What is the diagnosis and treatment plan for a patient with leukocytosis, iron deficiency, hyperlipidemia, and impaired renal function?

Assessment and Management of Leukocytosis with Iron Deficiency in a Patient with Mild Renal Impairment

The patient requires iron supplementation therapy for iron deficiency anemia with concurrent investigation of leukocytosis, while monitoring renal function. This recommendation is based on the laboratory findings showing low MCHC, elevated WBC count, and borderline eGFR.

Laboratory Abnormalities Analysis

Hematologic Findings

• Leukocytosis: WBC 15.12 x10³/μL (elevated)
  • Lymphocytosis: 58.9% (elevated)
  • Absolute lymphocyte count: 8.90 x10³/μL (elevated)
• Iron deficiency indicators:
  • Low MCHC: 31.6 g/dL (below reference range 31.7-35.3)
  • Poikilocytosis 3+ noted on peripheral smear
  • Low HDL cholesterol: 39 mg/dL (below reference range >40)

Renal Function

• eGFR: 62 mL/min (borderline, category G2 - mildly decreased)
• Creatinine: 1.26 mg/dL (within normal range but approaching upper limit)

Diagnosis and Management Plan

1. Iron Deficiency Anemia

The patient has laboratory evidence of iron deficiency with low MCHC and significant poikilocytosis 1, 2. Although ferritin and transferrin saturation results are not provided, the morphological changes strongly suggest iron deficiency.

Treatment recommendations:

• Oral iron supplementation: Ferrous sulfate 324 mg daily (providing 65 mg elemental iron) 2
• Continue for 3 months after normalization of hemoglobin to replenish iron stores
• Consider vitamin C supplementation with meals to enhance iron absorption 2

Monitoring:

• Check hemoglobin after 2-4 weeks of therapy
• Monitor ferritin and transferrin saturation after 2-4 weeks
• Follow-up CBC at 3-month intervals for one year 2

2. Leukocytosis Investigation

The marked lymphocytosis (absolute lymphocyte count 8.90 x10³/μL) requires further investigation:

• Peripheral blood smear review: Already shows poikilocytosis and smudge cells
• Infectious workup: Consider viral panel (EBV, CMV, HIV)
• Hematology consultation: To evaluate for possible lymphoproliferative disorder
• Flow cytometry: If lymphoproliferative disorder is suspected

3. Renal Function Management

The patient has mild renal impairment (eGFR 62 mL/min, CKD stage G2) 1:

• Blood pressure monitoring: At every clinic visit (target <130/80 mmHg) 1
• ACE inhibitor or ARB: Consider as first-line agent if hypertension is present 1
• Regular monitoring:
  • Check serum calcium, phosphorus every 3 months 1
  • Monitor nutritional status by measuring body weight and serum albumin every 3 months 1
  • Consider iPTH measurement if calcium/phosphorus levels become abnormal 1

4. Iron Deficiency in Context of Renal Impairment

Iron deficiency is common in CKD patients and may be both absolute and functional 3, 4:

• Diagnostic criteria for iron deficiency in CKD:

  • Absolute iron deficiency: TSAT ≤20% and serum ferritin ≤100 ng/mL 3
  • Functional iron deficiency: TSAT ≤20% with elevated ferritin 3

• Treatment considerations:

  • For CKD stage 3-5 (non-dialysis), either IV or oral iron is recommended 3
  • Given the patient's mild renal impairment, start with oral iron and assess response
  • If no response after 1-2 months, consider IV iron therapy 1

Follow-up Plan

1. Complete iron studies (ferritin, TSAT) if not already done
2. Initiate oral iron therapy immediately
3. Schedule follow-up in 4 weeks to assess:
   • Response to iron therapy
   • Leukocytosis trend
   • Renal function
4. Consider hematology referral if leukocytosis persists or worsens

Important Considerations

• The combination of iron deficiency and leukocytosis may indicate an underlying inflammatory condition 1, 5
• Inflammation can contribute to functional iron deficiency through hepcidin-mediated iron sequestration 1
• Chronic inflammation may also contribute to anemia in CKD through impaired erythropoietin production 5
• The presence of both iron deficiency and mild renal impairment increases cardiovascular risk 1