Hematology Interest Group Case Study June 11, 2017
CASE HISTORY A 16-year-old female presented to the emergency room with complaints of ongoing fatigue, malaise, sore throat, fever, chills, aches, and nausea for for a period of 10 days. Vitals were assessed and confirmed a fever fever of 99.5*F. On examination, tender posterior cervical lymphadenopathy lymphadenopathy was noted noted and abdominal inspection showed signs of of mild hepatosplenomegaly. hepatosplenomegaly. The physician ordered ordered a STAT STAT CBC with Differential, Erythrocyte Sedimentation Rate Test (ESR), Rapid Monospot Latex Agglutination, and a routine EBV IgM titer.
LABORATORY RESULTS
ESR
Patient’s Results
Reference Range
65 mm/hour
0 – 20 mm/hour
2
Patient’s Results
Reference Range
Red Blood Cell Count (RBC)
4.53 x 10 x106/uL
4.2 – 5.4 x 10 x106/uL
Hemoglobin (HgB)
13.1 g/dL
12-16 g/ dL
Hematocrit (Hct)
38.9 %
37-47%
Mean Corpuscular Volume (MCV)
85.9 fl
80-100 fl
Heam Corpuscular Hemoglobin (MCH)
29.0 pg
27-31 pg
Mean Corpuscular Hemoglobin Concentration (MCHC)
33.8 g/dL
32-36 g/dL
Red Cell Distribution Width (RDW)
12.6 %
11.5-14.5 %
Platelets
289 x 103/uL
140-440 x 103/uL
White Blood Cell Count (WBC)
11.0 x 10 x103/uL
4.8-10.8 x 103/uL
DxH 800 Interpretatio Interpretation/Flags n/Flags According to the hospital laboratory protocol on slide criteria, a blood smear was prepared based on the following: Definitive Flag: Lymphocytosis Flag: Lymphocytosis # >5.0 x103/uL Suspect Flag: Variant LY
The scatterplot shows marked populations in the variant lymphocyte region as indicated by the circled areas. There is also an increased predominance of the lymphocyte region.
3
Manual Differential Patient’s Results
Reference Range
Neutrophils
34.7% 3.8 x103/uL
50 – 70% 1.4-6.5 x103/uL
Lymphocytes
23.5% 6.1 x103/uL
20 – 40% 1.2 - 3.4x103/uL
Monocytes
7.9% 0.9 x103/uL
2-9% 0-0.7 x 103/uL
Eosinophils
1.4% 0.2 x103/uL
0-4 % 0-0.5 x 103/uL
Basophils
0.5% 0.1 x103/uL
0-2 % 0-0.2 x 103/uL
Atypical Lymphocytes
32%
0-8%
RBC Morphology
Normal
Normal
PLT Count and Morphology
Normal
Normal
Patient’s Results
Reference Range Negative
Rapid Monospot Sample
Agglutination
Positive Control
3+
Negative Control
0
Patient Sample
2+
Interpretation
Positive
EBV Antibody to Viral Capsid Antigen IgM
Patient’s Results
Reference Range
50.5 U/mL
0.0 - 43.9 U/mL
4
Peripheral Blood Smear
Manual differential showed pleomorphic population of many (32%) atypical lymphocytes favoring a reactive process. Rare apoptotic lymphocytes lymphocytes (top right and bottom bottom right panel shows shows apoptosis with with nuclear condensation and vacuoles) vacuoles) were also noted. Apoptosis, reactive lymphocytes, neutropenia, neutropenia, and monocytosis are strong indicators of a viral infection, such as infectious mononucleosis.
5
Diagnosis The CBC showed that the patient had minor leukocytosis leukocytosis and >20% atypical lymphocytes. lymphocytes. The ESR revealed a high sedimentation rate. Finally, the EBV Antibody to Viral Capsid Antigen IgM test came back positive, affirming the diagnosis of Mononucleosis.
Discussion Infectious mononucleosis is a contagious clinical syndrome seen primarily in teenagers and young adults. Infectious mononucleosis is most commonly caused by the Epstein-Barr virus (EBV) however other viruses can also cause this disease. The virus is commonly spread through bodily fluids, especially saliva. Typical symptoms of infectious mononucleosis include fatigue, headache, fever, sore throat and swollen lymph nodes with symptoms lasting two to four weeks. Once infected the virus integrates itself into the the cycle of healthy B lymphocytes and remains as a lifelong latent infection. infection. Reactivation of Epstein-Barr virus may occur in immunocompromised patients and rarely, in immunocompetent patients and is occasionally associated with malignancies such as Burkitt’s lymphoma. Laboratory Test Explained Explained 1. The CBC count count is is more useful useful in in ruling ruling out other other diagnos diagnoses es that may may mimic mimic IM. Leukocytos Leukocytosis is is considered the rule in infectious mononucleosis so the presence of a normal or decreased WBC count should suggest an alternative alternative diagnosis. Infectious mononucleosis mononucleosis is likely if the relative atypical lymphocyte count is equal to or greater than 20%. Atypical lymphocytes should not be confused with abnormal lymphocytes. Abnormal lymphocytes are associated with lymphoreticular malignancies, whereas atypical lymphocytes are associated with various viral and noninfectious “benign” diseases. 2. ESR is most useful useful in different differentiatin iating g group A streptococ streptococcal cal pharyngi pharyngitis tis from EBV infecti infectious ous mononucleosis. The sedimentation rate is elevated in most patients with EBV infectious mononucleosis, but it is not elevated elevated in group A streptococcal streptococcal pharyngitis. Because the the liver is uniformly involved involved in EBV infectious mononucleosis, mild elevation of the serum transaminases is a constant finding in early EBV infectious mononucleosis. Mild increases in the serum transaminases are also a feature of the infectious agents responsible for heterophile-negative infectious mononucleosis. mononucleosis. High elevation of the serum transaminases should suggest viral hepatitis. The serum alkaline phosphatase and gamma-glutamyl transpeptidase levels are not usually elevated in individuals with EBV infx mono. 3. The monospot monospot test is is a latex agglutination agglutination assay that that uses horse RBCs. Antibodies are sensitive sensitive and specific for EBV heterophile ab. Sensitivity is ~85% and specificity is ~100%. The heterophile test is less useful in children younger than 2 years, in whom the results are frequently negative.
6
Method: The BBL-MonoSlide Mononucleosis Test is a rapid, differential test for the serological detection of IgM class
heterophile antibodies associated with infectious mononucleosis. Principle: This test utilizes a disposable card, guinea pig kidney antigen for a bsorption, and specially treated horse
erythrocytes (color-enhanced) to increase specificity, sensitivity, sensitivity, and enhance readability.
4. EBV serological tests tests should be obtained obtained in patients with a mononucleosis mononucleosis like illness illness and a negative finding on the Monospot test. The antibody response to specific specific EBV serological testing consists of measuring the antibody response to surface and core EBV viral proteins. For clinical purposes, the most useful EBV-specific antibodies are the VCAs and the EBNA. Both VCA and EBNA antibodies are usually reported as IgM or IgG antibodies. Acute infection is diagnosed in patients who have an increased EBV IgM VCA titer. Later in the course of infection, the increase in IgM VCA antibodies may be accompanied by an increase increase in IgG VCA antibodies and and an increase in IgG EBNA antibodies. antibodies.
References 1. Lenn Lennon on P, P, Crot Crotty ty M, M, Fento Fenton n JE. JE. Infectious mononucleosis. mononucleosis. BMJ. BMJ. 2015; 350: h1825. PubMed 2. Luzu Luzuri riag agaa K, Sull Sulliv ivan an JL. JL. Infectious Infectious mononucleosis. N mononucleosis. N Engl J Med. 2010; 362(21): 1993-2000. PubMed 3. Taylor Taylor GS, Long HM, Brooks Brooks JM, Rickins Rickinson on AB, AB, Hislop Hislop AD. AD. The The immunology of Epstein-Barr virus-induced disease. Annu disease. Annu Rev Immunol. 2015; 33: 787-821. PubMed 4. Voulou Voulouman manou ou EK, EK, Rafaili Rafailidis dis PI, PI, Falaga Falagass ME. Current ME. Current diagnosis and management of infectious mononucleosis. Curr mononucleosis. Curr Opin Hematol 19:14-20, 2012. 5. https:// https://www.c www.cdc.go dc.gov/eps v/epsteintein-barr/ barr/labo laborator ratory-tes y-testing ting.html .html
Read more on our website
Samantha Dewey, MLS(ASCP)SH © Hematology Interest Group
