The effects of prolonged lithium exposure on the immune system of normal control subjects: serial serum soluble interleukin-2 receptor and antithyroid antibody measurements

Lithium can cause hyperthyroidism as well as hypothyroidism: A systematic review of an under-recognised association

OBJECTIVE

Hypothyroidism is a well-documented consequence of lithium treatment. Less well known is a possible association between lithium therapy and hyperthyroidism. This may have clinical implications as rapid changes in thyroid hormones may worsen a person's affective state, while symptoms of hyperthyroidism can mimic those of mania. We therefore systematically reviewed the published literature for evidence of lithium-induced hyperthyroidism.

METHODS

We searched PubMed, Embase and CINAHL for articles where individuals developed biochemically confirmed hyperthyroidism (with or without clinical symptoms), while on lithium therapy for an affective illness. We included case reports, case series, cross-sectional, case control and cohort studies.

RESULTS

We included 52 studies, 39 of which were individual case reports and 3 were case series. There were 10 cross-sectional or case control or cohort studies. All the research designs suggested an association between the prescription of lithium and hyperthyroidism. However, these findings were limited by the quality of the included studies, small number of participants and the general lack of either a clear temporal relationship or dose response.

CONCLUSION

Hyperthyroidism is an uncommon side-effect of lithium compared to hypothyroidism but may have clinical implications. However, large prospective studies are required to clarify this association and to further inform the management of patients treated with lithium where hyperthyroidism occurs.

Prevalences of autoimmune diseases in schizophrenia, bipolar I and II disorder, and controls

Previous studies on the relationship between autoimmune diseases, schizophrenia, and bipolar disorder are mainly based on hospital discharge registers with insufficient coverage of outpatient data. Furthermore, data is scant on the prevalence of autoimmune diseases in bipolar subgroups. Here we estimate the self-reported prevalences of autoimmune diseases in schizophrenia, bipolar disorder type I and II, and controls. Lifetime prevalence of autoimmune diseases was assessed through a structured interview in a sample of 9076 patients (schizophrenia N = 5278, bipolar disorder type I N = 1952, type II N = 1846) and 6485 controls. Comparative analyses were performed using logistic regressions. The prevalence of diabetes type 1 did not differ between groups. Hyperthyroidism, hypothyroidism regardless of lithium effects, rheumatoid arthritis, and polymyalgia rheumatica were most common in bipolar disorder. Systemic lupus erythematosus was less common in bipolar disorder than in the other groups. The rate of autoimmune diseases did not differ significantly between bipolar subgroups. We conclude that prevalences of autoimmune diseases show clear differences between schizophrenia and bipolar disorder, but not between the bipolar subgroups.

Lithium-associated hyperthyroidism

Goiters and hypothyroidism are well-known patient complications of the use of lithium for treatment of bipolar disease. However, the occurrence of lithium-induced hyperthyroidism is a more rare event. Many times, the condition can be confused with a flare of mania. Monitoring through serial biochemical measurement of thyroid function is critical in patients taking lithium. Hyperthyroidism induced by lithium is a condition that generally can be controlled medically without the patient having to discontinue lithium therapy, although in some circumstances, discontinuation of lithium therapy may be indicated. We report on a patient case of lithium-associated hyperthyroidism that resolved after discontinuation of the medication.

Changes in Serum Tumor Necrosis Factor (TNF-α) with Kami-Shoyo-San Administration in Depressed Climacteric Patients

An herbal medicine (Kampo) is widely used to prevent or treat climacteric symptoms. In order to investigate the potential involvement of tumor necrosis factor (TNF)-α in susceptibility to mood disorder in climacteric women and to clarify the relationship between immune function and the efficacy of herbal medicine, we compared serum TNF-α levels in two treated groups, with and without concurrent use of herbal medicine. This study included 113 consecutive depressed menopausal patients who visited the gynecological and psychosomatic medicine outpatient clinic of the Osaka Medical College Hospital in Japan. Fifty-eight patients were administered Kami-shoyo-san according to the definition of above Sho. In contrast, 55 patients who were different in Sho of Kami-shoyo-san were administered antidepressants. Hamilton Rating Scale for depression (HAM-D) scores were determined at baseline and 12 weeks after starting treatment (endpoint). TNF-α concentrations were analyzed before and after 12 weeks of treatment. Kami-shoyo-san significantly increased plasma concentrations of TNF-α after 12 weeks of treatment, to 17.22 ± 6.13 pg/ml from a baseline level of 14.16 ± 6.27 pg/ml (p = 0.048). The percent change in plasma concentration of TNF-α differed significantly between the Kami-shoyo-san therapy group and the antidepressant therapy group at 4 weeks (12.0 ± 7.8% and -1.22 ± 0.25%, respectively, p <0.01), 8 weeks (19.7 ± 3.4% and -2.45 ± 0.86%, respectively, p <0.01), and 12 weeks (21.3 ± 5.4% and -6.81 ± 2.2%, respectively, p <0.001). We found in this study that Kami-shoyo-san, an herbal medicine, increased plasma TNF-α levels in depressed menopausal patients. Cytokines may play various roles in mood and emotional status via the central nervous system and may be regulated by herbal medicines, although the interactions are very complex.

Lithium: a review of its metabolic adverse effects

Treatment with lithium has long been recognized to be associated with metabolic adverse effects notably hypothyroidism, hyperparathyroidism, weight gain and nephrogenic diabetes insipidus. It is important that clinicians prescribing lithium are aware of these adverse effects and have a strategy for their detection and management. We review aspects of these actions of lithium including their prevalence, risk factors, biochemical changes involved and management, and discuss some advances that have been made in their understanding in recent years.

Thyroid abnormalities in lithium-treated patients

The purposes of this study were to evaluate possible effects of lithium on thyroid function, determine the relationship among thyroid function, antibody levels, and demographic/clinical variables, and establish the prevalence of lithium-related goiter, clinical hypothyroidism, and thyroid antibodies. Forty-nine patients who had taken lithium for a minimum of 6 months were enrolled, as were 46 age- and sex-matched controls naïve to lithium use. Blood was drawn to measure levels of total and free T3, T4, thyroid-stimulating hormone (TSH), and antimicrosomal and antithyroglobulin antibodies. Thyroid volume was quantified on ultrasonography. Twenty-nine patients in the study group (59%) and 7 in the control group (15%) had goiter. Free T4 levels were significantly lower in the study group, and TSH levels were higher. Among lithium-treated patients, 12% had clinical hypothyroidism and 2% had subclinical hypothyroidism. Thyroid antibodies were present in 23% of the lithium group and 15% of the control group. No significant relationship was apparent among thyroid antibodies, thyroid volume, and clinical hypothyroidism. Our findings suggested that along with its goitrogenic effects, lithium inhibited thyroid function and led to clinical hypothyroidism. Older age, family history of thyroid disorders, and the presence of thyroid antibodies significantly influenced thyroid function in the present study.

The effects of lithium on ex vivo cytokine production

BACKGROUND

Studies suggest that lithium may have profound immunomodulatory effects in animal models as well as in humans.

METHODS

In this study, whole blood cultures from normal control subjects were established for 5 days and the effects of lithium on cytokine production were investigated. Because many of lithium's actions have been postulated to be modulated through phosphoinositide (PI), protein kinase C (PKC) and cyclic adenosine monophosphate (c-AMP) signaling pathways, the effects of myo-inositol and prostaglandin E(2), alone or in combination with lithium, were also investigated.

RESULTS

We found that lithium caused an increase in interleukin-4 and interleukin-10 levels, traditionally classified as T-helper lymphocyte type-2 cytokines, and a decrease in interleukin-2 and interferon-gamma levels, traditionally classified as T-helper lymphocyte type-1 (TH-1) cytokines. This shift cannot be fully explained by lithium's actions on the PI, PKC, or c-AMP messenger systems.

CONCLUSIONS

Monocytes exposed to lithium in the presence of a mitogen for 5 days produced a shift toward the production of TH-2 cytokines and away from the production of TH-1 cytokines. The study suggests that lithium may have complex time-dependent effects on immune function.

Plasma concentrations of interleukin-1beta, interleukin-6, soluble interleukin-2 receptor and tumor necrosis factor alpha of depressed patients in Japan

There are a number of investigations which indicate the important relationship between depression and cytokines. In this study, we investigated plasma interleukin (IL)-1beta, IL-6, soluble IL-2 receptor (sIL-2R) and tumor necrosis factor (TNF)-alpha of depressed patients whose clinical evaluation was performed by the Hamilton Rating Scale for Depression (HAM-D) and the Profile of Mood States (POMS). They were compared with those of the control subjects, and before and after treatment with antidepressants. Before the treatment, plasma IL-1beta, IL-6, sIL-2R and TNF-alpha of the patients were not significantly different from those of the control subjects. sIL-2R was positively correlated with the POMS-tension-anxiety subscale and tended to have a positive correlation with HAM-D. After pharmacotherapy, TNF-alpha levels of the depressed patients increased, without any relationship between the change in the HAM-D or the POMS and the change in TNF-alpha. These results suggest that the plasma sIL-2R concentration is associated with mood state, and that the plasma TNF-alpha concentration is increased after pharmacotherapy in Japanese depressed patients.

Effects of symptomatic severity on elevation of plasma soluble interleukin-2 receptor in bipolar mania

BACKGROUND

Circulating soluble interleukin-2 receptors (sIL-2Rs) and soluble interleukin-6 receptors (sIL-6Rs) are stable immune measures. Elevated plasma sIL-2R levels are present in patients with schizophrenia, major depression, and bipolar mania, but not with minor psychiatric disorders. The increased plasma sIL-2R levels are state-dependent in bipolar mania. However, altered production of plasma sIL-6R and the effects of clinical characteristics on plasma sIL-6R and sIL-2R levels in bipolar disorder remains uncertain.

METHODS

Plasma sIL-2R and sIL-6R levels were measured in 31 Taiwanese bipolar manic (DSM-IV) patients with Young Mania Rating Scale (YMRS) scores of > or =26 as well as during the subsequent remission (YMRS< or =12), and equal numbers of age- and gender-matched healthy controls. The relationships of clinical variables such as age, age of onset, smoking, medication status, coexisting psychotic features, number of prior episodes, duration of illness, presence of depression before or following the manic episode, and manic severity to plasma sIL-2R and sIL-6R levels in acute mania along with remission were examined.

RESULTS

Plasma sIL-2R but not sIL-6R levels were significantly higher in acute mania than in subsequent remission (P<0.05) and controls (P<0.0005). In acute mania, the plasma sIL-2R levels were significantly correlated to YMRS scores (r=0.34, P<0.05). The remaining clinical variables had no effect on plasma sIL-2R and sIL-6R levels in acute mania or remission. There was a significantly positive relationship between the reduction of plasma sIL-2R levels from the acute to follow-up measurements (DeltasIL-2R) and symptomatic improvement of acute mania (DeltaYMRS) (r=0.61, P<0.001).

LIMITATIONS

Our sample included medicated and unmedicated patients in acute mania. The psychotropic medication may have divergent effects on the plasma sIL-2R levels in acute mania and subsequent remission.

CONCLUSIONS

Elevation of plasma sIL-2R but not sIL-6R levels in bipolar mania supports the idea that the immunomodulatory mechanism may vary in different psychotic disorders. In contrast to being a trait marker in schizophrenia and depressive disorder, plasma sIL-2R levels may be considered a biological indicator of manic severity in a group of bipolar affective patients.

The immunoregulatory effects of antidepressants

There is some evidence that major depression is accompanied by activation of the inflammatory-response system (IRS). It has been hypothesized that increased production of proinflammatory cytokines may play a role in the etiology of major depression. If increased production of proinflammatory cytokines is at all involved in the etiology of depression, one would expect antidepressive treatments to have negative immunoregulatory effects. This paper reviews the effects of antidepressants, such as tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), heterocyclic antidepressants (HCAs), serotonin-noradrenaline reuptake inhibitors (SNRIs), lithium, l-5-hydroxytroptophan (L-5-HTP), reversible inhibitors of MAO-A (RIMA) on the production of proinflammatory cytokines, e.g. interferon-gamma (IFNgamma), and negative immunoregulatory cytokines and agents, e.g. interleukin-10 (IL-10). In depressed patients, prolonged treatment with antidepressants and mood stabilizers normalizes signs of activation of the IRS, such as increased serum IL-6 and acute phase protein concentrations. In vitro, it has been shown that various types of antidepressive drugs, including TCAs (imipramine; clomipramine); SSRIs (citalopram, fluoxetine, sertraline); lithium; SNRIs (venlafaxine); HCAs (trazodone); RIMAs (moclobemide) and L-5-HTP significantly suppress the ratio of IFNgamma/IL-10 production by peripheral blood immunocytes. These antidepressant drugs appear to have a common effect on the IRS, i.e. in vitro they increase the production of IL-10 by peripheral blood leukocytes. Thus, the results suggest that antidepressants have negative immunoregulatory effects. It may be speculated that antidepressants exert some of their antidepressant effects through their negative immunoregulatory capacities. Copyright 2001 John Wiley & Sons, Ltd.

Plasma levels of cytokines and soluble cytokine receptors in psychiatric patients upon hospital admission: effects of confounding factors and diagnosis

It has been hypothesized that the immune system plays a pathogenetic role in psychiatric disorders, in particular in major depression and schizophrenia. This hypothesis is supported by a number of reports on altered circulating levels and in vitro production of cytokines in these disorders. However, the respective evidence is not consistent. This may be in part due to an incomplete control for numerous confounding influences in earlier studies. We investigated the plasma levels of cytokines and soluble cytokine receptors in psychiatric patients (N = 361) upon hospital admission and compared the results to those obtained in healthy controls (N = 64). By multiple regression analysis we found that circulating levels of interleukin-1 receptor antagonist (IL-1Ra), soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptors (sTNF-R p55, sTNF-R p75) and IL-6 were significantly affected by age, the body mass index (BMI), gender, smoking habits, ongoing or recent infectious diseases, or prior medication. Cytokine or cytokine receptor levels were significantly increased in patients treated with clozapine (sIL-2R, sTNF-R p75), lithium (TNF-alpha, sTNF-R p75, IL-6) or benzodiazepines (TNF-alpha, sTNF-R p75). Taking all these confounding factors into account, we found no evidence for disease-related alterations in the levels of IL-1Ra, sIL-2R, sTNF-R p75 and IL-6, whereas levels of TNF-alpha and sTNF-R p55 in major depression and sTNF-R p55 in schizophrenia were slightly decreased compared to healthy controls. We conclude that, if confounding factors are carefully taken into account, plasma levels of the above mentioned cytokines and cytokine receptors yield little, if any, evidence for immunopathology in schizophrenia or major depression.

Activation of indices of cell-mediated immunity in bipolar mania

BACKGROUND

Evidence supports that macrophages as well as lymphocytes and their products may be involved in the pathophysiology of psychiatric disorders. Whether patients with bipolar disorder have activation or reduction of immunity during a manic episode remains unclear.

METHODS

The purpose of this case-control study was to investigate the lymphocyte proliferation to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogen, and plasma levels of soluble interleukin-2 receptor (sIL-2R) and sIL-6R in patients with bipolar mania (DSM-III-R). The subjects were 23 physically healthy patients with Young Mania Rating Scale (YMRS) scores > or = 26 as well as aged < or = 45 years and 23 age- and gender-matched normal control subjects. The above immune variables were measured in acute mania and consequent remission (YMRS scores < or = 12) among bipolar patients.

RESULTS

The lymphocyte proliferation to PHA and the plasma sIL-2R levels, but not sIL-6R, of bipolar patients were significantly higher in acute mania than in consequent remission. These elevations were not due to differences in medication status. Only in acute mania were the plasma sIL-2R levels of patients significantly higher than control subjects. A positive correlation between the changes of manic severity and plasma sIL-2R levels was observed. Remitted bipolar patients and normal control subjects did not differ in any of these measures.

CONCLUSIONS

Cell-mediated immunity activation in bipolar mania was demonstrated and may be through a specifically state-dependent immune response.

The effects of lithium therapy on thyroid and thyrotropin-releasing hormone

Lithium is used in the prophylaxis of bipolar depressive disorder in augmentation treatment of depression and in the therapy of some cases of unipolar depression. Lithium affects cell function via its inhibitory action on adenosine triphosphatase (ATPase) activity, cyclic adenosine monophosphate (cAMP), and intracellular enzymes. The inhibitory effect of lithium on inositol phospholipid metabolism affects signal transduction and may account for part of the action of the cation in manic depression. Lithium also alters the in vitro response of cultured cells to thyrotropin-releasing hormone (TRH) and can stimulate DNA synthesis. Lithium is concentrated by the thyroid and inhibits thyroidal iodine uptake. It also inhibits iodotyrosine coupling, alters thyroglobulin structure, and inhibits thyroid hormone secretion. The latter effect is critical to the development of hypothyroidism and goiter. Effects on brain deiodinase enzymes and alterations in thyroid hormone receptor concentration in the hypothalamus are under investigation in relation to the therapeutic effect of lithium. The ion affects many aspects of cellular and humoral immunity in vitro and in vivo. This accounts for a rise in antithyroid antibody titer in patients having these antibodies before lithium administration whereas there is no induction of thyroid antibody synthesis de novo. Goiter, due to increased thyrotropin (TSH) after inhibition of thyroid hormone release, occurs at various reported incidence rates from 0%-60% and is smooth and nontender. Subclinical and clinical hypothyroidism due to lithium is usually associated with circulating anti-thyroid peroxidase (TPO) antibodies but may occur in their absence. Iodine exposure, dietary goitrogens, and immunogenetic background may all contribute to the occurrence of goiter and hypothyroidism during long-term lithium therapy. It is currently unclear whether the reported association of lithium therapy and hyperthyroidism are causal, although there is suggestive epidemiological evidence. Finally, lithium therapy is associated with exaggerated response of both TSH and prolactin to TRH in 50%-100% of patients, although basal levels are not usually high. It is probable that the hypothalamic pituitary axis adjusts to a new setting in patients receiving lithium.