内脏利什曼病患者骨髓及血内病原体特异性kDNA片段PCR扩增用于诊断的研究

目的 :建立简易、准确的诊断内脏利什曼病和病原体鉴定技术。方法 :采用作者设计的杜氏利什曼原虫 ( L.d.)种特异引物 和 ,经 PCR扩增样品内病原体 k DNA2 97bp片段 ,检测 2 2例确诊内脏利什曼病 ( VL )患者骨髓、血、血清共 55份样品和 4例临床疑诊为黑热病患者的骨髓 (共 2 6例 ,59份样品 )。结果 :( 1) PCR法与骨髓涂片镜检符合率为 96.2 % ( 2 5/2 6) ;( 2 ) PCR法检测骨髓、血及血清的总阳性率为 95.4 % ( 2 1/2 2 ) ;( 3) PCR法检测 2 2例骨髓、 16例血样品及 17例血清样品 ,阳性率分别为 91% ( 2 0 /2 2 )、 68.8% ( 11/16)及 2 9.4 % ( 5/17)。 15例骨髓对照样品得自 9例白血病患者及 6例健康人。血及血清对照样品各得自 5例健康人。全部对照未见扩增产物 ,均为阴性。结论 :采用引物 和 进行 PCR扩增检测血内 k DNA特异片段诊断内脏利什曼病有较好前景。     

The high sensitivity of a PCR-ELISA in the diagnosis of cutaneous and visceral leishmaniasis caused by Leishmania infantum

In general, the conventional techniques available for the diagnosis of leishmaniasis have relatively low sensitivity. This means that parasite-rich samples (which can usually only be collected by very invasive methods, such as bone-marrow aspiration) must be employed. This problem has not yet been solved even by use of the PCR-based techniques currently available. However, a new PCR-ELISA has been developed for the diagnosis of cutaneous (CL) and visceral leishmaniasis (VL) caused by Leishmania infantum. This assay appears to have sufficient sensitivity to be effective in the diagnosis of VL not only when bone-marrow aspirates are investigated but also when the samples are of peripheral blood. Overall, the ability of the PCR-ELISA to detect Leishmania, in 76 samples (22 of peripheral blood, 36 bone-marrow aspirates and 18 skin samples) from 72 patients living in a endemic region, was better than that of culture or the examination of Giemsa-stained smears. For example, L. infantum kDNA was detected by PCR-ELISA in 15 (83%) of the 18 skin samples from suspected cases of CL, whereas the combined use of several classical techniques only confirmed the presence of amastigotes in five (28%) of these samples. Similarly, only 21 individuals were diagnosed as having VL by conventional techniques whereas 30 were found Leishmania-positive in the PCR-ELISA. The new PCR-ELISA also appears to be a suitable technique for detecting leishmanial kDNA in samples of peripheral blood from cases of L. infantum-HIV co-infection. The assay is more sensitive than the combined use of several conventional techniques in the diagnosis of subclinical VL, probably because those with subclinical infection have relatively low parasitic loads that are generally undetectable using the other techniques.     

Sensitivity of bone marrow aspirates in the diagnosis of visceral leishmaniasis

Bone marrow aspirates are believed to provide a safer but less sensitive method in the diagnosis of visceral leishmaniasis (VL) compared with splenic aspirates. We examined the effect of the number of fields and the time of observation on bone marrow smear sensitivity and compared it to our experience with spleen aspiration. Bone marrow smears of 98 patients and splenic aspirates from 120 patients were examined. Among 87 patients with VL, the sensitivity of bone marrow aspirates was 40.2%, 65.5%, 89.7%, 92%, and 95.4% at 1, 5, 20, 30, and 60 minutes, respectively. The sensitivity of spleen aspirate examination was 93% for 114 patients. One patient died of shock after spleen aspiration. A bone marrow smear is very sensitive if examined thoroughly, reaching a sensitivity similar to that of spleen aspirate. We propose that a bone marrow smear be established as the technique of choice for the parasitologic diagnosis of VL.     

Leishmania tropica-isolated patient with visceral leishmaniasis in southern Iran

Visceral leishmaniasis (VL) is caused by various strains of Leishmania donovani, Leishmania infantum, and Leishmania chagasi with different geographical distribution. The aim of this study was to identify the strains of Leishmania that can cause VL in southern Iran. DNA of Leishmania were extracted from the slides of bone marrow aspirates (#42) and spleen punctures (#22), which were positive for leishman body from the patients who were referred to the hospitals affiliated with Shiraz University of Medical Sciences. Differences in Leishmania strains were determined by size difference of the polymerase chain reaction (PCR) amplification as visualized on agarose gel. PCR results and smears had 100% correlation. The dominant strain of Leishmania was L. infantum (63 out of the 64 cases), but one case of L. tropica was also detected. VL mostly involves children below 2 years of age in Iran, therefore infection with L. infantum was expected, but this study is the first report of VL that is caused by L. tropica in Iran.     

Short report: detection of Leishmania DNA by polymerase chain reaction on blood samples from dogs with visceral leishmaniasis.

Immunological, parasitological, and molecular techniques were applied to blood samples of dogs to diagnose Leishmania infections. In 1997, 644 domestic dogs were studied. Peripheral blood samples were collected for serological diagnosis and detection of Leishmania parasite by polymerase chain reaction (PCR). The indirect immunofluorescence test was positive in 139 (21.6%) of 644 dogs examined. The PCR was performed in 70 blood samples and 3 bone marrow aspirates. A 120-bp fragment specific for Leishmania was present in PCR hybridization analysis of all seropositive samples in the molecular assays. The PCR hybridization test, which used a minicircle of Leishmania chagasi as a probe, was negative in 20 seronegative dogs. These results suggest that a combined PCR-Southern hybridization technique is a highly sensitive approach to diagnose leishmaniasis in dogs, which are a zoonotic reservoir of leishmaniasis for humans.     

Visceral leishmaniasis caused by Leishmania (Viannia) braziliensis in a patient infected with human immunodeficiency virus

The current article reports the case of a 19-month-old-girl, from the state of Minas Gerais, Brazil, with visceral leishmaniasis, by Leishmania (Viannia) braziliensis, and Human Immunodeficiency Virus (HIV) co-infection. The child's mother and father, aged 22 and 27 years old, respectively, were both HIV positive. The child was admitted to the General Pediatric Center, in Belo Horizonte, presenting high fever, fatigue, weight loss and enlargement of liver and spleen. Indirect immunofluorescent test revealed a titer of 1:320 for Leishmania. Such result was confirmed by the presence of amastigotes in bone marrow aspirate samples and culture of promastigote forms. Parasites were identified as being Leishmania (Viannia) braziliensis through PCR, using a L. braziliensis complex primer and a generic primer, followed by hibridization. Specific leishmaniasis therapy (Glucantime register mark or target antimonial) was intravenously administered.     

Diagnosis of visceral leishmaniasis by the polymerase chain reaction using blood, bone marrow and lymph node samples from patients from the Sudan

We have evaluated the sensitivity of the polymerase chain reaction (PCR) as a diagnostic tool for Leishmania donovani using blood, bone marrow and lymph node samples from Sudanese patients with a confirmed infection. Forty patients were diagnosed by microscopic examination of bone marrow or lymph node samples. The PCR was able to detect parasite DNA in 37 out of 40 blood samples. In bone marrow and lymph node samples, the PCR was able to detect parasite DNA in all 7 and 6 samples, respectively. We suggest that the PCR should be considered as a valuable and sensitive tool for the diagnosis of L. donovani infection. However, if PCR diagnosis is to supplement or even replace microscopic diagnosis in developing countries, a large number of patients with no apparent signs of infection and patients with other diseases have to be tested in order to evaluate its true potential.     

Influence of peripheral blood admixture on the number of hematopoietic progenitor cells (CFU-GM and BFU-E) in human bone marrow aspirates

Peripheral blood contamination in human bone marrow aspirates was calculated from the ratios between the erythrocyte and nucleated cell counts in both the bone marrow aspirate and a simultaneously obtained peripheral blood sample. This method is based upon experimental data which showed that the erythrocytes in bone marrow aspirates are mainly derived from the intravascular blood compartment. A strong negative correlation was found between the peripheral nucleated cell fraction (FBl) and the number of myeloid progenitor cells in 65 bone marrow samples (correlation coefficient r = -0.51; p less than 0.001). A similar correlation was found between erythroid progenitor cells and peripheral blood fraction (r = -0.55; p less than 0.01). The culture conditions were continuously monitored, using large batches of frozen marrow samples as controls. The correction for peripheral blood admixture permits a more reliable and reproducible interpretation of the quantitative results obtained from studies on the number of clonogenic cells in human bone marrow aspirates. Moreover, the method allows the interpretation of data obtained from bone marrow samples which are heavily contaminated by peripheral blood.     

Comparison of PCR with stained slides of bone marrow and lymph nodes aspirates with suspect diagnosis for leishmaniasis

Visceral leishmaniasis (VL), also known as kala-azar, is a disseminated protozoan infection caused by Leishmania donovani complex. Traditionally the definite diagnosis is made by amastigote detection in the tissue. The aim this study was to evaluate the PCR technique in stained slides of bone marrow and lymph nodes aspirates with suspect diagnosis for leishmaniasis. Slides were selected totaling 62 suspect cases (33 bone marrow samples and 29 lymph node samples) and 17 positive cases (8 bone marrow and 9 lymph node). From 62 suspect cases, 39 (62.90%) were confirmed to be positive being 17 (n = 29) lymph node aspirates and 22 (n = 33) bone marrow. This finding is in agreement with the higher sensitivity of the PCR assay compared to direct microscopic observation. In conclusion, the findings of this study supports the use of PCR on archive cytological preparation stained slides for the diagnosis of canine visceral leishmaniasis, emphasizing the higher sensitivity of this technique when compared to direct microscopic examination and mostly the use of the suspect status for the cytology samples that presents the previously mentioned particularities with focus on detecting the oligosymptomatic or assymptomatic dogs in endemic areas functioning as potential reservoirs for this disease.     

Preliminary study on investigation of zoonotic visceral leishmaniasis in endemic foci of Ethiopia by detecting Leishmania infections in rodents

Objective:To investigate the zoonotic visceral leishmaniasis(ZVL) by identification of the most probable reservoir hosts using parasite isolation and analysis of a possible transmission dynamics of the disease in extra-domestic agricultural fields and rural villages.Methods:Rodents were collected from selected study sites in kala-azar endemic areas based on information for localities of kala-azar cases for screening of Leshmania infections using parasitological,serological and polymerase chain reaction(PCR) from March.2013 to January,2014.Ketamine(Clorketam Veterinary) was used to anaesthesize the rodents according the prescribed dosage(average 2 mg/kg for intra-venous route).The blood obtained using sterile needle was dropped into sterile filter paper and allowed to air dry before sealing in plastic bags.The tissues from liver,spleen and skin were macerated in Locke's solution before transferring them into NNN medium.Blood and touch smears of liver,spleen,skin and bone marrow were prepared for fixing using methanol and staining by Giemsa stain for microscopy.These tissues were also ascd for DNA extractions and PCR amplification of Leishmania infection.Results:A total of 335 rodents(13 species) were analyzed by sampling internal organs.The infection rate by PCR was 11.1%(6/54) for Arvicanthis nilothicas compared to 17.6%(3/17) and 12.5%(2/16) for Acomys cahirinus and Tarera(C) robustus respectively.Almost all the infections were found from bone marrow samples(8/48 or 16.7%) compared with 1/91(1.1%) liver,2/87(2.2%) spleen and 0/87(0%) skin.In all study sites with past human VL cases,rodents and proved vectors shared similar habitats.Conclusions:Leishmania donovani might circulate among different species of rodents in kala-azar endemic lowlands and valleys of Ethiopia by Phlebotamus orientalis and Phlebotomus martini.Detailed studies to substantiate the preliminary data on the possible role of these rodents arc urgently needed.     

Detection of disseminated tumor cells in patients with cervical cancer

PURPOSE: Detection of disseminated tumor cells in a cohort of patients presenting the entire spectrum of invasive cervical cancer. METHODS: Disseminated tumor cells were detected in blood samples taken at different times during surgery or in bone marrow aspirates by a HPV type-specific nested PCR enzyme immunoassay (n-PCR-EIA). A group of 24 patients with HPV-positive cervical cancers representing early and late stages were evaluated, and 15 patients with breast cancer and without HPV-related genital disease served as controls. RESULTS: Disseminated tumor cells were detected in blood samples and/or bone marrow aspirates of 6 of 24 patients. A significant association was found between detectable disseminated tumor cells and recurrent disease ( P=0.013) and between disseminated tumor cells and survival of the patients ( P=0.0054). There was also a clear association between the presence of disseminated tumor cells and tumor size and/or positive lymph node status which, however, was not statistically significant. There was no evidence of increased shedding of tumor cells during surgery. CONCLUSION: Detection of disseminated tumor cells in blood or bone marrow may prove to be of prognostic value, particularly for early-stage cervical cancers.     

Distinguishing visceral leishmaniasis from intolerance to pegylated interferon-alpha in a thalassemic splenectomized patient treated for chronic hepatitis C

A 37-year-old splenectomized man affected by beta-thalassemia and chronic hepatitis, recently treated with pegylated interferon-alpha (Peg-IFN), was admitted because of elevated fever lasting 3 months and unresponsiveness to broad-spectrum antibiotics. Laboratory studies showed white blood cell and platelet counts within the normal range but lower than observed before Peg-IFN treatment and an elevated erythrocyte sedimentation rate. The blood transfusion rate was reported to be increased compared with the period preceding Peg-IFN treatment. A diagnosis of visceral leishmaniasis (VL) was made after Leishmania amastigotes were identified from Giemsa-stained smears of bone marrow aspirates. Cure occurred after liposomal amphotericin B was administered. Symptoms of VL may be difficult to distinguish from the manifestations of Peg-IFN intolerance. We suggest that VL must be suspected in any immunodepressed patient with an unexplained fever and a history of exposure in an endemic area.     

PCR扩增技术用于犬内脏利什曼病病原体kDNA的检测

本文报导了用作者设计的一对寡核苷酸引物Ⅰ和Ⅱ以及文献报导的一对引物A、B检测内脏利什曼病病犬的骨髓、脾和外周血内的病原体kDNA,并和骨髓涂片检查利什曼原虫的结果进行了比较。共检测人工感染犬12只,骨髓涂片阳性者8例,其中PCR检测骨髓组织样品阳性者7例,检测脾组织样品阳性者3例;对照组犬脾、骨髓和外周血所有组织样品均为阴性。根据实验结果认为此法用于检测犬内脏利什曼病病原体kDNA有较好的效果。     

PCR-based detection of Leishmania DNA in skin samples of post kala-azar dermal leishmaniasis patients from an endemic area of Bangladesh

Post kala-azar dermal leishmaniasis (PKDL) is a sequel of visceral leishmaniasis (VL) and PKDL patients are an important reservoir for anthroponotic transmission of VL. Therefore, diagnosis and treatment of PKDL is important for the kala-azar elimination program in South Asia, including Bangladesh. While definitive diagnosis of PKDL is still based on microscopy, despite the low sensitivity of this method of diagnosis, PCR for identification of kinetoplast DNA (kDNA) from Leishmania parasites is expected to be a rapid and sensitive diagnostic method. We attempted PCR-based diagnosis from skin biopsy specimens and compared PCR to other available detection methods in order to determine the acceptability and feasibility of the PCR diagnostic method in an endemic area of VL in Bangladesh. Both skin biopsy specimens and blood samples were collected from 110 patients suspected to have PKDL from 6 subdistrict health complexes in Mymensingh, Bangladesh. Using microscopy, we identified 32 samples (29.1%) that were positive for Leishmania. Immunochromatography tests indicated that 85 samples (77.3%) were positive for Leishmania. In contrast, a total of 104 (94.5%) samples tested positive using nested PCR, while unaffected portions of skin from PKDL patients tested negative. Sequencing analysis of the PCR products indicated that the amplified portion had more than 98% nucleotide sequence identity to the Leishmania donovani reference strain, D10. These findings indicate that the PCR method using a skin biopsy is highly sensitive and useful for confirmatory diagnosis of PKDL.     

A microculture technique for isolating live Leishmania parasites from peripheral blood of visceral leishmaniasis patients

Current procedures for diagnosing Leishmania parasites from patients involve invasive and dangerous tissue aspiration. We have developed a non-invasive and highly sensitive microculture method that can isolate parasites from the buffy coat of the patient's peripheral blood. The parasites were cultured in 96-well culture plates. Nineteen parasitologically proven visceral leishmaniasis (VL) patients were included in the study. Using this technique, we were able to isolate parasites from 16 (84%) samples. However, all 19 (100%) samples were positive on culture of splenic aspirates. We conclude that this technique is useful for the isolation and cryoconservation of parasites from patients' blood. This simple method could be tried as a first-instance alternative before other more sensitive procedures such as splenic aspirate; however, negative results should be confirmed by tests with higher sensitivity.     

实时定量PCR检测B细胞非霍奇金淋巴瘤患者外周血和骨髓IgH基因重排及临床意义

目的:检测B细胞非霍奇金淋巴瘤(B-NHL)患者外周血和骨髓中IgH基因重排并探讨其在临床诊治中的应用。方法:利用SYBR GreenⅠ荧光染料,采用实时定量PCR方法,以IgH基因为标志,对B-NHL患者治疗后采集的15例外周血及10例骨髓的IgH基因重排进行定量分析。结果:15例外周血及10例骨髓均检测到IgH基因拷贝数,外周血和骨髓差异无统计学意义(P>0.05)。结论:实时定量PCR方法对外周血和骨髓中IgH基因重排定量分析,可以作为B-NHL鉴别诊断和随访微小残留病的辅助手段,并对判断疗效、预测复发有一定的临床意义。外周血和骨髓IgH基因拷贝数差异无统计学意义。     

DNA-flow cytometry of blood and bone marrow in chronic myelogenous leukemia

Flow cytometric analysis of bone marrow aspirates and blood samples in 42 patients with chronic myelogenous leukemia (CML) at various disease stages was performed to determine the size of the S-phase compartment of bone marrow and blood. 25 healthy controls were studied for comparative information with both DNA-flow cytometry (DNA-FCM) and 3H-thymidine autoradiography. A correction procedure was applied for peripheral nucleated cell admixture in bone marrow aspirates. The fraction of peripheral nucleated cells in bone marrow aspirates (Fpb) in individual patients was considerable, especially in those with a very high white blood cell count (greater than 100 x 10(9)/l). The size of the S-phase compartments of bone marrow (% Sbm) in patients with CML at diagnosis and in patients at apparent hematological remission was of the same order of magnitude as in normal bone marrow. However, in 3 out of 4 patients at malignant metamorphosis in which the % Sbm could be reliably determined, this percentage was significantly higher than normal (p = 0.013). In 4 out of 11 patients at malignant metamorphosis aneuploidy was noticed. From these findings it is concluded that bone marrow cell proliferation in CML patients at diagnosis and during apparent remission is not essentially different from normal. However, at malignant metamorphosis changes occur in ploidy level and proliferative activity, which can be detected by DNA-FCM already in an early phase.     

Rapid clearance of circulating Leishmania kinetoplast DNA after treatment of visceral leishmaniasis

With the aim of evaluating the utility of the detection of Leishmania kDNA in peripheral blood for the cure assessment of visceral leishmaniasis (VL), a PCR based method was performed in patients with confirmed VL at three follow-up periods after specific chemotherapy with pentavalent antimonial. In 16 out of 17 (94.1%) patients with pre-treatment detectable kDNA that were clinically cured, the PCR turned negative up to 37 days after the initiation of treatment, remaining negative over 90 days after treatment. The clearance of Leishmania kDNA from peripheral blood of patients with VL hints to occur during or shortly after treatment concurring or preceding clinical recovery.     

A simplified and standardized polymerase chain reaction format for the diagnosis of leishmaniasis

BACKGROUND: Definite diagnosis of Leishmania infections is based on demonstration of the parasite by microscopic analysis of tissue biopsy specimens or aspirate samples. However, microscopy generally shows low sensitivity and requires invasive sampling. METHODS: We describe here the development of a simple and rapid test for the detection of polymerase chain reaction-amplified Leishmania DNA. A phase 1 evaluation of the text was conducted in clinical samples from 60 nonendemic and 45 endemic control subjects and from 44 patients with confirmed cutaneous leishmaniasis (CL), 12 with mucocutaneous leishmaniasis (MCL), and 43 with visceral leishmaniasis (VL) from Peru, Kenya, and Sudan. RESULTS: The lower detection limits of the assay are 10 fg of Leishmania DNA and 1 parasite in 180 microL of blood. The specificity was 98.3% (95% confidence interval [CI], 91.1%-99.7%) and 95.6% (95% CI, 85.2%-98.8%) for nonendemic and endemic control samples, respectively, and the sensitivity was 93.2% (95% CI, 81.8%-97.7%), 91.7% (95% CI, 64.6%-98.5%), and 86% (95% CI, 72.7%-93.4%) for lesions from patients with CL or MCL and blood from patients with VL, respectively. CONCLUSIONS: The Leishmania OligoC-TesT showed high specificity and sensitivity in clinical samples and was able to detect the parasite in samples obtained by less invasive means, such as blood, lymph, and lesion scrapings. The assay is a promising new tool for simplified and standardized molecular detection of Leishmania parasites.