[A case of secondary pulmonary cryptococcosis with pleural effusion involving type 1 allergy]

A 69-year-old man who had been followed for pneumoconiosis complained of dyspnea with effort. He was hospitalized because chest roentogenography showed pleural effusion. Further examination of this pleural effusion revealed an eosinophilic cell population and with a varied appearance. First, we suspected tuberculous pleuritis from the characteristics of the pleural effusion, but we could not demonstrate the existence of any acid-fast bacilli. During diagnostic studies, the patient's respiratory status gradually worsened, making it impossible to obtain essential findings. We initiated steroid administration as an antidote to progressive respiratory failure, and carried out bronchoscopy; As a result, we diagnosed secondary pulmonary cryptococcosis from bronchoalveolar lavarge and transbronchial lung biopsy. Pulmonary cryptococcosis with pleural effusion is rare, and this may be the first report of a case involving a type 1 allergy. We speculate that immunological dysfunction contributed to disease progression in this case.

Leflunomide-related lung injury in patients with rheumatoid arthritis: imaging features

Imaging findings of 26 cases of leflunomide (Arava)-related acute lung injury were analyzed. Thirteen cases had pre-existing interstitial pulmonary disease on chest X-ray or computed tomography. The main features of clinically determined leflunomide-induced acute lung injury were similar to those caused by other drugs: diffuse or widespread patchy ground-glass opacities and/or consolidation, frequently accompanied by septal thickening and intralobular reticular opacities. We categorized these findings into four patterns: diffuse alveolar damage (DAD), acute eosinophilic pneumonia, hyperreaction, and cryptogenic organizing pneumonia. The DAD group had a higher mortality rate, but statistically not a significant one. It is impossible to exclude infectious disease such as pneumocystis carinii pneumonia based on imaging findings, and detailed correlation of imaging findings with clinical and laboratory findings is essential in order to make a correct diagnosis.

Role of Toll-like receptor 2 in recognition of Legionella pneumophila in a murine pneumonia model

Legionella pneumophila is an intracellular organism and the major aetiological agent of Legionnaires' disease. Although recent progress has identified Toll-like receptors (TLRs) as receptors for recognition of pathogen-associated molecular patterns in a variety of micro-organisms, understanding the contribution of TLRs to the host response in L. pneumophila infection is still limited. This study examined the roles of TLR2 and TLR4 in murine L. pneumophila pneumonia and an in vitro infection model using bone-marrow-derived macrophages. TLR2-deficient mice, but not TLR4-deficient mice, demonstrated higher lethal sensitivity to pulmonary challenge with L. pneumophila than wild-type mice (P<0.05). Although no differences in pulmonary bacterial burden were observed among the mouse strains examined, lower values of macrophage inflammatory protein-2 (MIP-2), keratinocyte-derived cytokine and interleukin (IL)-6 and higher IL-12 levels were noted in lung homogenates of TLR2-deficient mice compared with the wild-type control and TLR4-deficient mice. Recruitment of inflammatory cells, particularly neutrophils, was severely disturbed in the lungs of TLR2-deficient mice. Reduced MIP-2 production was demonstrated in bone-marrow-derived macrophages from TLR2-deficient mice in response to live L. pneumophila and purified LPS of this strain, but not Escherichia coli LPS. These data highlight the involvement and importance of TLR2 in the pathogenesis of L. pneumophila pneumonia in mice. The results showed that TLR2-mediated recognition of Legionella LPS and subsequent chemokine-dependent cellular recruitment may be a crucial host innate response in L. pneumophila pneumonia.

A case of bucillamine-induced interstitial pneumonia with positive lymphocyte stimulation test for bucillamine using bronchoalveolar lavage lymphocytes

A 64-year-old woman with rheumatoid arthritis and treated with bucillamine presented with a productive cough. No obvious infiltration was detected in chest radiography, but CT revealed patchy ground glass opacities in bilateral lung fields. Her serum KL-6 level was elevated and transbronchial lung biopsy showed interstitial pneumonia. Drug lymphocyte stimulation test (DLST) for bucillamine was negative for blood lymphocytes, but positive for bronchoalveolar lavage (BAL) lymphocytes. The pneumonitis improved after the cessation of bucillamine. We therefore made a diagnosis of bucillamine-induced interstitial pneumonia. DLST with BAL lymphocytes is thus suggested to be useful for such diagnoses.

[A case of polymyositis with concomitant diffuse alveolar damage following interstitial pneumonia]

A 68-year-old woman had been given a diagnosis of interstitial pneumonia (NSIP pattern) and followed up at our hospital for 3 years. She was admitted to our hospital because of dyspnea, lower limb edema and myalgia. On admission, serum CPK and CRP levels were elevated and an electromyogram suggested inflammatory myopathy. We diagnosed polymyositis (PM) with progressive interstitial pneumonia (IP). Although methylprednisolone pulse therapy and immunosuppressive agents were administered, pulmonary lesions became aggravated. The patient died due to respiratory failure as a result of the progress of IP. The autopsy lung revealed diffuse alveolar damage (DAD) at the both acute and fibrotic phases, suggesting that DAD could coincide with PM. We report here a rare case of polymyositis with diffuse alveolar damage (DAD).

Repeated exposure to low-dose diesel exhaust after allergen challenge exaggerates asthmatic responses in mice

BACKGROUND

In conjunction with allergens, diesel exhaust particles act as an adjuvant to enhance IgE responses, inducing expression of cytokines/chemokines and adhesion molecules, and increasing airway hyper-responsiveness (AHR). As most studies were designed to expose animals to diesel exhaust throughout the periods of both sensitization and allergen challenge, it remains unclear whether diesel exhaust (DE) exposure exaggerates airway responses in asthmatic animals.

OBJECTIVE

To study effects of exposure to low-dose DE on AHR and allergic airway inflammation in asthmatic mice.

METHODS

BALB/c mice were sensitized by intraperitoneal injection of ovalbumin and challenged by intranasal administration with ovalbumin. They were exposed to low-dose DE for 7 h/day, 5 days/week, for up to 12 weeks. AHR to methacholine was evaluated by whole-body plethysmography as well as bronchoalveolar lavage cell analysis and cytokine gene expression in lungs.

RESULTS

Repeated exposure of asthmatic mice to low-dose DE resulted in increased AHR and gene expression of several pro-asthmatic cytokines/chemokines, but these effects rapidly subsided with continued exposure to DE.

CONCLUSION

Repeated exposure to low-dose DE after ovalbumin challenge exaggerates allergic responses in mice, but effects are not prolonged with continuous DE exposure.

[Idiopathic pulmonary fibrosis (IPF)]

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease that prognosis (INF) has not improved by available therapy. Recently, much attention has focused on the utility of the T-helper type 1 cytokine interferon (IFN)-gamma as a treatment for IPF. The rationale for its use has been based on observations of its properties as an inhibitor of fibroblast proliferation, collagen synthesis and deposition, and expression of profibrotic cytokines. The clinical trial is advanced aiming at the prognosis improvement of IPF patients. Small-scale controlled clinical study in 1999, IFN-gamma has improved the respiratory functions of IPF, which was resistant to steroid therapy. Be based on these results, phase III large-scale study mainly in North America, the lagged effect of respiratory function aggravation was expected in IPF, in which pulmonary functions are mildly or moderately deteriolated. But in progressive cases, interferon gamma-1b did not affect progression-free survival, pulmonary function, or the quality of life.

[A case of multicentric Castleman disease showing diffuse cystic change in the lung]

A 31-year-old woman was admitted to our hospital because of progressive dyspnea and chest X-ray abnormality. She was given a diagnosis of bronchial asthma 3 years previously. She had received medical treatment, but her dyspnea did not improve. Chest CT showed multiple thin-walled cysts and centrilobular nodules throughout both lungs. Video-assisted thoracoscopic lung biopsy revealed remarkable plasmacytic infiltration in the bronchioles and its surrounding interstitium. Small cystic lesions were detected and with remarkable mural plasmacytic infiltration. The immunohistochemistry showed infiltrated plasmacytes with polyconal characteristics. Her biochemical examinations showed polyclonal hyperimmunoglobulinemia and a high range of serum IL-6. In addition, CT scans showed multiple mediastinal and intraperitoneal lymphadenopathy. From these examinations, she was given a diagnosis of multicentric Castleman disease (MCD) with pulmonary involvement showing diffuse cystic change. This case showed an unusual pattern of MCD with pulmonary involvement. However, we suggest that MCD also should be considered as a differential diagnosis in cases with diffuse lung cystic changes.

Diffuse panbronchiolitis in East Asia

Diffuse panbronchiolitis is characterized by chronic sinobronchial infection and diffuse bilateral centrilobular lesions consisting of peribronchial infiltration of inflammatory cells. At present, it is known that diffuse panbronchiolitis is relatively restricted to East Asia. This uneven distribution is suspected to be highly associated with genetic predisposition located between human leucocyte antigen-A and -B loci. Low-dose, long-term macrolide therapy for the disease was suggested from a detailed observation of a single case that significantly improved by erythromycin therapy. Otherwise simple bactericidal activity of macrolides has been assumed as a candidate because of their clinical effect on the pathogenesis. In the last 10 years, the possible mechanism underlying the effectiveness of macrolide therapy has been dynamically investigated. To understand the pathological features and potential targets for macrolides in diffuse panbronchiolitis, the authors introduce the incidence of diffuse panbronchiolitis in East Asia, the profile of the disease and then trace the history of macrolide therapy in this review. The proposed mechanism of action includes the inhibition of excessive mucus and water secretion from the airway, the inhibition of neutrophil, and sometimes of lymphocyte and macrophage accumulating in the airway, the inhibition of transcription factors expressing several cytokines and the attenuation of bacterial virulence. Intracellular mechanisms of the action of macrolide are a hot topic of interest in research. The anti-inflammatory activity of macrolides is independent of their bactericidal effect, and a new anti-inflammatory analogue without antimicrobial activity should be developed to minimize the emergence of macrolide-resistant microorganisms and to maintain the safety of this treatment.

Dietary fat and meat intake and idiopathic pulmonary fibrosis: a case-control study in Japan

SETTING

There is sparse epidemiologic information regarding the role of dietary factors in the development of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE

To examine the relationship between specific types of fatty acids and selected foods high in fat and IPF in Japan.

DESIGN

Included were 104 cases aged > or = 40 years who had been diagnosed in the last 2 years in accordance with the most recent criteria. Controls aged > or = 40 years consisted of 56 hospitalised patients diagnosed as having acute bacterial pneumonia and four out-patients with common cold.

RESULTS

Intake of saturated fatty acids, mono-unsaturated fatty acids, n-6 polyunsaturated fatty acids and meat was independently associated with an increased risk of IPF. Specifically, the multivariate OR for comparison of the highest with the lowest quartile of intake of saturated fatty acids was 6.26 (95%CI 1.79-24.96, P for trend = 0.01) and for meat it was 7.19 (95%CI 2.15-27.07, P for trend = 0.02). Intake of cholesterol, n-3 polyunsaturated fatty acids, fish, eggs and dairy products was not related to the risk.

CONCLUSION

These findings suggest that consumption of saturated fatty acids and meat may increase the risk of IPF.

Case-control study of medical history and idiopathic pulmonary fibrosis in Japan

OBJECTIVES

A few epidemiological studies have indicated that a patient's past medical history may contribute to the risk of developing idiopathic pulmonary fibrosis (IPF). A relationship between a history of selected disorders and the risk of IPF was assessed in a multicentre hospital-based case-control study in Japan.

METHODOLOGY

Included in the study were 104 patients of IPF, aged 40 years or over, who had been diagnosed within the previous 2 years, in accordance with the most recent criteria. Control subjects, aged 40 years or over, consisted of 56 hospitalized patients diagnosed as having acute bacterial pneumonia and four outpatients with the common cold. Adjustment was made for age, gender, region, pack-years of smoking, employment status, occupational exposure and BMI.

RESULTS

Medical histories of hypertension, hyperlipidaemia, coronary heart disease, diabetes mellitus, hepatitis C virus infection, tuberculosis, asthma, atopic dermatitis and allergic rhinitis were not statistically significantly associated with the risk of IPF, although cases were more likely to have suffered from allergic rhinitis and less likely to have been asthmatics than control subjects. Having a child with a history of allergic rhinitis, but not of asthma or atopic dermatitis, was significantly related to an increased risk of IPF.

CONCLUSIONS

These findings suggest that a genetic predisposition to allergic rhinitis may be associated with an increased risk of IPF.

[Bacteriological and pathological analysis on the pathogenetic factors for cavitary and nodular bronchiectatic type of pulmonary Mycobacterium avium-intracellulare complex disease]

A total of 101 strains of Mycobacterium avium complex (MAC), consisting of 86 M. avium and 15 M. intracellulare strains, were examined by DNA sequencing. The frequency of radiological types [cavitary (Cav) type and nodular bronchiectatic (NB) type] was similar in each species, thus, both species are equal causes of the two radiological types of MAC disease. We also examined serovars of the isolated strains using extracted glycopeptidelipid antigens and thin layer chromatography. Cav type patients discharged a single serovar MAC, while NB type patients discharged two serovar MACs simultaneously. RFLP pattern obtained by the use of IS1245, revealed no clustering of the strains specific for Cav type and NB type. Histopathological examinations of the bronchial lesions in 40 MAC cases and 49 multi-drug resistant tuberculosis (MDR-TB) cases were performed on the surgically removed lung specimens. Lymphocytic infiltration, epithelioid cell granuloma formation, epithelial desquamation and ulceration, as well as smooth muscle atrophy as a cause of bronchiolectasis, were observed more often and were more severe in the peripheral bronchial walls of the NB type than the Cav type of MAC, and as compared with those of MDR-TB cases.

EM703 improves bleomycin-induced pulmonary fibrosis in mice by the inhibition of TGF-beta signaling in lung fibroblasts

BACKGROUND

Fourteen-membered ring macrolides have been effective in reducing chronic airway inflammation and also preventing lung injury and fibrosis in bleomycin-challenged mice via anti-inflammatory effects. EM703 is a new derivative of erythromycin (EM) without the bactericidal effects. We investigated the anti-inflammatory and antifibrotic effects of EM703 in an experimental model of bleomycin-induced lung injury and subsequent fibrosis in mice.

METHODS

Seven-week-old male ICR mice were used. All experiments used eight mice/group, unless otherwise noted in the figure legends. Bleomycin was administered intravenously to the mice on day 0. EM703 was orally administered daily to mice. All groups were examined for cell populations in the bronchoalveolar lavage (BAL) fluid and for induction of messenger RNA (mRNA) of Smad3 and Smad4 in the lung tissues by reverse transcriptase (RT)-polymerase chainreaction (PCR) on day 7. Fibroblastic foci were assessed histologically, and the hydroxyproline content was chemically determined in the lung tissues on day 28. We performed assay of proliferation and soluble collagen production, and examined the induction of mRNA of Smad3 and Smad4 by RT-PCR in murine lung fibroblast cell line MLg2908. We also examined Smad3, Smad4 and phosphorylated Smad2/3 (p-Smad2/3) protein assay by western blotting in MLg2908.

RESULTS

Bleomycin-induced lung fibrosis, and the infiltration of macrophages and neutrophils into the airspace were inhibited by EM703. The expression of Smad3 and Smad4 mRNA was clearly attenuated by bleomycin, but was recovered by EM703. EM703 also inhibited fibroblast proliferation and the collagen production in lung fibroblasts induced by Transforming growth factor-beta (TGF-beta). The expression of Smad3 and Smad4 mRNA in murine lung fibroblasts disappeared due to TGF-beta, but was recovered by EM703. EM703 inhibited the expression of p-Smad2/3 and Smad4 protein in murine lung fibroblasts induced by TGF-beta.

CONCLUSION

These findings suggest that EM703 improves bleomycin-induced pulmonary fibrosis in mice by actions of anti-inflammation and regulation of TGF-beta signaling in lung fibroblasts.

[Clinical studies on the pathogenetic factors of cavitary and nodular bronchiectatic types in pulmonary Mycobacterium avium complex disease]

We investigated the clinical, laboratory and radiological findings of 273 newly diagnosed cases of pulmonary Mycobacterium avium complex (MAC) disease, who were diagnosed in our hospital during 7 years from January 1996 to December 2002. Radiological findings of all cases were classified at the time of diagnosis into 2 patterns, the cavitary (Cav) type and the nodular bronchiectasis (NB) type. Clinical and laboratory findings at the time of diagnosis of 44 death cases were compared with those of 273 newly diagnoses cases, to analyze the prognostic factors of this disease. MAC disease cases showed a marked increase in number in recent years, but only in women. Mean age at the first visit was 65.7 years in men and 63.2 years in women, and when limited to fatal cases, it was 72.3 years in men and 69.4 years in women. Low body weight in terms of body mass index (BMI) and moderately low serum albumin level were found at the time of the first hospital visit in all the newly diagnosed and death cases. In the fatal cases, the peripheral blood lymphocyte counts revealed a relatively smaller number than the normal range, and the PPD skin test showed a negative reaction in 57.7% of all cases, suggesting the presence of lowered cell-mediated immunity at the time of diagnosis. Whether malnutrition occurs as a result of MAC disease or the individuals with lower nutrition level are easy to develop to MAC disease remains to be clarified. In regard to radiological findings, many cavitary (Cav) type cases were found in men and nodular bronchiectasis (NB) type in women among newly diagnosed cases, while the cavitary type was observed in many in both men and women fatal cases. The mean duration period from diagnosis to death was 28.3 months in men and 60.2 months in women, showing a longer survival after diagnosis, perhaps due to earlier hospital visits by women. The average age at death was 74.4 years old in men and 73.8 years old in women, and the two radiological patterns did not change throughout the entire disease course.

Beneficial effect of polymyxin B-immobilized fiber column (PMX) hemoperfusion treatment on acute exacerbation of idiopathic pulmonary fibrosis

OBJECTIVE

This study was aimed to investigate the effect of polymyxin B-immobilized fiber column (PMX) hemoperfusion treatment on the acute exacerbation of idiopathic pulmonary fibrosis (IPF).

PATIENTS AND METHODS

Six patients with a clinical diagnosis of idiopathic pulmonary fibrosis (IPF) who developed acute exacerbation were included in this study. Although five of six patients were treated with high-dose corticosteroid therapy, mechanical ventilation was necessary for all six patients due to severe respiratory failure. Blood endotoxin levels were undetectable in all patients. PMX treatment was performed on these six patients.

RESULTS

In four of six patients, alveolar-arterial difference of oxygen (AaDO(2)), serum KL-6 and lactate dehydrogenase (LDH) were improved after PMX treatment. These four patients were successfully weaned from mechanical ventilation and survived more than 30 days after the initial PMX treatment.

CONCLUSION

These data suggest a potential beneficial effect of PMX treatment on acute exacerbation of IPF.

[Pneumocystis jiroveci pneumonia as a complication of glucocorticoid therapy for interstitial pneumonia]

We evaluated the clinical features of pneumocystis jiroveci pneumonia (PCP) as a complication of glucocorticoid therapy for interstitial pneumonia We analyzed 74 interstitial pneumonia patients receiving glucocorticoid therapy, of whom 7 patients developed PCP. At the time of PCP diagnosis, the average duration of the glucocorticoid therapy was 71 days and the average daily dose of predonisolone was 37 mg. Circulating CD4+ lymphocyte counts were 370/microl on the average and more than 200/microl in three cases. PCP cases showed less circulating lymphocyte counts four weeks after the initiation of the therapy. Any cases receiving sulfamethoxazole-trimethoprim (TMP-SMX) did not develop PCP. In conclusion, interstitial pneumonia patients, who are treated with glucocorticoid, are benefit from TMP-SMX as PCP prophylaxis, but CD4 + lymphocyte counts greater than 200/microl is no reason to denying PCP.

Enhanced vagal modulation and exercise induced ischaemia of the inferoposterior myocardium

OBJECTIVE

To determine whether the Bezold-Jarisch reflex or enhancement of vagal nerves, which are preferentially distributed in the inferoposterior myocardium, results from exercise induced ischaemia in this region.

METHODS

On the basis of exercise myocardial scintigraphy and coronary angiography, 145 patients were classified as follows: group I, 34 patients with inferoposterior ischaemia; group A, 32 with anterior ischaemia; and control, 79 without ischaemia. The relation between ischaemic areas and ECG leads with ST segment changes and vagal modulation assessed by heart rate variability (HRV) (high frequency (HF) component (0.15-0.40 Hz) and coefficient of HF component variance (CCVHF), which is the square root of HF divided by mean RR interval) were assessed.

RESULTS

The rate of ST segment depression in any lead did not differ between group I and group A. HF and CCV(HF) were similar before exercise but higher in group I than in group A and the control group after exercise (mean (SEM) HF: 94 (17) ms2, 41 (7) ms2, and 45 (6) ms2, respectively, p = 0.021; CCV(HF): 1.18 (0.09)%, 0.81 (0.07)%, and 0.89 (0.05)%, p = 0.0053). Furthermore, the percentage change in CCV(HF) before and after exercise was higher in group I than in group A or controls (mean (SEM) 22 (10)%, -24 (4)%, and -21 (3)%, p < 0.0001). The optimal cut off for diagnosis of inferoposterior ischaemia was -5% with a sensitivity of 74%, specificity 75%, and accuracy 75%.

CONCLUSIONS

Vagal modulation as assessed by HRV analysis was enhanced in association with exercise induced inferoposterior ischaemia. Exercise ECG testing combined with HRV analysis would increase accuracy in the diagnosis of ischaemic areas in selected patients with angina pectoris.

Promoter Analysis and Aberrant Expression of theMUC5BGene in Diffuse Panbronchiolitis

Diffuse panbronchiolitis (DPB) is a chronic inflammatory airway disease predominantly affecting Asian populations. DPB is considered to be a complex genetic disease. Considering the mucous hypersecretion of the disease, we hypothesized that the transcriptional activity of mucin genes may be altered in DPB. We analyzed nucleotide sequences of regulatory region of six mucin genes--MUC1, MUC2, MUC4, MUC5AC, MUC5B, and MUC7--and detected their promoter polymorphisms. Among them, the insertion/deletion polymorphism identified in the MUC5B gene was significantly associated with the disease (p = 0.0001). Transcriptional activity observed in the three major promoter haplotypes corresponded to the strength of the disease association in which these haplotypes are involved. Immunohistochemistry of the lung tissues of DPB revealed that MUC5B was abundantly expressed not only in bronchial glands but also in increased numbers of goblet cells on the bronchial surface, where MUC5AC is predominant and MUC5B expression is generally scarce in the normal lung. Marked mucous hypersecretion observed in DPB may be partly explained by increased and aberrant expression of MUC5B. The possible involvement of MUC5B gene in DPB was demonstrated. A further role of the MUC5B polymorphism in its pathogenesis should be studied in the future.

[Expectation of new treatments for idiopathic interstitial pneumonias]

Idiopathic pulmonary fibrosis (IPF), a chronic form of idiopathic interstitial pneumonia, has a poor prognosis with an average life expectancy of 3-4 years from the time of diagnosis. Although patients with IPF have been treated with steroids or immunosuppressants to control the inflammation that occurs earlier in the course of disease, these drugs have not improved the survival of patients with IPF. Recently, several clinical studies of antifibrotic drugs have been conducted in patients with IPF. In Japan, we demonstrated that pirfenidone prevents deterioration of pulmonary function and significantly decreases the incidence of acute exacerbation of IPF in a well-designed, placebo-controlled, double-blind, randomized study. We have also adopted a new system for evaluation of dynamic pulmonary function, which involves measuring the lowest SpO2 level during a 6-minute walk at a constant speed and assessing the pulmonary capacity of patients with IPF. In a study of patients with pulmonary fibrosis associated with Hermansky-Pudlak syndrome in the United States, pirfenidone slowed the decrease in %FVC in patients with a %FVC of >60%, but had no significant effects on patients with a %FVC of < or =60%. Large-scale clinical studies of INF-gamma in patients with IPF in North America and Europe have reported decreases in the mortality of patients with mild IPF with a FVC of >60%, although percentages of patients with disease status rated as 'exacerbated', 'unchanged' and 'improved' after treatment did not differ between the INF-gamma and placebo groups. This presentation reported important future strategies for the treatment of IPF.

Direct determination of MUC5B promoter haplotypes based on the method of single-strand conformation polymorphism and their statistical estimation

Haplotype-based human genome research is important in identifying disease susceptibility genes efficiently. Although haplotype reconstruction by statistical methods is widely used, direct haplotype determination by molecular techniques has also been developed as a complementary method for statistical estimation. In this study, we demonstrate a molecular haplotyping method making use of single-strand conformation polymorphism (SSCP) gels. We identified 10 common SNPs and a dinucleotide insertion/deletion polymorphism within 2-kb region upstream of the transcription initiation site of MUC5B and determined haplotype structure, dividing the region into two DNA fragments. Real haplotypes were determined unambiguously by our SSCP-based analysis with fragments longer than 1 kb. Haplotypes reconstructed from diploid genotypes in the same region by the statistical methods including EM algorithm were also evaluated. Direct comparison between statistical estimation and direct determination of haplotypes revealed that major haplotypes containing multiple marker sites showing strong LD are estimated in great accuracy but that a variety of haplotypes reflecting weak LD are not reconstructed precisely enough. Our data can be helpful in implementing molecular haplotyping or statistical estimation, since usage of these methods may be determined depending on the haplotype structures.