Postpartum autoimmune thyroid syndrome

Endocrine Autoantibodies Determine Immune Checkpoint Inhibitor-induced Endocrinopathy: A Prospective Study

CONTEXT

Incidence and awareness of endocrine-related adverse events (ERAE) associated with use of immune checkpoint inhibitors (ICI) has grown with increased ICI use, yet mechanisms for ERAE prediction, surveillance, and development are not well established.

OBJECTIVE

We prospectively evaluated the impact of endocrine autoimmunity on ERAE development and overall survival (OS).

METHODS

Adults ≥ 18 years of age prescribed ICI treatment for advanced or metastatic solid tumors and no known active/past endocrine disorders were eligible for enrollment. Thyroid, adrenal, and pancreatic antibodies as well as hormone levels were assessed prior to ICI treatment and at 8 to 9 weeks and 36 weeks after treatment for ERAE in relation to presence and changes in endocrine-specific antibodies, hormone levels, and OS.

RESULTS

Sixty patients were enrolled and ERAE were detected in 14 (23.3%), with a median onset of 52 days (IQR, 38.5-71.5) after first ICI dose. Hypothyroidism occurred in 12 (20%) patients, and 2 (3.33%) patients developed hypophysitis. Diabetes and primary adrenal insufficiency were not observed. Antibodies were detected in 14 patients (11 at baseline, 3 developed during follow-up) and their presence was significantly associated with ERAE (R2 59.3%, P < 0.001). Thyroid peroxidase antibody (20%) and thyroid-stimulating immunoglobulin (3.3%) were most common, and anti-GAD was present in 1 patient. The presence of ERAE was associated with a more favorable OS (P = 0.001).

CONCLUSION

Endocrine-specific autoantibodies play an important role in ERAE pathogenesis and may serve as predictive markers for early identification and treatment of ICI-induced endocrinopathies.

Steroid-responsive encephalopathy associated with autoimmune thyroiditis presenting with a postpartum psychosis

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a rare condition characterised by neuropsychiatric symptoms, presence of antithyroid antibodies and significant response to steroid therapy. Postpartum psychosis (PP), although having a low prevalence, is a psychiatrical emergency with potentially serious impact in the mother and children. PP has an atypical presentation when compared with affective or psychotic episodes unrelated to pregnancy. Autoimmune dysfunction is frequent in the postpartum period and is closely related to PP. We report a case of a primiparous woman in her 20s with PP who did not respond to initial treatment with antipsychotics. After reassessment, SREAT was considered in the differential diagnosis. Neuropsychiatric symptoms improved dramatically after 72 hours of treatment with high-dose steroids treatment and the patient was discharged after 16 days. In women with PP, an autoimmune cause must be ruled out before assuming a psychiatry aetiology.

Health-related quality of life in women with autoimmune thyroid disease during pregnancy and postpartum: systematic review including 321,850 pregnancies

BACKGROUND

Utilities of the general population or expert estimates have been used for all published cost-effectiveness analyses of screening for thyroid disorders in pregnancy.

METHODS

A systematic review CRD42019120897 of studies with patient-reported outcomes (PRO) and laboratory evidence of thyroid function/autoimmunity was conducted using PubMed, Cochrane Central, EconLit, SocIndex, DARE, NHS EEDS, Annual Reviews, and CINAHL. Quality was assessed using Joanna Briggs Institute appraisal tool.

RESULTS

Of 664 abstracts screened, we analyzed 97 full texts. All studies describing the impact of thyroid disease on the generic QoL excluded pregnant and postpartum women. 21 reports of acceptable quality (321,850 pregnancies) determined depression and anxiety with validated tools and/or reported subjective symptoms. During pregnancy, contradictory conclusions were published on the impact of thyroid disease on PRO. Postpartum, antithyroid antibodies coincide with alexithymia and depression, postpartum thyroiditis negatively impacts mood. No conclusion could be drawn on the impact of thyroid hormonal levels.

CONCLUSIONS

The generic QoL in autoimmune thyroid disease during pregnancy has never been described, which represents an obstacle for the construction of economic models. We found contradictory information on the impact of thyroid disease on depression, anxiety, and specific symptoms.

Postpartum Thyroiditis in Women With Euthyroid and Hypothyroid Hashimoto's Thyroiditis Antedating Pregnancy

CONTEXT

Postpartum thyroiditis (PPT) is defined as the occurrence of de novo autoimmune thyroid disease accompanied by thyroid dysfunction in the first year postpartum. However, hormonal changes resembling the typical pattern of PPT have been reported to occur even in women with pregestational Hashimoto's thyroiditis (HT) on levothyroxine (LT4).

OBJECTIVE

To evaluate the risk of PPT in women with HT antedating pregnancy.

DESIGN/SETTING

Retrospective chart review of pregnant women with HT antedating pregnancy seen in a university hospital (2008-2017), who were followed from preconception up to 1 year after delivery.

PATIENTS

167 women preconceptionally diagnosed with HT and classified as hypothyroid HT (hypo-HT; n = 98) or euthyroid HT (eu-HT; n = 69), according to their thyroid status at the time of diagnosis.

OUTCOME MEASURES

PPT occurrence and associated clinical characteristics/risk factors.

RESULTS

PPT occurred in 65/167 women, with a rate statistically greater in the eu-HT than in the hypo-HT group (68.1% vs 18.4%; odds ratio [OR] 9.49, 95% confidence interval [CI] 4.62-19.49). Most of the women experiencing PPT in both groups were euthyroid at the time of first-trimester evaluation (39/47 eu-HT [83%] and 16/18 hypo-HT [88.9%]). Multivariate regression analysis showed eu-HT group and first-trimester euthyroidism to be positively associated with PPT occurrence (ORs 10.71 and 3.89, respectively).

CONCLUSION

PPT may occur in hypo-HT women on LT4 therapy, although significantly less frequently than in eu-HT women. The 4-fold higher risk of PPT in HT women maintaining euthyroidism at first -trimester of gestation suggests that the risk of PPT could be related to the amount of unaffected thyroid tissue.

Thyroid dysfunction following pregnancy and implications for breastfeeding

Subclinical autoimmune thyroiditis exacerbates after delivery through immune rebound mechanisms and results in 5 types of thyroid dysfunction. The prevalence of postpartum thyroid dysfunction is around 5% in mothers in the general population. Typically, an exacerbation induces destructive thyrotoxicosis followed by transient hypothyroidism, known as postpartum thyroiditis. Late development of permanent hypothyroidism is found frequently and patients should be followed up once every one to two years. Destructive thyrotoxicosis in postpartum thyroiditis should carefully be differentiated from post-partum Graves' disease. Postpartum thyroiditis typically occurs 1-4 months after parturition whereas Graves' disease develops at 4-12 months postpartum. Anti-TSH receptor antibodies (TRAb) are typically positive and thyroid blood flow is high in Graves' disease, whereas these features are absent in postpartum thyroiditis. Postpartum Graves' disease should be treated with antithyroid drugs.

Comparative frequency of four different types of pregnancy-associated thyrotoxicosis in a single thyroid centre

Background

Pregnancy and delivery markedly influence thyroid function. However, the comparative prevalence of gestational thyrotoxicosis (GT), new onset of Graves’ disease during pregnancy (GD during pregnancy), postpartum destructive thyrotoxicosis (PPT), and postpartum Graves’ thyrotoxicosis (PPGD) has not yet been determined.

Methods

We prospectively registered and performed a review of 4127 consecutive non treated female patients with thyrotoxicosis, seen between August 2008 and December 2013 in our outpatient clinic of Kuma Hospital. 187 out of the 4127 women had new diagnosis of thyrotoxicosis during pregnancy or in the postpartum period. We investigated the prevalence of new diagnosis of GT, GD during pregnancy, PPT and PPGD and compared the characteristics of these types of thyrotoxicosis. The postpartum period is defined as twelve months after delivery.

Results

Out of 187 pregnant or postpartum women, we identified 30 (16.0%) with GT, 13 (7.0%) with GD during pregnancy, 42 (22.5%) with PPT, and 102 (54.5%) with PPGD. The onset time of thyrotoxicosis during pregnancy, i.e., both GT and GD during pregnancy, was delayed by a couple of weeks when hCG peaked at 10 gestational weeks. Seventy-six percent of patients with PPT developed thyrotoxicosis between delivery and 4 months postpartum; on the other hand, 83.3% of patients with PPGD developed thyrotoxicosis at 6 months postpartum or later.

Conclusions

We named gestational thyrotoxicosis, new onset of Graves’ disease during pregnancy, postpartum destructive thyrotoxicosis, and postpartum Graves’ thyrotoxicosis as pregnancy-associated thyrotoxicosis. A clinically significant number of women developed Graves’ disease in the postpartum period in a single thyroid centre.

Differentiation of postpartum Graves' thyrotoxicosis from postpartum destructive thyrotoxicosis using antithyrotropin receptor antibodies and thyroid blood flow

BACKGROUND

Postpartum thyroid dysfunction occurs in approximately 5-10% of women in the general population within one year of delivery. Differentiation of postpartum Graves' thyrotoxicosis (PPGr) from postpartum destructive thyrotoxicosis (PPDT) is essential because of the difference in treatment measures between the two. However, it is sometimes difficult because radioactive iodine uptake is contraindicated when patients are lactating. We examined the usefulness of determining the time of onset postpartum and measurement of antithyrotropin (anti-TSH) receptor antibodies and thyroid blood flow.

METHODS

Forty-two patients with newly developed thyrotoxicosis after delivery were examined: 18 had Graves' disease and 24 had destructive thyrotoxicosis. Serum free thyroxine (fT4), free triiodothyronine (fT3), and TSH were measured by chemiluminescent immunoassays. Anti-TSH receptor antibodies (TRAb), antithyroglobulin antibodies (TgAb), and antithyroid peroxidase antibodies (TPOAb) were measured by the Elecsys electrochemiluminescence immunoassay. Thyroid volume and blood flow (TBF) were measured quantitatively by color flow Doppler ultrasonography.

RESULTS

Onset of thyrotoxicosis was distributed from 2 to 12 months postpartum. Twelve (85.7%) of 14 patients who developed thyrotoxicosis at three months or earlier after delivery had PPDT. On the other hand, all 11 patients who developed thyrotoxicosis at 6.5 months or later had PPGr. All patients with PPGr had positive TRAb (14.9±14.9 IU/L, mean±standard deviation (SD)) and all patients with PPDT had negative TRAb (0.1±0.3 IU/L, p<0.0001). Fifteen (83.3%) of 18 PPGr patients had high TBF of more than 4.0% (8.9±4.4), and all PPDT patients had low TBF of <4.0% (1.6±1.0, p<0.0001). The fT3/fT4 ratio was higher in PPGr (64.0±23.9) than in PPDT (38.9±13.1, p<0.0002), but absolute values overlapped between the two.

CONCLUSION

Early onset of thyrotoxicosis postpartum was associated mainly with PPDT, and a late onset was suggestive of PPGr. Positive TRAb and high TBF >4.0% are indicators of postpartum onset of Graves' disease.

Thyroid dysfunction associated with administration of the long-acting gonadotropin-releasing hormone agonist

Gonadotropin-releasing hormone (GnRH) agonist has been used in the treatment of a wide variety of sex-hormone-related diseases, as the administration of GnRH agonist can alter the secretion of gonadotropin and sex hormones. Recently, we found that the long-acting GnRH agonist aggravated hyperthyroidism and induced painless thyroiditis. This is the first report to demonstrate the association of thyroid dysfunction with GnRH agonist injection in Korea. Here, we report three cases and emphasize the clinical importance of this aggravating factor in autoimmune thyroid disease.

A case of painless thyroiditis in a very early stage of pregnancy

We report a case of painless thyroiditis detected during the first trimester of pregnancy. A 29-year-old Japanese woman was hospitalized because of thyrotoxicosis and she was confirmed to be pregnant. The gestational age was 4 weeks. Blood examinations revealed negative TSH receptor antibodies, however, we started potassium iodide because we were unable to rule out Graves' disease. Thyroid hormone levels were normalized in 3 weeks and remained low even after discontinuation of medication. She received replacement therapy with levothyroxine sodium hydrate till 3 months after delivery. Painless thyroiditis can be one of the differential diagnoses of thyrotoxicosis in a very early stage of pregnancy.

Thyroid function and human reproductive health

Via its interaction in several pathways, normal thyroid function is important to maintain normal reproduction. In both genders, changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism and were already reported many years ago. Male reproduction is adversely affected by both thyrotoxicosis and hypothyroidism. Erectile abnormalities have been reported. Thyrotoxicosis induces abnormalities in sperm motility, whereas hypothyroidism is associated with abnormalities in sperm morphology; the latter normalize when euthyroidism is reached. In females, thyrotoxicosis and hypothyroidism can cause menstrual disturbances. Thyrotoxicosis is associated mainly with hypomenorrhea and polymenorrhea, whereas hypothyroidism is associated mainly with oligomenorrhea. Thyroid dysfunction has also been linked to reduced fertility. Controlled ovarian hyperstimulation leads to important increases in estradiol, which in turn may have an adverse effect on thyroid hormones and TSH. When autoimmune thyroid disease is present, the impact of controlled ovarian hyperstimulation may become more severe, depending on preexisting thyroid abnormalities. Autoimmune thyroid disease is present in 5-20% of unselected pregnant women. Isolated hypothyroxinemia has been described in approximately 2% of pregnancies, without serum TSH elevation and in the absence of thyroid autoantibodies. Overt hypothyroidism has been associated with increased rates of spontaneous abortion, premature delivery and/or low birth weight, fetal distress in labor, and perhaps gestation-induced hypertension and placental abruption. The links between such obstetrical complications and subclinical hypothyroidism are less evident. Thyrotoxicosis during pregnancy is due to Graves' disease and gestational transient thyrotoxicosis. All antithyroid drugs cross the placenta and may potentially affect fetal thyroid function.

Obstetric management of thyroid disease

Timely treatment of thyroid disease during pregnancy is important in preventing adverse maternal and fetal outcome. At present, thyroid testing is performed on symptomatic pregnant women or those with a history of the disease. Hypothyroidism is very often subclinical in nature and not easily recognized without specific screening programs. Even mild maternal thyroid hormone deficiency may lead to neurodevelopment complications in the fetus. Early maternal thyroxine therapy might be beneficial in these women. The main diagnostic indicator of thyroid disease is the measurement of serum thyroid stimulating hormone and free thyroxine. Availability of gestation-age-specific thyroid stimulating hormone (TSH) thresholds is an important aid in the accurate diagnosis and treatment of thyroid dysfunction. Pregnancy-specific free thyroxine thresholds not presently available are also required. Gestational iodine deficiency is still prevalent in some areas of the United Kingdom. Thyroid peroxidase antibody (TPO Ab) in combination with thyroglobulin autoantibody (TgAb) is an accurate predictor of postpartum thyroiditis (PPT). Early screening and treatment of PPT may be justified on the grounds that it is relatively common and causes considerable postpartum morbidity. Large-scale intervention trials are urgently needed to assess the efficacy of preconception or early pregnancy screening for thyroid disorders.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader should be able to state that thyroid gland physiology changes with pregnancy, recall that levels of thyroid hormones are gestational-age related, and explain that accurate interpretation of both antepartum and postpartum levels of thyroid hormones are important in preventing pregnancy-related complication secondary to thyroid dysfunction and in the diagnosis and management of postpartum thyroiditis.

Quantitative measurement of thyroid blood flow for differentiation of painless thyroiditis from Graves' disease

OBJECTIVE

Differentiation between destruction-induced thyrotoxicosis and Graves' thyrotoxicosis is important for selection of proper therapy. It is, however, often difficult to make this distinction without measurement of radioactive iodine uptake. We investigated the possibility that assessment of thyroid blood flow would allow differentiation between the two entities.

PATIENTS AND MEASUREMENTS

One hundred and fourteen untreated patients with thyrotoxicosis (56 Graves' disease, 28 painless thyroiditis, 30 subacute thyroiditis) and 25 normal controls were examined. Serum levels of freeT4 (FT4), freeT3 (FT3) and TSH were measured by chemiluminescent immunoassay, and anti-TSH receptor antibodies (TSH-binding inhibitory immunoglobulin, TBII) were measured by enzyme-linked immunosorbent assay. Thyroid volume and blood flow (TBF) were measured quantitatively by ultrasonography.

RESULTS

TBF was significantly higher in Graves' disease (mean +/- 1SD: 14.9 +/- 6.4%, P < 0.0001) than in painless thyroiditis (0.8 +/- 0.5%), subacute thyroiditis (0.9 +/- 0.7%) and in normal controls (0.8 +/- 0.5%). All patients with Graves' disease had TBF values of more than 4% and all patients with painless thyroiditis and subacute thyroiditis had TBF values less than 4%. TBF values significantly correlated with values of radioactive iodine uptake (RAIU) either at 3 h (r = 0.492, P < 0.01) or 24 h (r = 0.762, P < 0.001) within the Graves' disease and painless thyroiditis groups. There was no relationship between TBF values and thyroid volumes or values of TBII in the Graves' disease group. All patients with Graves' disease had positive TBII of 15% or more. Three of 28 patients with painless thyroiditis and one of 30 patients with subacute thyroiditis had positive TBII.

CONCLUSION

TBF was quantitatively measured by power Doppler ultrasonography and was more effective than TBII for differentiation between destruction-induced thyrotoxicosis (painless or subacute thyroiditis) and Graves' thyrotoxicosis. TBF values of less than 4% in untreated thyrotoxic patients are laboratory signals of destruction-induced thyrotoxicosis and if these are determined, the radioactive iodine uptake test can be omitted for differential diagnosis of these two types of thyrotoxicosis.

Thyroid disease in pregnancy

Thyroid testing during pregnancy should be performed on symptomatic women or those with a personal history of thyroid disease. Overt hypothyroidism complicates up to 3 of 1,000 pregnancies and is characterized by nonspecific signs or symptoms that are easily confused with complaints common to pregnancy itself. Physiologic changes in serum thyroid-stimulating hormone (TSH) and free thyroxine (T(4)) related to pregnancy also confound the diagnosis of hypothyroidism during pregnancy. If the TSH is abnormal, then evaluation of free T(4) is recommended. The diagnosis of overt hypothyroidism is established by an elevated TSH and a low free T(4). The goal of treatment with levothyroxine is to return TSH to the normal range. Overt hyperthyroidism complicates approximately 2 of 1,000 pregnancies. Clinical features of hyperthyroidism can also be confused with those typical of pregnancy. Clinical hyperthyroidism is confirmed by a low TSH and elevation in free T(4) concentration. The goal of treatment with thioamide drugs is to maintain free T(4) in the upper normal range using the lowest possible dosage. Postpartum thyroiditis requiring thyroxine replacement has been reported in 2% to 5% of women. Most women will return to the euthyroid state within 12 months.

Ratio of serum free triiodothyronine to free thyroxine in Graves' hyperthyroidism and thyrotoxicosis caused by painless thyroiditis

The serum T3 to T4 ratio is a useful indicator for differentiating destruction-induced thyrotoxicosis from Graves' thyrotoxicosis. However, the usefulness of the serum free T3 (FT3) to free T4 (FT4) ratio is controversial. We therefore systematically evaluated the usefulness of this ratio, based on measurements made using two widely available commercial kits in two hospitals. Eighty-two untreated patients with thyrotoxicosis (48 patients with Graves' disease and 34 patients with painless thyroiditis) were examined in Kuma Hospital, and 218 patients (126 with Graves' disease and 92 with painless thyroiditis) and 66 normal controls were examined in Ito Hospital. The FT3 and FT4 values, as well as the FT3/FT4 ratios, were significantly higher in the patients with Graves' disease than in those with painless thyroiditis in both hospitals, but considerable overlap between the two disorders was observed. Receiver operating characteristic (ROC) curves for the FT3 and FT4 values and the FT3/FT4 ratios of patients with Graves' disease and those with painless thyroiditis seen in both hospitals were prepared, and the area under the curves (AUC), the cut-off points for discriminating Graves' disease from painless thyroiditis, the sensitivity, and the specificity were calculated. AUC and sensitivity of the FT(3)/FT(4) ratio were smaller than those of FT(3) and FT(4) in both hospitals. The patients treated at Ito hospital were then divided into 4 groups according to their FT4 levels (A: < or =2.3, B: >2.3 approximately < or =3.9, C: 3.9 approximately < or =5.4, D: >5.4 ng/dl), and the AUC, cut-off points, sensitivity, and specificity of the FT(3)/FT(4) ratios were calculated. The AUC and sensitivity of each group increased with the FT4 levels (AUC: 57.8%, 72.1%, 91.1%, and 93.4%, respectively; sensitivity: 62.6%, 50.0%, 77.8%, and 97.0%, respectively). The means +/- SE of the FT3/FT4 ratio in the Graves' disease groups were 3.1 +/- 0.22, 3.1 +/- 0.09, 3.2 +/- 0.06, and 3.1 +/- 0.07, respectively, versus 2.9 +/- 0.1, 2.6 +/- 0.07, 2.5 +/- 0.12, and 2.3 +/- 0.15, respectively, in the painless thyroiditis groups. In the painless thyroiditis patients, the difference in the FT3/FT4 ratio between group A and group D was significant (p<0.05). Thus, the FT3/FT4 ratio in patients with Graves' disease likely remains unchanged as the FT4 level rises, whereas this ratio decreases as the FT4 level rises in patients with painless thyroiditis. In conclusion, the FT3/FT4 ratios of patients with painless thyroiditis overlapped with those of patients with Graves' disease. However, this ratio was useful for differentiating between these two disorders when the FT4 values were high.

Stress and thyroid autoimmunity

While many studies have shown a connection between stress and autoimmune disease, most of the evidence for stress contributing to the onset and course of autoimmune disease is circumstantial and the mechanisms by which stress affects autoimmune disease are not fully understood. The best circumstantial evidence for an effect of stress on autoimmune thyroid disease is the well-known relationship between the onset of Graves' hyperthyroidism and major stress but even this is debated. However, most of the recent case-control studies have supported stress as a factor that affects the onset and clinical course of Graves' disease. On the other hand, there have been few reports concerning the possible relationship between stress and Hashimoto's thyroiditis. Because the onset and course of Hashimoto's thyroiditis is generally insidious, the effect of stress on Hashimoto's thyroiditis might be overlooked. Numerous human and animal studies have demonstrated that psychological and physiologic stressors induce various immunologic changes. Stress affects the immune system either directly or indirectly through the nervous and endocrine systems. These immune modulations may contribute to the development of autoimmunity as well as the susceptibility to autoimmune disease in genetically predisposed individuals. Stress can be one of the environmental factors for thyroid autoimmunity.

Transient appearance of lactate dehydrogenase (LDH)-linked immunoglobulin and thyroid dysfunction at the postpartum period

Here, we report a 28-year-old woman who transiently showed lactate dehydrogenase (LDH)-linked immunoglobulin during postpartum thyroiditis. She demonstrated high levels of serum LDH (794 IU/l) and thyroid hormones 7 months after delivery. Electrophoretic isoenzyme analysis of LDH showed an abnormal broadband caused by LDH-linked immunoglobulin (IgG-kappa). Transient thyrotoxicosis due to postpartum thyroiditis improved without any specific treatment, and elevated serum concentration of LDH decreased to the normal level (395 IU/l) with disappearance of LDH-linked IgG. LDH-linked immunoglobulin may also appear at the postpartum period.

Serum concentrations of dehydroepiandrosterone and dehydroepiandrosterone sulfate and their relation to cytokine production during and after normal pregnancy

BACKGROUND

Since dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) have been suggested to have immunoregulatory effects, changes in the levels of these substances during and after pregnancy might affect the maternal immune system. We examined serum concentrations of DHEA and DHEAS, and cytokine production during pregnancy and after delivery.

METHODS

The subjects were 73 normal pregnant, 76 normal postpartum and 30 normal non-pregnant women. Whole-blood was stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin and the levels of cytokines in the supernatant were measured using enzyme-linked immunosorbent assay (ELISA). DHEA and DHEAS were measured using ELISA and gas chromatography-mass spectrometry (GC-MS), respectively.

RESULTS

The serum DHEA levels increased in the first and in the second trimesters and decreased after delivery until 11 months postpartum. DHEAS levels were decreased in the second and in the third trimesters and returned to non-pregnant levels after pregnancy. All measured cytokines (IFN-gamma, IL-2, IL-4 and IL-10) were decreased during pregnancy and subsequently increased postpartum. We found significant negative correlations between DHEA and cytokine levels.

CONCLUSIONS

Increase of serum DHEA in the first and the second trimesters may suppress immune reaction during pregnancy, while a decrease of DHEA after delivery may induce postpartum enhancement of the maternal immune system. DHEA may be involved in modifying the maternal immune responses during and after pregnancy.

Relation Between Post-partum Liver Dysfunction and Anti-cytochrome 2D6 Antibodies

PROBLEM

Autoimmune thyroid disease frequently aggravates or develops after delivery through the immune rebound mechanism. However, little is known about the post-partum development of autoimmune hepatitis (AIH).

METHOD OF STUDY

We examined 18 patients who developed liver dysfunction after delivery or abortion. Serial examinations were performed in 10 of these cases. Anti-cytochrome 2D6(CYP2D6) antibodies, which are liver-specific autoantibodies, were measured using a sensitive radioligand assay.

RESULTS

Liver dysfunction developed between 1 and 5 months after delivery and was mild and transient except in one case. One patient developed liver dysfunction after abortion. Eight of 10 patients who underwent serial serologic examinations were positive for anti-nuclear antibodies, but anti-smooth muscle antibodies were positive in only three patients, and were present only at low titer. None of the patients had anti-mitochondrial antibodies. Nine of these 10 cases were diagnosed as definite or probable AIH according to the international scoring system of AIH. Nine of these 10 patients were positive for anti-CYP2D6 antibodies. The increase of anti-CYP2D6 antibodies was slightly delayed compared to increase of aminotransferase. Of the 18 patients who developed liver dysfunction, 15 cases (83.3%) were positive for anti-CYP2D6 antibodies. Of the 77 post-partum control subjects only three (3.9%) had positive antibodies.

CONCLUSIONS

Autoimmune hepatitis developed after delivery, similarly to the development of post-partum autoimmune thyroid disease. Measurement of anti-CYP2D6 antibodies by a sensitive radioligand assay could provide information important for the detection of post-partum AIH.

Possible induction of Graves' disease and painless thyroiditis by gonadotropin-releasing hormone analogues

Prolonged administration of gonadotropin-releasing hormone (GnRH) analogues induce a decrease in serum estrogen level, which may aggravate subclinical or mild autoimmune thyroid disease. Two patients developed Graves' thyrotoxicosis in association with an increase in anti-thyrotropin (TSH) receptor antibody activities at 4 months after initiation of buserelin acetate. GnRH analogue therapy was discontinued at the time of diagnosis but it took more than 2 years of methimazole therapy to obtain remission of Graves' disease. Another patient developed painless thyroiditis in association with an increase in antithyroid microsomal antibodies at 4 months after initiation of leuprolide acetate. These results indicate that GnRH analogues possibly induce clinical onset of Graves' thyrotoxicosis or destruction-induced thyrotoxicosis. Clinicians should be aware of this phenomenon. All patients who are to receive GnRH analogue therapy should be examined for antithyroid antibodies and family history of autoimmune thyroid disease, and should be followed accordingly.

Association of seasonal allergic rhinitis is high in Graves' disease and low in painless thyroiditis

Hashimoto's thyroiditis is thought to be a T-helper cell type 1 (TH1)-dependent disease, but it is not clear whether Graves' disease is T-helper cell type 2 (TH2)-predominant or not. TH1-predominant diseases are infrequently and TH2-predominant diseases are frequently associated with allergic diseases. We examined the prevalence of seasonal allergic rhinitis to Japanese cedar pollen, a typical TH2-associated disease, in patients with Graves' disease (n = 126), painless thyroiditis (n = 46) and Hashimoto's thyroiditis (n = 88), and compared them to healthy controls (n = 766). Gender and age distribution were not different among patient groups and healthy controls, except for the higher age of patients with Hashimoto's thyroiditis. The prevalence of seasonal allergic rhinitis was significantly high in patients with Graves' disease (42.9%, p < 0.05) and low in patients with painless thyroiditis (13.0%, p < 0.01) but was not different in patients with Hashimoto's thyroiditis (26.1%) compared to that of healthy controls (32.6%). When patients with painless thyroiditis were included in Hashimoto's thyroiditis group, the prevalence of seasonal allergic rhinitis was 21.6% and significantly different from that of healthy controls (p < 0.05). These data indicate that Graves' disease is TH2 predominant and painless thyroiditis is a TH1-predominant disease. Our findings suggest that the shift from TH2 toward TH1 immunogenesis may be important for achieving earlier remission of Graves' disease.

Blocking-type anti-TSH receptor antibodies and relation to responsiveness to antithyroid drug therapy and remission in Graves' disease

OBJECTIVE

Antithyroid drugs are effective in some patients with Graves' disease but not in others. The factors responsible for this difference are still unknown. We examined the relationship between the nature of anti-TSH receptor (TSH-R) antibodies and responsiveness to drugs in Graves' disease.

PATIENTS

Twenty-eight untreated patients with Graves' disease were treated with thiamazole and followed for up to 13 years.

MEASUREMENT

Antithyroid microsomal antibodies (MCHAs) and antithyroglobulin antibodies (TGHAs) were measured by the passive haemagglutination method. Anti-TSH-R antibodies were measured by a radioreceptor assay (TBII), and thyroid-stimulating antibodies (TSAbs) and TSH-stimulation blocking antibodies (TSBAbs) were measured by bioassays using FRTL-5 cells. Blocking antibodies were also measured by the conversion assay. In order to confirm the usefulness of the conversion assay, in vitro experiments using mixtures of TSAb serum and TSBAb serum were performed.

RESULTS

In in vitro conversion experiments, the conversion assay sensitively detected coexisting blocking antibodies. TSBAb was found in seven patients and a positive conversion ratio was found in four patients, and, of these, three patients had both antibodies. Finally, eight patients (28.6%) had blocking antibodies and 25 of 28 patients (89.3%) had stimulating antibodies. These patients with blocking antibodies (Group A) responded well initially to antithyroid drugs and showed earlier normalization of the serum T4 level (3.0 +/- 1.2 weeks) than patients without blocking antibodies (Group B, 10.7 +/- 8.5, P < 0.001). Unexpectedly, remission of Graves' thyrotoxicosis was earlier in Group B (5.1 +/- 4.4 years) than in Group A (8.0 +/- 4.3 years, P < 0.05). Other parameters, including serum T4, goitre size, ophthalmopathy, TBII, TSAb, TGHA and MCHA, were not different between the two groups.

CONCLUSIONS

Graves' patients with coexisting blocking antibodies initially respond well to thiamazole but are relatively slow to achieve remission. Measurement of blocking antibodies may be useful for selection of treatment options in Graves' disease.

Development of liver dysfunction after delivery is possibly due to postpartum autoimmune hepatitis. A report of three cases

Autoimmune diseases, especially autoimmune thyroid disease, frequently develop after delivery due to the immune rebound mechanism. Most cases involve transient dysfunction of affected organs. We examined three patients who developed liver dysfunction after delivery. They were all diagnosed with definite or probable autoimmune hepatitis using the scoring system of the International Autoimmune Hepatitis Group. Moreover, all of them had anti-CYP2D6 antibodies detected by a sensitive radioligand assay. Our findings strongly suggest that liver dysfunction is induced by postpartum autoimmune hepatitis, and clinicians should be aware of this disease.

Simple and practical parameters for differentiation between destruction-induced thyrotoxicosis and Graves' thyrotoxicosis

OBJECTIVE

Differentiation of destruction-induced thyrotoxicosis from Graves' thyrotoxicosis is important for selection of therapy. It is, however, often difficult to make this distinction without measurement of radioactive iodine uptake. We searched for simple and practical parameters that might allow differentiation between the two entities.

PATIENTS

One hundred and eleven untreated patients with thyrotoxicosis (69 Graves' disease, 21 painless thyroiditis, 21 subacute thyroiditis) and 45 normal controls were examined.

MEASUREMENTS

Serum levels of free T4 (FT4) and free T3 (FT3) were measured by radioimmunoassay, and anti-TSH receptor antibodies (TBII) were measured by radioreceptor assay. Peripheral leucocyte counts and the percentages of eosinophils and monocytes were measured using an automated leucocyte differential system.

RESULTS

Peripheral eosinophils were significantly higher in Graves' disease (3.54 +/- 4.18%, P < 0.05) and lower in subacute thyroiditis (1.08 +/- 1.03%, P < 0.001) than in normal controls (2.26 +/- 1.33%). Peripheral monocytes were significantly higher in painless thyroiditis (6.87 +/- 2.85%, P < 0.01) than that in normal controls (4.63 +/- 2.14%). In comparison between groups, FT3 was higher with Graves' disease (20.55 +/- 10.29 pmol/l) than both painless thyroiditis (11.59 +/- 8.22 pmol/l, P < 0.001) and subacute thyroiditis (15.27 +/- 8.63 pmol/l, P < 0.05). The eosinophil to monocyte (Eo/Mo) ratio, FT3/FT4 ratio and Eo/Mo ratio multiplied by FT3 (pmol/ml) (Eo/Mo.FT3) were calculated and compared in these three disease groups. The Eo/Mo ratio, FT3/FT4 ratio and Eo/Mo.FT3 were significantly higher in patients with Graves' thyrotoxicosis (0.782 +/- 0.759, 0.399 +/- 0.089, 16.7 +/- 23.5 pmol/l, respectively) than in those with painless thyroiditis (0.259 +/- 0.157, 0.304 +/- 0.072, 2.43 +/- 1.49 pmol/l, respectively) and subacute thyroiditis (0.234 +/- 0.241, 0.335 +/- 0.057, 2.98 +/- 3.51 pmol/l, respectively). Twenty-two of 24 (91.7%) thyrotoxic patients with Eo/Mo < 0.2 had destruction-induced thyrotoxicosis (painless or subacute thyroiditis). Twenty-two of 28 (78.6%) thyrotoxic patients with FT3/FT4 < 0.3 had destruction-induced thyrotoxicosis. Thirty-six of 42 (85.7%) thyrotoxic patients with Eo/Mo.FT3 < 4.5 had destruction-induced thyrotoxicosis. The Eo/Mo ratio, FT3/FT4 ratio and Eo/Mo.FT3 were found to be similarly useful for differentiation between the two types of thyrotoxicosis. All thyrotoxic patients with TBII > or = 20% had Graves' disease and 76.4% of patients with TBII < 20% had destruction-induced thyrotoxicosis.

CONCLUSION

The Eo/Mo ratio, FT3/FT4 ratio, and Eo/Mo.FT3 are simple, practical parameters and were as effective as TBII for differentiation of destruction-induced thyrotoxicosis (painless or subacute thyroiditis) from Graves' thyrotoxicosis. Eo/Mo < 0.2 and/or Eo/Mo.FT3 < 4.5 in untreated thyrotoxic patients are laboratory signals of destruction-induced thyrotoxicosis, and if these are determined, the radioactive iodine uptake test can be omitted for differential diagnosis of these two types of thyrotoxicosis.