To Explore The Valuation And Influenced Factors Of The Modified Z-N Stain In Diagnosis Of Tuberculous Meningitis

Objective: Tuberculous meningitis (TBM)， is a non-suppurativeinflammatory diseases of the meninges caused by Mycobacteriumtuberculosis.It is the most dreaded manifestation of tuberculosis, secondary topulmonary tuberculosis, and is a common infection of the central nervoussystem especially in developing countries like the China where tuberculosis isendemic,and is associated with high mortality and morbidity. Diagnosis oftuberculous meningitis is still difficult,to directly detected in CSF or cultureisolated Mycobacterium tuberculosis has been considered the gold standardfor the diagnosis of TBM experiments[1], Mycobacterium tuberculosis grownmore slowly, increasing the generation time of14-20hours, the traditionalculture techniques require4-6w can detect the growth of Mycobacteriumtuberculosis, if relying solely on training techniques, easy to delay diagnosisand treatment. Although there are now improved cultivation techniques, butstill need2-3w before the results, and the results are easily affected by samplespecimens. In recent years, the rapid development of technology makesdetection of Mycobacterium tuberculosis culture shortens the time average of9d[2]. However, due to expensive, limiting their use in developing countries.Acid-fast stain is still simple, fast, inexpensive way to diagnosis oftuberculosis infection traditional acid-fast stain of acid-fast bacilli detectionrate is low, the significance of the clinical diagnosis of tuberculous meningitisis unlikely. Our lab has been modified by acid-fast stain, the positive rate isgreatly improved. The results show that this method for the diagnosis oftuberculous meningitis with high sensitivity. Then by analyzing the generalstatus of TBM，the relationship between Modified acid-fast stain and thecourse of treatment、CSF cytology、biochemistry of CSF, we can know thevalue in the diagnosis of tuberculous meningitis. Methods: The case group were45cases（85copies of CSF）clinicaldiagnosis of tuberculous meningitis patients, By comparing the relationshipbetween Modified Z-N stain and the course of treatment,CSFcytology,protein,glucose,chloride,and explore the influnced factors ofModified Z-N stain to give the theoretical basis for diagnosis TBM in clinicalwork.Results:1Clinical data analysis: Tuberculous meningitis patients might manifest aslong-lasting fever, headache, also can manifest as nausea vomiting, meningealstimulation sign, consciousness obstacle， night sweat， brain focalsigns,weight loss et al，but it lack of specificity, can not be as an evidence foridentify with other diseases.45cases of TBM patients met inclusion criteriaincluding30cases of males and15females, aged15years to67years, anaverage of35.7years old.8cases in which less than20years old,20-40yearsold in17cases,20cases more than40years, The symptom duration of thecases varied between seven hours and five months. according to the courseis divided into acute (<2w)27cases，of subacute (2-4w)11patients， withchronic (>4w)7cases.2Cerebrospinal fluid routine and biochemical examination results: The case group, the average number of white blood cells count were93.13±119.13×106/L; the average glucose were2.84±1.08mmol/L；protein’saverage were1.21±1.06g/L;chloride’s average were120.45±8.22mmol/L;the average pressure of lumbar puncture were222.42±87.50mmH2O.3The positive rate of AFB from CSF with light microscope：Positiveresults by the modified Z-N stain were found in36adults of45patients withtuberculous meningitis, the positive rate is80.00%, On modified Z-N stain,AFB was seen in58of the85copies CSF. the positive rate is68.24%.In the85parts of CSF specimens,4of6CSF specimens are positive in definite TBMgroup;13of26CSF specimens are positive in probable TBM group;31of41CSF specimens are positive in possible TBM group;11of22CSF specimensare positive in impossible TBM group. There is no significant difference of each group analyzed by CSF specimens (P=0.057).4the comparison between the modified Z-N stain of MTB and XpertMTB/RIF in the case group:85copies of tuberculous meningitis in patientswith cerebrospinal fluid,18copies CSF were detected by modified Z-N stainand Xpert MTB/RIF at the same time,We founded that1copy CSF in18copies from the case group was positive dectected by Xpert MTB/RIF. Andmeantime,We found that13copies CSF in18copies were positive bymodified Z-N stain.5the relationship between the modified Z-N stain and CSF cytology：81copies CSF were detected by modified Z-N stain and CSF cytology at thesame time,55copies were presenting Lymphocyte reaction，14copies werepresenting mixed reaction，By comparison, P＞0.05，the difference was notstatistically significant.6the relationship between the modified Z-N stain and whether neutrophilsin CSF cytological：81copies CSF were detected by modified Z-N stain andCSF cytology at the same time, we compare positive rates of modified Z-Nstain between50copies which CSF cytology was found neutrophils and31copies which CSF cytology was not found neutrophils, P＞0.05, the differencewas not statistically significant.7the relationship between modified Z-N stain and CSF glucose:78copiesCSF were detected by modified Z-N stain and CSF biochemistry at the sametime, In the case group,we compare positive rates of modified Z-N stainbetween50copies whose CSF glucose was higher than and equal to2.50mmol/L and27copies whose CSF glucose was lower than2.50mmol/L, P＞0.05, the difference was not statistically significant.8the relationship between modified Z-N stain and CSF chloride：78copies CSF were detected by modified Z-N stain and CSF biochemistry at thesame time，In the case group,we compare positive rates of modified Z-N stainbetween49copies which CSF chloride was higher than and equal to120.00mmol/L and29copies which CSF chloride was lower than120.00mmol/L, P＞0.05, the difference was not statistically significant. 9the relationship between modified Z-N stain and CSF protein:79copiesCSF were detected by modified Z-N stain and CSF protein at the same time.9.1we compare positive rates of modified Z-N stain of the following threegroups:9copies which CSF protein was lower than0.40g/L，37copies whichCSF protein was between0.40-1.00g/L,33copies which CSF protein washigher than or equal to1.00g/L,P＞0.05, the difference was not statisticallysignificant.9.2we compare positive rates of modified Z-N stain of the following threegroups:9copies which CSF protein was lower than0.40g/L，59copies whichCSF protein was between0.40-2.00g/L,11copies which CSF protein washigher than or equal to2.00g/L,P＞0.05, the difference was not statisticallysignificant.10the relationship between modified Z-N stain and before and aftertreatment:22copies CSF were detected by modified Z-N stain beforeantituberculosis treatment，51copies CSF after antituberculosis treatment，Positive rates of the two groups were compared，P＜0.05, the difference wasstatistically significant.Conclusion:1Modified acid-fast stain could obviously increase the detectable rate ofAFB in CSF copies compared with traditional acid-fast stain. The positive rateof modified Z-N stain is higher than the Xpert MTB/RIF. Its specificity islower than Xpert MTB/RIF. The modified acid-fast stain, as a method forscreening TBM, is very useful, should combined with other examinations todefinite TBM.2Modified Z-N stain of CSF is not closely related to the descending ofCSF glucose and chloride, also not related to the level of CSF protein.3If clinical suspicion of tuberculous meningitis, acid-fast stain should beroutinely performed in front of anti-TB treatment, the positive rate can be higher than the post-treatment.