How to manage ulcerative colitis with thrombocytosis and eosinophilia?

Management of Ulcerative Colitis with Thrombocytosis and Eosinophilia

Treat the underlying ulcerative colitis aggressively with standard UC therapy, as thrombocytosis and eosinophilia are typically reactive inflammatory markers that resolve with disease control, while simultaneously screening for and preventing thromboembolic complications.

Understanding the Clinical Context

Thrombocytosis (platelets >450 × 10⁹/L) in ulcerative colitis is a reactive phenomenon reflecting systemic inflammation, where platelets amplify inflammatory and immune responses in chronic inflammation 1. This is not a separate disease requiring specific platelet-directed therapy, but rather a marker of disease severity that resolves with UC remission 1.

Eosinophilia in UC patients requires careful diagnostic consideration:

• Focal eosinophilic infiltration can occur in UC itself, particularly in the rectum, though severe infiltration is unusual 2
• Rule out eosinophilic gastrointestinal disease (eosinophilic colitis or eosinophilic esophagitis), which would require different management 3
• Consider hypereosinophilic syndrome/chronic eosinophilic leukemia if eosinophilia is marked and persistent, though this is rare 2

Treatment Algorithm

Step 1: Assess UC Disease Severity and Initiate Appropriate Therapy

For Moderate-to-Severe UC:

• Start biologic therapy early rather than gradual step-up, particularly in patients at high risk of colectomy 4
• Infliximab or vedolizumab are preferred first-line biologics over adalimumab or golimumab based on network meta-analysis 4
• Infliximab dosing: standard 5 mg/kg at weeks 0,2, and 6, then every 8 weeks for maintenance 5, 6
• Consider higher dosing (10 mg/kg) in patients with severe disease, low albumin, or high inflammatory burden, though guidelines cannot make definitive recommendations due to limited evidence quality 5

For Acute Severe UC (ASUC):

• Intravenous methylprednisolone 40-60 mg/day is the mainstay of initial therapy 3
• Assess response after 3-5 days by monitoring symptoms, serum C-reactive protein, and albumin levels 7
• If steroid-refractory, initiate rescue therapy with infliximab or cyclosporine 3, 5

For Mild-to-Moderate UC:

• Oral 5-ASA 2.0-4.8 g daily, with combination oral and rectal therapy offering superior remission rates 4
• If inadequate response within 2 weeks, escalate to corticosteroids (prednisolone 40 mg daily) 4

Step 2: Address Thrombocytosis-Related Thrombotic Risk

Thromboprophylaxis is mandatory in hospitalized UC patients with thrombocytosis:

• Start prophylactic anticoagulation to prevent venous thromboembolism, as UC patients have increased thrombotic risk that is amplified by thrombocytosis 1, 7
• Screen for symptoms of deep venous thrombosis and pulmonary embolism throughout treatment 1
• The thrombocytosis will resolve as UC inflammation is controlled; no specific antiplatelet therapy is needed beyond prophylactic anticoagulation 1

Step 3: Investigate and Manage Eosinophilia

Determine if eosinophilia is UC-related or represents a separate condition:

If eosinophilia is mild and focal on biopsy:

• This likely represents reactive eosinophilia from UC inflammation 2
• Proceed with standard UC therapy; eosinophilia should resolve with disease control 2

If eosinophilia is severe, diffuse, or persistent despite UC treatment:

• Obtain endoscopy with biopsies to assess for eosinophilic gastrointestinal disease 3
• If eosinophilic esophagitis is diagnosed, initiate proton pump inhibitor therapy twice daily for 8-12 weeks as first-line treatment 3
• Topical steroids are highly effective for eosinophilic esophagitis if PPI therapy fails 3
• Consider hematology consultation if peripheral eosinophilia is marked (>1500/μL) to evaluate for hypereosinophilic syndrome 2

Step 4: Monitor Treatment Response

Use biomarkers to guide therapy adjustments:

• Fecal calprotectin >150 mg/g, elevated fecal lactoferrin, or elevated CRP in patients with moderate-to-severe symptoms reliably indicate active inflammation 3
• In patients with moderate-to-severe symptoms and elevated biomarkers, treatment adjustment can proceed without endoscopic confirmation 3
• Repeat endoscopy if symptoms recur on treatment to assess for treatment failure or alternative diagnoses 3

Treatment targets:

• Aim for complete remission: symptomatic, endoscopic, and biochemical remission without corticosteroids 4, 8
• Continue the same agent that induced remission for maintenance therapy 4

Critical Pitfalls to Avoid

Do not treat thrombocytosis as a primary hematologic disorder requiring specific platelet-lowering therapy; it is a reactive marker that resolves with UC control 1.

Do not miss eosinophilic gastrointestinal disease masquerading as UC; severe or diffuse eosinophilic infiltration warrants investigation for a separate eosinophilic disorder 2, 3.

Do not delay thromboprophylaxis in hospitalized UC patients with thrombocytosis, as they are at particularly high risk for venous thromboembolism 1, 7.

Do not use immunomodulators (azathioprine, 6-mercaptopurine) or anti-TNF/anti-integrin therapies if eosinophilic esophagitis is diagnosed, as these are ineffective for that condition 3.

Do not continue corticosteroids beyond induction if biologics achieve remission; the goal is corticosteroid-free remission 4, 6.