Recurrent Gonococcemia Reveals X-Linked Properdin Deficiency: A Case Study
Overview
This case report describes a 29-year-old male with two episodes of disseminated gonococcal infection (DGI) who was diagnosed with X-linked properdin deficiency. The deficiency, previously linked to meningococcal infections, is identified here as a novel risk factor for recurrent DGI, highlighting the need for complement pathway evaluation in such cases.
Background
Disseminated gonococcal infections (DGI) are severe manifestations of Neisseria gonorrhoeae infection and are increasingly concerning due to rising antibiotic resistance. Complement system deficiencies, particularly in the alternative pathway, predispose individuals to invasive infections by gram-negative diplococci. Properdin deficiency, an X-linked disorder, is known to increase susceptibility to meningococcal disease but has not been previously associated with DGI. Early recognition and immunological workup in recurrent DGI cases are essential for targeted management and prevention.
Data Highlights
Parameter
Result
Reference Range
Complement C3
1.55 g/L
0.9–1.8 g/L
Complement C4
0.33 g/L
0.1–0.4 g/L
CH50
>61 U/mL
31.6–57.6 U/mL
Alternative Pathway 50 (AP50)
<10%
60%–140%
Properdin Antigen Level
<1.75 mg/L
12–40 mg/L
Key Findings
The patient experienced two episodes of disseminated gonococcal infection, confirmed by blood cultures positive for Neisseria gonorrhoeae.
Complement C3, C4, and CH50 levels were normal, but AP50 was markedly reduced, indicating alternative pathway dysfunction.
Properdin antigen levels were significantly decreased, confirming type I properdin deficiency.
Genetic analysis revealed a novel pathogenic stop codon mutation in exon 4 of the properdin gene on the X chromosome.
Properdin deficiency, previously linked to meningococcal disease, is identified here as a risk factor for recurrent DGI.
Vaccination against meningococcal, pneumococcal, and Haemophilus influenzae type b infections was initiated following diagnosis.
Clinical Implications
Clinicians should consider screening for alternative complement pathway deficiencies, including properdin deficiency, in patients presenting with recurrent disseminated gonococcal infections. Early identification allows for implementation of targeted vaccination strategies and genetic counseling to prevent invasive infections in affected families. Awareness of this association is particularly important given the rising antibiotic resistance in Neisseria gonorrhoeae.
Conclusion
This unique case establishes a novel link between X-linked properdin deficiency and recurrent disseminated gonococcal infections, underscoring the importance of comprehensive immunological evaluation in such patients. Proper identification facilitates appropriate preventive and therapeutic interventions.
References
Original Case Report 2024 -- Recurrent Gonococcemia Uncovers X-Linked Properdin Deficiency
