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Blood · The Evidence Behind the Case
The acute-phase response as a slow fuse — check our reasoning
This module reads Stina’s chronic labs — reactive thrombocytosis, sterile neutrophilia, years of raised ESR and CRP, and above all serum amyloid A — as one sustained acute-phase response quietly seeding amyloidosis, and holds two findings outside it: a true erythrocytosis on an inappropriate EPO, and an MGUS. Here is what that rests on, and how strong each piece is.
Arrived here from a search?
This page belongs to a teaching case built around familial Mediterranean fever, an IL-1β-driven autoinflammatory disease. If you found it searching a blood finding — persistently raised SAA or CRP, reactive thrombocytosis, sterile neutrophilia, erythrocytosis with an inappropriately high EPO, MGUS in a young adult, it is an evidence-anchored starting point.
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Each claim, its evidence, and how strong it is
| Chart finding | The claim the module makes | Supporting evidence | How strong? |
|---|---|---|---|
| Markers high for years Chart Clue #14 | A sustained acute-phase response is the raw material for future amyloidosis — not “counts a touch high, nothing to chase”. | SAA & occult inflammation in asymptomatic FMF (2019) · Acute-phase reactants predict FMF amyloidosis (2007) | FMF cohorts |
| Serum amyloid A The slow fuse | Liver-made SAA, chronically elevated, is the precursor of AA amyloid; persistent elevation predicts amyloidosis, and colchicine prevents it. | SAA in asymptomatic FMF · SAA & amyloidosis risk · EULAR/PReS 2024 | FMF cohorts + guideline |
| Reactive thrombocytosis & neutrophilia During flares | Platelet and neutrophil counts track FMF activity; IL-6 drives reactive thrombopoiesis through thrombopoietin (general mechanism). | Acute-phase response in FMF (Ann Rheum Dis 2002) · Hematological markers in FMF (Rheumatol Int 2023) · IL-6 & thrombopoiesis (Blood 2001) | FMF cohorts + general mechanism |
| Erythrocytosis on high EPO Held open | A true erythrocytosis with an inappropriately elevated EPO, JAK2 negative, sits outside the acute-phase story — a deliberate differential seed, unrelated to FMF. | The TEMPI syndrome (Blood 2020 review) · TEMPI syndrome (NEJM 2011) | Teaching aside — not FMF |
| MGUS at 40 Held apart | A monoclonal gammopathy of undetermined significance is a plasma-cell clone, not a product of the liver’s alarm; it is watched and carried to the Immunity module. | MGUS natural history (general hematologyThe study of blood and blood disorders. references) | General |
| Her specific numbers Module’s own detail | The 2015 panel (Hct 49, RBC 5.6, Hb 16.4, MCV 88; platelets 410/560; WBC 11,800 with 78% neutrophils; ESR 58, CRP 41, SAA 190/38; EPO 44; JAK2 negative; red-cell mass 36; M-protein 0.6 IgG-κ; plasma cellsImmune cells that develop from B cells and produce antibodies. 6%) is this case’s narrative, consistent with the case timeline’s “erythrocytosis, MGUS at 40 by SPEP, SAA, protein gap” — not a published record. | The case timeline (this course) | Case narrative |
Think · not graded
Which rows are FMF cohorts, which are general mechanism, which is a teaching aside deliberately unrelated to FMF, and which is the module’s own detail? Does the reasoning survive if the specific numbers change?
Spot-check your thinking: true or false?
How to read the strength column
Guideline — an expert panel pools many studies into practice recommendations. Trial — patients assigned to a treatment and compared. Cohort — a group of patients measured the same way; good for how often something happens. Case series or review — several patients described together, or the settled background. General mechanism — textbook physiologyThe study of how the body functions. rather than a study of this disease. Case report — one striking patient; it shows that something can happen, not how often.
Every Evidence page in the course uses the same labels.
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Lived experience and evidence
A note on validity — from the author
Stina is not a composite. Stina is me. The years of markers dismissed as “a touch high” were mine — and they were not noise; they were a slow fuse burning toward my kidneys. And a hematocritThe percentage of blood volume occupied by red blood cells. called dehydrationA condition in which fluid loss exceeds intake, leading to a decrease in total body water. five times was mine too — a loose end I am still holding.
This page holds both truths at once. The lived experience is real; the research support is what earns the case a place in a science course, and the steps that rest on this case’s own narrative are flagged. If you are a clinician who arrived from a patient, treat this as a validated starting point that respects the patient’s experience and then hands you the literature.
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Beyond Stina — other reasons a panel reads this way
A reactive thrombocytosis, a raised CRP, a high hematocrit and an M-spike each have a long list of their own. Knowing the neighbours is how a clinician reads six findings as four-plus-two — and then asks what is upstream.
Polycythemia vera
A JAK2-driven marrow making red cellsThe basic structural and functional units of life. on its own: high hematocrit with a low EPO, often high platelets and white cells too; phlebotomy and aspirin — the primary polycythemiaAn overproduction of red blood cells due to bone marrow abnormalities. her negative JAK2 and high EPO rule out.
Secondary polycythemia with a reason
Altitude, smoking, sleep apnoea, lung or heart disease, a high-affinity hemoglobinThe oxygen-carrying protein in red blood cells that gives blood its red color.: high hematocrit, high EPO, and a cause the oxygen sensor can name.
Essential thrombocythemia
A marrow making platelets on its own (JAK2, CALR, MPL): a count that never settles between flares, with clotting and bleeding risk — the primary thrombocytosis her settling count argues against.
Iron deficiency and pernicious anemia
The two filling failures: microcytic hypochromic cells with a low ferritin A protein that stores iron in the liver and other tissues., or macrocytic cells with hypersegmented neutrophils and no intrinsic factorA stomach-secreted protein necessary for vitamin B12 absorption — Maria and Maude.
Multiple myeloma
What MGUS is watched for: a plasma-cell clone above 10% with CRAB features — calcium, renal failure, anemiaA condition characterized by a deficiency of red blood cells or hemoglobin, leading to reduced oxyge, bone lesions — none of which she has.
Sepsis and bacterial infection
The acute-phase response with a germ: neutrophilia with bands, high CRP and a high procalcitonin, positive cultures — the pattern hers mimics and lacks.
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Reliable information — a link library
Rare-disease organizations
NORD — National Organization for Rare Disorders
Plain-language disease reports and patient organizations.
NIH GARD — Genetic and Rare Diseases Information Center
The NIH rare-disease reference, with a live help line.
Orphanet
The European rare-disease encyclopedia; look up a syndrome by its signsObjective clinical findings observable by a provider (e.g., edema, fever)..
MedlinePlus Genetics
Condition-by-condition summaries from the National Library of Medicine.
FMF, the acute-phase response and amyloid
MedlinePlus Genetics — Familial Mediterranean Fever
The National Library of Medicine’s condition page.
Amyloidosis Foundation
AA amyloidosis explained for patients and families.
American Society of Hematology — Blood basics
Erythrocytosis, thrombocytosis and MGUS explained for patients.
International Myeloma Foundation — MGUS
What “undetermined significance” means and how it is watched.
NIH Office of Dietary Supplements — Iron
What iron does in red cells, and how much the body needs.
Links checked September 2026.
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References
1. Acute phase response in familial Mediterranean fever. Ann Rheum Dis 2002.
2. Hematological markers in FMF: disease severity and amyloidosis. Rheumatol Int 2023.
3. Serum amyloid A to identify occult inflammation in asymptomatic FMF. 2019.
4. Acute-phase reactants predict FMF-associated amyloidosis. 2007.
6. The TEMPI syndrome (review). Blood 2020. (unrelated to FMF)
7. Sykes DB et al. The TEMPI syndrome. N Engl J Med 2011.
8. OpenStax Anatomy & Physiology 2e, Chapter 18 — The Cardiovascular System: Blood.
9. EULAR/PReS recommendations for the management of FMF: 2024 update.
Standing reference anchors: EULAR/PReS FMF management: 2024 update · GeneReviews: FMF · Infevers — MEFV registry
Next · Module 15
The Heart
Sharp chest pain at 3 a.m. that eased when she leaned forward, a scratchy rub on the stethoscope, and a small effusion on echo. The next module builds the heart and reads recurrent pericarditis as serositis wrapping the sac around it.
Reliable information on rare diseases
NORD · NIH GARD · Orphanet · MedlinePlus Genetics: FMF · FMF & AID Global Association · Autoinflammatory Alliance · Global Genes · Amyloidosis Foundation
Stina has one rare disease. In the United States, about 1 in 10 people live with one of the more than 7,000 known rare diseases. These organizations are where patients, families and clinicians go for trustworthy information.
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← Familial Mediterranean Fever — case home
All pages for Module 14 — Blood
14.0 Module Overview
14.1 The Red Cell Finding That Fits Nothing
14.2 What’s in Blood
14.3 Red Cells and Hemoglobin
14.4 Making and Recycling Red Cells
14.5 The Clotting Story
14.6 The Defenders
14.7 The Acute-Phase Alarm
14.8 Conclusion and Assessment
14.9 Evidence Behind the Case
All Modules
- Anatomical Language, Membranes & Homeostasis
- Just Enough Chemistry
- The Cell & Its Transport
- Making Cells & Proteins
- The Integumentary System
- The Skeletal System
- The Muscular System
- Nervous Tissue & the Senses
- The Spinal Cord
- The Brain & the Blood–Brain Barrier
- The Autonomic Nervous System
- Special Senses (in developmentThe process of growth and differentiation.)
- The Endocrine System
- Blood
- The Heart
- Blood Vessels
- The Digestive System
- The Respiratory System
- The Urinary System
- Fluids, Electrolytes & Acid–Base Balance
- The Reproductive System
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List of terms
- hematology
- plasma cells
- physiology
- hematocrit
- dehydration
- cells
- primary polycythemia
- hemoglobin
- ferritin
- intrinsic factor
- anemia
- signs
- development