What factors predispose an immunocompetent patient to Sarocladium kiliense infection?

Predisposing Factors for Sarocladium kiliense Infection in Immunocompetent Patients

Sarocladium kiliense infection in immunocompetent patients occurs primarily through traumatic skin disruption or iatrogenic breaches of anatomical barriers, particularly following invasive procedures involving the sinuses, central nervous system, or respiratory tract. 1, 2

Primary Route: Breach of Anatomical Barriers

The most critical predisposing factor is direct inoculation through invasive procedures or trauma:

• Neurosurgical procedures, particularly transnasal endoscopic surgery for cerebrospinal fluid rhinorrhea repair, create direct pathways for fungal invasion from colonized sinuses into sterile spaces 2
• Chronic sinusitis serves as a reservoir for fungal colonization that can seed deeper structures when anatomical barriers are breached 2
• Cutaneous and soft-tissue disruption from traumatic injury (natural disasters, motor vehicle accidents, war injuries), surgery, or burns represents the most common portal of entry in truly immunocompetent patients 1

Occult Immunosuppression Masquerading as Immunocompetence

A critical pitfall is assuming true immunocompetence when subtle immunosuppression exists:

• Recent corticosteroid use, even if discontinued, can create a window of vulnerability for opportunistic fungal infections 1, 3
• Underlying sarcoidosis or other inflammatory conditions may involve intrinsic immune dysregulation despite appearing "immunocompetent" 3
• Diabetes mellitus, particularly poorly controlled, predisposes to fungal infections including rare molds 1
• Malnutrition, protein-losing disorders, or extremes of age represent forms of secondary immunodeficiency often overlooked 1

Environmental and Anatomical Risk Factors

Local tissue factors and environmental exposures facilitate infection:

• Structural lung disease or abnormal anatomy increases susceptibility to respiratory fungal colonization and subsequent invasive disease 1
• Smoking and poor dental hygiene compromise mucosal barriers and local immune defenses 4
• Geographic exposure to endemic fungal regions, though Sarocladium is ubiquitous in soil and plant material 5

The "Apparently Immunocompetent" Paradox

Most reported Sarocladium infections in "immunocompetent" patients reveal predisposing factors upon careful investigation:

• The case series literature demonstrates that truly immunocompetent patients with Sarocladium infections almost universally have either recent invasive procedures or occult immunosuppression 2, 5, 3
• Iatrogenic immunosuppression history must be specifically sought, as patients may not volunteer information about recent steroid courses or immunomodulatory therapy 3
• The absence of obvious immunocompromise should prompt investigation for subtle immune defects, including functional antibody deficiencies or complement deficiencies 1

Clinical Algorithm for Risk Assessment

When evaluating an immunocompetent patient with Sarocladium infection, systematically assess:

1. Recent invasive procedures (within 3-6 months), particularly involving sinuses, CNS, or respiratory tract 2
2. Corticosteroid exposure within the past 6 months, regardless of duration or indication 3
3. Underlying chronic conditions: diabetes, chronic sinusitis, structural lung disease, inflammatory disorders 1, 2
4. Traumatic skin or tissue injury with environmental exposure 1
5. Occult immunodeficiency: Consider screening for HIV, immunoglobulin levels, and lymphocyte subsets if no other risk factors identified 1

Key Caveat

The term "immunocompetent" in Sarocladium case reports is often misleading—most patients have identifiable risk factors when thoroughly investigated, and the presence of this infection should itself prompt reconsideration of immune status 2, 5, 3. The combination of anatomical barrier disruption plus even subtle immune compromise creates the perfect storm for this opportunistic pathogen.