Immunological similarity of thyroid stimulating antibody (TSAb) and thyroid blocking antibody (TBAb) with animal IgG.

Previously we reported neutralization and partial purification of TSAb and TBAb activity using heterophilic antibody (Ab) to animal IgG from Graves' disease. Thus, we examined immunological similarity of TSAb and TBAb with animal IgG using experimentally generated anti-animal IgG [dog (d), bovine (b), porcine (p) and rabbit (rb)] Abs. TBII activity of TSAb- and TBAb-positive serum was neutralized by these anti-animal IgG Abs. Applied TSAb- or TBAb-IgG protein (purified by Protein A) on these anti-animal IgG Abs-bound column was found mainly in the unbound fraction (UF) (>65%) and partially in the bound fraction(BF) (<35%). The TBII and TSAb activity of TSAb-IgG in the BF showed significantly higher than the UF. Thus, the ratio of TBII activity (U/L)/mg protein in the BF/UF was high. TBII activity of TBAb-IgG was similarly purified by this column. We examined immunological characteristics of TSAb-and TBAb-Fab or F(ab')2 using rabbit anti-bF(ab')2 Ab. TBII and TSAb activity of TSAb-Fab or- F(ab')2 and TBII activity of TBAb-Fab or -F(ab')2 were neutralized by anti-bF(ab')2 Ab. Partial purification of TSAb- or TBAb-Fab and -F(ab')2 by anti-bF(ab')2 Ab-bound column was also possible. Immunological similarity of TSAb- and TBAb-IgG with animal IgG such as d, b, p, rb by anti-animal IgG Ab, and TSAb- or TBAb-Fab and -F(ab')2 with bFab by anti-bF(ab')2 Ab were demonstrated. These fact suggest that both Fab and Fc portion of TSAb- and TBAb-IgG molecule have immunological similarity with animal IgG.

Neutralization and purification of thyroid stimulating antibody (TSAb) and thyroid blocking antibody (TBAb) by heterophilic antibody to animal IgG in Graves' disease.

There are several reports that sera from Graves' patients contain heterophilic antibody (Ab) to animal IgG such as human anti-mouse antibody (HAMA). We examined the binding of TSAb and TBAb with heterophilic Ab. The binding of animal IgG with patient's IgG was examined by the inhibition of animal IgG on the binding of labeled bovine (b) IgG with patient's IgG. The binding to labeled bIgG was detected in the serum of 5 patients (2.7 %) among 185 patients with Graves' disease. The binding of the labeled bIgG with patient's IgG was inhibited by animal serum or the crude IgG (45% ammonium sulfate fraction of serum)(such as dog, horse, bovine, porcine, goat, ovine, rabbit, guinea-pig, rat, mouse) except human, monkey and chick. This heterophilic Ab which had cross-reaction with mammalian IgG (except human, monkey) was used as human anti-animal IgG Ab. TBII and TSAb activity of TSAb-positive serum, and TBII activity of TBAb-positive serum were neutralized by incubation with this Ab-bound column. Partial purification of TSAb- or TBAb- IgG from Protein A-purified TSAb- or TBAb-IgG was possible using this Ab-bound column. TBII and TSAb activity of TSAb-IgG and TBII activity of TBAb-IgG were neutralized by incubation with rabbit anti-human (h) IgG Ab (having cross-reaction with animal IgG). Further purification of Protein A-purified TSAb-IgG or TBAb-IgG by rabbit anti-hIgG Ab-bound column was impossible. The binding of TSAb and TBAb with heterophlic Ab means that TSAb-and TBAb-specific IgG have immunological similarity with mammalian species IgG compared to human IgG.

[Case of an hemodialysis patient with MYH9 disorders].

A 70-year-old woman was admitted to our hospital for repair of vascular access for maintenance hemodialysis. She had been undergoing the maintenance hemodialysis for 20 years, however, her underlying renal disease had not been identified. The laboratory data on admission revealed marked thrombocytopenia with giant platelets and a Dohle body-like cytoplasmic inclusion body in granulocytes. The same hematological abnormalities were also detected in the peripheral blood smear of her daughter. We suspected hereditary macrothrombocytopenia and performed gene analysis of the MYH9 gene that encodes the nonmuscle myosin heavy chain-II A (NMMHC- II A). Mutational analysis showed the heterozygous mutation, c. 1841 G>A, in exon 38 of the MYH9 gene (E1841 K). We further examined intracellular NMMHC- II A localization in granulocytes by immunofluorescent analysis. The results revealed that one or two NMMHC- II A-positive granules were observed in neutrophils, whereas these granules were not detected in the granulocytes of normal healthy volunteers. From these analyses, we diagnosed her disease as MYH9 disorder, especially as a May-Hegglin abnormality. Thrombocytopenia is sometimes observed in maintenance hemodialysis patients. To avoid inappropriate medical intervention for the thrombocytopenia, MYH9 disorders should be differentiated.

Inhibitory effect of thyroid blocking antibody (TBAb) on the thyroid stimulatory effect of human chorionic gonadotropin (HCG) and equine chorionic gonadotropin (ECG).

We examined the inhibitory effect of thyroid blocking antibody (TBAb) on the thyroid stimulating activity of human chorionic gonadotropin (HCG) and equine CG (ECG). Five TBAb positive sera obtained from patients who had been hypothyroid but were currently on T4 treatment. The TSH binding inhibitory immunoglobulin (TBII) activities of the sera were 60-160 IU/L. Inhibition of TSH binding to the TSH receptor (TSHR) [TSH binding inhibition (TBI) activity] of HCG or ECG, and inhibition of TBAb on HCG or ECG-stimulated cAMP production were examined. Both HCG and ECG preparations showed weak TBI activity in the presence of small amounts of protein [bovine serum albumin (BSA)] but were negative in the presence of large amounts of protein [normal human serum (NHS) or BSA]. Four thousand IU/mL of HCG and ECG preparation caused cAMP production similar to 100 microU/mL of bovine (b) TSH. The inhibitory effect of TBAb on cAMP production by this amount of HCG or ECG was then examined. The inhibitory effect of TBAb on cAMP production by HCG and ECG was similar to bTSH, and TBAb positive sera with more than 40 IU/L TBII activity completely blocked cAMP production by HCG, ECG and bTSH. This suggests that common alpha -subunit of both HCG and TSH are involved in the inhibitory effect of TBAb. Previous reports demonstrated that the thyroid stimulating activity of thyroid stimulating antibody (TSAb) was blocked by deglycosylated HCG (competitive antagonist of TSH binding to TSHR). The fact and our present study suggest that TSH, HCG ECG, TSAb and TBAb have a similar binding site (alpha-subunit-mimicking binding site) on the TSH receptor.

[Elevation of tumor markers as a diagnostic clue in two cases of symptomless late recurrence after resection of gastric cancer].

We present two cases of late recurrence after gastrectomy for gastric carcinoma. Both patients had medical examinations regularly and had no symptom of recurrence and serum tumor markers remained normal after surgery. 7 and 8 years after resection of gastric cancer, serum tumor marker levels elevated and cancer recurrence was confirmed by lymph node swelling by CT and PET study. Case 1 was a 69-year-old woman. 7 years after distal gastrectomy, CA 19-9 elevated and late recurrence of gastric carcinoma was diagnosed. Case 2 was a 63-year-old woman, 8 years after total gastrectomy, CEA elevated and late recurrence of gastric carcinoma was diagnosed. Late recurrence more than 5 years after resection of gastric cancer is not rare, and periodic examination of tumor markers would be helpful to diagnose recurrence before it becomes symptomatic.

Increased receptor binding by bovine (b) TSH bound to monoclonal antibody to bTSHbeta-subunit.

TSH receptor (R) binding and cAMP production by bovine (b) TSH-bound to a monoclonal antibody (MoAb) or polyclonal antibody (Ab) to bTSH were examined, using TSH receptor (R) coating tube and porcine thyroid cells. (125) I-bTSH bound-to MoAbs to bTSH(alpha) or discontinuous type MoAb showed TSHR binding (10%) similar to intact (125) I-bTSH. TSHR binding was completely decreased (<2%) when (125) I-bTSH was bound by polyclonal Abs to bTSH(alpha) in Graves' patient or rabbit polyclonal Abs to bTSH. When either of the two MoAb (No. 1 and 2) to bTSH(beta) was bound to (125) I-bTSH, TSHR binding was 4 times higher (40%) compared to intact (125) I-bTSH. Binding of another MoAb (No. 3) caused no increased binding. TSHR binding of intact (125) I-bTSH was decreased from 10% to 2% by excess amounts of bTSH. Binding of (125) I-bTSH bound to MoAb to bTSH(beta) (No. 1 and 2) decreased from 40% to 30% by excess amounts of bTSH. When (125) I-bTSH bound-Fab of MoAb was used, the binding was reduced from 30 to 10% (No. 1) and from 25 to 6% (No. 2), respectively. In contrast, cAMP production by bTSH was decreased by pre-binding of all MoAbs and polyclonal Abs. Binding of (125) I-MoAb to bTSH (beta) to a synthetic peptide array of bTSH (beta) sequence was examined by the radioautography. The epitope of MoAb to bTSH(beta) was suggested to be LPK (beta 42-44) for No. 1, KLF (beta 39-41) for No. 2 and PKYA (beta 43-46) for No. 3, respectively, although the existence of discontinuous epitope could not be ruled out. The increased TSHR binding and the decreased cAMP production by bTSH bound to MoAbs may be due to the conformational change of TSH molecule or TSHR by binding of both bTSH and MoAb.

[Improvement of thrombocytopenia with normalization of thyroid function in a patient with Graves disease].

A 39-year-old man was admitted to our hospital because of hyperthyroidism complicated with fever, atrial fibrillation with rapid ventricular response and congestive heart failure. Laboratory data revealed pancytopenia with a white blood cell count of 3360/microl, Hb 9.6 g/dl, and a platelet count of 88000/ul. After initiation of treatment with 30 mg of thiamazole daily, the patient's thyroid function improved but 4 weeks later, thiamazole induced agranulocytosis occurred and the drug was discontinued. After recovery from agranulocytosis, a subtotal thyroidectomy was performed, and the patient's pancytopenia rapidly improved. In this case, hyperthyroidism itself appeared to be closely related to the development of thrombocytopenia.

[A case of minimal invasive carcinoma from intraductal papillary mucinous neoplasm with invasive ductal carcinoma of the pancreas].

A 69-year-old man was referred to our hospital for epigastralgia. He was found to have elevation of serum amylase and CA19-9. Ultrasonography, abdominal CT, MRCP, ERCP and EUS showed the cystic lesion and a possibility of an other tumor. There was a stenosis of the main pancreatic duct (MPD) at the pancreas head and dilatation of the MPD from the body to the tail. Intraductal papillary mucinous neoplasm (IPMN) of the branch pancreatic duct was diagnosed, and there was a likelihood of ductal carcinoma of the pancreas. We therefore performed pancreatoduodenectomy. Pathological finding showed invasive carcinoma from an intraductal papillary mucinous neoplasm with invasive ductal carcinoma of the pancreas.

Antibody to immunoglobulin G and polyethylene glycol augment cyclic adenosine monophosphate production by TSH receptor antibody bound to porcine thyroid cells.

Anti-immunoglobulin G (IgG) augments cyclic adenosine monophosphate (cAMP) production by thyroid-blocking antibody (TBAb) bound to porcine thyroid cells (PTC). This is described as a conversion phenomenon. We reported the effect of polyethylene glycol (PEG) to augment thyroid-stimulating antibody (TSAb) activity in a PTC assay. In the present experiment we examined the effect of anti-immunoglobulin G (IgG) and PEG on cAMP production from TBAb or TSAb bound to PTC. TBAb bound to PTC was separated from unbound TBAb by centrifugation after a first incubation (0.5 hour at 37 degrees C) of TBAb-IgG with PTC. TBAb bound to PTC were incubated with anti-human (h)IgG or hIgG fragments [F(ab')(2), Fc, Fd, H chain or L-chain] for 4 hours at 37 degrees C in the second incubation. Anti-IgG or anti-IgG fragments increased cAMP production. No conversion was caused by protein A, protein L, or PEG (5%). PEG did not augment cAMP production by these IgG antibodies. PEG augmented cAMP production during incubation of TSAb-IgG bound to PTC, but anti-IgG did not. PEG significantly augmented cAMP production by coincubation of TSAb-IgG bound to PTC and the unbound TSAb-IgG (obtained from the first incubation). A similar augmentative effect of PEG was also observed in experiments using TSAb-F(ab')(2) and TSAb-Fab. cAMP production by PTC bound by both TBAb- and TSAb-IgG was increased by co-incubation with anti-IgG, but was not increased by PEG. In conclusion, anti-IgG specifically increased cAMP production from TBAb bound to PTC (conversion phenomenon) and PEG specifically increased cAMP production by TSAb bound to PTC. Different mechanisms enhance cAMP production by TSAb and conversion of TBAb.

Quinine-resistant severe falciparum malaria effectively treated with atovaquone and proguanil hydrochloride combination therapy.

A 22-year-old Japanese man noticed pyrexia and diarrhea after travel to Guinea. Notable physical findings included hepatosplenomegaly. Treatment with oral quinine and minocycline was started after definitive diagnosis of falciparum malaria by blood smear. Initially, parasitemia and body temperature decreased but by the third night of therapy his temperature increased to 40 degrees C with a slight increase of parasite count. When quinine treatment was changed to atovaquone/proguanil, his temperature dropped immediately and complete plasmodial elimination was confirmed on microscopic examination. Subsequent recrudescence of the disease was not observed. It was concluded that the antimalarial treatment with atovaquone/proguanil might become invaluable in Japan.

[A case of recurrent aspiration pneumonia by achalasia].

A 56-year-old woman came to our hospital with the symptoms of anorexia, body weight loss and sustained cough. Chest radiography showed diffuse, rounded, high-attenuation areas in both lung fields. The diagnosis was difficult, but, because of the symptoms and chest radiograph, we suspected miliary tuberculosis. Finally, we diagnosed her illness as achalasia with aspiration pneumonia, because we found a dilated esophagus and diffuse, rounded, high attenuation areas in chest CT scan films. Neither Mycobacterium tuberculosis nor tuberculous granulation was present in transbronchial lung biopsy specimens. Only inflammation was found in those slides. The gastrofiberscope was useful for searching for tumors, but not for diagnosing achalasia. Consequently, we identified the achalasia from the radiographic findings with the use of barium, but the patient's symptoms might not have led to that diagnosis because she was younger than the age range in which aspiration pneumonia usually occurs. The achalasia was treated with surgery rather than balloon dilation, since that was the patient's choice. Three months after surgery, her lungs had improved and body weight had increased by about 10 kg.

Conversion of TBAb response to TSAb response by anti-human IgG antibody.

Previously, we reported the conversion phenomenon (CP) of thyroid blocking antibody (TBAb) to thyroid stimulating antibody (TSAb) by induced cAMP production during incubation of TBAb-bound porcine thyroid cells (PTC) with rabbit anti-IgG Ab. In the present experiment we examined the CP by TBAb-positive sera with high TSH binding inhibitor immunoglobulin (TBII) activity in primary hypothyroidism. Two patients with extremely high TBII patients; patient No.1 (35 yo male) with TSH 26.5µU/ml, TSAb negative, TBII 4,600 U/L, TBAb100% and patient No.2 (40 yo female) with TSH 4.5µU/ml, TSAb negative, TBII 1,620 U/L, TBAb 99.8% were examined. Cyclic AMP production was examined by 2nd incubation (3h) of anti-IgG Ab with TBAb-bound PTC that was made by 1st incubation (0.5h) of TBAbpositive serum and PTC. When sera (0.001-0.05 ml) of patient No.1 and No.2 were tested, cAMP production showed 980- 3,700% and 570-3,000% in a dose-dependent manner, respectively. Cyclic AMP production was also observed by anti- IgG fragments Ab [(Fab')2, Fab and light chain]. Cyclic AMP production by anti-F(ab')2 was higher than anti-Fab Ab, and cAMP by anti-κ Ab was significantly higher (>3 fold) than anti-λ Ab. Cyclic AMP production by TBAb-positive sera with high TBII activity (35-270 U/L) showed a correlation with serum TBII activity (R=0.76). The fact that all high TBAb-positive sera show the CP of TBAb to TSAb suggests that TSAb activity may be present in TBAb molecule and TBAb may be the precursor of TSAb.

A novel hypothesis for the etiology of Graves' disease: TSAb may be thyroid stimulating animal IgG-like hormone and TBAb may be the precursor of TSAb.

There are doubtful points about the theory that autoimmunity with auto-antibody (Ab) to TSH receptor (R) causes hyperthyroidism in Graves' disease (GD). A main doubtful point is no curative effect of corticosteroid on Graves' hyperthyroidism in spite of curative effect of corticosteroid for all autoimmune diseases. Recently we demonstrated the immunological similarity of TSAb and TBAb-IgG to animal IgGs, except for human (h)IgG, by neutralization and purification of TSAb and TBAb-IgG using (1) heterophilic Ab to animal IgG in GD sera and (2) experimentally generated anti-animal IgG Abs [such as dog (d), bovine (b), porcine (p), and rabbit (rb)]. Furthermore, greater immunological similarity of Fab- and F(ab')(2)-portion of TSAb- and TBAb-IgG to bovine Fab, compared to hFab, was demonstrated using goat anti-bovine F(ab')(2) Ab. Existence of b and p TSH-like portions in the LATS-IgG molecule (probably Fab portion) was suggested by a previous report of neutralization of LATS activity by anti-b- or anti-p-TSH Ab. We suggested the existence of a mammalian animal-TSH-like structure, excepting hTSH, in the TSAb-IgG molecule (probably Fab portion), by discovery of anti-mammalian TSH Ab (such as d, b, p, guinea-pig, rat, whale, except h) in sera of GD. Lately, similar TSHR binding of H- and L-chain of human stimulating monoclonal TSHR Ab (M22)-Fab with TSH-α and-ß subunit was reported. This evidence suggests that Fab portion of TSAb has a structure like mammalian TSH, but not hTSH. IgG-λ type of d, horse, b, p, goat, ovine is 95% and IgG-κ type is 5%, while human κ and λ chain is 60:40. Previous report that LATS (TSAb)-IgG composed of predominant λ type is supporting evidence that TRAb-IgG has immunological similarity with these animal IgGs compared to hIgG. We speculate that TSAb-IgG may be referred as a mermaid consisted in face (Fab) and trunk-leg (Fc). Face may be a kind of hormone with animal TSH-like structure and trunk-leg has animal IgG-like structure (in spite of no antibody function). There are many reports for co-existence of TSAb and TBAb-IgG in sera of GD. We reported conversion from TBAb (non-thyroid stimulating type IgG) to TSAb by co-incubation of anti-hIgG Ab (containing anti-animal IgG Ab as a cross-reaction) with TBAb-bound porcine thyroid cells. Thus, we suggest that TBAb may be the precursor form of TSAb.

Morphological analysis of biofilm of peritoneal dialysis catheter in refractory peritonitis patient.

A 66-year-old man undergoing peritoneal dialysis (PD) was admitted to our hospital for treatment of PD-related peritonitis. Culture of the PD fluid revealed the presence of Citrobacter freundii, and therapy with ceftazidime was started intraperitoneally. The cell count in PD fluid slowly decreased over time during the first 2 weeks of treatment, but increased again on the 14th hospital day. A second culture of the PD fluid revealed the presence of Enterococcus species. A switch in antibiotic therapy to vancomycin did not improve the cell count in the PD fluid. A third culture of the PD fluid revealed the presence of Stenotrophomonas maltophilia. The PD was discontinued and the catheter removed on the 28th hospital day. Examination of the catheter revealed that the inner tip was coated with a fibrous sheet of cells, suggesting biofilm formation. Following catheter removal, the patient was administered intravenous ciprofloxacin, and the inflammatory reaction started to disappear immediately and had completely disappeared after 1 week of treatment. Microscopic analysis of the fibrous structure on the catheter revealed multiple layers of various inflammatory cells. Immunostaining revealed the presence of CD44-positive polynuclear cells, indicating neutrophils, facing the catheter lumen. CD68-positive cells, indicating macrophages, were observed in the following layer, and keratin-positive cells, indicating peritoneal mesothelial cells, were present at the bottom of the structure. Based on the immediate improvement of PD-related peritonitis after catheter removal, we presumed that this biofilm contributed to the intractability of the patient's peritonitis. Morphological analysis of catheter revealed that both the mesothelial cells and the various inflammatory cells may have contributed to biofilm development.

The effects of nonionic polymers on thyroid stimulation and TSH receptor binding by the human monoclonal TSH receptor autoantibody M22.

BACKGROUND: Nonionic polymers such as polyethylene glycol (PEG), polyvinyl alcohol (PVA), and dextran amplify the ability of thyroid stimulating antibodies (TSAbs) from patients with Graves' disease to stimulate cAMP production in thyroid cells. Therefore we sought to determine if nonionic polymers also augment the effects of the human thyroid stimulating monoclonal antibody (M22) on isolated thyroid cells. METHODS: The ability of nonionic polymers to alter the effects of M22 on certain parameters in porcine thyroid cells was examined. These parameters were augmentation of cAMP production (TSAb activity), inhibition of bovine thyrotropin (bTSH)-induced cAMP production (TBAb activity), and inhibition of bTSH binding to the TSH receptor (TSHR) (TBI activity). RESULTS: Stimulation of cAMP production by M22 in porcine thyroid cells was augmented by PEG, PVA, and dextran in a manner similar to that of Graves' serum. In contrast, TSH-stimulated cAMP production was not increased by nonionic polymers. M22-stimulated cAMP production was completely inhibited by the sera of patients with TBAb activity, and this inhibition was diminished by PEG. M22 and TBI activity in first and second generation assays and this activity was not affected by PEG. Binding of biotin-M22 to TSHR-coated plate wells (third generation assay) was not significantly increased by co-incubation with polymers. PEG augmented the binding of (125)I-M22 to TSHR-coated tubes by twofold, but this was associated with a threefold increase in nonspecific binding. There was no increase in total and nonspecific (125)I-TSH binding. This means that PEG has less than a twofold augmentative effect on (125)I-M22 binding to the TSHR. CONCLUSION: Nonionic polymers have similar effects in augmenting cAMP production in porcine thyroid cells in response to stimulation either by M22 or Graves' disease serum. The mechanism of this effect on the thyroid stimulating activity of M22 is unclear. The hypothesis that nonionic polymers augment M22 thyroid stimulation by increasing the mass of M22-occupied TSH receptors is not supported by the present study.

Effect of darbepoetin alfa on renal anemia in Japanese hemodialysis patients.

INTRODUCTION: A long-acting erythropoiesis-stimulating agent named "darbepoetin alfa" (CAS 11096-26-7) was recently developed. Though it is already in use worldwide, especially in western countries, its efficacy and safety for Asian patients have not been well evaluated yet. The purpose of this study was to evaluate the efficacy and safety of short-term darbepoetin alfa administration for Japanese hemodialysis patients. METHODS: Patients who had undergone maintenance hemodialysis were enrolled in this study. The erythropoiesis-stimulating agent was switched from epoetin alfa (CAS 113427-24-0) to darbepoetin alfa so as to control the hemoglobin (Hgb) value between 10 and 12 g/dl. The initial conversion ratio was made according to the manufacturer's recommendations. The factors relevant to the responsiveness to erythropoiesis were analyzed. RESULTS: One hundred and fifty-nine patients with a mean age of 67.6 years were enrolled. Two months after switching to darbepoetin alfa, the Hgb value had increased significantly (10.3 +/- 1.2 to 10.6 +/- 1.4 g/dl). Only iron supplementation correlated positively with the change of Hgb. In addition, 14.3% of patients had excess Hgb (Hgb > 12 g/dl) at the end of the study period, but only 5.6% patients at the run-in. Serious cardiovascular disease did not occur during the study period; however, the mean systolic blood pressure at the start of hemodialysis increased significantly and there was no correlation between the change of Hgb value and blood pressure. CONCLUSION: Darbepoetin alfa increases the Hgb value effectively in Japanese hemodialysis patients. Although no serious adverse events were apparent in our short-term analysis, the incidence of hypertension and excessive increase of the Hgb value must be noted.

A case of human fasciolosis: discrepancy between egg size and genotype of Fasciola sp.

In human fasciolosis, differential diagnosis of the causative flukes, Fasciola hepatica and Fasciola gigantica, is problematic. We report a rare case of human fasciolosis in which an adult worm was recovered from the bile duct of a Japanese man. Morphometric data of the worm were consistent with those of F. hepatica, whereas the size of eggs in the stool indicated infection with F. gigantica. Nucleotide sequences of ITS-1 and -2 and CO1 genes of the DNA extracted from the eggs revealed that the genotype was that of F. hepatica. These findings suggest that the size of eggs is not a suitable marker for species identification in human fasciolosis, especially in settings such as the East Asian region where different karyotypes and hybrid genotypes of F. hepatica and F. gigantica have been found.

Cytotoxic T-cell non-Hodgkin's lymphoma of the thyroid gland.

An 86-year-old female was diagnosed with peripheral T-cell lymphoma, unspecified, which affected only her thyroid gland. Lymphoma cells were TIA-1(+), suggesting cytotoxic T-cell origin. She had not suffered from autoimmune thyroiditis and showed normal thyroid function. Without any specific therapies, the lymphomatous lesion showed the partial spontaneous regression before diagnostic hemithyroidectomy, and she had been well for 2 years without relapse. This is the first case of primary thyroid lymphoma of cytotoxic T-cell origin that showed spontaneous regression.

Demonstration of anti-TSH antibody in TSH binding inhibitory immunoglobulin-positive sera of patients with Graves' disease.

OBJECTIVES: The presence of anti-TSH antibodies in Graves' patients with unusually low TSH binding inhibitory immunoglobulin (TBII) has been reported. Recently, we found the first case of an anti-TSH antibody in TBII-positive sera of patients with Graves' disease. The prevalence and immunological specificity of this anti-TSH antibody were examined. DESIGN: The presence of 125I-bovine(b) TSH binding antibody in TBII positive serum was examined by prolonged incubation of more than 1 day because only weak binding occurred after 1 h incubation at 37 degrees C. The clinical course of these patients and binding characteristics of anti-bTSH antibody were examined. RESULTS: The corrected method-TBII activity (%)[1 - (a - b)/(c - d)] x 100 and the standard method-TBII activity (%) [1 - (a - d)/(c - d)] x 100 [a, 125I-bTSH binding with TSH receptor (R) in the presence of test serum; b, 125I-bTSH binding with test serum; c, 125I-bTSH binding with TSH R in the presence of normal serum; d, 125I-bTSH binding with normal serum] were calculated. The corrected method-TBII activity was always higher than the standard method-TBII activity in anti-bTSH antibody-positive serum. Anti-bTSH antibody-positive cases in TBII-positive Graves' disease were found in approximately 1% of Graves' patients. Anti-bTSH antibodies were confirmed as IgG from the increase of precipitated radioactivity by adding rabbit antihuman IgG antibody after the incubation of 125I-bTSH with test serum. These antibodies bind with not only bTSH, bTSH(alpha) and bLH, but also porcine (p)TSH, pTSH(alpha) and pFSH. However, these antibodies did not bind with human TSH. Binding of 125I-bTSH with patient's serum was neither inhibited by other Graves' thyroid stimulating antibody (TSAb), nor thyroid blocking antibody (TBAb) in primary hypothyroidism. CONCLUSIONS: The presence of anti-bTSH antibody in TBII-positive serum of high titre means that TBII-positive sera cannot rule out the absence of anti-bTSH. Thus, determination of 125I-bTSH binding with test serum in TSH receptor assays is necessary to determine the precise TBII activity and to detect anti-bTSH antibody.