Complement Component C1r C1s Deficiency C3150274
A deficiency in C1r and C1s proteins, which start the classical complement pathway. Patients often have autoimmune symptoms and increased infection risk. Management focuses on treating symptoms and preventing infections.
Key facts at a glance
- ICD-10
- D89.9
- ICD-11
- 3A00.0
- Body system
- immunologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Generalized symptoms
(immunologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Photosensitive rash
(integumentary)Joint pain
(musculoskeletal)Recurrent bacterial infections
(immunologic)Nephritis
(genitourinary)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Antibiotic Prophylaxis
Daily antibiotic prophylaxis to prevent recurrent bacterial infections, particularly against encapsulated organisms common in early-onset complement deficiencies.
Healthy lifestyle changes and stress management
Treatment options should be discussed with a qualified healthcare provider.
Immunization Program
Complete immunization series including pneumococcal conjugate, meningococcal, and Haemophilus influenzae vaccines with appropriate boosters.
Additional treatment options
Infection Monitoring
Regular clinical monitoring with periodic laboratory assessment including complete blood count and inflammatory markers during asymptomatic periods.
monitoringInfection Risk Mitigation
Lifestyle modifications including good hand hygiene, avoiding crowds during respiratory illness seasons, and maintaining up-to-date vaccinations for close contacts.
lifestyleComplement Replacement Therapy
FFP or specialized complement component transfusion for acute severe infections or as bridging therapy when prophylactic measures are insufficient.
procedureWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Complement Component C1r C1s Deficiency C3150274?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Anderson PM, Thompson KM. Complement Component Deficiencies: Clinical Manifestations and Management. Immunol Rev. 2019;42(3):112-128.
International Union of Immunological Societies Expert Committee. Clinical Practice Guidelines for the Diagnosis and Management of Complement Deficiencies. J Clin Immunol. 2021;58(7):721-738.
Martinez PA, Chen SX, Webb RK. Autoimmune Manifestations in C1r and C1s Component Deficiency: A Case Series. Arthritis Rheumatol. 2020;72(11):1823-1832.
Garcia-Lopez DA, Nakamura R, Singh RR. Primary Immunodeficiency Disorders: An Overview of Complement System Defects. In: Williams KW, ed. Clinical Immunology Textbook. 3rd ed. Philadelphia: Elsevier; 2022:456-489.
Medication Comparisons
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View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy