Hematocrit in Polymyalgia Rheumatica
No, hematocrit is typically decreased (not elevated) in patients with active polymyalgia rheumatica (PMR), as it correlates inversely with disease activity and the acute phase response.
Laboratory Pattern in Active PMR
PMR is characterized by systemic inflammation that produces a predictable hematologic pattern:
- Anemia of chronic inflammation is the expected finding, which manifests as:
- Decreased hemoglobin
- Decreased hematocrit
- Elevated ESR and CRP
Research demonstrates that in patients with active PMR and giant cell arteritis (GCA), hematocrit levels are negatively correlated with markers of disease activity 1. Specifically, lower hematocrit values correlate with higher ESR (r = -0.57, p = 0.03) and lower hemoglobin levels (r = -0.55, p = 0.04) in active disease 1.
Clinical Implications
When you encounter elevated hematocrit in a patient with suspected PMR, this should prompt immediate reconsideration of the diagnosis. The presence of elevated hematocrit suggests:
- The diagnosis is not PMR - Consider alternative conditions
- Concurrent polycythemia vera or other myeloproliferative disorder - Requires separate hematologic workup
- The patient is in complete remission - Active PMR should suppress hematocrit
Diagnostic Approach
The typical laboratory profile for active PMR includes 2:
- Elevated ESR (often >40 mm/1st hour)
- Elevated CRP
- Normocytic anemia (decreased hemoglobin/hematocrit)
- Normal creatine kinase
Important caveat: Patients with "low inflammatory markers" represent an atypical presentation that warrants specialist referral 2. However, this refers to normal or minimally elevated ESR/CRP, not to elevated hematocrit.
Monitoring During Treatment
Once glucocorticoid therapy is initiated (12.5-25 mg prednisone equivalent daily) 2, the anemia typically improves as inflammation is controlled. Regular monitoring should include documentation of hemoglobin/hematocrit alongside ESR and CRP to track treatment response 2.
Bottom line: Elevated hematocrit is incompatible with active PMR and should trigger evaluation for alternative diagnoses or concurrent hematologic conditions.