Blog http://www.clinlabnavigator.com/Clinlab/Blog/ Thu, 25 May 2017 17:18:56 -0400 Joomla! - Open Source Content Management en-gb Hepatitis C Virus Testing Guidelines http://www.clinlabnavigator.com/hepatitis-c-virus-testing-guidelines.html http://www.clinlabnavigator.com/hepatitis-c-virus-testing-guidelines.html

Many people with Hepatitis C virus (HCV) do not know they are infected. Since many people can live with HCV for decades without developing symptoms, testing is critical. HCV infection can progress to cirrhosis and hepatocellular carcinoma. Highly effective medications are now available that can cur HCV infection.

The Center for Disease Control and Prevention (CDC) recommends testing the following individuals for HCV infection:

  • Adults born from 1945 through 1965 should be tested at least once in their lifetime and more frequently if they are at ongoing risk
  • Persons who currently or previously inject drugs
  • Patients who have HIV infection
  • Patients with persistently abnormal alanine aminotransferase (ALT) levels
  • Patients treated with clotting factor concentrates produced before 1987
  • Patients who have ever received long-term hemodialysis
  • Patients who were recipients of either blood transfusions or organ transplants before July 1992, or who were notified their donor later tested positive for HCV
  • Children born to HCV-positive women
  • Healthcare, emergency medical, and public safety workers with exposure to HCV-positive blood through needle sticks, sharps, or mucosal exposures

CDC also suggests that HCV testing may benefit:

  • Recipients of transplanted tissues
  • Persons who inject drugs
  • Intranasal cocaine and other non-injecting illegal drug users
  • Persons with a history of tattooing or body piercing
  • Persons with a history of multiple sex partners or sexually transmitted infections
  • Long-term steady sex partners of HCV-positive persons
  • Persons who engage in high-risk sexual activity and with history of sexually transmitted infections

The initial test should be an immunoassay for HCV antibody. Individuals with reactive test results should be confirmed with quantitative real-time PCR for HCV RNA. Patients, who have confirmed positive results for HCV infection, should then have their HCV genotype determined. If an individual has HCV genotype 1a, they should be further tested for NS5a drug resistance.

All patients with chronic HCV infection should be tested for evidence of current or previous Hepatitis B (HBV) infection by measuring Hepatitis B surface antigen (HBsAg) and Hepatitis B core antibody (anti-HBc). This testing should be completed before initiating HCV treatment because HBV may be reactivated.

Reference:

CDC Testing Recommendations for Hepatitis C Virus Infection: http://www.cdc.gov/hepatitis/hcv/guidelinesc.htm

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 21 May 2017 21:32:43 -0400
IgA Vasculitis http://www.clinlabnavigator.com/iga-vasculitis.html http://www.clinlabnavigator.com/iga-vasculitis.html

IgA vasculitis affects small blood vessels and typically causes petechiae and purpura that is not accompanied by thrombocytopenia or coagulopathy. It was previously called Henoch Schonlein purpura. IgA vasculitis occurs most commonly in children between the ages of 3 and 15 years of age and is often preceded by upper respiratory tract infections. The majority of cases are self limited and require no specific therapy.

The classical triad in children includes:

  • Palpable purpura without thrombocytopenia or coagulopathy
  • Abdominal pain
  • Arthritis or arthralgia
  • Renal disease causing proteinuria and hematuria

In contrast to other vasculitides, most cases of IgA vasculitis begin with the onset of cutaneous lesions prior to other manifestations. Approximately two thirds of children develop gastrointestinal and renal involvement. Gastrointestinal involvement is usually characterized by colicky abdominal pain that often resembles an acute abdomen. IgA vasculitis most often involves the large joints of the legs, but any joint can be involved.

The diagnosis of IgA vasculitis is usually based on clinical manifestations. Serum IgA levels are elevated in 50 to 75% of cases, especially those with renal involvement. Onset of IgA vasculitis after a respiratory tract infection is often associated with decreased levels of complement C3 and C4. Platelet count and coagulation tests are normal. Tests for autoantibodies such as ANA and ANCA are negative. Skin biopsy reveals leukocytoclastic vasculitis involving postcapillary venules within the papillary dermis with predominant IgA deposition. It is important to note that IgA deposition may also be seen in leukocytoclastic vasculitis that is due to cryoglobulinemia or the use of certain medications, including tumor necrosis factor (TNF) alpha inhibitors.

Jennette JC et al. 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Arthritis Rheum 2013:65:1.

Piram M, Marh A. Epidemiology of immunoglobulin A vasculitis (Henoch-Schonlein): current state of knowledge. Curr Opin Rheumatol 2013;25:171. 

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 14 May 2017 20:48:32 -0400
Preeclampsia Screening Should Not Include Proteinuria http://www.clinlabnavigator.com/preeclampsia-screening-should-not-include-proteinuria.html http://www.clinlabnavigator.com/preeclampsia-screening-should-not-include-proteinuria.html

Preeclampsia affects approximately 4% of pregnancies in the United States. Preeclampsia is defined as the onset of hypertension occurring after 20 weeks of gestation, combined with either proteinuria or other signs or symptoms involving multiple organ systems. Preeclampsia causes adverse health effects in both mothers and infants. Serious maternal complications include stroke, retinal detachment, HELLP syndrome and eclampsia. The latter can cause maternal brain damage, aspiration pneumonia, pulmonary edema, placental abruption, disseminated coagulopathy, acute renal failure, cardiopulmonary arrest, and coma. Adverse perinatal outcomes for the fetus and newborn include intrauterine growth restriction, oligohydramnios, low birth weight, and stillbirth. Preeclampsia leads to early induction of labor or cesarean delivery and subsequent preterm birth.

The United States Preventive Services Task Force (USPSTF) recently updated their recommendation on screening for preeclampsia during pregnancy. USPSTF found that screening and early treatment reduce maternal and perinatal morbidity and mortality. USPSTF recommends screening for preeclampsia with blood pressure measurements throughout pregnancy. The agency did not find sufficient evidence to support point of care urine testing for proteinuria. Urine dipstick tests for proteinuria had sensitivity ranging from 0.22 to 1.00 and specificity ranging from 0.36 to 1.00. Sensitivity of the protein to creatinine ratio ranged from 0.65 to 0.96 and specificity ranged from 0.49 to 1.00. These performance statistics were obtained by screening women with preeclampsia and not all pregnant women. 

According to USPSTF, proteinuria measurement should be reserved for diagnosis of preeclampsia. Recently revised criteria for the diagnosis of preeclampsia include; elevated blood pressure (140/90 mm Hg or greater on 2 occasions after 20 weeks of gestation) and proteinuria, which is defined as 300 mg/dL of protein or greater in a 24 hour urine collection or a protein to creatinine ratio of 3 mg/g or greater. If quantitative analysis is not available, a urine protein dipstick reading of >1 can be substituted. If proteinuria is not present, then the presence of thrombocytopenia, renal insufficiency, abnormal liver function, pulmonary edema, and cerebral or visual symptoms can be used to make the diagnosis.

USPSTF’s revised recommendation is similar to the recommendation of the American College of Obstetricians and Gynecologists. ACOG recommends obtaining blood pressure measurements at every prenatal visit and using a detailed medical history to evaluate for risk factors for preeclampsia.

US Preventive Services Task Force, Screening for Preeclampsia. JAMA 2017;317:1661-67.

American College of Obstetricians and Gynecologists. Hypertension in Pregnancy. Washington, DC: American College of Obstetricians and Gynecologists; 2013. 

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 07 May 2017 21:05:41 -0400
Undetectable HDL Cholesterol http://www.clinlabnavigator.com/undetectable-hdl-cholesterol.html http://www.clinlabnavigator.com/undetectable-hdl-cholesterol.html

Very low or undetectable HDL cholesterol can be caused by paraprotein interference with the direct homogeneous assay or the development of autoantibodies to apoA1, which is the primary protein in HDL particles. Drug therapy with fibrates, anabolic steroids and thiazolidinediones can also drastically reduce HDL cholesterol. Genetic diseases such as Tangier disease, apoA-1 deficiency and LCAT deficiency are associated with very low HDL cholesterol levels.

More recently, a case study published in the February issue of Clinical Chemistry described a patient with undetectable HDL cholesterol that was associated with Babesiosis microti infection. HDL cholesterol returned to normal following antibiotic therapy and resolution of the infection. The authors suggest that the production of interleukin 10 disturbs lipoprotein metabolism and produces acquired HDL deficiency. However, they acknowledge that undetectable HDL is an unusual finding relative to the numbers of severe sepsis cases. Alternatively, Babesia may directly interfere with HDL cholesterol synthesis.

Bock JL, Senzel L, Spitzer ED and Bifulco W. Undetectable HDL Cholesterol in a Patient with Flu-Like Illness. DOI: 10.1373/clinchem.2016.258616 Published February 2017.

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 30 Apr 2017 20:14:33 -0400
Foodborne Illnesses in 2016 http://www.clinlabnavigator.com/foodborne-illnesses-in-2016.html http://www.clinlabnavigator.com/foodborne-illnesses-in-2016.html

Foodborne illness remains a substantial public health concern in the United States. FoodNet is a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service, and the Food and Drug Administration. FoodNet conducts active, population-based surveillance for laboratory-diagnosed infections caused by nine enteric pathogens including; Campylobacter, Cryptosporidium, Cyclospora, Listeria, Salmonella, Shiga toxin-producing Escherichia coli (STEC), Shigella, Vibrio, and Yersinia. Surveillance covers 10 sites representing approximately 15% of the U.S. population.

During 2016, FoodNet identified 24,029 cases, 5,512 hospitalizations, and 98 deaths attributed to foodborne illness. Infections were detected by culture or culture-independent diagnostic tests (CIDT). Parasitic infections were detected in clinical specimens by direct fluorescent antibody test, polymerase chain reaction, enzyme immunoassay, or light microscopy. CIDTs included tests for bacterial antigens, nucleic acid sequences, or Shiga toxin in a stool specimen or enrichment broth. The largest number of culture confirmed or CIDT positive–only infections in 2016 was reported for Campylobacter (8,547), followed by Salmonella (8,172), Shigella (2,913), STEC (1,845), Cryptosporidium (1,816), Yersinia (302), Vibrio (252), Listeria (127), and Cyclospora (55).

The number of infections detected by CIDT has been steadily increasing compared to culture. Increased use of CIDT may account for the increased incidence of Cryptosporidium, STEC, and Yersinia, and slight but not significant increases in incidence of Campylobacter, Salmonella, Shigella, and Vibrio. More widespread adoption of CIDT is likely to improve detection of foodborne illness.

Reference

Marder EP, Cieslak PR, Cronquist AB, et al. Incidence and Trends of Infections with Pathogens Transmitted Commonly Through Food and the Effect of Increasing Use of Culture-Independent Diagnostic Tests on Surveillance — Foodborne Diseases Active Surveillance Network, 10 U.S. Sites, 2013–2016. MMWR Morb Mortal Wkly Rep 2017;66:397–403. DOI: http://dx.doi.org/10.15585/mmwr.mm6615a1

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 23 Apr 2017 20:21:08 -0400
CMV Infection Risk in Newborns http://www.clinlabnavigator.com/cmv-infection-risk-in-newborns.html http://www.clinlabnavigator.com/cmv-infection-risk-in-newborns.html

Transfusion acquired cytomegalovirus (CMV) can cause serious complications and even death in very low birth weight infants. Because of this risk, transfusion services provide CMV negative blood components for fetal and intrauterine transfusions and for very low birth weight premature infants. When infants become infected with CMV, neonatologists often suspect that transfusion is the source of the infection. A donor with a recent CMV infection can harbor virus in their plasma or white blood cells even though they test negative for antibodies. The window period for CMV infection is estimated to be 6 to 8 weeks.

A prospective multicenter study sought to determine the source of postnatal CMV infection during the first 90 days after birth in 539 very low birth weight infants. Postnatal CMV infection was detected in 29 infants by both serological and nucleic acid tests. More than half of these infants had been transfused with cellular blood components that were CMV seronegative and leukocyte reduced. Testing of donors revealed that non of the infections were associated with transfusion. Instead, all of the infections were transmitted by CMV positive breast milk.

The findings of this study suggest that the risk of CMV transmission by blood transfusion is negligible when CMV seronegative and leukocyte reduced blood components are transfused. However, CMV transmission by breast milk from CMV-positive donors remains a serious risk.

Reference:

Josephson CD, Caliendo AM, Easley KA, Knezevic A, Shenvi N, Hinkes MT, Patel RM, Hillyer CD, Roback JD. Blood Transfusion and Breast Milk Transmission of Cytomegalovirus in Very Low-Birth-Weight Infants: A Prospective Cohort Study. JAMA Pediatr 2014;168(11):1054-62.

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 09 Apr 2017 20:56:45 -0400
Screening for Celiac Disease http://www.clinlabnavigator.com/screening-for-celiac-disease.html http://www.clinlabnavigator.com/screening-for-celiac-disease.html

Celiac disease is an autoimmune disease that occurs in genetically predisposed adults and children after exposure to dietary gluten. Classic celiac disease is associated with symptoms of malabsorption. However, many patients experience other symptoms such as anemia, osteoporosis, fatigue, peripheral neuropathy, ataxia, stomatitis, dermatitis herpetiformis, infertility, fetal loss or short stature. The estimated prevalence of celiac disease in the United States is 0.71% in adults and 0.76% in children. Most celiac disease in believed to be undetected despite the widespread availability of noninvasive serologic tests such as anti-tissue transglutaminase IgA antibody. Individuals with atypical or nonspecific symptoms may not be diagnosed for many years.

Screening of the general population might enable earlier detection and treatment. However, a recent review by The United States Preventive Services Task Force (USPSTF) concluded that there is insufficient evidence to support screening for celiac disease in asymptomatic persons. USPSTF found no studies on the benefits of treatment of screen-detected celiac disease compared to treatment that is initiated after clinical diagnosis.

References

US Preventive Services Task Force, Screening for Celiac Disease: US Preventive Services Task Force Recommendation Statement, JAMA 2017;317:1252-57.

Choung RS and Murray JA. The US Preventive Task Force Recommendation on Screening for Asymptomatic Celiac Disease: A Dearth of Evidence. JAMA 2017;317:1221-23.

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 02 Apr 2017 20:45:59 -0400
Hashtags for Clinical Pathology http://www.clinlabnavigator.com/hashtags-for-clinical-pathology.html http://www.clinlabnavigator.com/hashtags-for-clinical-pathology.html

Twitter has become a very active social media site for all subspecialties of Pathology.  Recently, Symplur published a list of Pathology Tag Ontology, which was developed by the USCAP Social Media Subcommittee. Pathology Tag Ontology is a standardized list of social media communication descriptors.

Originally, individuals interested in Pathology could just follow the #pathology hashtag. However, Pathology is an incredibly diverse specialty with many subspecialties and the content within a single hashtag became too voluminous to follow. This new list contains standardized hashtags for most subspecialties of pathology and laboratory medicine. Now it is much easier to follow specific disciplines and collaborate with your peers.  Below, I have listed the standardized hashtags that have been created for clinical pathology and laboratory medicine.

#labmed for laboratory medicine

#ClinPath for Clinical Pathology

#BloodBank for blood banking and transfusion medicine

#HemePath for Hematopathology

#MolDx for Molecular Pathology

#pathinformatics for Pathology Informatics

The complete list of standardized hashtags for Pathology can be found at:

https://www.symplur.com/healthcare-hashtags/ontology/pathology/

Although they were not included in the standardized list, I also follow:

#clinmicro

#clinchem

#microbiology

#parasites

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 26 Mar 2017 21:36:41 -0400
Metabolic Syndrome http://www.clinlabnavigator.com/metabolic-syndrome.html http://www.clinlabnavigator.com/metabolic-syndrome.html

The metabolic syndrome is defined as the co-occurrence of metabolic risk factors for both type 2 diabetes and cardiovascular disease. These risk factors include abdominal obesity, hyperglycemia, dyslipidemia, and hypertension. All of them are related to insulin resistance. Other names for this syndrome include the dysmetabolic Syndrome, Syndrome X, Insulin Resistance Syndrome , or the obesity dyslipidemia syndrome.

Several medical organizations have published definitions for the metabolic syndrome. The National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) is the most widely used in the United States. ATPIII criteria for diagnosis of the metabolic syndrome include the presence of any three of the parameters summarized in the following table.

Parameter AACE NCEP WHO IDF

Obesity

   Men

   Women

Waist

>102 cm

>80 cm

Waist

>102 cm

>80 cm

BMI

>30

>30

Waist

>94 cm

>80 cm

BP

   Men

   Women

 

>130/85

>130/85

 

>130/85

>130/85

 

>140/90

>140/90

 

>130/85

>130/85

Triglycerides >150 >150 >150 >150

HDL

   Men

   Women

<40

<50

<40

<50

<35

<40

<40

<50

Glucose

   Fasting

   2h OGTT

 

110-125

140-200

 

100

 

110-125

140-200

 

>100

Microalbumin    

20 ug/min

30 mg/g

 

NCEP: National Cholesterol Education Program; IDF: International Diabetes Federation;  WHO: World Health Organization; AACE: American Association of Clinical Endocrinologists

 

The major difference between these criteria is in the tests for glucose intolerance. Both the AACE and WHO recommend an oral glucose tolerance test (OGTT), even in patients without an elevated fasting glucose. ATP III does not recommend OGTT in such persons, because they believe that the increased sensitivity does not outweigh the increased cost and inconvenience. WHO includes elevated microalbumin in their diagnostic criteria, but the other 2 organizations do not.

NCEP requires 3 of 5 abnormalities for diagnosis of insulin resistance syndrome. WHO requires evidence of glucose intolerance plus 2 more abnormalities. AACE does not specify a defined number of abnormalities and leaves the diagnosis to clinical judgment. IDF requires increased waist circumference, with ethnic-specific waist circumference cut-points plus two of the other criteria.

Using NCEP criteria, data from the National Health and Nutrition Survey (NHANES) from 1999 to 2002 indicated that 34.5% of adults in the United States have the metabolic syndrome. Identification of the metabolic syndrome is important because it is a significant risk factor for diabetes and cardiovascular disease.

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fplapp@kc.rr.com (Fred Plapp) Blog Sun, 19 Mar 2017 21:08:32 -0400