The potential transmission of pathogenic micro-organisms (disease causing micro-organisms) such as Hepatitis B and C, Pseudomonas, Tuberculosis and Carbapenem-resistant Enterobacteriaceae have been reported in a variety of published studies. These microorganisms can cause life threatening infections for hospitalised patients undergoing surgical procedures. It is therefore critical that medical devices are properly cleaned and appropriately disinfected or sterilised before they are used on patients. These types of infections are known as healthcare associated infections (HAI).
According to the World Health Organisation (WHO), surgical site infections are the most frequent type of HAI in low- and middle-income countries. The WHO also states that between 1.2 to 23.6 per cent per 100 patients undergoing surgical procedures develop surgical site infections in lower- and middle-income countries.
The ability of a microorganism to cause an infection in a patient depends on how virulent it was, how many were present, how susceptible the patient was and if there was a portal of entry into the patient. A contaminated medical device could facilitate a portal of entry for a pathogenic microorganism. If a patient develops a HAI it places a significant burden on the healthcare system. It will affect the patient’s length of stay in hospital, which could result in increased medical costs for the patient and his family, and it could cause long term disabilities or death of the patient.
The prevalence of HAI in sub-Saharan Africa is much higher (between 6.7 and 28 per cent) than in Europe. A patient with a predisposed infection like human immunodeficiency virus (HIV) or tuberculosis (TB) who undergoes a medical or surgical procedure with a poorly decontaminated instrument will, therefore, have an even greater chance of developing a HAI.
An important point to consider is that approximately 81 per cent of the 7 billion people in this world live in low and middle-income countries. Low and middle-income countries have resource constraints, which often prevent them or inhibit them from following international recognised repossessing guidelines.
Preventing HAI associated with contaminated devices should be a priority for all countries especially low and middle-income countries with resource constraints.
One solution is to follow manufactures instructions for use and create Standard Operating Procedures. Not all medical devices are cleaned and sterilised in the same manner, which is why it is important to follow the MIFU (manufacturer’s instructions for use). If the MFIU are not followed correctly it could result in direct harm to the patient and could also result in damage to the device itself. Some medical devices require more reprocessing steps than others, which could include the reprocessing instructions for brushing, flushing and ultrasonic cleaning for example.
Another way to prevent outbreaks of infection associated with contaminated medical devices is to ensure that those persons tasked with decontaminating devices are well trained or educated in their field. It is the responsibility of the healthcare institution to train their staff, and the training should be based on various manufacturers’ instructions for decontamination.
In the South African context, groups and pockets of Central Sterile Services Department (CSSD) staff (those responsible for decontamination) took it upon themselves to come together in various regions to share their knowledge and experiences. In addition, they organised presentations by device manufacturers that were able to assist the healthcare institutions by providing in-service education and training materials.
Another way to prevent outbreaks of infection associated with contaminated medical devices is to ensure that those persons tasked with decontaminating devices are well trained or educated in their field.
In 2013, the pockets of CSSD staff were united into a national organisation known as the CFSA (CSSD forums of South Africa). Prior to the formation of the CFSA, CSSD departments were like lost souls, with each unit trying to do the best they could with the knowledge that had been collected over the years with in service training and reading.
The first national event was a congress hosted at the Africa Health in 2013. Partnering with Africa Health has facilitated a basis for learning, being exposed to local and international best practices. As noted by the author “it felt as if we all had purpose and we realised that we did not have enough information or proper reference guides to do our work optimally”.
Regular regional CSSD forums are hosted throughout South Africa every year. CSSD’s now have a network through which they could communicate and share knowledge, uniting staff from different hospital groups in both the private and provincial sector. The CFSA standard operating procedures where written and CSSD practices are based on scientific knowledge and not just on assumption.
The CFSA has become a formidable body that grows every year in association with Africa Health. We are exposed to the latest scientific information and research and with our national chairperson attending international congresses and bringing the knowledge home.
Although we have come a far way in our practices we need to grow even further, this can only be done together as a collective society. As the CFSA grows in strength we hope to share our knowledge with all who want to learn from us on the African continent and beyond.
References available on request.
SSc is characterised by a heterogeneous group of autoantibodies directed against various antigenic targets. Some of the antibodies occur frequently, while others are very rare. A large proportion of sera from SSc patients show an isolated reaction with just one antigen. Therefore, comprehensive multiparametric analysis of different autoantibodies is essential to minimise diagnostic gaps and increase the serological detection rate for SSc. As different autoantibodies are associated with different organ manifestations, autoantibody detection can also aid prognosis.
Systemic sclerosis
SSc, also known as scleroderma, is an autoimmune connective tissue disease which occurs mainly in middle adulthood. Approximately 2 to 50 out of 100,000 people suffer from SSc worldwide. Early symptoms of SSc are shortening of the lingual frenum and Raynaud’s syndrome, followed by oedema of the hands and feet. The skin becomes stiff, atropic, waxy and thin. The hands become deformed (claw hand) with highly tapered finger ends (Madonna fingers), and the face becomes rigid and mask-like. In later stages, callosity of the inner organs, particularly the digestive tract, lungs, heart and kidneys occurs.
SSc is divided into different subsets. In limited cutaneous SSc, skin involvement is limited to the distal extremities. In the diffuse cutaneous SSc, the symptoms are diffusely distributed over the trunk, the proximal extremities and the face. A third subset without skin involvement is also known. The so-called CREST syndrome of SSc manifests with calcinosis, Raynaud’s syndrome, esophageal dysfunction, sclerodactyly (thin, pale, thickened and hairless skin on the fingers) and teleangiectasis (persistent pathological dilation of superficial skin vessels).
Diagnosis of SSc is made according to criteria established by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). However, clinical diagnosis can be difficult, especially in the early stages and in patients with the limited form of the disease. Currently known specific autoantibodies can be found in over 95% of patients with SSc. Autoantibody diagnostics facilitate early diagnosis of SSc and its differentiation from other collagenoses such as systemic lupus erythematosus, polymyositis, Sharp syndrome and Sjögren’s syndrome. The autoantibody specificities also provide an indication of the SSc subtype and serve as a tool for disease monitoring and prognosis.
Autoantibodies in SSc
Autoantibodies in SSc are directed predominantly against components of the cell nucleus. The target antigens include DNA topoisomerase 1 (Scl-70), centromere proteins (CENP A and B), RNA polymerase III (Rp 11 and RP155), PM-Scl complex proteins (PM-Scl100 and PM-Scl75), fibrillarin, as well as the rarer target antigens NOR (nucleolus organising region) 90, Th/To and Ku.
Different autoantibody specificities are associated with different types of SSc. Antibodies against Scl-70, RP155 and RP11 are characteristic for the diffuse form, while antibodies against CENP A, CENP B and Th/To occur in the limited form. Antibodies against Ku, PM-Scl75 and PM-Scl100 are indicative of an overlap syndrome.
Predictors of disease course
Autoantibody determination can be useful for predicting the disease outcome and organ involvement. In a recent study, five major autoantibody clusters with specific clinical and serological associations were defined in patients with SSc, namely centromere, strong RNA polymerase III, weak RNA polymerase, Scl-70, and other autoantibodies. The separation of anti-RNA polymerase III into two clusters based on the intensity of the reaction is a new aspect and may reflect different temporal stages of SSc disease. In further studies, significant associations have been found between anti-Scl70 and interstitial lung disease, anti-RNA polymerase III and renal crisis, anti-Th/To and pulmonary hypertension, and anti-U1 RNP and pulmonary arterial hypertension. Autoantibodies against Scl70, RNA polymerase III and U1 RNP are, moreover, associated with significantly reduced survival compared to anti-centromere antibodies. Thus, sub-classification and disease stratification using autoantibodies may have clinical utility, particularly in early disease.
Furthermore, a frequent co-existence of various rheumatoid disease-associated antibodies, including CENP A, CENP B and Scl-70, with antibodies characteristic for primary biliary cirrhosis has been observed, emphasising the importance of considering both of these diseases during serological diagnostics.
Autoantibody detection strategy
Autoantibodies in SSc are screened by indirect immunofluorescence test (IIFT) on HEp-2 cells and primate liver and confirmed by monospecific tests. In IIFT, SSc-associated autoantibodies give rise to various fluorescence patterns, for example nucleolar (eg. anti-Scl-70, anti-PM-Scl100, anti-PM-Scl75, anti-RP11, anti-RP155, anti-Th/To, anti-NOR90, anti-fibrillarin), centromere (anti-CENP A and anti-CENP B) or speckled (e.g. anti-Ku). Some typical patterns are shown in Figure 1.
Multiplex immunoblots are highly suitable for confirming antibody specificities, as many different antigens can be included on the test strips and analysed in parallel. In particular, line blots fitted with individual membrane chips allow antigens with widely different properties to be combined on one test strip. A dedicated immunoblot for SSc, the EUROLINE Systemic Sclerosis (Nucleoli) Profile (Figure 2), allows confirmation of 12 SSc-associated autoantibodies simultaneously. In particular, it allows the differentiation of antibodies that show a nucleolar pattern in IIFT. The antigens contained in the profile are Scl-70, CENP A, CENP B, RNA polymerase III subunits RP11 and RP155, fibrillarin, NOR-90, Th/To, PM-Scl100, PM-Scl75, Ku and PDGFR (platelet derived growth factor receptor). Ro-52 is also included to provide additional diagnostic information, although Ro-52 antibodies are not specific for SSc.
Clinical prevalence data
In a published clinical study, sera from 129 patients with clinically characterised SSc (diffuse and limited form), 142 disease controls (myositis, systemic lupus erythematosus, rheumatoid arthritis) and 60 healthy blood donors were investigated with the EUROLINE profile (Table 1). In 85% of the SSc sera, antibodies against at least one of the 12 relevant SSc antigens were detected. The prevalences ranged from 65% for anti-Scl-70 to 1% for the very rare parameter anti-PDGFR. Specificities for the individual antigens were at least 98%. In further published studies using large panels of SSc patients and control subjects, the overall autoantibody positivity rates in SSc patients using the immunoblot amounted to between 76% and 89%, with varying prevalences for the individual autoantibodies depending on the cohort. The specificities for all parameters were very high (93% to 100%).
Confirmation of IIFT results
The panel of 129 SSc sera and 142 control sera described above was also investigated by IIFT on HEp-2 cells. 99% of the SSc sera displayed an IIFT positive reaction, showing the patterns nucleolar (97 sera), centromere (12 sera), overlap nucleolar/centromere (2 sera) or others (17 sera). The EUROLINE confirmed 100% of the sera with centromere pattern and 93% of the sera with nucleolar pattern, amounting to an overall confirmation rate of 94% for the SSc monospecific patterns. Of the controls only 17 showed a nucleolar pattern in IIFT, with only three of these demonstrating typical SSc antibodies. These three positive sera originated from patients with myositis, which might indicate an overlap syndrome in these individuals.
Fully automated immunoblot processing
The immunoblot for systemic sclerosis described here can be processed manually or fully automatically, for example, using the EUROBlotOne (Figure 3). This device provides complete automation of all steps, from sample data entry to report release. Up to 44 strips can be incubated per run, and it is possible to combine the systemic sclerosis profile with other immunoblot profiles in a single run. Preanalytical errors, due to wrong positioning of samples, are avoided thanks to the integrated barcode scanner. Moreover, the device automatically takes pictures of the strips with the integrated camera, and evaluates, interprets and archives them with the user-friendly EUROLineScan software.
Perspectives
The identification of novel SSc-specific autoantibodies has greatly enhanced the serological diagnosis of SSc. Alongside the major markers anti-Scl70, anti-centromere and anti-RNA polymerase III, many rarer autoantibodies now contribute to diagnostics. There is, moreover, a growing body of evidence that SSc antibodies can be used as predictors of disease outcome and organ involvement. Immunoblots such as the EUROLINE are an ideal method for multiparametric, monospecific determination of antibody specificities. They are fast, easy to interpret, and fully automatable, and can be used in any routine diagnostic laboratory. As further novel autoantibodies become identified, immunoblots can be easily supplemented with additional parameters. The SSc immunoblot profile is also useful for studies into the clinical utility of comprehensive autoantibody testing in SSc. It is anticipated that ongoing research will help to elucidate the associations between specific antibodies and particular disease courses and outcomes, and increase the understanding of the pathogenicity of this challenging disease.
Figure 1: IIFT patterns for A) anti-Scl-70, B) anti-centromere and C) anti-PM-Scl
Figure 2: EUROLINE Systemic Sclerosis (Nucleoli) Profile
Figure 3. EUROBlotOne for fully automated processing of immunoblots
Table 1. Autoantibodies in systemic sclerosis
|
Autoantibodies against** |
Sensitivity |
Specificity |
|
Scl-70 |
65% |
99% |
|
CENP A |
11% |
99% |
|
CENP B |
13% |
99% |
|
RP11 |
5% |
100% |
|
RP155 |
7% |
100% |
|
Fibrillarin |
2% |
100% |
|
NOR90 |
4% |
99% |
|
Th/To |
6% |
98% |
|
PM-Scl100 |
7% |
99% |
|
PM-Scl75 |
12% |
98% |
|
Ku |
6% |
99% |
|
PDGFR |
1% |
100% |
**Analysed in 129 sera from SSc patients and 202 control sera
Liver cancer in adult men is the fifth most frequently diagnosed cancer worldwide, and is the second leading cause of cancer-related death in the world. In adult women, it is the ninth most commonly diagnosed cancer. In Asia, liver cancer is the fifth most common cancer. Asian countries account for 75–80% of the roughly 650,000 Hepatocellular carcinoma (HCC) cases reported globally each year.
HCC usually shows mild or no symptoms in the early stage. Symptoms are more prominent when HCC is advanced.
Hence, in many cases, the optimal treatment window lapses even before a definitive diagnosis is made, and the 5-year survival rate is <10%.
Without an effective treatment for advanced stage of hepatic cancer, we can only hope to improve patient outcome by surveillance for high-risk population to increase early detection of HCC.
High risk patients for HCC include those with chronic hepatitis C (CH-C), chronic hepatitis B (CH-B), alcoholic and non-alcoholic fatty liver diseases, and other types of chronic inflammation of the liver.
Surveillance of HCC is important for early detection. Imaging tests including computed tomography, magnetic resonance imaging and ultrasonography, with or without various kinds of contrast medium are important options for detecting HCC. In addition to the imaging tests, various kinds of biomarkers including alpha-fetoprotein (AFP), and protein induced by vitamin K absence or antagonist II (PIVKA-II) have been widely used for surveillance to detect HCC and monitor treatment response.
PIVKA-II was discovered in 1984 by Liebman et al. PIVKA-II, also known as des-gamma-carboxyprothorombin (DCP), is an abnormal prothrombin precursor produced by Hepatocellular carcinoma cells, and is characterised by the incomplete or lack of carboxylated glutamic acid (Gla) residues found in normal prothrombin.
PIVKA-II has been an accepted biomarker for HCC surveillance and is currently included in evidence based Japanese and Asia Pacific Association for the Study of Liver (APASL) clinical guidelines. A US study reported a sensitivity and specificity of 89% and 95%, for differentiating patients with HCC from those with cirrhosis and chronic hepatitis.
In a French cohort, a case-control study was conducted to compare the performances of a-fetoprotein (AFP) and PIVKA-II serum levels for diagnosis of early stage HCC. For the diagnosis of early HCC, PIVKA-II had a sensitivity of 77% and a specificity of 82% at a cut-off of 42 mAU/ml, vs. 61% and 50% for AFP at a cut-off of 5.5 ng/ml (AUC 0.81 vs. 0.58, respectively).
As AFP and PIVKA-II are produced independently, these two markers serve as complementary markers for HCC. The combined use of AFP and PIVKA-II have demonstrated increased sensitivity and specificity than using either marker alone. As such, the APASL guidelines have recommended for PIVKA-II and AFP to be used together as simultaneous measurements of the two markers provides higher sensitivity without decreasing specificity.
The optimal interval of diagnostic tests in a surveillance programme should be determined based on cost-effectiveness as more frequent tests can detect HCC nodules of smaller size. Many studies have adopted an interval of six months between periodic diagnostic tests.
Current recommendations from the Japanese Society of Hepatology states that for patients with hepatitis B, hepatitis C, or cirrhosis , it is recommended that AFP, AFP-L3 fractions and PIVKA- II be measured once every six months. For the chronic hepatitis patients with cirrhosis, it is suggested that AFP, AFP-L3 fractions and PIVKA II be measured every 3-4 months.
With surveillance algorithms and the availability of PIVKA-II available in Asia Pacific, we are hopeful that HCC can be detected and treated earlier for better patient outcome.
