Red blood cell indices in different hemoglobinopathies: A cross-sectional study in Eastern India.

Introduction: Beta thalassemia and hemoglobin (HbE)-related hemoglobinopathies are common public health problems in developing countries. High-performance liquid chromatography (HPLC) is currently the diagnostic test of choice for carrier detection, but it is costly. Hence, some initial screening and complementary tests are required, which can be affordable. Aims: To find out the distribution of different red blood cell (RBC) indices in beta thalassemia trait (BTT) and HbE-related hemoglobinopathies and to determine their significance as screening tests to distinguish between these hemoglobinopathies. Study Settings and Design: This observational cross-sectional study has been carried out at an NABL (National Accreditation Board for Testing and Calibration Laboratories)-accredited Laboratory of Eastern India with approval from the concerned Institutional Ethics Committee from January 2021 to March 2021. Methods and Material: : HPLC tests and complete hemograms were performed on 2247 ethylenediaminetetraacetic acid anti-coagulated blood samples over 3 months. Patients <1 year of age or having a history of blood transfusion within the past 06 months were excluded. Statistical Analysis: : One-way analysis of variance along with Bonferroni post-hoc test was performed to find out significant differences of means of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin%, red blood cell (RBC) count, and red cell distribution width (RDW-CV) among concerned hemoglobinopathies. Results: The results show a significant difference of total RBC count, RDW, MCV, MCH, and MCHC between BTT and E-trait. No significant difference of mean was found between HbE homozygous and E-beta. E-trait differs from both HbE homozygous and E-beta significantly in three parameters, namely, RDW, MCV and MCH. A value of MCV at ≤73.8 fl and MCH at ≤21.9 pg may be a clue of diagnosis for BTT rather than E-trait with >90% sensitivity and >80% specificity. Conclusion: RBC indices vary significantly between BTT and other HbE-related hemoglobinopathies. They can specially be utilized to differentiate BTT and E-trait as supportive tests in addition to the gold standard test of HPLC.

Genomic Reduction at TTC Repeats in the Bacterial Genome of Treated Cases of Hansen's Disease: A Possible Survival Mechanism of Mycobacterium leprae.

INTRODUCTION: Mycobacterium leprae has a small genome and a tendency of persisting as a very low-grade infection. The authors have shown earlier, that the changes in TTC repeats, in M. leprae genome may contribute to the restriction of the pathogenicity of the bacterium and its survival strategy in case of pure neural Hansen's disease. We suspect, that a similar genomic reduction if happens in treated cases of Hansen's disease, can be a determining factor for developing persisters and relapse. AIM: The present study aimed to find out if there was any evidence of genomic reduction in treated cases of Hansen's disease that showed microbiological nonresponse. METHODS: Skin biopsies were taken from treated cases of Hansen's disease at tertiary centers in Kolkata and at Raipur who had bacterial index (BI) unchanged or increased compared to their pretreatment BI. Analysis for the mutation in rpoB gene and folP1 gene were done to rule out rifampicin and dapsone resistance, respectively. The entire TTC repeat region of the bacteria was amplified by polymerase chain reaction and was subjected to sequencing. The obtained sequences were then analyzed by CLUSTALW. RESULTS: A total of 127 patients were included in the study of which in 52 the BI remained same and 75 had an increase in BI, even after 6 months of completion of multidrug therapy. Among the samples, 2 had positive rpoB gene mutation. No mutation was found in the folP1 gene. The TTC repeat of both the rpoB-resistant samples was found to have 17 copies, which matched their pretreatment copy number. In other 125 cases, 60 cases showed no change from their pretreatment TTC number. Of those 65 samples that showed evidence of genomic reduction, 11 samples showed one copy, 41 showed 2 copies, and 13 showed 3 copies deletion. We also observed a significant regional variation. CONCLUSION: We concluded that there was evidence of genomic reduction, which might lead to microbiological nonresponse in treated cases of Hansen's disease. This indicated a possibility of future persistence and relapse.

Unique TTC Repeat Base Pair Loss Mutation In Cases of Pure Neural Leprosy: A Survival Strategy of Mycobacterium Leprae?

BACKGROUND: Genomic reduction helps obligate intracellular microbes to survive difficult host niches. Adaptation of Mycobacterium leprae in cases of pure neural leprosy (PNL) in the intracellular niche of peripheral nerves can be associated with some gene loss. Recently, a stable but variable number of tandem repefzats (TTC) have been reported in strains of M. leprae. FolP and rpoB genes are the two common mutation sites which deal with the susceptibility of the bacteria to drugs. AIM: We attempted to find if genomic reduction of M. leprae in context of these TTC repeats or mutations in folP1 and rpoB can be the reason for the restriction of M. leprae in the nerves in PNL. MATERIALS AND METHODS: DNA extracts taken from fine needle aspiration of affected nerves of 24 PNL cases were studied for tandem repeats with 21TTC primer in multiplex-PCR. Mutations were also studied by PCR Amplification of SRDR (Sulphone Resistance Determining Region) of the folP1 and multiple primer PCR amplification refractory mutation system (MARS) of the rpoB. RESULTS: Of the 24 PNL, only 1 patient showed mutation in the rpoB gene and none in the folp1 gene. Studying the mutation in TTC region of the M. leprae gene we found that all the cases have a loss of a few bases in the sequence. CONCLUSION: We can conclude that there is consistent loss in the bases in the TTC region in all cases of pure neural Hansen and we postulate that it may be an adaptive response of the bacteria to survive host niche resulting in its restriction to peripheral nerves.

Report of rpoB mutation in clinically suspected cases of drug resistant leprosy: a study from Eastern India.

BACKGROUND: The current strategy for leprosy control depends mainly on early case detection and providing the recommended multidrug therapy (MDT) dosage. Understanding the molecular mechanisms of drug resistance to each of these drugs is essential in providing effective treatment and preventing the spread of resistant strains in the community. The progress of molecular biology research provides a very efficient opportunity for the diagnosis of drug resistance by in vitro method. AIM: We aimed to investigate the point mutations within the rpoB gene region of the Mycobacterium leprae genome, which are responsible for resistance to rifampicin, in order to determine the emergence of drug resistance in leprosy in the Kolkata region of West Bengal. METHODS: A total of 50 patients with a relapse of leprosy were enrolled in the study. Skin smears were obtained for estimation of bacillary index and biopsies were obtained in 70% alcohol for extraction of DNA. The extracted DNA was amplified by M. leprae-polymerase chain reaction (PCR) targeting rpoB gene region. Every single nucleotide base in the sequence is aligned to reference sequence and identity gaps were determined by NCBI - BLAST. Later in-silico analysis was done to identify the changes in the translated protein sequences. RESULTS: A mutation at the base pair position 2275405 where G is replaced by C in the M. leprae genome, which corresponds to the coding region of rpoB gene (279 bp - 2275228 to2275506), was observed in two patients. This missense mutation in CAC codon brings about a glutamic acid to histidine change in the amino acid sequence of RNA polymerase beta subunit at the position 442 (Glu442His), a region specific for rifampicin interaction, which might be responsible for unresponsiveness to rifampicin by manifesting a stable bacteriological index in these 2 patients even after completion of 24 months of multibacillary multi-drug therapy (MB-MDT). LIMITATIONS: The major limitations of multiple-primer PCR amplification refractory mutation system (MARS) assay is that it capable of detecting mutation at codon 425 and cannot distinguish any silent amino acid changes. CONCLUSION: The study indicates the existence of rifampicin drug resistance in Eastern India.

Use of fine needle aspirate from peripheral nerves of pure-neural leprosy for cytology and PCR to confirm the diagnosis: a pilot study.

BACKGROUND: The diagnosis of pure neural leprosy (PNL) remained subjective because of over-dependence of clinical expertise and a lack of simple yet reliable diagnostic tool. The criteria for diagnosis, proposed by Jardim et al., are not routinely done by clinicians in developing country as it involves invasive nerve biopsy and sophisticated anti-PGL-1 detection. We conducted a study using fine needle aspiration cytology (FNAC) coupled with Ziehl Neelsen staining (ZN staining) and Multiplex-Polymerase Chain Reaction (PCR) specific for M. leprae for an objective diagnosis of pure neural leprosy (PNL), which may be simpler and yet reliable. AIM: The aim of the study is to couple FNAC with ZN staining and multiplex PCR to diagnose pure neural leprosy patients rapidly, in simpler and yet reliable way. METHODS: Thirteen patients of PNL as diagnosed by two independent consultants were included as case, and 5 patients other than PNL were taken as control in the study. Fine needle aspiration was done on the affected nerve, and aspirates were evaluated for cytology, ZN staining and multiplex-PCR. RESULTS: Out of the 13 cases where fine needle aspiration was done, M. leprae could be elicited in the nerve tissue aspirates in 5 cases (38.4%) with the help of conventional acid-fast staining and 11 cases (84.6%) with the help of multiplex PCR. On cytological examination of the aspirates, only 3 (23%) cases showed specific epithelioid cells, whereas 8 (61.5%) cases showed non-specific inflammation, and 2 (15.3%) cases had no inflammatory cells. CONCLUSION: Our study demonstrates that in the field of laboratory diagnosis of PNL cases, FNAC in combination with ZN staining for acid-fast bacilli (AFB) and Multiplex-PCR can provide a rapid and definitive diagnosis for the majority of PNL cases. FNAC is a less-invasive, outdoor-based and simpler technique than invasive nerve biopsy procedure. Thus, this study may enlighten the future path for easy and reliable diagnosis of PNL.

Fite-Faraco staining in combination with multiplex polymerase chain reaction: a new approach to leprosy diagnosis.

BACKGROUND: Leprosy is not always an easy disease to diagnose, and patients can remain undiagnosed for longtime, not only at the peripheral clinics but also even at places with higher medical facilities, so, there is an urgent need for rapid and definitive modalities for leprosy diagnosis. This prospective study evaluates the ability of Fite-Faraco staining (FF staining) and multiplex polymerase chain reaction (PCR) over hematoxylin and eosin staining (H and E staining) and Ziehl-Neelsen staining (ZN staining). AIMS: The aim of this perspective study is to evaluate the effectiveness of FF staining in combination with multiplex PCR for the early and rapid diagnosis of leprosy than any other coexisting diagnosis tool. METHODS: Patients with new skin patches or nodules with or without evidence of nerve damage were selected for the study. Punch biopsy was collected according to standard procedures. Each biopsy sample was divided into two equal parts, one half was fixed in 4% (v/v) buffered neutral formalin and then accordingly embedded in paraffin. Sections were stained by three different methods: H and E staining for histopathological examination, ZN staining, and FF staining for detection of acid-fast bacilli (AFB). And the other part was subjected for DNA extraction and PCR was carried out by the obtained DNA sample. RESULTS: H and E staining, ZN staining, FF staining, and PCR yield 58.2%, 50.9%, 60%, and 67.7% successful diagnosis of leprosy. The true diagnostic performances for these techniques were as follows: H and E staining - sensitivity 70.6%, positive predictive value (PPV) 81.9%, negative predictive value (NPV) 53.6%. For ZN staining - sensitivity 59.9%, PPV 69%, NPV 45.7%. For FF staining - sensitivity 74.6%, PPV 85.9%, NPV 56.7%, and for PCR - sensitivity 87.8%, PPV 95.6%, NPV 71.2%. CONCLUSION: The combination of FF staining and PCR was shown to provide a rapid and definitive diagnosis in the majority of leprosy suspected cases with a higher positive likelihood ratio (+LR) of 7.76 and 2.716, respectively, than H and E staining of 2.244 and ZN staining of 1.378.