complement factor I deficiency

Complement factor I (CFI) deficiency is a rare immunodeficiency disorder that affects the immune system's ability to regulate the complement pathway, leading to recurrent infections and other complications.

Key Features:

• Recurrent Infections: People with CFI deficiency are prone to recurring bacterial infections, particularly those caused by encapsulated bacteria such as Stre

Complement Factor I Deficiency Signs and Symptoms

Complement factor I (CFI) deficiency is a rare genetic disorder that affects the immune system's ability to fight infections. The signs and symptoms of CFI deficiency can vary depending on the individual, but here are some common manifestations:

• Recurrent Infections: People with CFI deficiency are prone to recurrent infections, including those of the upper respiratory tract, ears, skin, and urinary tract [1].
• Severe Systemic Infections: A deficiency in CFI can lead to severe systemic infections, which can be life-threatening if left untreated [4].
• Ineffective Opsonization: The inability to effectively opsonize pathogens (mark them for destruction) can lead to persistent infections and inflammation [6].
• Lytic Activity Defects: Lytic activity defects can result in the uncontrolled amplification of C3 cleavage, leading to a severe secondary C3 deficiency [7].
• Central Nervous System Inflammation: Complete CFI deficiency may present with isolated and severe CNS inflammation without associated systemic features or prior non-CNS episodes [8].

It's essential to note that the signs and symptoms of CFI deficiency can be similar to those of other complement deficiencies, making diagnosis challenging. A comprehensive medical evaluation, including laboratory tests and genetic analysis, is necessary to confirm the condition.

References: [1] - Context result 1 [4] - Context result 4 [6] - Context result 6 [7] - Context result 7 [8] - Context result 8

Complement factor I (CFI) deficiency can be challenging to diagnose, but various tests can help confirm the condition. Here are some diagnostic tests that may be used:

• CH50 test: This test specifically measures the ability of the patient's serum to lyse antibody-coated sheep erythrocytes, which is a measure of the classical complement pathway. A low CH50 level may indicate CFI deficiency [5].
• C3 and C4 quantification: These tests measure the levels of C3 and C4 proteins in the blood, which are components of the complement system. Low levels of these proteins can suggest CFI deficiency [8][14].
• Complement functional assays: These tests assess the function of the complement system by measuring its ability to lyse bacteria or other cells. A deficiency in CFI activity may be detected through these assays [3][4][13].
• Protein quantification and autoantibody analysis: These tests can help identify the molecular defect responsible for CFI deficiency, such as mutations in the CFI gene [14].

It's essential to note that a combination of these tests may be necessary to confirm CFI deficiency, as a single test result may not be sufficient. A comprehensive diagnostic process should include complement functional assays, protein quantification, and autoantibody analysis to accurately diagnose this condition.

References:

[3] Context 4 [4] Context 5 [8] Context 8

Based on the provided context, it appears that there are limited reports of treatment for complement factor I deficiency.

• According to search result [7], Complement inhibitory therapies (such as eculizumab) offer new potential treatment, underlining the importance of prompt recognition, and real-time management.
• Search result [8] mentions a case where intense immunotherapy and Eculizumab were used to treat a severe myelitis associated with complement factor I deficiency.

However, it's essential to note that there is no recommended treatment for low or absent MBL (Manuscript B-Likely), as mentioned in search result [5]. Additionally, immunoglobulin replacement therapy is not indicated for this purpose.

It seems that the current understanding of treating complement factor I deficiency is still evolving and more research is needed to establish effective treatments.

Complement Factor I Deficiency Differential Diagnosis

The differential diagnosis for complement factor I (CFI) deficiency includes a range of conditions that can present with similar clinical features, such as recurrent infections and immune complex-mediated diseases. Some of the key differentials to consider are:

• B cell immunodeficiency: This condition is characterized by impaired B cell function, leading to reduced antibody production and increased susceptibility to infections.