African Journal of Laboratory Medicine最新文献

Background: Autoantibodies are vital biomarkers for the diagnosis, assessment and prognostic determination of various autoimmune disorders.

Objective: This study aimed to evaluate the performance of the two AtheNA Multi-Lyte^® systems for the detection of various autoantibodies.

Methods: A total of 105 systemic lupus erythematosus patients, 35 patients with other autoimmune diseases (diseased controls), and 30 healthy volunteers (healthy controls) at Zagazig University Hospitals, Zagazig city, Al Sharqia governorate were tested for anti-double-stranded DNA (anti-dsDNA) antibodies using indirect immunofluorescence (IIF) and the AtheNA Multi-Lyte^® anti-nuclear antibodies-II system between May 2020 and April 2022. Seventy-five patients with clinically suspected autoimmune vasculitis (AIV) and 25 healthy volunteers were also tested for anti-myeloperoxidase and anti-proteinase 3 antibodies using IIF, the AtheNA Multi-Lyte^® AIV system, and enzyme-linked immunosorbent assay (ELISA).

Results: The AtheNA anti-dsDNA test (98.5%) was more specific than IIF (96.9%) for diagnosing systemic lupus erythematosus, but both tests had the same sensitivity (38.1%). Combining both methods increased sensitivity to 47.6%, while increasing the cut-off of the AtheNA anti-dsDNA test to 134 international units/mL increased specificity to 100%. The AtheNA Multi-Lyte AIV system exhibited substantial agreement with IIF regarding anti-myeloperoxidase testing (κ = 0.65) and almost perfect agreement with ELISA (κ = 0.85). The AtheNA Multi-Lyte^® AIV system exhibited perfect agreement with IIF (κ = 1) and substantial agreement with ELISA for anti-proteinase 3 testing (κ = 0.63).

Conclusion: AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

What this study adds: It is necessary to evaluate various autoantibodies detection assays to increase both sensitivity and specificity of autoimmune diseases diagnostic approaches. AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

Background: Sepsis is characterised by multi-organ failure due to an uncontrolled immune response to infection. Sepsis prevalence is increased in developing countries and requires prompt diagnosis and treatment. Reports, although controversial, suggest that full blood count parameters and cell ratios could assist in the early screening for sepsis.

Objective: The study evaluated the use of haematological cell ratios in screening for sepsis in a South African population.

Methods: The study retrospectively analysed the complete blood counts, blood cultures (BC) and biochemical test results of 125 adult patients who presented between January 2021 and July 2021 at a hospital in Cape Town. An ISO15189-accredited laboratory performed all of the tests. We compared and correlated the automated differential counts, neutrophil, monocyte and platelet-to-lymphocyte ratios with procalcitonin levels. A p-value of < 0.05 was considered significant.

Results: Sixty-two sepsis patients (procalcitonin > 2 ng/L and positive BC) were identified and compared to 63 non-sepsis controls. All cell ratios were significantly elevated in sepsis patients (p < 0.001). However, the two groups had no significant difference in absolute monocyte counts (p = 0.377). In addition, no correlation was detected between any cell ratios and procalcitonin.

Conclusion: In combination with complete blood count parameters, haematology cell ratios can be used for early sepsis detection. The full blood count is widely available, inexpensive, and routinely requested by emergency care clinicians. Although procalcitonin and BC remain the gold standard, the calculation of cell ratios could provide a simple screening tool for the early detection of sepsis.

What this study adds: This study adds evidence to the proposal that calculating haematological cell ratios assists in the early screening of sepsis in a South African setting.

Background: Urinary tract infections are common bacterial infections affecting millions worldwide. Although treatment options for urinary tract infections are well established, with ciprofloxacin long considered one of the antibiotics of choice, increasing antibiotic resistance may delay the initiation of appropriate therapy. While this increase in antimicrobial resistance has been demonstrated in multiple studies around the world, there is a dearth of information from developing countries.

Objective: This study aimed to describe the antimicrobial susceptibility patterns of commonly isolated bacterial uropathogens in a South African hospital.

Methods: Antimicrobial susceptibility data of isolates obtained from urine specimens at the RK Khan Hospital, a regional hospital in KwaZulu-Natal, South Africa, between January 2018 and December 2020 were retrieved from the hospital's laboratory information system and analysed to determine the differences in resistance rates between the most frequently isolated bacterial uropathogens.

Results: Of the 3048 bacterial urinary pathogens isolated between 2018 and 2020, Escherichia coli (1603; 53%) was the most common, followed by Klebsiella spp. (437; 14%). Both E. coli and Klebsiella spp. showed high rates of resistance to amoxicillin/clavulanic acid (29.8% and 42.3%) and ciprofloxacin (37.7% and 30.4%). Nitrofurantoin resistance was low among E. coli (6.2%) but high among Klebsiella spp. (61.3%).

Conclusion: E. coli and Klebsiella spp. in this study were highly resistant to amoxicillin/clavulanic acid and ciprofloxacin, two of the frequently prescribed oral treatment options.

What this study adds: This study highlights the importance of regular local antimicrobial resistance surveillance to inform appropriate empiric therapy.

Background: Rifampicin resistance missed by commercial rapid molecular assays but detected by phenotypic assays may lead to discordant susceptibility results and affect patient management.

Objective: This study was conducted to evaluate the causes of rifampicin resistance missed by the GenoType MTBDRplus and its impact on the programmatic management of tuberculosis in KwaZulu-Natal, South Africa.

Methods: We analysed routine tuberculosis programme data from January 2014 to December 2014 on isolates showing rifampicin susceptibility on the GenoType MTBDRplus assay but resistance on the phenotypic agar proportion method. Whole-genome sequencing was performed on a subset of these isolates.

Results: Out of 505 patients with isoniazid mono-resistant tuberculosis on the MTBDRplus, 145 (28.7%) isolates showed both isoniazid and rifampicin resistance on the phenotypic assay. The mean time from MTBDRplus results to initiation of drug-resistant tuberculosis therapy was 93.7 days. 65.7% of the patients had received previous tuberculosis treatment. The most common mutations detected in the 36 sequenced isolates were I491F (16; 44.4%) and L452P (12; 33.3%). Among the 36 isolates, resistance to other anti-tuberculosis drugs was 69.4% for pyrazinamide, 83.3% for ethambutol, 69.4% for streptomycin, and 50% for ethionamide.

Conclusion: Missed rifampicin resistance was mostly due to the I491F mutation located outside the MTBDRplus detection area and the L452P mutation, which was not included in the initial version 2 of the MTBDRplus. This led to substantial delays in the initiation of appropriate therapy. The previous tuberculosis treatment history and the high level of resistance to other anti-tuberculosis drugs suggest an accumulation of resistance.

Background: Haemolysis - one of the major limiting factors of red cell concentrate quality - must be measured as a quality-monitoring requirement. According to international quality standards, percentage haemolysis must be monitored in 1.0% of red cell concentrates produced monthly and maintained under 0.8%.

Objective: This study assessed three alternative methods for determining plasma haemoglobin concentration in peripheral blood banks that lack a plasma or low haemoglobin photometer - the gold-standard method - in Sri Lanka.

Methods: A standard haemolysate was prepared using an unexpired whole blood pack of normal haemoglobin concentration. A concentration series from 0.1 g/dL to 1.0 g/dL was prepared by diluting portions of standard haemolysate with saline. The alternative methods, namely visual haemoglobin colour scale, spectrophotometric calibration graph, and standard haemolysate capillary tube comparison, were designed using this concentration series and were used to test red cell concentrates received at the Quality Control Department of the National Blood Center, Sri Lanka, from February 2021 to May 2021.

Results: A strong correlation was observed between the haemoglobin photometer method and the alternative methods (R = ~0.9). Based on the linear regression model, the standard haemolysate capillary tube comparison method was the best of the three alternative methods (R ² = 0.974).

Conclusion: All three alternative methods are recommended for use in peripheral blood banks. The standard haemolysate capillary tube comparison method was the best model.

[This corrects the article DOI: 10.4102/ajlm.v11i1.1803.].

Background: Research and clinical use of clinical pharmacology laboratories are limited in low- and middle-income countries. We describe our experience in building and sustaining laboratory capacity for clinical pharmacology at the Infectious Diseases Institute, Kampala, Uganda.

Intervention: Existing laboratory infrastructure was repurposed, and new equipment was acquired. Laboratory personnel were hired and trained to optimise, validate, and develop in-house methods for testing antiretroviral, anti-tuberculosis and other drugs, including 10 high-performance liquid chromatography methods and four mass spectrometry methods. We reviewed all research collaborations and projects for which samples were assayed in the laboratory from January 2006 to November 2020. We assessed laboratory staff mentorship from collaborative relationships and the contribution of research projects towards human resource development, assay development, and equipment and maintenance costs. We further assessed the quality of testing and use of the laboratory for research and clinical care.

Lessons learnt: Fourteen years post inception, the clinical pharmacology laboratory had contributed significantly to the overall research output at the institute by supporting 26 pharmacokinetic studies. The laboratory has actively participated in an international external quality assurance programme for the last four years. For clinical care, a therapeutic drug monitoring service is accessible to patients living with HIV at the Adult Infectious Diseases clinic in Kampala, Uganda.

Recommendations: Driven primarily by research projects, clinical pharmacology laboratory capacity was successfully established in Uganda, resulting in sustained research output and clinical support. Strategies implemented in building capacity for this laboratory may guide similar processes in other low- and middle-income countries.

Background: Integrated health systems with strong laboratory networks are critical in improving public health. The current study assessed the laboratory network in Ghana and its functionality using the Assessment Tool for Laboratory Services (ATLAS).

Intervention: A national-level laboratory network survey was conducted among stakeholders of the Ghanaian laboratory network in Accra. Face-to-face interviews were conducted from December 2019 to January 2020, with follow-up phone interviews between June and July 2020. Also, we reviewed supporting documents provided by stakeholders for supplementary information and transcribed these to identify themes. Where possible, we completed the Laboratory Network scorecard using data obtained from the ATLAS.

Lessons learnt: The Laboratory Network (LABNET) scorecard assessment was a valuable addition to the ATLAS survey as it quantified the functionality of the laboratory network and its overall advancement toward achieving International Health Regulations (2005) and Global Health Security Agenda targets. Two significant challenges indicated by respondents were laboratory financing and delayed implementation of the Ghana National Health Laboratory Policy.

Recommendations: Stakeholders recommended a review of the country's funding landscape, such as funding laboratory services from the country's internally generated funds. Also, they recommended laboratory policy implementation to ensure adequate laboratory workforce and standards.

Between April and May 2022, 10 healthy adult non-patients were recruited from Pusan National University Hospital. Venous blood drawn into a syringe was transferred into test tubes with a zero-to-45-minute delay. The transfer was done sequentially in two positions with the syringe and the needle adaptor end (1) heading downwards and (2) heading upwards. Haemoglobin levels gradually increased over time in position 1 transfer while they gradually decreased in position 2. Therefore, blood must be transferred quickly from a syringe to a tube for reliable test results.

What this study adds: Our findings confirm that delays between blood collection and transfer can affect haemoglobin levels.