[Comparison of chest CT findings between suspected and definite cases of primary pulmonary M. avium complex infection]

It is very difficult to treat pulmonary infection with MAC, because we have few effective drugs against this organism. In this situation, an early diagnosis and treatment are very important to manage this disease. We evaluated chest CT scans of the primary pulmonary MAC infection which had no underlying lung diseases and no immunocompromised diseases such as HIV infection. We defined suspected cases of pulmonary MAC infection as cases in which abnormal features of chest CT scans were recognized but frequency of detection of organisms of MAC did not fulfil the diagnostic criteria for atypical mycobacteriosis according to Japanese Mycobacteriosis Research Group of the National Chest Hospitals. CT scans of suspected cases were compared with the definite cases. Results obtained were as follows: 1. In classification by CT scans of primary pulmonary MAC infection, the proportion of localized type and diffuse type was the same both in suspected and definite cases. In localized type, more tuberculosis-like pattern was seen in definite cases. 2. In suspected cases, characteristic features of CT scans of primary pulmonary MAC infection were recognized in the same frequency as in definite cases. 3. In pulmonary tuberculosis-like type, definite cases showed more cavitary lesions than suspected cases. These results showed that a careful long term follow-up of suspected cases with frequent bacteriological tests of sputum and chest CT scannings was important for early diagnosis of primary pulmonary MAC infection.

Tight junctions in the rat parotid gland

The aim of this study was to elucidate the distribution and morphological changes of tight junctions during secretion in parotid gland acinar cells. Localization of tight junction-associated polypeptide ZO-1, and of tight junction transmembrane protein Occludin, was examined in rat parotid gland by immunofluorescence and immunogold labelling of ultrathin sections. Adult male Sprague-Dawley rats were intraperitoneally injected with IPR and, after 10 and 30 minutes, parotid glands were extirpated. In control specimens, positive immunoreaction for ZO-1 and Occludin was observed on the adluminal side between adjacent cells in the form of narrow elongated profiles corresponding to intercellular canaliculi. After IPR injection, canaliculi became dilated and fluorescence was no longer seen as a continuous line but appeared as an aggregation of separate bright particles. ZO-1 was more widely distributed and was recognized in other areas of the cytoplasm as well. Concurrently, omega-shaped concavities, marked by actin fluorescence, appeared along the intercellular canaliculi. We concluded that, during exocytosis, the selective permeability barrier to the paracellular pathway, based on tight junctions, becomes more leaky, owing to segregation of Occludin caused by intracellular ZO-1 distributional changes associated with actin filaments.

Decrease of nitric oxide end-products during coronary circulation reflects elevated basal coronary artery tone in patients with vasospastic angina

The aim of this study was to investigate the role of nitric oxide (NO) in the coronary circulation and its relation to basal coronary artery tone in patients with vasospastic angina (VSA). We evaluated the level of nitric oxide end-products (NOx; nitrite + nitrate) in coronary circulation blood using an HPLC-Griess system for nine patients with VSA and nine control patients. All of the patients with VSA experienced focal spasm in the proximal to middle segments of the left anterior descending coronary artery (LAD) in response to intracoronary injection of ergonovine maleate. The luminal diameter of the coronary artery was measured in each patient by quantitative coronary arteriography. Blood samples for NOx measurement were obtained from the coronary sinus (NOxV) and the ostium of the left coronary artery (NOxA). The NOx difference, calculated from the coronary venous-arterial difference in NOx, was close to zero for the control patients whereas it was clearly negative for the patients with VSA. In addition, the NOx difference in the patients with VSA showed a negative correlation with basal coronary artery tone (r = -0.91, p < 0.01) and a positive correlation with the dose of ergonovine required for spasm provocation (r = 0.77, p < 0.05). These results indicate that increased basal coronary artery tone and higher susceptibility to ergonovine in patients with VSA would be a consequence of coronary endothelial dysfunction as is indicated by NOx.

Presence of 22-kDa protein reacting with sera in piglets experimentally infected with Brachyspira hyodysenteriae

In order to examine the effect of spectinomycin on outbreaks of swine dysentery, experimental infection of piglets with Brachyspira hyodysenteriae was carried out. Feed with and without spectinomycin (SP) was given to each piglet ad libitum and the susceptibility of the piglets to infection with B. hyodysenteriae was compared between SP-treated and untreated piglets. The results showed that the SP-treated piglets did not display clinical signs of swine dysentery unlike the untreated piglets. The sera obtained from these piglets were examined by the microscopic agglutination test and antibodies to B. hyodysenteriae in both groups of experimentally infected piglets were detected and the reaction was serogroup-specific. The agglutination titers were very high in the untreated piglets with dysentery while the titers in the SP-treated piglets were lower than those in the untreated piglets. In addition, the immunoblotting technique was applied and the results demonstrated that 22- and 17-kDa proteins in strain ATCC 31212 (serogroup B) reacted strongly with the sera from the untreated piglets but not with the sera from the SP-treated piglets. The 22- and 17-kDa proteins also reacted with strain ATCC 27164 (serogroup A) which belongs to a different serogroup. The 22- and 17-kDa proteins were also confirmed in six other strains of B. hyodysenteriae which belong to six different serogroups. These proteins were sensitive to proteinase K. These results indicate that the 22- and 17-kDa proteins are common to eight strains of B. hyodysenteriae which differ serologically from each other.

[Evaluation of CT appearance of Mycobacterium avium complex infection--comparison with bronchiectasia]

We compared computed tomographic pictures (CT) of primary pulmonary mycobacterium avium complex (MAC) infection with bronchiectasia (BE). These patients were examined during the period from 1988 to 1996. There were 51 patients of pulmonary MAC infection group (13 males and 38 females) with a mean age of 67.5 years and 27 patients of BE group (8 males and 19 females) with a mean age of 53.9 years. The results were as follows: 1. In both groups, bronchiectasis was most commonly found in the middle lobe and in the lingula. In pulmonary MAC infection group, 38 patients (74.5%) had bronchiectasis in the middle lobe, and 40 patients (78.4%) had them in the lingula. In BE group, 18 patients (66.7%) had them in the middle lobe and in the lingula respectively. In the lower lobe, bronchiectasis of BE group was observed more frequently. And in pulmonary MAC infection group, 15 patients (29.4%) had bronchiectasis in the central zone, 42 patients (82.4%) had them in the intermediate zone, and all 51 patients had them in the peripheral zone. On the other hand, in BE group, 18 patients (66.7%), 27 patients (100%) and 21 patients (77.8%) had them in the central zone, in the intermediate zone and in the peripheral zone respectively. Bronchiectasis of pulmonary MAC infection was observed in peripheral zone more frequently than that of BE group. 2. By the type of bronchiectasis, saccular bronchiectasis was observed more frequently in BE group than in pulmonary MAC infection group. 3. Nodules were seen in pulmonary MAC infection group significantly more than in BE group. They were seen in 96% of lobes with bronchiectasis, and 50% of lobes without bronchiectasis in pulmonary MAC infection group. It was thought that the bronchiectasis with nodules predominantly in the peripheral zone was a characteristic CT finding of primary pulmonary MAC infection. As this finding was different from that of BE, it is suggested that primary pulmonary MAC infection caused this type of bronchiectasis.

False positive appearance of subarachnoid hemorrhage on CT with bilateral subdural hematomas

We describe a patient with bilateral traumatic subdural hematomas in whom CT findings of hyperattenuation in the basal cisterns and subarachnoid spaces falsely suggested superimposed acute subarachnoid hemorrhage.

[Expression of CD44 standard and CD44 variant 6 in human lung cancer]

We immunohistochemically examined the expression of CD44 standard (CD44 st) and CD44 variant 6 (CD44 v6) in 112 cases of primary lung cancer, and their relationship to the clinical milieu, including the clinical stage. In 46 cases of squamous cell carcinoma, expression of CD44 st was observed in 45.7% of the cases, and expression of CD44 v6 was observed in 60.9%. In 43 cases of adenocarcinoma, positive staining of CD44 st and CD44 v6 was seen in 2.3% and 4.7% of the cases, respectively. None of 21 small cell carcinomas was positive for CD44 st or CD44 v6. In squamous cell carcinomas, the expression of CD44 st and CD44 v6 was observed at a rate significantly higher than in other histologic type. Most specimens positive for CD44 st stained positively for CD44 v6. Therefore, it seems likely that the CD44 expression observed in squamous cell carcinoma of the lung was a variant CD44 containing the domain encoded by variant exon 6. The expression of CD44 v6 was not related to the clinical stage. Significant association between CD44 v6 and differentiation of squamous cell carcinoma was seen; 2/7 (28.6%) for poorly differentiated, 19/31 (61.3%) for moderately differentiated, and 7/8 (87.5%) for well differentiated squamous cell carcinomas (p = 0.02 by trend test). It was previously reported that CD44 st and CD44 v6 were expressed in both normal bronchial epithelium and squamous cell metaplasia. These results suggest that the expression of CD44 v6 in squamous cell carcinoma of the lung may reflect the immunohistochemical characteristics of the tissue from which such carcinoma emerge.

Unification of the genera Serpulina and Brachyspira, and proposals of Brachyspira hyodysenteriae Comb. Nov., Brachyspira innocens Comb. Nov. and Brachyspira pilosicoli Comb. Nov

The phylogenetic positions of Serpulina hyodysenteriae, Serpulina innocens, Serpulina pilosicoli and Brachyspira aalborgi were studied. Complete 16S ribosomal DNA sequences of these three species and B. aalborgi revealed that their 16S rDNA sequences were related more than 96.0%. The mol% guanine plus cytosine (G+C) of B. aalborgi DNA was 27.1, and was similar to those of the 3 members of the genus Serpulina. The homologous rates using 31P-labeled B. aalborgi chromosome DNA in DNA-DNA reassociation tests were 22.0% to S. hyodysenteriae, 19.1% to S. innocens and 17.2% to S. pilosicoli. Therefore, we propose to transfer the three species of the genus Serpulina to the genus Brachyspira. Descriptions of Brachyspira hyodysenteriae comb. nov., Brachyspira innocens comb. nov. and Brachyspira pilosicoli comb. nov., and an emended description of B. aalborgi are given. Phenotypic characteristics of the 4 members of the genus Brachyspira were also studied. They fermented fructose, galactose, glucose, lactose, maltose, mannose, raffinose and trehalose; however, B. aalborgi did not ferment raffinose. All of them hydrolyzed esculin but did not produce indole except for B. hyodysenteriae. The protein profile of B. aalborgi was different from those of the four strains of B. hyodysenteriae, B. innocens and B. pilosicoli, but the heavy bands with molecular sizes of 49.4 and 52.3 kDa of B. aalborgi were quite similar to those of B. innocens in the points of quantity and molecular size. In immunoblotting tests, B. aalborgi reacted well with anti-B. innocens and B. pilosicoli sera, but reacted weakly with anti-B. hyodysenteriae serum. Only one heavy band and several faint bands were revealed by the reaction between B. aalborgi and anti-B. hyodysenteriae serum, and the heavy band was common among these strains.

Ultrastructure of collagen fibers in the outer membrane of recurrent chronic subdural hematoma

The three-dimensional structure of the collagen fibers in the outer membrane of recurrent chronic subdural hematoma was studied by scanning electron microscopy (SEM). Specimens obtained at surgery were treated with NaOH at room temperature to digest away all cellular components and expose the collagen fibers. SEM observation of the dural side of the outer membrane showed the collagen fibers were woven into a compact feltwork with a dense arrangement. The fiber bundles had a honeycomb structure framed by the collagen fibers. Observation of the hematoma side found the collagen bundles had a sparse wavy appearance. The arrangement of the collagen fibers on the dural side is different from that on the hematoma side. The thick outer membrane may be formed by granulation resulting from inflammatory reaction. Collagen fibrillar networks are not fragile, and may reinforce the outer membrane of the recurrent hematoma.

Isolation of virulent and intermediately virulent Rhodococcus equi from soil and sand on parks and yards in Japan

Rhodococcus equi is an emerging opportunistic pathogen of human immunodeficiency virus-infected patients. However, little is known about the distribution of virulent and intermediately virulent R. equi in human environment. In the present study, R. equi was isolated from 173 of 234 (73.9%) samples collected from soil and sand on 115 parks and 49 yards in Japan. The numbers of R. equi from soil and sand ranged from 2.5 x 10(1) to 1.2 x 10(5) per gram of sample. None of 1,294 isolates from those samples showed virulence-associated 15- to 17-kDa antigens and a 20-kDa antigen. These results suggest that avirulent R. equi is widespread in parks and yards, but the human environment has not been contaminated with virulent and intermediately virulent R. equi strains yet.

P53 immunostaining predicts chemosensitivity in non-small cell lung cancer: A preliminary report

PURPOSE

Although resistance to chemotherapy is a major problem in cancer treatment, there is no predictor of treatment response. Recent reports suggest that p53 status may provide a genetic basis for drug resistance.

METHODS

Transbronchial biopsy specimens from 18 patients with non-small cell lung cancer were evaluated for p53 expression using anti-p53 antibody (DO-1). After biopsy, these patients received more than two courses of identical chemotherapy including cisplatin, carboplatin, and vindesine.

RESULTS

Ten of 18 (56%) patients responded to chemotherapy. The accumulation of p53 protein was detected in 10 of 18 (56%) patients. Positive staining for p53 was significantly correlated with unresponsiveness to chemotherapy. Other factors, including gender, performance status, body weight loss, serum albumin, and serum LDH, did not correlate with the immunohistochemical expression of p53.

CONCLUSIONS

These results suggest that immunostaining with p53 can be a predictor of the response to chemotherapy in non-small cell lung cancer. Further studies are needed to confirm the relationship between p53 expression and chemosensitivity.

Identification of intermediately virulent Rhodococcus equi isolates from pigs

We recently reported the existence of Rhodococcus equi isolates with at least three virulence levels, isolated from AIDS patients: virulent R. equi having 15- to 17-kDa antigens that kills mice with 10(6) cells, intermediately virulent R. equi having a 20-kDa antigen that kills mice with 10(7) cells, and avirulent R. equi that does not kill mice with 10(8) cells or more (S. Takai, Y. Imai, N. Fukunaga, Y. Uchida, K. Kamisawa, Y. Sasaki, S. Tsubaki, and T. Sekizaki, J. Infect. Dis. 172:1306-1311, 1995). Virulent R. equi having the 15- to 17-kDa antigens has been isolated frequently from horses and their environment, but the source of intermediately virulent R. equi having the 20-kDa antigen is poorly understood. There are many reports of the isolation of R. equi from the lymph nodes of pigs with and without lesions resembling those of tuberculosis. Therefore, we analyzed antigens of R. equi isolates from the submaxillary lymph nodes of pigs by immunoblotting with monoclonal antibodies against these virulence-associated antigens. Immunoblots of whole-cell antigen preparations of R. equi pig isolates revealed the presence of the 20-kDa antigen in almost all the pig isolates studied, and these isolates were intermediately virulent for mice. We also demonstrated that the expression of the 20-kDa antigen and its pathogenicity in mice were associated strongly with the presence of five large, distinct plasmids of 70 to 95 kb; two of the five plasmids from pig isolates were the same sizes as those from human isolates. These results suggest that R. equi having the 20-kDa antigen exists in the submaxillary lymph nodes of pigs and that the source of infection in some human cases might be associated with pigs and their environment.

Tolosa-Hunt syndrome with atypical intrasellar and juxtasellar lesions--two case reports

Two patients with Tolosa-Hunt syndrome (THS) who had atypical lesions in the intrasellar and juxtasellar regions are reported. They manifested with painful ophthalmoplegia. Magnetic resonance imaging (MRI) commonly showed an increase in the volume of the cavernous sinus occupied by homogeneously well-enhanced lesions in both cases. These lesions extended to the intrasellar and juxtasellar regions with meningela enhancement. Follow-up MRI after steroid treatment demonstrated normalized or decreased size of the cavernous sinus. These findings suggested nonspecific inflammatory granulomatosis with atypical extension.

[Autoimmune hemolytic anemia reactivated by alpha-interferon therapy in a case of chronic active C-type hepatitis]

A case with autoimmune hemolytic anemia (AIHA) induced by interferon-alpha (IFN-alpha) is presented. A 40-year-old male who had a previous history of autoimmune hemolytic anemia, agranulocytosis and thrombocytopenia was admitted to our hospital because of chronic C type hepatitis. Liver biopsy was performed, which diagnosed chronic active hepatitis and IFN-alpha was administrated at a dose of 3 Meg unit per day. 11 days after the initiation of the therapy he developed hemolytic anemia, but Coombs tests were negative. Although IFN was withdrawn 15 days later, anemia became progressively more serious. 20 days later, both direct and indirect Coombs tests became positive. He was diagnosed as AIHA and treated with methylprednisolone pulse therapy, then he recovered soon afterward. Further analysis of Coombs tests revealed that he had both cold type and warm type (IgG) autoantibodies which was the same type of antibodies for AIHA he suffered 10 years ago. In conclusion, latent AIHA may be reactivated by the treatment with IFN-alpha.

[Bilateral ankle ulcers associated with hydroxyurea therapy for chronic myelogenous leukemia]

Bilateral ankle skin ulcers developed in a 61-year-old man in the chronic phase of chronic myelogenous leukemia receiving hydroxyurea therapy. The circulating immune complex (anti-C3d antibody) was high in this case, but vasculitis was not observed in the pathological findings of biopsied skin materials. This association has been reported in patients who had chronic myelogenous leukemia or other myeloproliferative disorders and were treated with hydroxyurea. It is likely that skin ulcers are caused by hydroxyurea.

Lipid composition of platelets in patients with non-insulin-dependent diabetes mellitus: studies before and after treatment of diabetes

The study was designed to investigate whether impaired composition of platelet lipids in untreated diabetic patients improved after diabetic treatment. Fourteen untreated patients with non-insulin-dependent diabetes mellitus (NIDDM) and 15 healthy control subjects were studied. In the diabetic patients, the ratio of free cholesterol to phospholipid (FC/PL) in platelets of 0.33 +/- 0.02 (mean +/- SEM) at pre-treatment, which was statistically (p < 0.05) higher than that of 0.26 +/- 0.02 in control subjects, was significantly decreased to the value of 0.29 +/- 0.02 (p < 0.01) after insulin therapy. Platelet FC level of 9.77 +/- 0.77 micrograms 10(-8) cells pre-treatment was significantly (p < 0.01) reduced to the value of 7.72 +/- 0.38 micrograms 10(-8) cells post-treatment. Platelet PL level showed no significant changes after the treatment. There was a significantly (p < 0.01) positive correlation between the decrease in FC/PL of platelets and that in haemoglobin A1c (HbA1c) after treatment for diabetes (rs = -0.729). These results indicate that the impaired lipid composition in platelets can be improved after an adequate glycaemic control in patients with NIDDM.

[Pure red cell aplasia complicated with polyarthritis, angitis, and acute renal failure]

A case of pure red cell aplasia (PRCA) with various complications polyarthritis, angitis, acute renal failure and DIC was successfully treated with steroid pulse therapy was described. A 55-year-old woman was hospitalized with a 9-month of intermittent but progressive joint pain, morning stiffness, general fatigue, and fever. Her initial laboratory evaluation revealed a hemoglobin of 4.4 g/dl and absence of reticulocyte. Her bone marrow aspirate showed no erythroblast which was compatible with a diagnosis of PRCA. Marked leukocytosis and thrombocytosis, positive antinuclear antigen, elevation of gammaglobulin and C-reactive protein and the presence of polyarthritis and angitis which was confirmed by renal angiography, indicated an underlying autoimmune disorders. Steroid pulse therapy was administered at 500 mg/day for 3 days, resulting in the complete response in both red cell aplasia and above findings. PRCA is known to be associated with systemic lupus erythematosus and rheumatoid arthritis very rarely, but this case did not fulfill the criteria of known collagen diseases, and there is no previous report representing PRCA with various complications such as polyarthritis, angitis and acute renal failure. This case may help us to understand more about the relationship between PRCA and autoimmune disorders.

[Lower lung field tuberculosis]

Lower lung field tuberculosis has been considered as rare disease, but it was observed about ten percent in the literature. It seemed that the important problems in lower lung field tuberculosis are delay and difficulty of diagnosis. The materials for this report was accumulated over a period of 10 years, from January 1983 to December 1992 at the National Sanatorium Fukuoka-Higashi Hospital. The criteria for lower lung field tuberculosis are: (1) disease confined to lower lobe except for S6a, middle lobe and lingular segment, (2) bacteriologically and/or histologically proved diagnosis of tuberculosis, (3) clinically considered as tuberculosis for which improved by only anti-tuberculous drugs. During this period, 672 new patients suffering from active pulmonary tuberculosis were admitted to the sanatorium. Of the total of 672 patients, 57 patients were selected as the criteria for lower lung field tuberculosis. The incidence of them was 8.5 percent of the total new admissions. Of these 57 patients, 30 were females and 27 males. The mean age of these 57 patients was 59.4 years ranging between 19 and 86 years. The incidence of them obtained through ten years did not show any tendency to increase or decrease. The respiratory and general symtoms most commonly observed were cough and chest pain. The average duration of used for diagnosis of the lower lung field tuberculosis over 65 years old was 71.7 days and it seemed to show the delay and difficulty of diagnosis.

[Interferon-alpha therapy in the myeloproliferative variants of hypereosinophilic syndrome]

Two cases of hypereosinophilic syndrome (HES) that seemed to be myeloproliferative disorders were treated with interferon-alpha (IFN-alpha). Case 1 was a 45-year-old man with HES who was unresponsive to prednisolone. Because Flaum's hematologic grading score was 8 points, he was diagnosed as a myeloproliferative variant of HES. Although his condition was well controlled by hydroxyurea (HU), cardio-pulmonary insufficiency with refractory eosinophilia developed after 4 years. Instead of HU, IFN-alpha dramatically decreased eosinophil counts, and the clinical situation has stabilized since. Case 2 was a 30-year-old man with HES whose grading score was 9 points. IFN-alpha therapy was started when an accelerated phase of neutrophil dominant with chromosomal abnormality (8 trisomy) occurred. However, he died because of no response to IFN-alpha and other chemotherapy. In both cases, studies of eosinophil colony formation revealed no excess of eosinophil colony-stimulating factor from their lymphocytes. Flaum's hematologic grading score was useful for the diagnosis of myeloproliferative variants of HES. IFN-alpha successfully induced hematologic remission in one case, and this therapy may be beneficial for these patients as a first line agent.

[Cyclosporin for pure red cell aplasia caused rapid improvement of anemia and increase of CD4/8 ratio]

Ciclosporine (CS) caused rapid improvement of anemia and increase of CD 4/8 ratio in two patients with pure red cell aplasia (PRCA). One case was a 45 year old female who were unresponsive to steroids, plasmapheresis and high dose cyclophosphamide, and another was a 61 years old man with diabetes mellitus (DM) without any treatment for PRCA. In both cases hemoglobin increased soon after the initiation of CS and CD 4/8 ratio also rose from 0.80 to 1.47 and 1.78 to 1.98, respectively. There was no side effects to interrupt the course of the therapy. CS seems to inhibit the production of cytokines such as IL-2 and IFN-gamma, and it damages the activated suppressor/cytotoxic T cells. CS is an effective drug for not only refractory cases but the first step therapy for the untreated patients.

[A case of hemophagocytic syndrome with multiple myeloma]

A case with multiple myeloma complicated with hemophagocytic syndrome (HS) is presented. Because pancytopenia, liver dysfunction and increase of mature histiocytes in the bone marrow appeared rapidly a diagnosis of HS was made. The patient died of multiple organ failure, despite steroid therapy. Autopsy revealed marked invasion of hemophagocytic histiocytes not only into the bone marrow but also into many other organs such as the liver, lymph nodes and kidneys. HS is a histiocyte proliferative disorders, which is likely to be seen in immunocompromised hosts, but there is no previous report about HS and multiple myeloma.

[Interferon therapy of idiopathic thrombocytopenic purpura]

The authors evaluated the efficacy of a daily administration of recombinant human alpha 2a interferon (IFN), given at a dose of 300MU for 12 consecutive days, in patients with steroid-nonresponsive or -dependent idiopathic thrombocytopenic purpura (ITP). Nine patients received courses of IFN therapy. Mean platelet counts rose from 1.39 to 10.9 x 10(4)/microliters and PAIgG decreased from 151.7 to 59.7 ng/10(7) cells. The maximum rise in platelet counts occurred from 10 to 42 days (mean 19.1) after the initiation of IFN. Complete response (CR) was achieved in 3 of 13 courses (23.1%), and partial response (PR) in 8 (61.5%). One CR case continued for longer than 20 months without further treatment, but intermittent IFN therapy was necessary for the other. The increment of the platelet counts was transient in all of the partial responders. No severe side effect requiring interruption of the course of IFN was experienced. Both serum IgG and PAIgG significantly correlated with the increment of platelet counts, therefore the mechanism of IFN on ITP was presumed to be associated with the inhibition of autoantibody production. Daily administration of IFN appears to be an effective and safe treatment protocol for refractory ITP.