Clinical comprehensive evaluation of recombinant Mycobacterium tuberculosis fusion protein / 中国药房

OBJECTIVE To evaluate the effectiveness， safety， economy， innovation， suitability and accessibility of recombinant Mycobacterium tuberculosis fusion protein （EC）， and to provide evidence for selecting skin detection methods for tuberculosis infection diagnosis and auxiliary diagnosis of tuberculosis. METHODS The effectiveness and safety of EC compared with purified protein derivative of tuberculin （TB-PPD） were analyzed by the method of systematic review. Cost minimization analysis， cost-effectiveness analysis and cost-utility analysis were used to evaluate the short-term economy of EC compared with TB-PPD， and cost-utility analysis was used to evaluate the long-term economy. The evaluation dimensions of innovation， suitability and accessibility were determined by systematic review and improved Delphi expert consultation， and the comprehensive score of EC and TB-PPD in each dimension were calculated by the weight of each indicator. RESULTS The scores of effectiveness， safety， economy， innovation and suitability of EC were all higher than those of TB-PPD. The affordability scores of the two drugs were consistent， while the availability score of EC was lower than those of TB-PPD. After considering dimensions and index weight， the scores of effectiveness， safety， economy， innovation， suitability， accessibility and the comprehensive score of EC were all higher than those of TB-PPD. CONCLUSIONS Compared with TB-PPD， EC performs better in all dimensions of effectiveness， safety， economy， innovation， suitability and accessibility. However， it is worth noting that EC should further improve its availability in the dimension of accessibility.

To study the prevalence of latent tuberculosis infection among medical students

Background: Risk of developing latent tuberculosis infection increases in medical students with their higher exposure to TB care facilities. Objective: To study the prevalence of latent TB infection among students attending professional degrees MBBS, BDS, MD, MS, MDS at King George’s Medical University, India. Methods: This study was carried out with Tuberculin skin testing among students and active TB cases were excluded. A standard dose of 0.1?mL of purified protein derivative was slowly injected intra dermally into non-dominant forearm. After 48-72 hours, the reaction was estimated by measuring the transverse diameter of the induration. Results: Total 561 students had given consent to get enrolled. Prevalence of latent tuberculosis infection was significant with period of clinical exposure (p-value < 0.05), average size of induration (p-value < 0.001), and history of prior Tuberculin Skin Test (p-value < 0.001). However it was not significant with the age (p-value > 0.05), gender (p-value > 0.05), and history of contact with active cases of TB (p-value > 0.05). Conclusion: The prevalence of latent tuberculosis infection is higher in post graduate students followed by interns and final year students due to more exposure to patients in wards and clinics at King George’s Medical University, India.

Successful Treatment of Recalcitrant Ungual Wart with Tuberculin Purified Protein Derivative Immunotherapy

Summary@#Despite a variety of therapeutic options that is available, treatment of warts remains challenging and rate of recurrence is high. Intralesional immunotherapy is an emerging therapy for warts. Tuberculin purified protein derivative (PPD) is one of the immunotherapeutic antigens used for the treatment of warts. Here we report a case of recalcitrant periungual wart successfully treated with tuberculin immunotherapy.

A double-blind, randomized controlled trial on the efficacy and safety of intralesional 2% zinc sulfate in the treatment of verruca vulgaris in a tertiary hospital

Background@#Verruca vulgaris ranked 10th in the top 10 diseases in 2019 seen among the Philippine Dermatological Society training institutions. The efficacy of immunotherapy, such as intralesional zinc sulfate (ZS), for warts were reported. Considering the limited studies with promising results on verruca, a study on the efficacy and safety of intralesional zinc in the treatment of verruca was considered.@*Objective@#This study aims to determine the efficacy and safety of intralesional 2% ZS in comparison to intralesional purified protein derivative (PPD) among adult patients with verruca vulgaris.@*Methods@#This is a double-blind, randomized, controlled trial involving 44 patients allocated to group ZS (n=22) and PPD (n=22). Intralesional injections of ZS or PPD to the largest wart were done at weeks 0, 2, 4, 6, 8, 10. Clearance and size reduction of the target and distant wart at 12th week and recurrence at 14th week were assessed. Adverse effects were checked.@*Results@#At the 12th week of treatment, higher proportion in group ZS patients achieved total resolution of the target lesion compared to PPD, but results were not statistically significant (29% vs. 19%). Both groups showed decline in the target lesion size. The median size reduction between the two groups showed no significant differences. Three patients from group ZS showed clearance of distant warts while none in group PPD. There was no recurrence of all previously resolved warts. Adverse reactions were pain, edema, and erythema.@*Conclusion@#Intralesional 2% zinc sulfate (29%) was efficacious and safe compared to Intralesional PPD (19%) but the difference was not statistically significant. There was clearance of distant warts in 5% of group ZS patients. The mild adverse events did not warrant discontinuation of treatment.

A double-blind, randomized controlled trial to compare the effectiveness and safety of purified protein derivative of tuberculin antigen with Mycobacterium w vaccine in the treatment of multiple viral warts

Background: Present day therapeutic modalities for viral warts are mostly ablative in nature, limited by high recurrence rates and are unsuitable for numerous lesions. Immunotherapy has the potential to overcome these limitations. Aims: This study aimed at comparing efficacy and safety of and quality of life changes with intradermal purified protein derivative (PPD) of tuberculin antigen and Mycobacterium w (Mw) vaccine in immunotherapy of warts. Methods: Patients with multiple (≥5) warts were randomized (1:1) into two groups (PPDand, Mw vaccine groups). Fortnightly, 0.1 ml of either medicine was injected intradermally over the deltoidregion till complete resolution or a maximum of six doses. Patients were followed-up for another 3 months for recurrence. Results: Sixty-four participants received either PPD or Mw vaccine. The number of warts were comparable at baseline (P = 0.089, Mann–Whitney test), and reduced significantly with treatment in both groups (P < 0.001, Friedman's ANOVA), as seen from the fourth follow-up onwards with Mw and fifth follow-up onwards with PPD (P < 0.05, Post hoc Dunn's test). Intergroup comparison showed significantly more (P < 0.05, Mann–Whitney test) reduction with Mw than PPD at the sixth and seventh follow-up. The size of warts also reduced significantly (P < 0.001) in both groups from the third follow-up onwards. Complete remission was more (P = 0.539, Fischer's exact test) in the Mw group (68.8%) than the PPD group (50%); and was significantly higher (P = 0.049, Mann–Whitney test) in patients having shorter duration of warts. Adverse events were significantly more (P < 0.001) with Mw including ulceration (50%), discharge (15.6%), pain-swelling-induration and scar at the injection site (97% each), whereas some of those receiving PPD noted erythema and scaling at the injection site (18.8%), and post-inflammatory hyperpigmentation (12.5%). No recurrence was seen till the end of the study. Limitation: Unicentric trial. Conclusion: Intradermal injection of Mw vaccine was more effective but had a higher incidence of adverse effects compared to PPD of tuberculin antigen in patients with warts.

​Interpretation And Clinical Correlation Of Tuberculin Skin Test Results Among Clinically Diagnosed Childhood Tuberculosis

Background: Diagnosing tuberculosis (TB) was still a worldwide big challenge in cases with negative reports of Xpert MTB/RIF, smear, and culture test of acid-fast bacilli (AFB). A single, direct Xpert MTB/RIF test identified 98.2% of the sputum smearpositive TB cases and 72.5% of those with sputum smear-negative TB. Such a diagnosis was often made based on the clinicalcriteria and other supportive findings like tuberculin skin test (TST).Objective: Hence, this study was to help in the diagnosis and treatment of clinically diagnosed childhood TB, especially in thelimited resource rural areas and developing countries.Materials and Methods: Based on the WHO revised criteria of TB diagnosis, to include clinically diagnosed TB instead ofsmear-negative TB disease, an operational definition of clinically diagnosed TB for the selection of participants for TST wasestablished for this study. Based on the recommendation of the CDC team at the Saskatchewan Lung Association, 2007-03-21at the Wayback Machine, the TST results of the study were interpreted.Results: Hence, in our study, the sensitivity of TST was 82.35% (≥10 mm) in the age group of 1–4 years and 60.16% (≥15 mm)in the age group of >4–12 years. However, this study shows that the positivity rate of TST was increased from 60.16% (≥15 mm)to 86.15% (≥10 mm), if the TST results≥10 mm were interpreted as positive even in this age group of >4 years–12 years.Conclusion: In such very difficult situations of clinically diagnosed TB, this study observed that empiric anti-TB treatment may bestarted without microbiological confirmation to clinically diagnosed childhood TB patient with negative reports of Xpert MTB/RIF,smear, and culture test of AFB, presented with one or more of the following symptoms and signs of clinically diagnosed childhoodTB: (1) Chronic anorexia, (2) ill health and fatigue, (3) weight loss of >5% during the past 3 months or documented failure to striveduring the preceding 3 months, (4) night sweating and persistent fever >2 weeks, and (5) non-remitting cough >2 weeks but cannot bediagnosed clinically by any possible causes than TB, and positive TST report, in resource-limited rural areas anddeveloping countries.

Efficacy of intralesional purified protein derivative for cutaneous warts: A meta-analysis

Introduction@#Intralesional purified protein derivative (PPD) is an affordable therapeutic option that has been studied for cutaneous warts. However, the lack of good evidence precludes its widespread use.@*Objective@#To determine the efficacy and safety of intralesional PPD in the treatment of cutaneous warts.@*Methods@#A systematic search for controlled clinical trials comparing intralesional PPD and placebo or any conventional therapy was conducted using electronic databases. The included studies were assessed for risk of bias, and data such as clearance rate of target and distant lesions, recurrence rate, and adverse events were extracted. Analysis was done through RevMan v5.3.@*Results@#Four controlled clinical trials composed of 205 patients were included. All of the studies compared intralesional PPD to placebo as comparator. Intralesional PPD had a significantly higher clearance rate of target wart (RR=0.43[0.22,0.84], P=0.01) and a significantly higher clearance rate of distant lesions (RR=0.59[0.41,0.85], P=0.005) as compared to placebo. However, there was no significant difference in the recurrence rate (RR=0 [-0.07,0.07], P=0.98). Adverse events reported were only considered minor.@*Conclusion@#Intralesional PPD is an effective and safe treatment option for cutaneous warts. However, more well-structured RCTs with longer follow-up period and those comparing it with conventional treatment are needed to further support its use.

Immunotherapy using purififi ed protein derivative in the treatment of warts: An open uncontrolled trial.

Background: Warts are known to clear spontaneously with the development of cell-mediated immunity (CMI) to the virus. Purifi ed protein derivative (PPD) of tuberculin bacilli has been used as a non-specific stimulant of CMI to achieve this outcome. Aim: To study the effect of PPD in the treatment of warts. Methods: Patients with difficult-to-treat warts were selected for immunotherapy. Each patient received 2.5 TU of PPD intralesionally in a few warts. A total of four sessions were given at 2 weekly intervals and patients were followed up for 6 months after the last dose. Results: Sixty-one patients were recruited of which 55 completed 6 months follow up and were available for analysis. Of these, 25 had verruca vulgaris, 18 had verruca plana and 12 had plantar warts. Forty two (76%) patients showed complete clearance after four sessions while the remaining 13 (24%) patients were non-responders. One patient developed a recurrence after total clearance during the follow-up period. Adverse effects were erythema, edema and pain at the site of injections. Limitations: As this was an uncontrolled trial, there is no comparison with a non-intervention group. Also, a Mantoux test was not done due to practical difficulties. Conclusion: Immunotherapy with PPD is helpful in the treatment of cutaneous warts.

Performance of bovine-PPD based whole blood IFN-γassay for rhesus macaques / 中国比较医学杂志

Objective To assess the potential of whole blood IFN-γassay for diagnosing mycobacterium in rhesus macaques.Methods Firstly, basic serum IFN-γconcentrations of TST-negative and -positive rhesus macaques were detected.Then, heparinized whole blood from TST-negative and-positive rhesus macaques was incubated with PBS and 200 IU bovine-PPD ( tuberculin purified protein derivative ) for about 24 h, respectively.The supernatant plasma were harvested and used to determine the concentrations of IFN-γ.The results of plasma IFN-γconcentrations and stimulation index ( SI) were used to analyze the diagnostic potential of the whole blood IFN-γassay.Results The basic serum concentrations of IFN-γfor the TST-positive monkeys were significantly higher than that of the TST-negative macaques, showing a high coefficient of variation.There was no significant effect on the production of IFN-γin the TST-negative macaques.While significantly elevation of IFN-γconcentrations was found in stimulated plasma of TST-positive macaques (P<0.01).The SI of TST-positive macaques was significantly higher than the TST-negative ones.ROC curve analysis revealed that IFN-γconcentrations and SI could be used as evaluation index of whole blood IFN-γassay.Conclusions Based on a small sample experiment we have demonstrated that whole blood IFN-γassay may be one possible auxiliary diagnostic method for tuberculin skin test.

Enhancement of vitamin A combined vitamin D supplementation on immune response to Bacille Calmette-Guérin vaccine revaccinated in Chinese infants

OBJECTIVE@#To investigate whether there is an association between diameter of bacille Calmette-Guérin (BCG) scars and effect of purified protein derivative (PPD) reaction and to determine whether vitamin A (VA) combined vitamin D (VD) supplementation influences the immune response to BCG revaccinated in Chinese infants.@*METHODS@#A cross-section and 3-month community-randomised trial was conducted. A total of 5 629 infants at 3, 6 and 12 months of age in Junan County of China were examined for BCG scar formation. Then, 597 revaccinated infants were randomly assigned to supplementation (n=307) and control (n=290) groups. The supplementation group were daily assigned to 1 500 IU VA and 500 IU VD for 3 months. Then all infants were subjected to skin test with PPD.@*RESULTS@#The diameter of BCG scars was positively correlated with diameter of skin indurations of PPD (r=0.17, P<0.05) in the 5 629 infants. The rate of positive response to PPD was higher in the supplementation group than in the control group (96.1% versus 89.7%, P<0.05, prevalence ratio 1.07, 95% CI 1.02-1.12). The prevalence ratio of PPD response for the supplementation group compared with that for the control group was 1.07 (95% CI 1.01-1.13) for the males and 1.08 (95% CI 1.00-1.17) for the females. For the supplementation group, the males got larger tuberculin induration than the females [(0.73±0.21) cm versus (0.67±0.20) cm, P<0.05) after intervention.@*CONCLUSIONS@#The diameter of BCG scars was effectively correlated with PPD response, which indicates BCG scar formation may be an useful tool to evaluate the effect of tuberculosis prevention. VA combined VD supplementation may play an immuno-regulatory role in BCG revaccination. This may contribute to the prevention of childhood tuberculosis.

Use of recombinant purified protein derivative (PPD) antigens as specific skin test for tuberculosis.

Background & objectives: Purified protein derivative (PPD) is currently the only available skin test reagent used worldwide for the diagnosis of tuberculosis (TB). The aim of this study was to develop a Mycobacterium tuberculosis specific skin test reagent, without false positive results due to Bacillus Calmette-Guerin (BCG) vaccination using recombinant antigens. Methods: Proteins in PPD IC-65 were analyzed by tandem mass spectrometry and compared to proteins in M. tuberculosis culture filtrate; 54 proteins were found in common. Top candidates MPT64, ESAT 6, and CFP 10 were overexpressed in Escherichia coli expression strains and purified as recombinant proteins. To formulate optimal immunodiagnostic PPD cocktails, the antigens were evaluated by skin testing guinea pigs sensitized with M. tuberculosis H37Rv and BCG. Results: For single antigens and a cocktail mixture of these antigens, best results were obtained using 3 μg/0.1 ml, equivalent to 105 TU (tuberculin units). Each animal was simultaneously tested with PPD IC-65, 2 TU/0.1 ml, as reference. Reactivity of the multi-antigen cocktail was greater than that of any single antigen. The skin test results were between 34.3 and 76.6 per cent the level of reactivity compared to that of the reference when single antigens were tested and 124 per cent the level of reactivity compared to the reference for the multi-antigen cocktail. Interpretation & conclusions: Our results showed that this specific cocktail could represent a potential candidate for a new skin diagnostic test for TB.

Delayed-type hypersensitivity skin test responses to PPD and other antigens among BCG-vaccinated HIV-1-infected and healthy children and adolescents / Resposta de testes de hipersensibilidade tardia utilizando PPD e outros antígenos em crianças e adolescentes saudáveis e infectados pelo HIV-1 e vacinados com BCG

INTRODUCTION: Among HIV-1-infected patients, CD4+ T cell counts are well-established markers of cell-mediated immunity. Delayed-type hypersensitivity (DTH) skin tests can be used to evaluate in vivo cell-mediated immunity to common antigens. METHODS: DTH responses to tuberculin purified protein derivative (PPD), sporotrichin, trichophytin, candidin and streptokinase/streptodornase antigens were assessed. Thirty-six HIV-1-infected children/adolescents and 56 age- and sex-matched HIV-1/HIV-2-seronegative participants were tested. All participants had a BCG scar. Fisher's exact test was used to evaluate significant differences between groups (p<0.05). RESULTS: The main characteristics of the HIV-1 patients were as follows: median age 8.1 years; 20/36 were males; 35 were vertical transmission cases; 34 were AIDS cases under antiretroviral therapy; median viral load = 3.04 log10 copies/ml; median CD4+ T cell count = 701 cells/μl. A total of 25 percent (9/36) and 87.5 percent (49/56) of HIV-1-infected and healthy participants, respectively, displayed DTH reactivity to at least one antigen (p<0.001). Among HIV-1-infected participants, reactivity to candidin predominated (8/36, 22.2 percent), while PPD positivity prevailed among healthy participants (40/56, 71.4 percent). PPD reactivity in the HIV-1-positive group was 8.3 percent (p<0.01). The median PPD induration was 2.5mm (range: 2-5mm) in the HIV-1 group and 6.0 mm among healthy participants (range: 3-15mm). There was no correlation between PPD positivity and age. No correlation between CD4+ T cell counts and DTH reactivity was observed among HIV-1-infected patients. CONCLUSIONS: DTH skin test responses, including PPD reactivity, were significantly lower among HIV-1-infected participants compared to healthy controls, which likely reflects advanced disease and T cell depletion.

INTRODUÇÃO: A contagem de células CD4+ representa marcador da resposta imune celular em pacientes infectados pelo HIV-1. Testes cutâneos de hipersensibilidade tardia (DTH) podem ser empregados para avaliar in vivo respostas celulares a antígenos comuns. MÉTODOS: DTH para derivado proteico purificado de tuberculina (PPD), esporotriquina, tricofitina, candidina e estreptoquinase/estreptodornase foram realizados. Foram testados crianças/adolescentes infectados pelo HIV-1 (n=36) e indivíduos saudáveis (n=56), soronegativos para HIV-1/HIV-2 pareados por sexo-idade, todos com cicatriz vacinal por BCG. Teste exato de Fisher foi aplicado (p<0,05). RESULTADOS: Entre as crianças/adolescentes infectados pelo HIV-1, mediana de idade=8,1 anos; 20/36 eram do sexo masculino; 35 casos de transmissão vertical; 34 casos de AIDS sob terapia antirretroviral; mediana de carga viral = 3.04lc10 cópias/ml; mediana de contagem de células CD4+ = 701 células/μl. Entre os infectados e saudáveis a reatividade DTH a pelo menos um dos antígenos foi, respectivamente, 25 por cento (9/36) e 87,5 por cento (49/56) (p<0,001). Reatividade à candidina predominou nos infectados (8/36, 22 por cento) e ao PPD nos indivíduos saudáveis (40/56, 71,4 por cento). A reatividade ao PPD entre infectados foi de 8,3 por cento (p<0,01). A mediana da induração ao PPD foi 2,5mm (variação: 2-5mm) entre infectados e 6,0mm (variação: 3-15mm) entre os saudáveis. Não observamos correlação entre positividade ao PPD e idade. No grupo de infectados, não observamos correlação entre contagens de células CD4+ e reatividade ao DTH. CONCLUSÕES: Respostas DTH significativamente diminuídas, incluindo a reatividade ao PPD foram observadas em crianças/adolescentes infectados pelo HIV-1 comparadas com controles saudáveis, provavelmente refletindo doença avançada e supressão da imunidade mediada por células T.

Comparison of serological responses in two different populations with pulmonary tuberculosis

Observational studies on the humoural immune responses of the Warao indigenous people from Delta Amacuro, an isolated area, were compared with urban residents of the Venezuelan capital. Mycobacterium tuberculosis-specific reactivities (IgM, IgE, sIgA, IgG and IgG subclasses) were measured by ELISA using PPD and 38-kDa M. tuberculosis antigens. A total of 294 individuals were studied, 162 Warao (indigenous people) and 132 Creole (non-indigenous people). The patient group consisted of 87 Warao patients and 58 Creole patients, while the control group consisted of 75 Warao controls and 74 Creole controls. Combinations among the isotypes studied were performed. The findings showed that for the Warao people, sensitivity to the combination including anti-PPD IgG and IgE was 92.0 percent, while for the Creole people, sensitivity to the combination including anti-PPD IgG but more so anti-PPD IgG1 and IgG2 was 90.0 percent. Simple tests were able to show higher specificities, which were population-specific; specificities were anti-PPD IgG3, 100.0 percent and anti-PPD IgM, 97.4 percent for the Warao and Creole peoples, respectively. In conclusion, while simple tests reached high specificity, the multi-isotype tests improved sensitivity; the latter shows this approach may be useful in diagnostic testing.

Effect of Tuberculin Skin Test on Ex-vivo Interferon-gamma Assay for Latent Tuberculosis Infection / 결핵및호흡기질환

BACKGROUND: Recently, two commercialized whole-blood assays, QuantiFERON(R)-TB Gold (QFT) and T SPOT-TB(R)(SPOT), which measure the IFN-gamma released in the whole blood after being incubation with mycobacterial antigens, were approved for the diagnosis of a latent tuberculosis infection (LTBI). However, there is data on whether or not the previously used PPD skin tests (TST) have any influence on the diagnostic ability of these ex-vivo IFN-gamma assays. METHOD: Forty-six 15 year-old students who did not appear to be infected with Mycobacterium tuberculosis were enrolled in this study. The peripheral blood was collected and used for two IFN-gamma assays. The IFN-gamma assays and TST were performed at the baseline (1st). The TST was repeated two months later (2nd), and the IFN-gamma assays were repeated two (2nd) and four months (3rd) later only in those subjects who had negative results at the baseline in both the IFN-gamma assays and TST. An induration size > 10 mm was considered to be positive in the TST. RESULTS: The mean TST value was 3.1 +/- 5.4 mm (range: 0-20). Of the 46 subjects examined, 13 subjects (28.3%) showed positive results in the two-step TST. Nine (19.6%) were SPOT-positive and only one (2.2%) was QFT-positive. The 2nd and 3rd QFT were carried out in 23 and 25 all-negative subjects, respectively, and all showed negative results. The 2nd SPOT was performed in 23 subjects and only one (4.3%) showed a weak-positive result. CONCLUSION: Even though there were some discrepancies in the results of the two ex-vivo IFN-gamma assays, it appears that their results were not influenced by a previous TST carried out in two or four months earlier.

Comparative Reactivity of 2 TU and 5 TU PPD Skin Tests

PURPOSE: These days 5 TU purified protein derivative (PPD) is substituted with 2 TU PPD for the tuberculin skin test, a test essential in the diagnosis of tuberculosis in pediatric population. However, there had been no adequate criteria for the positivity of 2 TU PPD skin test. This study was performed to clarify the criteria of positive reactivity of 2 TU PPD skin test. The reactivity of 2 TU PPD was compared to that of 5 TU PPD. METHODS: One hundred and six medical students were tested with Mantoux method. Diameters of induration were measured 72 hours after the intradermal injections of 2 TU and 5 TU PPDs. Past history and family history of tuberculosis, history of BCG administration and the presence of BCG scar were recorded. RESULTS: One hundred and three subjects completed the study. Mean diameter of 2 TU tuberculin test was 10.3 mm and that of 5 TU test was 14.4mm, which was significantly different (P<0.001). The diameters were 0-24mm in the 2 TU test and 0-25mm in the 5 TU test. The diameter of induration in 2 TU test was positively correlated to that in 5 TU test (r2=0.63). Eighty-six subjects (83.5%) in the 2 TU test and 92 subjects (89.3%) in the 5 TU test had diameters of induration of 5mm or more; 59 (57.3%) subjects in the 2 TU test and 83 (80.6%) subjects in the 5 TU test had diameters of induration of 10 mm or more; 27 (26.2%) in the 2 TU test and 64 (62.1%) in the 5 TU test had diameters of induration of 15mm or more. Seventy-six of 103 subjects (73.7%) had greater diameters of induration in 5 TU test than in 2 TU, 22 (21.4%) had the same diameters, and 5 (4.9%) had greater diameters of induration in 2 TU test than in 5 TU test, and the last 5 subjects had indurations of more than 10mm diameter in both 2 TU and 5 TU tests. CONCLUSION: The criterion of positivity in 2 TU PPD skin test, essential for the diagnosis of tuberculosis, is different from that in 5 TU test. In this study, 6 mm or more was adequate for the criterion of positivity and 10mm or more for the criterion of strong positivity. Further studies should be done to establish a criterion for the pediatric population.

PREPARATION AND APPLICATION OF BCG-PPD / 微生物学通报

BCG Purified Protein Derivative (BCG-PPD)was isolated and purified from BCG Culture filtrate by trichloroacetic acid and ammonium sulfate methods. The purity of BCG-PPD was Similar to PPD-S(international standard) and PPD-C(China), but more than that of PPD-CT68 (Canada)and PPD-RT23(Danish). The Delayed-Type Hyperseusitivity(DTH) to BCG-PPD was more sensitivity than other PPD on BCG vaccinated guinea pigs, but less sensitivity than other PPD on Mycobacterium tuberculosis infected guinea pigs. The conversion rate and induration diameter to BCG-PPD was higher than PPD in 333 of 12 weeks after BCG vaccination newborns, but lower than that of other PPD in 97 tuberculosis patients. It was shown that DTH reaction to PPD was more sensitivity in Mycobacteria homogeneous strain vaccinated individual than Mycobacteria heterogeneous strain vaccinated individual. It was demonstrated that BCG-PPD was better than other PPD on observation conversion rates and induration diameter of BCG vaccinated individual. It maybe help to identification BCG vaccinated or tuberculosis infected with DTH of BCG-PPD and PPD in same individual.