Recognizing Symptoms and Emergency Red Flags

In CD27 deficiency, symptoms generally fall into two categories: “everyday” health challenges that require consistent management, and urgent warning signs that require immediate medical evaluation. Because this condition makes the immune system less effective at fighting certain viruses and bacteria, even seemingly minor illnesses need close attention ^[1][2].

Everyday Symptoms and Routine Health

Many people with CD27 deficiency first come to medical attention because of hypogammaglobulinemia—a condition where the body does not produce enough antibodies (immunoglobulins) ^[3]. This leads to a pattern of frequent infections that may seem typical of childhood but happen too often or last too long.

• Recurrent Respiratory Infections: Frequent bouts of ear infections (otitis), sinus infections (sinusitis), and lung infections (pneumonia) are common ^[1][2].
• Bronchiectasis: Over time, repeated lung infections can cause bronchiectasis, a condition where the airways of the lungs become permanently widened and scarred, making it harder to clear mucus ^[3].
• Uveitis: This is an inflammatory condition of the eye that can cause redness, pain, and sensitivity to light. It is a known complication of CD27 deficiency and requires evaluation by an ophthalmologist ^[2].
• Persistent EBV: Unlike most people who clear the Epstein-Barr Virus (EBV) after an initial infection, individuals with CD27 deficiency may have persistent “viremia,” where the virus remains active in the blood for long periods ^[1][3].

Warning Signs and Medical Emergencies

Patients with a combined immunodeficiency need a written, individualized fever plan from their treating center. You will often need to make same-day contact for any fever at or above your center’s specified threshold. Do not wait three days to report a fever.

If you observe any of the following warning signs, contact your immunology or hematology team promptly. Go to the nearest emergency department if there are signs of instability, such as severe breathing difficulty, shock, unresponsiveness, or severe abdominal pain.

1. Signs of HLH (Hemophagocytic Lymphohistiocytosis)

HLH is a life-threatening state of extreme immune overactivation. It is often triggered by an EBV infection in patients with CD27 deficiency ^[4][5]. Note: HLH cannot be diagnosed at home from symptoms alone; it requires laboratory testing for markers like cytopenias, high ferritin, or liver dysfunction.

• Persistent High Fever: A fever that reaches your clinic’s threshold and does not go away, often accompanied by unusual sleepiness, extreme lethargy, or confusion ^[6][4].
• Abdominal Changes: A noticeably swollen or “full” belly, which can be caused by a massive enlargement of the liver (hepatomegaly) or spleen (splenomegaly) ^[7][8].
• Jaundice or Bleeding: Yellowing of the skin or eyes (jaundice), or unexplained significant bruising and bleeding (coagulopathy) ^[9][8].
• Neurological Changes: New confusion, severe headaches, seizures, or a sudden change in personality or alertness ^[7][9].

2. Signs of Lymphoproliferative Disease or Lymphoma

Because the immune system cannot control EBV-infected cells, those cells may begin to grow uncontrollably, leading to lymphoproliferative disease or cancers like Hodgkin lymphoma ^[1][10]. These symptoms require prompt assessment but do not automatically require an emergency department visit in the absence of instability.

• Swollen Lymph Nodes: New, firm, or rapidly growing lumps in the neck, armpits, or groin ^[3][11].
• Night Sweats and Weight Loss: Drenching sweats at night (requiring a change of pajamas) or unexplained weight loss ^[10].
• Persistent Cough or Breathing Trouble: This can occur if enlarged lymph nodes in the chest press against the airways ^[9].

Managing Viral Illnesses and EBV

Because EBV is ubiquitous in the environment, exposure is common and often unknowable. You do not need to report every suspected exposure, nor does every sore throat indicate an emergency. However, if you or your child develop a documented significant illness or symptoms compatible with infectious mononucleosis (prolonged fever, severe sore throat, extreme fatigue), you must contact your care team ^[12][4]. They will determine if viral load monitoring or organ function tests are necessary to ensure the condition is not progressing toward HLH ^[12][6].

Always follow the specific, individualized action plan provided by your immunologist ^[13][8].