Patients

Thyroid dysfunction is more common in human immunodeficiency virus (HIV) patients. But the effects of highly active antiretroviral therapy (HAART) and hepatitis B/C virus (HBV/HCV) coinfection on thyroid function is unclear. We retrospectively reviewed the data of 178 HIV patients and determined the prevalence of thyroid dysfunction and the relationship between thyroid hormone levels, CD4 cell count, HIV-1 duration, HAART duration/regimens, and HBV/HCV coinfection. Of the 178 patients, 59 (33.1%) had thyroid dysfunction, mostly hypothyroidism. Thyroid dysfunction was significantly more frequent in the HAART group (41/104, 39.4%) than in the HAART-naïve group (18/74, 24.3%; P < 0.05). The mean CD4 cell count was significantly lower in patients with hypothyroidism (372 ± 331/μL) than in the other patients (P < 0.05). The FT4 level was significantly lower in the HAART group than in the HAART-naïve group (1.09 ± 0.23 versus 1.20 ± 0.29 pg/mL, P < 0.05). FT3/FT4 levels were negatively related to HIV duration and FT3 levels were positively related to CD4 cell (P < 0.05). HBV patients had lower FT3 levels, while HCV patients had higher FT3 and FT4 levels (P < 0.05). Thyroid dysfunction is more common in HIV patients on HAART, mainly manifested as hypothyroidism. FT3/FT4 levels are correlated with HIV progression. HBV/HCV coinfection increases the probability of thyroid dysfunction.

Prevalence and Predictors of Thyroid Dysfunction in Patients with HIV Infection and Acquired Immunodeficiency Syndrome: An Indian Perspective

Background. Predictors of thyroid dysfunction in HIV are not well determined. This study aimed to determine the prevalence and predictors of thyroid dysfunction in HIV infected Indians. Methods. Consecutive HIV patients, 18-70 years of age, without any severe comorbid state, having at least 1-year follow-up at the antiretroviral therapy clinic, underwent clinical assessment and hormone assays. Results. From initially screened 527 patients, 359 patients (61.44 ± 39.42 months' disease duration), having good immune function [CD4 count >200 cell/mm(3): 90.25%; highly active antiretroviral therapy (HAART): 88.58%], were analyzed. Subclinical hypothyroidism (ScH) was the commonest thyroid dysfunction (14.76%) followed by sick euthyroid syndrome (SES) (5.29%) and isolated low TSH (3.1%). Anti-TPO antibody (TPOAb) was positive in 3.90%. Baseline CD4 count had inverse correlation with TPOAb after adjusting for age and body mass index. Stepwise linear regression revealed baseline CD4 count, TPOAb, and tuberculosis to be best predictors of ScH after adjusting for age, weight, duration of HIV, and history of opportunistic fungal and viral infections. Conclusion. Burden of thyroid dysfunction in chronic HIV infection with stable immune function is lower compared to pre-HAART era. Thyroid dysfunction is primarily of nonautoimmune origin, predominantly ScH. Severe immunodeficiency at disease onset, TPOAb positivity, and tuberculosis were best predictors of ScH.

Thyroid screening in HIV-infected patients with antiretroviral therapy

BACKGROUND

The literature reports an increased incidence of thyroid disorders in human immunodeficiency virus (HIV)-positive persons. We therefore retrospectively analyzed the strategy of collecting thyroid parameters on a routine basis.

METHODS

Overall 410 patients (147 women, 263 men; age, 10-74 years; median age, 45 years) were included. For screening purposes, three parameters were determined; basal thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3). Descriptive and statistical analyses were performed in the patient groups with increased bTSH (> 4.0 µU/ml) and with decreased fT4 (< 8.9 pg/ml) to evaluate possible correlation with age, gender, duration of antiretroviral therapy (ART), substance classes of ART (nucleosidal reverse transcriptase inhibitors (NRTIs), nonnucleosidal reverse transcriptase inhibitors, and protease inhibitors (PIs)), Centers for Disease Control and Prevention (CDC) disease stage, lowest number of CD4 cells during course of disease, and coexistent hepatitis C.

RESULTS

Elevated bTSH was found in 27 patients (median, 5.26 µU/ml), who also showed a correlation with ART duration and NRTI use. Decreased fT4 was seen in 53 persons, and a correlation with PI intake was observed. Of these patients, 31 exhibited normalization in follow-up. Decreased fT3 was observed in eight cases related to nonthyroid illness, and fT3 was elevated in ten patients. No overt hyperthyroidism was noticed; three cases of subclinical hyperthyroidism were transient.

CONCLUSIONS

In the examined group of patients, the prevalence of abnormal thyroidal parameters was 23 %. Decreased fT4, which does not require therapy, was observed most frequently (12 %) and correlated with PI use. On the other hand, elevated bTSH (6 %) correlated with ART duration and NRTI use. In mild subclinical hypothyroidism as observed in this patient population, thyroxine medication is not indicated in principle. Annual TSH screening is probably sufficient in HIV-infected patients with no clinical symptoms suggestive for thyroid disease.

Thyroid dysfunction in human immunodeficiency virus-infected children and its correlation with CD4(+) T lymphocyte count

CONTEXT

Thyroid dysfunction has been reported in human immunodeficiency virus (HIV)-infected individuals including children. Some studies have reported that thyroid dysfunction may be a marker of severity or progression of HIV.

AIMS

The aim was to study thyroid function in HIV-infected children with and without highly active anti-retroviral therapy (HAART).

SETTINGS AND DESIGN

Cross-sectional study carried out at a teaching hospital with Anti-Retroviral Therapy Centre (Centre of Excellence) of National AIDS Control Organization.

SUBJECTS AND METHODS

Thyroid stimulating hormone (TSH), total thyroxine (T4), and total tri-iodothyronine (T3) were analyzed in 60 pediatric HIV cases: 30 on HAART and 30 HAART naive. Correlation of T3, T4, and TSH with CD4 count was assessed.

STATISTICAL ANALYSIS USED

Data reported as mean ± standard deviation and as the number of cases and percentages. Comparison between groups was done by independent sample t-test and χ(2)-test. Spearman's correlation coefficient is used to assess the association between thyroid dysfunction and CD4 count.

RESULTS

Thyroid function abnormality was seen in five out of 30 patients in both patients on HAART or without HAART therapy. Among patients on HAART, three had hypothyroidism, and two had biochemical feature of sick euthyroid syndrome. Among the HAART naive group, sub-clinical hypothyroisim was seen in four, and one had biochemical feature of sick euthyroid syndrome. None of the patients had clinical features of thyroid dysfunction. There is a highly significant correlation (P = 0.01) between TSH and CD4 count.

CONCLUSIONS

Thyroid dysfunction is quite common among pediatric HIV cases. An inverse correlation is seen between TSH and CD4 count indicating trend for hypothyroidism as HIV disease progress.

Endocrine alterations in HIV-infected patients

AIMS AND OBJECTIVES

To study the frequency of thyroid, adrenal and gonadal dysfunction in newly diagnosed HIV-infected patients and to correlate them at different levels of CD4 cell counts.

MATERIALS AND METHODS

Forty-three HIV-positive cases were included in the study group. Cases were divided into three groups on the basis of CD4 cell count. Serum free T3, free T4, TSH, Cortisol, FSH, LH, testosterone and estradiol were estimated by the radioimmunoassay method. Hormone levels between cases were compared and their correlation with CD4 count was analyzed.

RESULTS

Prevalence of gonadal dysfunction (88.3%) was the most common endocrine dysfunction followed by thyroid (60.4%) and adrenal dysfunction (27.9%). Secondary hypogonadism (68.4%) was more common than primary (31.6%). Low T3 syndrome, that is, isolated low free T3, was the most common (25.6%) thyroid dysfunction followed by secondary hypothyroidism (16.2%) and subclinical hypothyroidism (11.6%). Adrenal excess (16.3%) was more common than adrenal insufficiency (11.6%). The difference in hormonal dysfunction between male and female was statistically insignificant (P > 0.05). 27.9% of patients had multiple hormone deficiency. There was negligible or no correlation between CD4 count and serum hormone level.

CONCLUSION

In our study, endocrine dysfunction was quite common among HIV-infected patients but there was no correlation between hormone levels and CD4 count. Endocrine dysfunctions and role of hormone replacement therapy in HIV-infected patient needs to be substantiated by large longitudinal study, so that it will help to reduce morbidity, improve quality of life.

Thyroid abnormalities

Thyroid abnormalities and nonthyroidal illness complicate human immunodeficiency virus (HIV) infection. Among the effects that result from HIV and other opportunistic infections, distinctive features of HIV infection include early lowering of reverse tri-iodothyromine (T3) levels, with normal free T3 levels. Later, some patients develop an isolated low free thyroxine level. After highly active antiretroviral therapy, the immune system reconstitutes in a way that leads to dysregulation of the autoimmune response and the appearance of Graves disease in 1% to 2% of patients. Opportunistic thyroid infections with unusual organisms are most commonly asymptomatic, but can lead to acute or subacute thyroiditis.

Histopathological Changes of the Thyroid and Parathyroid Glands in HIV-Infected Patients

Objective. To study histopathology of the thyroid and parathyroid glands in HIV-infected African Americans in the United States. Methods. A retrospective review of 102 autopsy cases done by the Department of Pathology at Howard University Hospital from 1980 through 2007 was conducted. The histopathological findings of the thyroid and parathyroid glands were reviewed, both macroscopically and microscopically. A control group of autopsy patients with chronic non-HIV diseases was examined. Results. There were 71 males (70%) and 31 females (30%) with an average age of 38 years (range: 20–71 y). Thirteen patients with abnormal thyroid findings were identified. Interstitial fibrosis was the most common histological finding (4.9%), followed by thyroid hyperplasia (1.9%). Infectious disease affecting the thyroid gland was limited to 2.9% and consisted of mycobacterium tuberculosis, Cryptococcus neoformans, and cytomegalovirus. Kaposi sarcoma of the thyroid gland was present in only one case (0.9%). Parathyroid hyperplasia was the most common histological change noted in the parathyroid glands. Comparing the histological findings of cases and controls, we found a similar involvement of the thyroid, with a greater prevalence of parathyroid hyperplasia in HIV patients. Conclusion. Thyroid and parathyroid abnormalities are uncommon findings in the HIV-infected African American population.

HIV and thyroid dysfunction

Human Immunodeficiency virus (HIV) infection and Acquired Immunodeficiency Syndrome (AIDS) are associated with dysfunction of many endocrine organs and their axis. HIV infectivity leads to altered metabolism, poor oral intake and increased prevalence of weight loss and wasting which may have a role in thyroid dysfunction. Overt thyroid dysfunction occurs at similar rates as the general population while subclinical disease such as nonthyroidal illness (sick euthyroid syndrome), subclinical hypothyroidism and isolated low T4 levels are more frequent. Moreover, HAART therapy can complicate thyroid function further through drug interactions and the immune reconstitution inflammatory syndrome (IRIS). In this review we report the common thyroid dysfunctions associated with HIV before and after HAART therapy. We discuss presentation, diagnostic work up, treatment and follow up in each condition.

Thyroid function in newly diagnosed HIV-infected patients

BACKGROUND

A variety of HIV-related endocrine dysfunctions including adrenal, gonadal and thyroid disorders have been reported. We aimed to compare between the markers of thyroid function in newly diagnosed HIV-infected patients and healthy volunteers as a control group. The prevalence of the thyroid abnormalities in HIV-infected patients was assessed and the levels of thyroid autoantibodies were also determined.

METHODS

A total of 100 newly diagnosed HIV-infected patients having a CD4 cell count of 180-350 cells/mm(3) were enrolled in the study. Same number of healthy volunteers were also included for comparison. Measurements of thyroid function tests including thyroid-stimulating hormone (TSH), free thyroxin and free triiodothyronine levels beside thyroid autoantibodies, including antithyroglobulin (ATBG) and antithyroid peroxidase (ATPO), were carried out for all patients and volunteers.

RESULTS

In total, 70% of HIV-infected patients had normal thyroid function tests when compared with control individuals, while 30% of HIV-infected patients had abnormal thyroid function. Of the 30 cases, 11 cases had abnormal TSH values, with increased TSH predominant (7% of HIV cases) than decreased TSH (4% of patients) values. Incidence of thyroid abnormalities ranging from hypothyroidism (subclinical and overt: 6% and 1%, respectively) to hyperthyroidism (2%) and nonthyroidal illness (9%) were estimated in HIV-infected patients. The values of thyroid autoantibodies were almost normal in HIV-infected patients, except the three cases presented with elevated ATBG, indicating that thyroid abnormalities were not due to elevated ATBG and ATPO.

CONCLUSIONS

Thyroid hormones are of great importance and due to high prevalence of thyroid function abnormality, it is recommended that thyroid function tests should be monitored in all HIV-infected patients before starting the treatment.

Viruses and thyroiditis: an update

Viral infections are frequently cited as a major environmental factor involved in subacute thyroiditis and autoimmune thyroid diseases This review examines the data related to the role of viruses in the development of thyroiditis.

Our research has been focused on human data. We have reviewed virological data for each type of thyroiditis at different levels of evidence; epidemiological data, serological data or research on circulating viruses, direct evidence of thyroid tissue infection. Interpretation of epidemiological and serological data must be cautious as they don't prove that this pathogen is responsible for the disease. However, direct evidence of the presence of viruses or their components in the organ are available for retroviruses (HFV) and mumps in subacute thyroiditis, for retroviruses (HTLV-1, HFV, HIV and SV40) in Graves's disease and for HTLV-1, enterovirus, rubella, mumps virus, HSV, EBV and parvovirus in Hashimoto's thyroiditis. However, it remains to determine whether they are responsible for thyroid diseases or whether they are just innocent bystanders. Further studies are needed to clarify the relationship between viruses and thyroid diseases, in order to develop new strategies for prevention and/or treatment.

The role of selenium, vitamin C, and zinc in benign thyroid diseases and of selenium in malignant thyroid diseases: Low selenium levels are found in subacute and silent thyroiditis and in papillary and follicular carcinoma

BACKGROUND

Thyroid physiology is closely related to oxidative changes. The aim of this controlled study was to evaluate the levels of nutritional anti-oxidants such as vitamin C, zinc (Zn) and selenium (Se), and to investigate any association of them with parameters of thyroid function and pathology including benign and malignant thyroid diseases.

METHODS

This controlled evaluation of Se included a total of 1401 subjects (1186 adults and 215 children) distributed as follows: control group (n = 687), benign thyroid disease (85 children and 465 adults); malignant thyroid disease (2 children and 79 adults). Clinical evaluation of patients with benign thyroid disease included sonography, scintigraphy, as well as the determination of fT3, fT4, TSH, thyroid antibodies levels, Se, Zn, and vitamin C. Besides the routine oncological parameters (TG, TSH, fT4, ultrasound) Se was also determined in the cases of malignant disease. The local control groups for the evaluation of Se levels were taken from a general practice (WOMED) as well as from healthy active athletes. Blood samples were collected between 8:00 and 10:30 a.m. All patients lived in Innsbruck. Statistical analysis was done using SPSS 14.0. The Ho stated that there should be no differences in the levels of antioxidants between controls and thyroid disease patients.

RESULTS

Among the thyroid disease patients neither vitamin C, nor Zn nor Se correlated with any of the following parameters: age, sex, BMI, body weight, thyroid scintigraphy, ultrasound pattern, thyroid function, or thyroid antibodies. The proportion of patients with benign thyroid diseases having analyte concentrations below external reference cut off levels were 8.7% of cases for vitamin C; 7.8% for Zn, and 20.3% for Se. Low Se levels in the control group were found in 12%. Se levels were significantly decreased in cases of sub-acute and silent thyroiditis (66.4 +/- 23.1 microg/l and 59.3 +/- 20.1 microg/l, respectively) as well as in follicular and papillary thyroid carcinoma. The mean Se level in the control group was 90.5 +/- 20.8 microg/l.

CONCLUSION

The H0 can be accepted for vitamin C and zinc levels whereas it has to be rejected for Se. Patients with benign or malignant thyroid diseases can present low Se levels as compared to controls. Low levels of vitamin C were found in all subgroups of patients.

Thyroid function and anti-thyroid autoantibodies in untreated children with vertically acquired chronic hepatitis C virus infection

OBJECTIVE

The reported data on thyroid function and anti-thyroid autoantibodies in adults with untreated hepatitis C virus (HCV) infection are controversial. Data are scarce for HCV-infected children, and only in those treated with interferon-alpha (IFN-alpha). We investigated thyroid function and anti-thyroid autoantibodies in a cohort of untreated children with vertically acquired, chronic, HCV infection.

DESIGN AND PATIENTS

FT4 and TSH serum levels (measured by immunometric assays) and anti-thyroglobulin (TgA) and anti-thyroperoxidase (TPOA) antibodies (evaluated by fluorescence enzymatic immunoassays) were studied in 36 consecutive HCV-infected children and 150 age- and sex-matched controls. The prevalence of thyroid involvement was also related to family history of autoimmune disease, distribution of HCV genotypes, and duration and activity of HCV infection.

RESULTS

Four out of 36 (11.1%) HCV-infected children and 4/150 controls (2.7%) showed subclinical hypothyroidism [P = 0.04; relative risk (RR) 4.56, 95% confidence interval (CI) 1.08-19.21]. None of these had anti-thyroid autoantibodies. Two out of 36 (5.6%) HCV-infected children and 1/150 (0.7%) controls had increased TgA values with normal levels of TSH (P > 0.05). Subclinical hypothyroidism and anti-thyroid autoantibodies were not related to family history of autoimmune disease, duration of infection, HCV viral load, liver function or different HCV genotype distribution, but seemed to be related to the presence of active HCV infection.

CONCLUSIONS

Our data suggest a role for HCV infection in the development of nonautoimmune thyroid disease in untreated HCV-infected children, confirming previous studies in adults. Clinicians should be aware of thyroid dysfunction even in untreated children.

Thyroid function abnormalities in HIV-infected patients

Abnormal thyroid function test results are common among human immunodeficiency virus (HIV)-infected patients. Although the prevalence of overt thyroid disease does not appear to be significantly increased in HIV-infected patients, compared with the general population, specific patterns of abnormal thyroid function test findings are more frequently identified among HIV-infected patients. Among patients with advanced acquired immunodeficiency syndrome, nonthyroidal illness (i.e., euthyroid sick syndrome) is common. During antiretroviral therapy, the prevalence of 2 generally asymptomatic conditions (subclinical hypothyroidism, which is characterized by isolated elevated thyroid-stimulating hormone levels, and isolated low free thyroxine levels) is increased. In addition, Graves disease, which is marked by low thyroid-stimulating hormone and elevated thyroxine levels, may occur during immune reconstitution. Testing for thyroid disease among symptomatic patients should begin with measurement of the thyroid-stimulating hormone level. However, there is insufficient evidence to recommend routine thyroid screening of asymptomatic HIV-infected individuals. This review summarizes the current evidence regarding the optimal laboratory evaluation of thyroid function; highlights the causes, presentation, and treatment of thyroid dysfunction in HIV-infected patients; and discusses the controversies regarding screening.