Serum triiodothyronine values. Prognostic indicators of acute mortality due to Pneumocystis carinii pneumonia associated with the acquired immunodeficiency syndrome

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.

Thyroid function in human immunodeficiency virus patients treated with highly active antiretroviral therapy (HAART): a longitudinal study

OBJECTIVE

Given that few and controversial data have been reported on thyroid function in human immunodeficiency virus (HIV) patients on highly active antiretroviral therapy (HAART), we further investigated whether HAART affects thyroid hormones.

DESIGN AND PATIENTS

Two hundred two consecutive adult HIV patients in stable clinical condition were enrolled, 182 on HAART and 20 naïve; 128 were rechecked during follow-up. Body mass index (BMI), CD4 cell count, HIV RNA, hepatitis C and B virus status and infection duration were determined in all HIV patients and HAART duration in treated patients. In all patients and in 60 controls, the following were measured: FT4 and FT3 by radioimmunoassay; TSH, antithyroid peroxidase (TPO) and antithyroglobulin (TG) antibodies by immunoradiometric assay.

RESULTS

Abnormalities in thyroid function tests were found in 23/182 (12.6%) HAART patients, but not in naïve patients. Most abnormalities were subclinical hypothyroidism, with mean FT4 and TSH levels lower and higher, respectively, in HAART patients compared to naïve patients and controls, FT4 levels being significantly lower than controls. TSH negatively correlated with CD4 count nadir and positively with HAART duration. During follow-up, FT4 and FT3 significantly decreased and TSH increased in patients continuing HAART, whereas CD4 counts were unmodified; subclinical hypothyroid conditions persisted and further cases occurred, whereas the only hypothyroid patient who interrupted HAART shows a normalization of thyroid tests. Patients on stavudine, included in most hypothyroid patient protocols, had significantly lower FT4 levels with prolonged treatment.

CONCLUSIONS

HAART, particularly stavudine, is associated with a high prevalence of subclinical hypothyroidism. Hypotheses are made regarding responsible mechanisms and risk factors. Thyroid function should be tested and sequentially rechecked in HAART patients.

Human immunodeficiency virus infection and the thyroid

Abnormalities of thyroid function are associated with a number of systemic conditions, including patients infected with human immunodeficiency virus (HIV). Most patients with early HIV infection and a stable body weight have normal thyroid function. Subtle abnormalities of a number of thyroid function tests have been reported during the early asymptomatic phase of HIV disease. These include an inappropriately normal triiodothyronine (T(3)) and reduced reverse triiodothyronine (rT(3)), and increased thyroxine-binding globulin (TBG) levels. Opportunistic infections involving the thyroid gland, neoplasms such as lymphoma and Kaposi's sarcoma, and medications can alter the thyroid function in individuals with more advanced HIV infection. If thyroid dysfunction is diagnosed in an HIV-infected patient, it should be treated in the usual manner. However, high index of suspicion and caution in the interpretation of thyroid function tests in patients with HIV disease are needed for optimal diagnosis and treatment.

Indices of thyroid function and weight loss in human immunodeficiency virus infection and the acquired immunodeficiency syndrome

Abnormalities of thyroid hormone levels have been reported in the acquired immunodeficiency syndrome (AIDS), but there has been debate as to whether they are appropriate for the clinical status of the patients. Inappropriate maintenance of circulating 3,3',5-triiodothyronine (T3) levels could contribute to weight loss. Although many patients with AIDS have a history of wasting, recent data indicate that prolonged periods of stable weight occur in AIDS and that short-term weight loss is present in a subset of patients with anorexia, many of whom have active secondary infection (AIDS-SI). Therefore we analyzed thyroid hormone levels in a cohort of subjects that have been characterized in terms of recent weight loss and caloric intake. Asymptomatic patients with human immunodeficiency virus infection (HIV+) had short-term stable weights, normal caloric intake, and normal serum T3 levels. In AIDS, average short-term weight was stable, caloric intake was normal, and T3 levels were decreased by 19%. In AIDS-SI, both short-term weight loss and anorexia were significant, and this group showed a 45% decrease in T3 levels. The free T3 (FT3) index was decreased by 30% in AIDS and by 50% in AIDS-SI. Free thyroxine (FT4) levels were decreased while thyroxine-binding globulin (TBG) capacity was increased in HIV+ and AIDS; TBG sialylation was unchanged. Thyrotropin (TSH) levels were slightly increased in AIDS, although levels remained within the normal range. 3,3',5'-triiodothyronine (rT3) levels were decreased in HIV+, AIDS, and AIDS-SI. Thus asymptomatic patients with HIV infection whose weight is stable maintain normal T3 levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypothyroid-like regulation of the pituitary-thyroid axis in stable human immunodeficiency virus infection

Thyroid function and regulation were studied in 14 consecutive male outpatients with asymptomatic human immunodeficiency virus (HIV) infection (CDC II/III, n = 8) or AIDS (CDC IV, n = 6) who were free of concomitant infections and hepatic dysfunction, and in eight healthy, age- and weight-matched male controls. Blood was sampled every 10 minutes over 24 hours for measurement of thyrotropin (TSH). Thereafter, thyroid hormones and TSH responsiveness to thyrotropin-releasing hormone (TRH) were measured. Triiodothyronine (T3) and thyroxine (T4) did not differ between HIV-infected patients and controls, but HIV patients had lower thyroid hormone-binding index ([THBI] HIV patients, 1.01 +/- 0.02; controls, 1.11 +/- 0.03; P < .02), free thyroxine (FT4) index (94 +/- 3 v 110 +/- 4, P < .01), FT4 (11.8 +/- 0.4 v 14.3 +/- 0.4 pmol/L, P < .01), and reverse triiodothyronine (rT3) values (0.18 +/- 0.01 v 0.26 +/- 0.02 nmol/L, P < .001) and higher thyroxine-binding globulin ([TBG] 20 +/- 1 v 16 +/- 1 mg/L, P < .02) values. Mean 24-hour TSH levels were increased in HIV patients (2.39 +/- 0.33 v 1.44 +/- 0.16 mU/L, P < .05), associated with increased mean TSH pulse amplitude and TSH responsiveness to TRH. No differences were observed between asymptomatic HIV-seropositive and AIDS patients. In conclusion, there is a hypothyroid-like regulation of the pituitary-thyroid axis in stable HIV infection, which differs distinctly from the euthyroid sick syndrome in non-HIV-nonthyroidal illnesses.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of Pneumocystis carinii cyst density with mortality in patients with acquired immunodeficiency syndrome and pneumocystis pneumonia

Fifteen percent to 20% of patients with the acquired immunodeficiency syndrome and pneumocystis pneumonia do poorly despite early intervention. It is not known what distinguishes those who die, despite early intervention and aggressive therapy, from those who readily respond to therapy. We used image analysis to determine the relative abundance of cysts within aggregates of Pneumocystis carinii found in induced sputa (21 patients) and bronchoalveolar lavage fluid (14 patients) from 35 patients with pneumocystis pneumonia. We calculated a cyst density (number of cysts per area of aggregate) for each aggregate and a mean cyst density for all of the aggregates on the smear. Six patients died within 2 weeks of diagnosis; four of these six patients who had autopsies all had residual P carinii. The mean cyst density for those who died was 9.7 +/- 3.9 (range, 5 to 15 x 10(-3)). The 29 patients who survived beyond 2 weeks had a mean cyst density of 18.4 +/- 8.7 (range, 5 to 35 x 10(-3); P = .01). Mean cyst density was not influenced by the number of aggregates present in the smear, the variation in cyst density among aggregates in a smear, or the episode of pneumocystis pneumonia. Cyst density determinations alone should not be used to predict outcome for individuals with P carinii pneumonia until further study is completed. Nevertheless, the current study suggests that a low cyst density specimen, which may indirectly indicate a greater proportion of trophozoites compared with a high cyst density specimen, may be associated with an unfavorable outcome in acquired immunodeficiency syndrome-associated pneumocystis pneumonia.