A 41YearOld Man With Fever and Generalized Muscle Aches Chapter 20

1
A 41-Year-Old Man With Fever and Generalized
Muscle Aches Chapter 20
Eugene G. Martin, Ph.D. Associate Professor of
Pathology Laboratory Medicine

• Based upon LABORATORY MEDICINE CASEBOOK. An
  introduction to clinical reasoning
• Jana Raskova, MD Professor of Pathology
  Laboratory MedicineStephen Shea, MD
  Professor of Pathology Laboratory
  MedicineFrederick Skvara, MD Associate
  Professor of Pathology Laboratory MedicineNagy
  Mikhail, MD Assistant Professor of Pathology
  Laboratory MedicineUMDNJ-Robert Wood Johnson
  Medical SchoolPiscataway, NJ

2
History and Presentation

• 41-Year-old farmer from S. Jersey presents with
  fever, chills, headache, generalized muscle aches
  and a rash on the legs of approximately 5 days
  duration. Patient recounts removal of tick from
  the popliteal area 10 days earlier.
• Alert, oriented, good health, no distress
• Smoker 2 packs per day Non consumer of ETOH
• Physical
• BP 120/84, HR 88 RSR, Resp. Rate 20 per
  minute
• Temp. 101.2 F
• Several circular skin lesions on legs Largest
  7 cm in diameter
• No lymphadenopathy or joint abnormalities, no
  other skin lesions

3
HEMATOLOGY
4
Significance of ?MCH and Borderline MCV

• MCH (Mean Corpuscular Hemoglobin)
• Mean Corpuscular Hemoglobin (MCH) gives the
  average weight of hemoglobin per red blood cell.
• Decreased MCH is associated with microcytic
  anemia and increased MCH is associated with
  macrocytic anemia.
• ? MCH, Borderline MCV, Borderline low RBC
  Borderline Macrocytic Anemia

5
Anemia Assessment

• ?Normocytic, normochromic anemia
• Reticulocyte ?
• Hemolytic disease
• Acute blood loss
• Reticulocyte normal
• Malignancy
• Myeloma
• Chronic Disease
• Macrocytosis is seen in
• Megaloblastic anemias ?
• vitamin B12 and folate deficiency
• Some forms of chronic liver disease
• Microcytosis and hypochromia
• Iron deficiency anemia
• Spherocytosis
• Some forms of anemia of chronic disease

6
CHEMISTRY
7
Miscellaneous Tests
8
Skin Lesions

• Erthematous
• Annular
• Slight central pallor
• Minimally raised area near the center of the
  lesion on the lateral aspect of the left knee

9
Summary

• Flu-like symptoms, 1 week after first appearance
  of
• Characteristic annular, erythematous skin lesion
• History of a tick bite
• But undetectable antibodies to Borrelia
  burgdorferi ? Whats up?
• IgM antibodies dont show up until 3-6 weeks
  after onset of the disease ? Consistent with
  acute infection with Borrelia burgdorferi.

10
Polymerase Chain Reaction (PCR) for Borrelia
burgdorferi DNA

• Lane A Size Markers
• Lane B C Neg Controls
• Lane D M Pos Controls for Borrellia
  burgdorferi
• Lanes F J Neg patient specimens
• Lanes G K ß Globulin gene from neg specimens
• Lane H Our Patient
• Lane I - ß Globulin gene from Patient specimen
• The quality of specimen processing is established
  by screening for amplifiable DNA using so-called
  housekeeping genes - ß Globulin gene (lanes G
  K) (Neg specimen) I patient

11
Patient is begun on antibiotics

• Oral antibiotics were prescribed.
• What sometimes occurs subsequent to treatment
  with antibiotics?

12
Jarisch-Herxheimer reaction

• Antimicrobial treatment of Lyme Disease is
  occasionally (10) followed by
• Sudden fever, rigors, and persistent hypotension
• Associated with increases in plasma
  concentrations of tumor necrosis factor alpha
  (TNF-alpha), interleukin-6, and interleukin-8.
• More common in louse-borne relapsing fever
  (Borrelia recurrentis infection)
• Sheep anti-TNF-alpha Fab suppresses
  Jarisch-Herxheimer reactions experimentally
• In this case
• Fever subsided in two days
• CBC, chemistry repeated at end of treatment and
  were normal
• No evidence of Jarish-Herxheimer reaction

13
Consequences of Lyme disease

• Early
• Skin lesions
• Regional or generalized lymphadenopathy
• Neurologic involvement Usually resolves
  completely
• Meningitis
• Encephalitis
• Peripheral radiculoneuropathy
• Later
• Cardiac involvement fluctuating AV conduction
  block
• 60 of patients develop recurrent arthritis of
  large joints

14
Abnormalities with Lyme disease

• Detectable, specific IgM antibodies to Borrelia
  burgdorferi appear 3-6 weeks after onset of
  disease detected in about half the patients.
• Detectable IgG antibodies 8-12 weeks. Common in
  patients with late manifestations cardiac,
  nervous system, joint involvement
• Other non-specific laboratory findings found
  occasionally
• Elevated ESR
• Elevated SGOT (AST)
• Elevated WBC

15
Serology of Lyme disease

• ELISA testing
• 6 weeks gt IgM antibodies
• Months (8-12 weeks) gt IgG antibodies
• False positives
• Rheumatoid factor
• Infection Mono
• False negatives Test performed too early

16
What about reinfection?

• The presence of antibodies DOES NOT confer
  permanent protection to Lyme disease
• i.e. the patient is NOT immune to reinfection