A T-cell engaging bispecific antibody with a tumor-selective bivalent folate receptor alpha binding arm for the treatment of ovarian cancer

The use of T-cell engagers (TCEs) to treat solid tumors is challenging, and several have been limited by narrow therapeutic windows due to substantial on-target, off-tumor toxicities due to the expression of low levels of target antigens on healthy tissues. Here, we describe TNB-928B, a fully human TCE that has a bivalent binding arm for folate receptor alpha (FRα) to selectively target FRα overexpressing tumor cells while avoiding the lysis of cells with low levels of FRα expression. The bivalent design of the FRα binding arm confers tumor selectivity due to low-affinity but high-avidity binding to high FRα antigen density cells. TNB-928B induces preferential effector T-cell activation, proliferation, and selective cytotoxic activity on high FRα expressing cells while sparing low FRα expressing cells. In addition, TNB-928B induces minimal cytokine release compared to a positive control TCE containing OKT3. Moreover, TNB-928B exhibits substantial ex vivo tumor cell lysis using endogenous T-cells and robust tumor clearance in vivo, promoting T-cell infiltration and antitumor activity in mouse models of ovarian cancer. TNB-928B exhibits pharmacokinetics similar to conventional antibodies, which are projected to enable favorable administration in humans. TNB-928B is a novel TCE with enhanced safety and specificity for the treatment of ovarian cancer.

Circulating tumor DNA monitoring for early recurrence detection in epithelial ovarian cancer

OBJECTIVE

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. We examined the utility of circulating tumor DNA (ctDNA) as a prognostic biomarker for EOC by assessing its relationship with patient outcome and CA-125, pre-surgically and during post-treatment surveillance.

METHODS

Plasma samples were collected from patients with stage I-IV EOC. Cohort A included patients with pre-surgical samples (N = 44, median follow-up: 2.7 years), cohort B and C included: patients with serially collected post-surgically (N = 12) and, during surveillance (N = 13), respectively (median follow-up: 2 years). Plasma samples were analyzed using a tumor-informed, personalized multiplex-PCR NGS assay; ctDNA status and CA-125 levels were correlated with clinical features and outcomes.

RESULTS

Genomic profiling was performed on the entire cohort and was consistent with that seen in TCGA. In cohort A, ctDNA-positivity was observed in 73% (32/44) of presurgical samples and was higher in high nuclear grade disease. In cohort B and C, ctDNA was only detected in patients who relapsed (100% sensitivity and specificity) and preceded radiological findings by an average of 10 months. The presence of ctDNA at a single timepoint after completion of surgery +/- adjuvant chemotherapy and serially during surveillance was a strong predictor of relapse (HR:17.6, p = 0.001 and p < 0.0001, respectively), while CA-125 positivity was not (p = 0.113 and p = 0.056).

CONCLUSIONS

The presence of ctDNA post-surgically is highly prognostic of reduced recurrence-free survival. CtDNA outperformed CA-125 in identifying patients at highest risk of recurrence. These results suggest that monitoring ctDNA could be beneficial in clinical decision-making for EOC patients.

Abstract 6244: A T cell engaging bispecific antibody utilizing a bivalent tumor-selective folate receptor alpha binding arm for the treatment of ovarian cancer

The use of T cell engagers (TCEs) to treat solid tumors in humans is challenging, and several have been limited by narrow therapeutic windows due to substantial toxicity. Dose-limiting toxicities of TCEs include cytokine release syndrome (CRS) and on-target, off-tumor toxicities since many solid tumor target antigens are also expressed in healthy tissues, albeit at lower levels. While there have been improvements in the clinical management of immune-mediated toxicities such as CRS, on-target, off-tumor effects remain one of the primary challenges of using TCEs for treatment of solid tumors. Here, we describe TNB-928B, a novel fully human TCE that is bivalent for folate receptor alpha (FRα) that selectively targets FRα overexpressing tumor cells yet avoids targeting cells that express low levels of FRα found in normal human cells. Selectivity is conferred by an avidity effect of the FRα targeting arm in combination with a unique low-affinity CD3 arm and is anticipated to reduce the risk of adverse events in normal cells expressing low levels of FRα. TNB-928B induces preferential effector T cell activation, proliferation, and cytotoxic activity with minimal cytokine release, compared to a positive control containing OKT3, thereby improving the therapeutic index. Moreover, TNB-928B exhibits substantial ex vivo tumor cell lysis using endogenous T cells and is effective in vivo promoting T cell infiltration and tumor regression in mouse models of ovarian cancer. Together, these results demonstrate TNB-928B represents a novel next generation immunotherapy modality with enhanced safety and specificity for the treatment of ovarian cancer.

Citation Format: Brian C. Avanzino, Kirthana Prabhakar, Pranjali Dalvi, Sharon Hartstein, Hannes Kehm, Aarti Balasubramani, Andrew A. Boudreau, Ben Buelow, Karen Chang, Laura M. Davison, Suhasini Iyer, Vidyut Kalwit, Harbani Malik-Chaudhry, Will Pierson, Geovanni Pineda, Udaya S. Rangaswamy, Sowmya Saiganesh, Ute Schellenberger, Harshad S. Ugamraj, Roland Buelow, Jocelyn Chapman, Nathan D. Trinklein, Katherine E. Harris. A T cell engaging bispecific antibody utilizing a bivalent tumor-selective folate receptor alpha binding arm for the treatment of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6244.

Abstract 552: Circulating tumor DNA predicts disease recurrence in ovarian cancer patients

Introduction: Epithelial ovarian, fallopian tube, and peritoneal cancer (EOC) is the most lethal gynecologic malignancy with a 5-year survival rate of 47%. While primary treatment generally results in remission, most patients relapse within 3 years. CA-125 is a commonly used biomarker for recurrence detection, however, it lacks specificity and is not associated with improved survival. Here we examine the utility of circulating tumor DNA (ctDNA) as a biomarker for EOC by assessing its relationship to patient outcome and CA-125 when measured pre-surgically and during patient monitoring.

Methods: This study included patients diagnosed with stage I-IV EOC with plasma samples collected pre-surgically (n=44) and a group of patients (n=22) with serially collected samples after surgery. Median follow-up for patients with pre-surgical samples and with prospectively collected samples was 29 months (range: 6-150) and 15 months (range: 0.6-26), respectively. Whole exome sequencing was performed on patient tumors and matched normal tissue to design patient-specific ctDNA assays (bespoke mPCR NGS assay) for variant detection in plasma samples. The relationship between ctDNA status, CA-125 levels, and recurrence-free survival (RFS) were evaluated (Fisher's exact, log-rank test).

Results: Among patients with presurgical plasma samples high-grade serous was the most common histological subtype 66% (29/44). Endometrioid represented 11% (5/44) of tumors and 23% (10/44) were tumors of other epithelial subtypes. In this cohort 75% (33/44) had early-stage disease, 7% (3/44) were metastatic and 18% (8/44) had the unstaged disease. The presence of ctDNA was observed in 73% of samples at baseline with detection rates of 69% (20/29) for serous and 80% (4/5) for endometrioid histologies. Pre-surgical ctDNA detection was significantly associated with a higher grade (p=0.003). All patients with ctDNA negative status at baseline (n=12) survived until the end of follow-up (median: 25 months), while 3 deaths were observed among ctDNA positive patients (n=32; p=0.003).

In the sub-cohort of patients with prospective post-surgical plasma collection, ctDNA was observed in samples of all patients who relapsed (7/7; 100% sensitivity). ctDNA detection preceded radiological findings by a median of 9 months (range: 2-36). None of the patients with ctDNA negative status within 6 months after enrollment experienced disease progression (13/13; 100% specificity). The presence of ctDNA was observed to be a strong predictor of relapse (HR: 12.75, 95%CI: 1.7-94 p&lt;0.0001), while CA-125 was not significantly associated with RFS (HR: 1.3, 95%CI: 0.3-6.3; p=0.09).

Conclusions: The presence of ctDNA post-surgically is highly prognostic of decreased RFS and was found to be a stronger predictor of disease progression than CA-125 monitoring. These results suggest that monitoring ctDNA could be a useful tool in clinical decision making for patients with EOC.

Citation Format: Jocelyn S. Chapman, William E. Pierson, Karen Smith-McCune, Geovanni Pineda, Reena M. Vattakalam, Alexandra Ross, Meredith A. Mills, Carlos J. Suarez, Tracy Davis, Robert P. Edwards, Michelle Boisen, James M. Ford, June Y. Hou, Hsin-Ta Wu, Scott Dashner, Ekaterina Kalashnikova, Angel Rodriguez, Bernhard Zimmermann, Sarah Sawyer, Himanshu Sethi, Alexey Aleshin. Circulating tumor DNA predicts disease recurrence in ovarian cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 552.

Immune-Related Adverse Events and Immune Checkpoint Inhibitor Efficacy in Patients with Gastrointestinal Cancer with Food and Drug Administration-Approved Indications for Immunotherapy

INTRODUCTION

Immune-related adverse event (IRAE) onset may represent a clinical biomarker for anti-programmed cell death protein 1 (PD-1) antibody response based on emerging evidence from patients with various advanced malignancies. This phenomenon has not been previously reported in a multidisease cohort of patients with gastrointestinal (GI) cancer with Food and Drug Administration (FDA)-approved indications to receive immune checkpoint inhibitor therapy.

MATERIALS AND METHODS

The study was a multicenter retrospective cohort analysis of 76 patients with GI cancer who had received anti-PD-1 antibodies for FDA-approved indications. The primary and secondary outcomes of the study were progression-free survival (PFS) and overall survival (OS) in patients based upon IRAE presence, respectively. PFS and OS were estimated by the Kaplan-Meier method; a Cox proportional-hazards model adjusted for IRAE onset, patient age, and enrolling institution was used to analyze outcomes.

RESULTS

Median PFS and OS were prolonged in patients who experienced IRAEs compared with those who did not experience them (PFS: not reached [NR] vs. 3.9 months [hazard ratio (HR) 0.13, 95% confidence interval (CI) 0.05-0.3, p < .001]; OS: NR vs. 7.4 months [HR 0.11, 95% CI 0.03-0.36, p < .001]). Among patients who experienced IRAEs, there were no significant differences in PFS and OS by either initial IRAE severity, management, or time to onset.

CONCLUSION

Patients with gastrointestinal cancer who experienced IRAEs while on anti-PD-1 antibodies demonstrated significant improvements in PFS and OS compared with their counterparts who did not develop IRAEs. Although these findings add to results from studies in other tumor types, larger prospective studies are needed prior to clinical adoption of IRAE onset as a biomarker for immune checkpoint inhibitor response.

IMPLICATIONS FOR PRACTICE

Predictive clinical biomarkers for immune checkpoint inhibitor response have been understudied in the field of immuno-oncology. Immune-related adverse event onset appears to be one such biomarker. Across tumor types, immune-related adverse event onset has been associated with response to anti-programmed cell death protein 1 (PD-1) antibodies. The results of this study demonstrate this for the first time in patients with gastrointestinal cancer receiving anti-PD-1 antibodies. Before immune-related adverse event onset can be adopted clinically as a predictive biomarker for immune checkpoint inhibitor response, however, larger prospective studies are needed to better understand the nuances between immune-related adverse event characteristics (severity, site, management, timing of onset) and immune checkpoint inhibitor effectiveness.

[Isolation of Candida dubliniensis in different clinical samples. Analysis of phenotypical methods to differentiate it from Candida albicans]

In order to estimate the frequence of Candida dubliniensis in clinical samples in F. J. Muñiz Infectious Diseases Hospital, a total of 388 yeasts from September 2005 to August 2007. There were 212 isolates which presented a green color on CHROMagar Candida medium and produced germ tubes and chlamidoconidiae in milk-agar; so as to distinguish whether they corresponded to Candida albicans or C. dubliniensis, different phenotypical methods were utilized. It was also evaluated the usefulness of each one in order to suggest a simple, economic and reliable identification algorithm. Each isolate was subcultured in two chromogenic media and then, the following determinations were done: chlamidospores production in Staib-agar, tomato-carrot-agar and tobacco-agar, colonies macromorphology was also studied in the last medium; opacity-test in Tween 80-CaCl2 agar (lipase activity), growing capacity at 45 degrees C, and D-xylose assimilation. Thirteen strains (6.1%) corresponded to C. dubliniensis. The difference in color between both species on chromogenic media was not so stressed as it is pointed out in some works. The more specific and sensitive tests were the ability to grow at 45 degrees C, D-xylose assimilation, color and macroscopic appearance in tobacco-agar. Between 11.6% and 15.1% of C. albicans strains produced chlamidoconidiae in the 3 differential media tested. The opacity halo (lipase) was evident in 95.6% of C. albicans isolates but 2 out of 13 C. dubliniensis also presented precipitation halo. We consider that at least 3 different phenotypical methods should be used to distinguish properly these two species since none of the tests is absolutely sensitive or specific.

Mojave rattlesnakes (Crotalus scutulatus scutulatus) lacking the acidic subunit DNA sequence lack Mojave toxin in their venom

The venom composition of Mojave rattlesnakes (Crotalus scutulatus scutulatus) differs in that some individuals have Mojave toxin and others do not. In order to understand the genetic basis for this difference, genomic DNA samples from Mojave rattlesnakes collected in Arizona, New Mexico, and Texas were analyzed for the presence of DNA sequences that relate to the acidic (Mta) and basic (Mtb) subunits of this toxin. DNA samples were subjected to PCR to amplify nucleotide sequences from second to fourth exons of the acidic and basic subunits. These nucleotide sequences were cloned and sequenced. The nucleotide sequences generated aligned exactly to previously published nucleotide sequences of Mojave toxin. All DNA samples analyzed generated product using the basic subunit primers, and aligned identically to the Mtb nucleotide sequence. However, only 11 out of the 14 samples generated a product with the acidic subunit primers. These 11 sequences aligned identically to the Mta nucleotide sequence. The venom from the three snakes whose DNA did not amplify with the acidic subunit primers were not recognized by antibodies to Mojave toxin. This suggests that snakes with venom lacking Mojave toxin also lack the productive nucleotide sequence for the acidic subunit in their DNA.

Impaired temporo-occipital blood flow in an atypical CLN1 case with late infantile onset and granular osmiophilic deposits

A 5-year-old boy presented with frequent absences. Speech began to regress. He became ataxic, barely able to walk. Studies with Xe-133 and hexamethylpropylene amine oxime single-photon emission computed tomography revealed sharply decreased cerebral blood flow, especially in the occipital area. Landau-Kleffner syndrome was suspected but a sleep electroencephalogram showed few abnormalities. He was started on clorazepate and diltiazem. A skin biopsy to rule out possible CLN2 revealed, instead of the predicted curvilinear profiles, granular osmiophilic deposits, consistent with infantile neuronal ceroid lipofuscinosis (CLN1). The family reported increased seizure frequency and consulted with a colleague, who advised them to resume valproate and discontinue diltiazem. The boy died shortly thereafter. Decreased cerebral blood flow is a new finding in CLN1 with delayed onset. Calcium-channel blockers improve cerebral blood flow and perhaps delay clinical regression.

[Thyroid hemiagenesis associated with Basedow-Graves disease. Report of a case]

We report a 35 years old female with left lobe thyroid hemiagenesis who initially was euthyroid and then developed hyperthyroidism due to Graves disease. Hemiagenesis of the thyroid gland is a rare anomaly with an uncertain incidence; up to now 256 cases have been reported. The detection is often made by either clinical symptoms of thyroid dysfunction, by imaginological studies or surgical/pathological procedures. No explanation has been given for the development of this anomaly; left lobe aplasia and predominance of occurrence in women have been most frequently reported.

[Multiple endocrine neoplasia: a clinical model for applying molecular genetic techniques]

Multiple endocrine neoplasias (MEN) are syndromes inherited as autosomal dominant. The application of the techniques of molecular biology has made possible the identification of the genes causing MEN 1 and 2. The gene responsible for MEN 1 belongs to the family of tumor suppressor genes and encodes for a protein named MENIN whose function remains to be elucidated. The identification of mutant MEN 1 gene carriers who are at risk of developing this syndrome requires frequent biochemical screening for the development of endocrine tumors. MEN 2 is a consequence of mutations in the Ret proto-oncogene (c-Ret). This gene encodes for a tyrosine kinase receptor thought to play a role in the development of neural crest-derived tissue. Members of kindred with either MEN 2A or MEN 2B should be screened by direct DNA testing early in life for mutations in c-Ret. Those with the mutation should be advised to have thyroidectomy at five years of age in children with MEN 2A and earlier in children with MEN 2B. Some cases of sporadic MTC are actually MEN 2A or Familial MTC after c-Ret testing is done, therefore routine application of this test is recommended in all cases of apparent sporadic MTC.

[Treatment of diffuse hyperthyroid goiter with radioiodine: influence of propylthiouracil pretreatment]

BACKGROUND

To stabilize Graves disease and deplete the preformed hormone, the use of antithyroid drugs prior 131I therapy has been suggested, specially in those patients with severe thyrotoxicosis and in the elderly. However, PTU may reduce the effectiveness of 131I.

AIM

To study the effects of PTU pretreatment before 131I administration. SUBJETS AND METHODS: A retrospective analysis of the medical records of patients with Graves disease treated with 131I from 1989 to 1997 was made. Of 244 patients with adequate follow-up for at least 12 months after 131I treatment, 142 had not been pretreated and 102 had received PTU prior to 131I therapy. Pretreated patients were distributed according to the number of days that PTU was discontinued before receiving 131I, forming four groups (a = 5 d, b = 6-14 d, c = 15-30 d and d = 31-60 d). Radioiodine was delivered according to our protocol of 120 microCi per gram of thyroid tissue, as estimated by clinical examination. Therapy was considered successful when laboratory evidence of euthyroidism or hypothyroidism after one year of treatment was obtained and as a failure when undetectable TSH values persisted after 12 months of treatment with 131I.

RESULTS

All groups were comparable as to age, gender, goiter size, and 24 h radioiodine uptake. Control of hyperthyroidism was achieved in 76% of the non pretreated group. A similar percentage was observed in groups (b), (c) and (d). However, the disease was controlled in only 50% of group (a) patients (p < 0.003).

CONCLUSIONS

The therapeutic efficacy of 131I is significantly reduced when the PTU is stopped for only a few days prior to the use of radioiodine. We postulate that PTU has to be discontinued for at least 10 days before radioiodine administration.

Thinner abuse alters optokinetic nystagmus parameters

BACKGROUND

Deliberate self-inhalation of solvents such as thinner is a recognized problem in underdeveloped countries, with chronic abuse resulting in neurological impairment. In this article, we use electronystagmography (ENG) to study optokinetic nystagmus abnormalities (OKN) that may be induced by thinner consumption.

METHODS

Twenty-five patients exposed to thinner for 5-20 years, in an irregular fashion of consumption, were recruited from a toxicologic center. Twenty-five control subjects were invited to participate as volunteers matched by age (+/-2 years) and gender. At the time of evaluation, all had abstained from intoxicants for at least 4 weeks. ENG recordings were performed by clinicians masked to the patient's group. Clockwise and counterclockwise stimulation were performed at 20 and 40 degrees /sec.

RESULTS

None of the patients showed spontaneous nystagmus during the test period. Differences between thinner abusers and controls on clockwise and counterclockwise OKN on number of beats of nystagmus elicited on the 40 degrees /sec velocity were identified. The thinner abusers group showed a lesser number of nystagmus (p level was 0.02 and 0.005, respectively).

CONCLUSIONS

The present results confirm the sensibility of OKN as an early marker of solvent abuse. These results were obtained in middle-term chronic exposure to solvent mixtures and are in favor of both cortical and brainstem dysfunction.

[Thyroid function tests in normal pregnant women (third trimester) and in pregnant women with pregnancy cholestasis or with acute hepatitis]

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a disease of unknown cause characterized by pruritus and biochemical cholestasis in the 3rd trimester of pregnancy. Its pathogenesis may be due to the interaction of abnormalities in the metabolism of estrogens and progesterone, while still unknown environmental factor (s) modulate the expressivity of a genetic predisposing trait.

AIMS

To verify if thyroid function tests (TFT) are altered in ICP as in other hepatic diseases and whether a dietary iodine deficiency could be involved.

MATERIAL AND METHODS

From 1983 to 1986, 13 normal pregnancies (3rd trimester), 26 ICP patients (with 30 pregnancies) and 4 patients with acute non-A non-B hepatitis in pregnancy, were studied. Serum T3, rT3, T4, fT4 and TSH (before and after TRH) were measured by RIA; in ICP patients, measurements were repeated in puerperium. Urinary 24 h iodine excretion was measured in normal pregnancies and in 6 ICP patients.

RESULTS

In normal pregnancies, T3 (3.00 +/- 0.22 nmol/L) and rT3 (0.40 +/- 0.03 nmol/L) were higher than the values detected in non-pregnant women; other TFT were unchanged. Urinary iodine excretion was normal in all individuals tested. Patients with acute hepatitis in pregnancy or with ICP had lower T3 than normal pregnancies (1.82 +/- 0.19 nmol/L in hepatitis; 2.24 +/- 0.12 nmol/L in ICP; p < 0.01) and higher rT3 (0.80 +/- 0.25 nmol/L in hepatitis; 0.54 +/- 0.05 nmol/L in ICP; p < 0.05), while other TFT were unchanged. None of them had clinical signs of hypo or hyperthyroidism. A "euthyroid sick syndrome" was detected in 2 ICP patients and in 2 acute hepatitis in pregnancy. In puerperium of ICP patients, T3 and rT3 returned to levels in non-pregnant women.

CONCLUSIONS

In ICP patients, TFT show similar trends than in more severe hepatic and non-hepatic diseases. Although thyroid binding-globulin was not measured in our patients, the pattern of TFT suggests that an impaired peripheral (hepatic?) deiodination of T4 is responsible for these changes. The influence of a dietary iodine deficiency can be ruled out.

Hypocholesterolemic effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in the guinea pig: atorvastatin versus simvastatin

Male Hartley guinea pigs were fed a hypercholesterolemic diet rich in lauric and myristic acids with 0, 10, or 20 mg/kg of simvastatin or atorvastatin for 21 days. Atorvastatin and simvastatin resulted in a lowering of plasma low-density lipoprotein (LDL) cholesterol in a dose-dependent manner by an average of 48 and 61% with 10 and 20 mg/kg, respectively. Both statins were equally effective in lowering plasma LDL cholesterol and apolipoprotein B (apo-B) levels. Atorvastatin and simvastatin treatments yielded LDL particles that differed in composition from the control. Due to the relevance of LDL oxidation and cholesteryl ester transfer in plasma to the progression of atherosclerosis, these parameters were analyzed after statin treatment. Atorvastatin and simvastatin treatment decreased the susceptibility of LDL particles to oxidation by 95% as determined by the formation of thiobarbituric acid reactive substances. An 80% decrease in the transfer of cholesteryl ester between high-density lipoprotein (HDL) and the apo-B-containing lipoproteins was observed after simvastatin and atorvastatin treatment. In addition, statin effects on plasma LDL transport were studied. Simvastatin- and atorvastatin-treated guinea pigs exhibited 125 and 175% faster LDL fractional catabolic rates, respectively, compared with control animals. No change in LDL apo-B flux was induced by either treatment; however, LDL apo-B pool size was reduced after statin treatment. Hepatic microsomal free cholesterol was lower in the atorvastatin and simvastatin groups. However, only atorvastatin treatment resulted in an 80% decrease of acyl-CoA:cholesterol acyltransferase activity (P < 0.001). In summary, atorvastatin and simvastatin had similar LDL cholesterol lowering properties, but these drugs modified LDL transport and hepatic cholesterol metabolism differently.

Lingual thyroid: report of three cases

Lingual thyroid is a rare developmental disorder and is more frequent in women. The pathogenesis is unclear but may be related to the presence of maternal blocking autoantibodies against the thyroid. Treatment of this disorder includes the use of levothyroxine in order to correct the hypothyroidism, which is very frequent and to induce the shrinkage of the gland. When symptoms of obstruction or bleeding appear, ablative therapy by means of surgery or radioiodine is warranted. We report three cases and discuss the approach to diagnosis and a strategy for management.

Childhood absence epilepsy with tonic-clonic seizures and electroencephalogram 3-4-Hz spike and multispike-slow wave complexes: linkage to chromosome 8q24

Childhood absence epilepsy (CAE), a common form of idiopathic generalized epilepsy, accounts for 5%-15% of childhood epilepsies. To map the chromosomal locus of persisting CAE, we studied the clinical and electroencephalographic traits of 78 members of a five-generation family from Bombay, India. The model-free affected-pedigree member method was used during initial screening with chromosome 6p, 8q, and 1p microsatellites, and only individuals with absence seizures and/or electroencephalogram 3-4-Hz spike- and multispike-slow wave complexes were considered to be affected. Significant P values of .00000-.02 for several markers on 8q were obtained. Two-point linkage analysis, assuming autosomal dominant inheritance with 50% penetrance, yielded a maximum LOD score (Zmax) of 3.6 for D8S502. No other locus in the genome achieved a significant Zmax. For five smaller multiplex families, summed Zmax was 2.4 for D8S537 and 1.7 for D8S1761. Haplotypes composed of the same 8q24 microsatellites segregated with affected members of the large family from India and with all five smaller families. Recombinations positioned the CAE gene in a 3.2-cM interval.

[Treatment of Basedow-Graves' hyperthyroidism: retrospective analysis after 30 years]

BACKGROUND

It is still debated which is the best treatment for Basedow-Graves' hyperthyroidism (BGH). We reviewed 195 patients treated and followed-up during the past 30 years: 88 treated with propylthiouracil (PTU), 70 with 131I and 37 thyroidectomized.

AIM

to analyze the efficacy of each therapy in terms of achieving euthyroidism and the search of possible indexes for success. Surgery attained euthyroidism in 70.2% but has disadvantages; 131I accounted for the highest hypothyroid rate (72.1%) irrespective of the dose administered; PTU alone was successful in only 26.4% but combined with T4, success rose to 62.5% (p < 0.025). Suppression test and/or TRAb measurements after 6 mo PTU therapy were used to decide if therapy continued or was changed to other form of treatment. Using this criteria, 87.5% of pts with positive results achieved longstanding euthyroidism. Pretreatment predictive indexes were goiter size, T4 levels and 24 h/RAI uptake.

CONCLUSIONS

As 131I induces hypothyroidism in over 2/3 of pts and surgery besides its cost is not devoid of serious complications, we advocate for the use of PTU as first line therapy; combined treatment (PTU + T4) seems promising. If after 6 mo on PTU, TRAb or Suppression test do not improve, we recommend 131I or surgery.

[Subacute thyroiditis and concurrent suppurative thyroiditis in one case]

We report a 41 years old man admitted with a tender goiter, fever, thyrotoxic manifestations and atrial fibrillation. Laboratory confirmed the diagnosis of subacute thyroiditis and treatment with aspirin and propranolol was started, obtaining a rapid relief of symptoms and normalization of heart rate. On the tenth day after admission, severe dysphagia, dysphonia, irritative cough and further enlargement of the neck mass developed. Fine needle aspiration of the mass and thyroid ultrasound lead to the diagnosis of a thyroidal abscess, which was surgically excised, draining 250 ml of purulent material. Cultures were positive for Staphylococcus aureus. Patient was treated during 21 with cloxacilyn and discharged with normal thyroid function. Long term follow up has been uneventful.

[Determination of antibody antireceptor of TSH, experience in patients with thyroid disorders and controls]

In order to measure TSH receptor antibodies (TRAb) we tried to set up a radioreceptor assay using human thyroid membranes. Due to lack of appropriate binding activity of the material obtained, we decided to use a kit which provides solubilized porcine membrane-receptors to TSH instead of human membranes, as well as calibrators that have been standardized in a receptor assay against MRC LATS std B. With these reactives we have measured TRAb in sera from 7 normal controls (C), 54 thyrotoxic patients (43 diffuse goiters [BDH], 8 multinodular goiters [BHM] and 3 Subacute Thyroiditis [TSA]), 3 patients with Hashimoto's Thyroiditis (TH) and in 6 non-hyperthyroid Graves ophthalmopathy patients. Measurement were initially performed using calibrators and the results expressed as U/L; since a very good correlation between the expression U/L and the calculated Inhibition Index (I.I.) was found (r = 0.99, n = 15, p < 0.001), results are shown using latter. In C mean +/- SD value for I.I. was 3.4 +/- 2.37%, so we decided to use, as cut off criteria for differentiating between normal and abnormal results, the figure 11%, which represents the mean +/- 3 SD. According to this, 93% of BDH had elevated TRAb activity while only slightly more than one third of MBH had elevated values, this difference being highly significant (p < 0.0001); both TSA and TH patients showed low TRAb activity while all Graves ophthalmopathy pts had elevated values, thus suggesting that they had a latent disease. We concluded that the methodology that is adequate and practical for clinical purposes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of insulin-like growth factor I on HLA-DR antigen expression in cultured human thyrocytes: a component of the autoimmune process?]

The aim of this study was to determine whether IGF-1 and INS are able to induce HLA-DR antigen expression (AgHLA-DR) in cultured human thyrocytes. Cytotoxicity assay in thyroid epithelial cells (cultured for 7 days to avoid spontaneous antigen expression) from 14 patients operated due to different thyroidal diseases, was used to assess HLA-DR expression. AgHLA-DR was reinduced adding IFN-delta, IGF-1 or INS to the culture media, alone, combined or associated with TSH or TBII. Both IGF-1 and INS induced HLA-DR expression in a similar way as IFN-delta did, and the response was enhanced with their combination, suggesting that they have different sites of action. Their association with TSH or TBII further augmented the response. To determine if IGF-1 acts via lymphocyte IFN-delta secretion, peripheral lymphocytes from 5 normal subjects were cultured with and without IGF-1 and the supernatant was used as stimulator, observing a stimulation similar to that induced by IFN-delta. This finding supports the hypothesis that IGF-1 acts stimulating a specific tyrosine kinase protein (p56 1ck) which is located in T lymphocyte receptors. According to our results we can conclude that, at least in vitro, both IGF-1 and INS play a role in the immune process, probably exerting a paracrine effect on autoimmunity, acting as perpetuating factors.

[Intrathyroidal lymphocytes in autoimmune thyroid diseases]

Aiming to assess the autoimmune origin of certain thyroid diseases, we studied the phenotypic composition and the ability of intrathyroidal lymphocytes to a re-induce HLA-DR expression on autologous thyrocytes coming from patients with graves's disease, nodular goiter and papillary thyroid carcinoma. Lymphocytes coming only from graves's disease patients were capable of reinduce HLA-DR expression on autologous thyrocytes (24.1 +/- 13.6 vs 1.5 +/- 2.54% in nodular goiter and carcinoma), as interferon gamma did (17.4 +/- 8.34%). Phenotypic characterization showed a significant decrease of T-CD3 (total lymphocytes) and T-CD4 (helper) in lymphocytes coming from patients with nodular goiter and carcinoma, and a marked reduction of T-CD8 (suppressor) in lymphocytes coming from patients with graves disease. Thus the T-CD4/T-CD8 ratio varies according to the etiology of the thyroidal disease. The lack of suppressor activity would explain why cells coming only from patients with graves disease, show marked HLA-DR expression. These findings give little support to the autoimmune origin hypothesis for nodular goiter and thyroid carcinoma.

[Importance of gamma-interferon and DR expression in autoimmune thyroid disease]

The purpose of this paper is to study some of the mechanisms by which antigen presentation, one of the first steps in the immune process, is modulated. Three different experiments are performed: a) Using thyroid tissue from patients operated on for Graves' Disease, spontaneous HLA-DR and TPO antigen expressions were measured through the Cytotoxicity Assay; these findings were correlated with the presence of antiTPO in the sera of these patients. It was found that only patients whose thyroid tissue spontaneously expressed both antigens had circulating antiTPO in their sera, thus demonstrating that dual expression is basic for antibody production. b) Blood samples from other Graves' patients were obtained; peripheral lymphocytes were isolated and cultured in complete media for 5 days, then supernatant was separated and IFN-g concentration was measured by a sandwich type RIA; the same procedure was done in 12 normal controls in order to compare the results. It was found that lymphocytes from Graves' patients secreted significantly more IFN-g than normal controls (20.9 +/- 13.54 U/ml vs 3.7 +/- 3.22 U/ml respectively, p < 0.001) confirming that they were sensitized, so this determination could be used as a marker of immune process, if other infectious conditions are excluded; also it was found that IFN-g hypersecretion persists once hyperthyroidism has been treated, pointing out that the immune abnormality is still present.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experimental evidence that endogenous TSH modulates microsomal antigen expression: clinical implications]

The purpose of this work was to study if TSH has a role in TPO antigen expression in vivo. Using the cytotoxicity assay we measured TPO expression and correlated it with TSH serum levels in 3 groups of rats: control, hypothyroid and hypothyroid supplemented with thyroxine. For comparative purposes, in the cytotoxicity assay we used rat monoclonal antiTPO or human sera with high titles for antiTPO antibodies. Hypothyroid rats showed marked elevations of TSH serum levels and TPO antigen expression in their thyrocytes when compared to the control and supplemented group. A positive correlation between TPO antigen and TSH levels was observed (r = 0.69, p < 0.001). There was an excellent correlation between TPO results using rat monoclonal or human sera antibodies (r = 0.94 p < 0.0001). It is concluded that TSH modulates TPO antigen expression. These data are of clinical relevance considering that TSH modulates the expression of other antigens that can maintain the immune response and perpetuate the immune disease in patients with Graves disease treated with antithyroid drugs. Thus, the avoidance of TSH hypersecretion with administration of thyroxine could be useful to treat these patients.

[Lack of in vitro effect of antithyroid drugs upon peroxidase antigen expression in autoimmune thyroid disease]

The aim of this study is to determine whether antithyroid drugs (ATD) act via inhibiting thyroid hormone synthesis or by interfering with the immune process which leads to autoimmune disease. Previously we had demonstrated that ATD do not affect HLA-DR and TPO antigen expressions induced by appropriate stimulus in normal thyrocytes, so we decided to study what happens when the same experiments are performed using autoimmune thyrocytes. Cultured thyroid tissue from patients operated on for Graves' Disease or Hashimoto's Thyroiditis were stimulated with TSH or TBII alone or associated with ATD; TPO antigen expression was evaluated by the Cytotoxicity Assay using human monoclonal antiTPO. When autoimmune thyrocytes were cultured and no stimulus was used or with the addition of MMI or PTU alone, very low values of TPO expression were noted (8.6 +/- 6.7, 5.0 +/- 7.1 and 4.2% +/- 2.3% respectively); if they were stimulated with TSH or TBII, a sharp rise of TPO antigen expression was detected (54.4 +/- 23.3 and 62.6 +/- 16.5%), these figures being significantly different from unstimulated cells (p < 0.001). If both stimulus were used associated with ATD, the high TPO antigen expression was unaffected. It is concluded that, at least in vitro, ATD have no effect upon induced-antigen expression in autoimmune thyrocytes. Since they do not alter antigen presentation, a primary step in the immune process, it is difficult to accept that their mechanism of action is through interference with the immune response.

[Thyroid profile in normal pregnancy]

The aim of this study was to update the thyroid hormone profile in normal pregnant women with adequate iodine nutrition, to analyze the physiological changes that occur during pregnancy and to know the role that TBG and bHCG exert on these changes. One hundred six pregnant women without goiter, former thyroid diseases or positive antimicrosomal antibodies were studied. Fifty three of them were prospectively followed during the gestational period. Thirty age matched non pregnant women were studied as a control group. Serum T3t, T4t, T41, conventional and IRMA TSH, rT3, TBG, bHCG, antimicrosomal antibodies and urinary iodine content were measured. Median urinary iodine content was 18.9 ug/ml in pregnant women, discarding iodine deficiency, the main observed changes occurred between weeks 6 and 14 with significant elevations of T3t, T4t, T41, rT3, TBG and bHCG and TSH decrease. There was a positive correlation between TBG and T3t and T4t indicating a causal relationship. There was a negative correlation between T41 and TSH and between TSH and bHCG and a positive correlation between T41 and bHCG, suggesting a thyroid stimulator effect of bHCG which would raise T41 and thus inhibit TSH secretion.

[Treatment of hyperthyroidism during pregnancy: experience with 19 cases]

Untreated hyperthyroidism in pregnant women is associated with a high incidence of maternal and fetal complications. Thus, its treatment is mandatory, ideally using PTU because it has lesser transplacental passage. From 1987 and 1991 we have attended 19 hyperthyroid pregnant women. Of these, 18 had diffuse and 1 nodular goiter and in 10, thyrotoxicosis preceded pregnancy. PTU was used in 17 women (7 received it along the whole pregnancy), five had to be operated due to poor response, one received propranolol and one patient was not treated due to lack of attendance. Cesarean section was performed in 12 women, 5 had vaginal delivery, one had a miscarriage at the 20th week of pregnancy due to a neurological malformation and one patient was lost from control before delivery. The newborn of the untreated woman had a neonatal thyrotoxicosis and the resting 16 did not show evidence of thyroid disfunction. Newborns from mothers receiving PTU until delivery had significantly lower rT3 levels and non significant changes in T4 and T3. At the end of the observation period, 8 patients were euthyroid, 3 hypothyroid (2 after 131-l and 1 after surgery), 4 continued on PTU and 4 were lost from control. It is concluded that the outcome of pregnancy may be uneventful in hyperthyroid women provided that there is a close and adequate follow up.

Rapid preoperative preparation in hyperthyroidism

OBJECTIVE

We have evaluated an alternative method of preparation of hyperthyroid patients for surgery, using betamethasone, iopanoic acid and propranolol.

DESIGN

Betamethasone (0.5 mg every 6 hours), iopanoic acid (500 mg every 6 hours) and propranolol (40 mg every 8 hours) were given orally for 5 days; thyroidectomy was performed on the 6th day. We analysed patient acceptability, clinical and hormonal effects, ease of surgery and final outcome.

PATIENTS

Thirteen females and 1 male, aged 16-59 years, ten with diffuse goitre and four with nodular goitre were submitted to subtotal thyroidectomy because antithyroid drugs had failed to control thyrotoxicosis or because hyperthyroidism coexisted with other conditions (pregnancy, hypertensive disease).

MEASUREMENTS

Daily clinical assessments were made together with T3, T4 and rT3 serum concentrations before and while on drug treatment, during the surgical procedure and post-operatively.

RESULTS

Daily assessment showed progressive clinical improvement so that on day 5 the patients were considered clinically euthyroid. Serum levels of T3 (mean +/- SD) showed significant decrease (by 38.2 +/- 24.9%, P less than 0.01) as early as 24 hours after medication was started, reaching almost euthyroid levels on day 3; on the day of operation T3 had diminished by 64.5 +/- 16.6% (P less than 0.0001). Serum T4 concentration showed a slight but significant decrement only from day 4 on and never reached euthyroid levels. Serum rT3 values exhibited a brisk increment at 24 hours (+333 +/- 194%, P less than 0.0001) and remained elevated between 8 and 10 nmol/l until medication was stopped. Drug tolerance was considered as excellent since no serious side-effects were noted, even in pregnant patients. There were no anaesthetic incidents or postoperative complications and patients were discharged 48-72 hours after operation. The final outcome has been satisfactory and pregnant patients continued their pregnancies without incident, bearing normal children.

CONCLUSIONS

Pharmacological combination of betamethasone, iopanoic acid and propranolol has proved to be safe and effective and is of low cost. Provided there is adequate supervision of the patients, it may be used in patients requiring urgent thyroidectomy or in those who for reasons of non-compliance need a short preoperative regime.

[Spontaneous expression of class II (HLA-DR) molecules in thyroid pathology]

The spontaneous expression of Class II molecules (HLA-DR) was studied in cultured thyrocytes obtained from patients with Graves Disease (n = 7), Hashimoto's Thyroiditis (n = 5), euthyroid nodular goiter, (n = 12), papillary carcinoma (n = 5), and laryngeal carcinoma (3 normal thyroid glands). If nodular goiters and papillary carcinoma are of autoimmune origin, as Graves Disease and Hashimoto's Thyroiditis, they should spontaneously express HLA-DR antigen on their cell surface as this has been considered one of the initial steps of autoimmunity. The study was performed using the cytotoxicity assay. Immediately after the thyroid glands were obtained, thyrocytes were labelled with 51-Cr and incubated overnight; the cells were destroyed by adding monoclonal antiHLA-DR antibody and rabbit complement. The cytotoxicity index (CI% + SD) which reflects 51-Cr release from lyzed cells was used to measure antigen expression. While Graves Disease's and Hashimoto's Disease's thyrocytes expressed HLA-DR in high proportion, normal thyrocytes and thyroid cells from other diseases did so in minimal proportion (28.12 +/- 10.71 vs 2.26 +/- 2.32, p < 0.001). These findings strongly suggest that nodular goiters and papillary carcinoma are not of autoimmune origin since they are unable to express HLA-DR on their cell surface. It is postulated that HLA-DR expression is the result of the influence of T lymphocytes previously sensitized to thyroid antigens.

[Thyroid disease in progressive systemic sclerosis]

There is no agreement wither thyroid disease is a common feature of progressive systemic sclerosis (PSS). We evaluated 28 patients with proven PSS with determinations of T3, T4, TSH and Tg as well as antimicrosomal autoantibodies. Radioactive I uptake, thyroid scintigraphy, TRH test and fine needle biopsy were performed in selected patients. Twelve (43%) patients had clinical or laboratory evidence of thyroid dysfunction. Four patients had euthyroid goiter, 3 had evidence of autoimmune disease, 2 had chronic Hashimoto's thyroiditis, 1 was hypothyroid, 1 hyperthyroid and one has subacute thyroiditis. The CREST variant of PSS was most commonly associated with thyroid pathology. Our results indicated that thyroid disease is frequently associated to PSS. A complete clinical and laboratory evaluation is needed to confirm its presence.

[Problems in the diagnosis of thyroid dysfunction of the elderly adult]

Thyroid disfunction in the aged is often misdiagnosed either due to scanty symptoms, masking by other ailments or because function tests can be altered by extrathyroid causes such as chronic diseases, drugs or undernutrition. We surveyed 93 patients from 60 to 104 years old (73 females) living in geriatric homes. Most received at least 2 drugs for control of hypertension, coronary artery disease, diabetes, parkinsonism or psycho-organic deterioration. No clinical evidence of thyroid disfunction was found in 75 patients. T3 was 73.6 +/- 25.5 ng/dl, T4 7.3 +/- 1.8 micrograms/dl, TSH 2.8 +/- 0.9 uU/ml and rT3 32.2 +/- 16.3 ng/dl. Antimicrosomal antibodies were negative in all. Significant differences were found comparing these values with those obtained in 26 normal adults with mean age 39.9 years: T3 was lower and TSH and rT3 were higher in the elderly (p less than 0.0001). T3 decreased and rT3 increased in relation to age and males had significantly lower values of T3, T4 and TSH than females. Some evidence of thyroid disfunction was present in the remaining 18 patients: 9 had multinodular and/or positive antimicrosomal antibodies with euthyroid hormone levels; 6 had elevated T3, T4 and fT4 so hyperthyroidism was suspected; the remaining 3 patients had TSH levels above 20 uU/ml indicating the presence of hypothyroidism of which only one had some clinical manifestation. Thus, thyroid disfunction in the elderly + is not uncommon (3.2% of hyperthyroidism and 2.6% hypothyroidism in this series) in the absence of clinical manifestation. Treatment may improve the quality of life in these patients.

[Thyroid microsomal autoantibodies in thyroid disease: their value as an antigenic marker]

An autoimmune disease can be the cause of thyroid disfunction. Determination of autoantibodies titers is the best way of demonstrating its existence. We studied 172 thyroid patients (146 females, 26 males) with ages ranging from 15 to 81 years. Thyroid microsomal autoantibodies (TMA) were detected by a modified agglutination test (SERA-TEK kit, Ames Div); a dilution greater than or equal to 1/1600 was considered as diagnostic of autoimmune disease. Patients were classified according to morphological and functional status in 3 groups: GI = non toxic goiter, n = 98 (71 diffuse, 20 multi and 7 uninodular); GII = toxic goiter, n = 62 (52 diffuse, 4 multi, 2 uninodular and 4 subacute thyroiditis); G III = hypothyroidism, n = 12 (5 primary hypothyroidism and 7 chronic thyroiditis). A control group of 30 normal individuals, ages ranging from 19 to 85 years was also studied. Diagnostic titers of TMA were found in 30.8% of group I, 88.5% of group II, 91.6% of group III and only in 6.6% of controls. The high incidence of positive TMA in toxic diffuse goiter (96.1%) as well as in hypothyroid patients was expected since these are typical examples of thyroid autoimmune disease. In the non toxic goiter group, positive TMA were present in 50% of multinodular, 28% of uninodular and 25% of diffuse goiters and the incidence of positive TMA varied according to age, being higher over the age of 40 years and lower under the age of 20 years. We postulate that this unexpected high incidence of positive TMA in non toxic goiter is due to amelioration of chronic iodine deficiency inducing the expression of latent autoimmune disease.(ABSTRACT TRUNCATED AT 250 WORDS)

[Efficacy of propylthiouracil in the treatment of amiodarone-induced hyperthyroidism]

Amiodarone is a benzofuranic derivative widely used in cardiologic practice because of its excellent antiarrhythmic properties. Due to its high iodine content, it interferes with thyroid physiology and can cause either hyper or hypothyroidism. Amiodarone-induced hyperthyroidism should be considered as a serious complication since it develops in cardiac patients, the clinical diagnosis can be difficult and because conventional methods of therapy are said to be often ineffective. We analyze the outcome of 10 pts, chronically treated with Amiodarone (16-60 mo, mean 37.6 mo) who develop hyperthyroidism during the antiarrhythmic therapy. All patients had multinodular goiter. Overt clinical picture for thyrotoxicosis was seen in 7 of them and lab tests showed: rT3 = 101.1 +/- 14.9 ng/dl; T3 = 220.2 +/- 25 ng/dl; T4 = 15.6 +/- 1.9 micrograms/dl, TSH = 0.8 +/- 0.2 microU/ml and TRH response 0.0 microU/ml. Thyroid microsomal antibodies were negative in 3 pts studied. After Amiodarone was discontinued, patients were followed-up monthly. In 2, normalization of clinical and laboratory indexes were obtained at 40-60 d and no other medication was given. In the remaining, due to the intensity of clinical manifestations, PTU treatment was started (300 mg/d) After 4 mo, euthyroidism was achieved in 6 and it persisted after discontinuation of PTU has patient failed to respond to PTU, 131I was administered with excellent results. Patients have been followed-up up to 3 years after therapy without observing thyrotoxic relapses nor deterioration of their cardiological condition.2+ conventional therapies (PTU or 131I) have been, very effective.