Immunoglobulin Deficiency

📋 Key Information Summary

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Immunoglobulin (Ig) deficiency encompasses selective IgA deficiency, common variable immunodeficiency (CVID), IgG subclass deficiencies, and selective IgM deficiency — all predispose to recurrent sinopulmonary and mucosal infections.
Selective IgA deficiency (IgA <0.07 g/L with normal IgG/IgM) is the most prevalent primary immunodeficiency worldwide, affecting approximately 1 in 300–700 Caucasians; prevalence in Aboriginal and Torres Strait Islander populations is poorly characterised.
CVID is the most common symptomatic primary immunodeficiency in adults, characterised by hypogammaglobulinaemia, impaired vaccine responses, and increased susceptibility to autoimmune disease, granulomatous inflammation, and lymphoproliferative malignancy.
Diagnosis requires quantitative immunoglobulin measurement (IgG, IgA, IgM, IgE), functional antibody assessment (anti-pneumococcal, anti-tetanus), lymphocyte subset analysis, and exclusion of secondary causes (medications, malignancy, nephrotic syndrome, protein-losing enteropathy).
Intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg) replacement is the cornerstone of management for CVID and symptomatic IgG subclass deficiency; Australian Government–funded IVIg/SCIg access requires State/Territory Blood Authority approval.
Selective IgA deficiency rarely requires immunoglobulin replacement; most patients are managed with prompt antimicrobial therapy, vaccination optimisation, and mucosal hygiene measures.
IgA-deficient patients receiving blood products must receive IgA-depleted plasma to prevent anaphylaxis from pre-formed anti-IgA antibodies.
Pneumococcal vaccination with 13-valent conjugate (Prevenar 13®) followed by 23-valent polysaccharide (Pneumovax 23®) is essential; vaccine response assessment guides further management decisions.
Empirical antibiotics for acute infective exacerbations: amoxicillin–clavulanate first-line for lower respiratory tract infection; trimethoprim–sulfamethoxazole or doxycycline for Pneumocystis jirovecii prophylaxis when CD4 counts are reduced.
Aboriginal and Torres Strait Islander peoples experience higher rates of respiratory infections, bronchiectasis, and chronic suppurative lung disease — immunoglobulin deficiency should be considered in those with recurrent or severe sinopulmonary infections.
Long-term complications include progressive bronchiectasis, enteropathy, splenomegaly, autoimmune cytopenias, and a 1.8- to 4-fold increased risk of lymphoma; structured annual review is mandatory.
SCIg is increasingly preferred over IVIg for maintenance therapy in Australia, offering fewer systemic adverse effects, self-administration capability, and reduced hospital attendance burden — particularly advantageous for rural and remote patients.

Introduction & Australian Epidemiology

Immunoglobulin deficiency encompasses a heterogeneous group of primary and secondary immune disorders characterised by reduced or absent immunoglobulin production, predisposing affected individuals to recurrent sinopulmonary infections, mucosal infections, and immune dysregulation syndromes. Primary immunodeficiencies (PIDs) are intrinsic defects in immune cell development or function, whereas secondary causes — including nephrotic syndrome, protein-losing enteropathy, immunosuppressive therapy, haematological malignancy, and anti-convulsant medications — are more prevalent in general practice and must be excluded during diagnostic evaluation.

In Australia, selective IgA deficiency is estimated to affect 1 in 300–700 individuals of European descent, though significant underdiagnosis likely exists because most patients remain asymptomatic. The Australian Society of Clinical Immunology and Allergy (ASCIA) register records approximately 1,500–2,000 patients with CVID nationally, with an incidence of approximately 1 per 25,000–50,000. CVID typically presents in the second to fourth decade of life, with a slight female predominance in some cohorts. Secondary immunoglobulin deficiency is considerably more common, particularly in patients receiving rituximab, mycophenolate, or high-dose corticosteroids, and in those with nephrotic syndrome or B-cell lymphoproliferative disorders.

The burden of sinopulmonary disease in immunoglobulin-deficient patients is substantial. A 2019 Australian audit demonstrated that over 60% of CVID patients had radiographic evidence of bronchiectasis at diagnosis, and that delayed diagnosis — averaging 5–7 years after symptom onset — was associated with significantly worse pulmonary outcomes. Aboriginal and Torres Strait Islander peoples, who already experience disproportionately high rates of bronchiectasis and chronic suppurative lung disease, may be further disadvantaged if underlying immunoglobulin deficiency is not considered in the differential diagnosis.

This guideline provides a structured approach to the classification, diagnosis, and management of immunoglobulin deficiency in the Australian healthcare context, with emphasis on PBS-listed therapeutics, Australian Blood Authority–funded immunoglobulin access pathways, and considerations for equity of care in rural, remote, and Aboriginal and Torres Strait Islander communities.

Types of Immunoglobulin Deficiency

Selective IgA Deficiency

Selective IgA deficiency (SIgAD) is defined as a serum IgA level below 0.07 g/L in patients aged >4 years, with normal IgG and IgM concentrations and no other identified cause of hypogammaglobulinaemia. It is the most common primary immunodeficiency in Western populations. Most individuals are asymptomatic, but approximately 10–15% develop clinically significant recurrent respiratory infections, gastrointestinal disease, or autoimmune disorders. Patients who develop anti-IgA antibodies (approximately 1 in 300 SIgAD patients) are at risk of anaphylaxis during transfusion of IgA-containing blood products.

Common Variable Immunodeficiency (CVID)

CVID is the most prevalent symptomatic primary immunodeficiency in adults and is diagnosed when all of the following criteria are met: (a) markedly reduced IgG (at least 2 SD below age-adjusted mean) plus reduced IgA and/or IgM; (b) absent or markedly impaired vaccine responses; (c) exclusion of secondary causes; (d) onset typically after age 2 years. The European Society for Immunodeficiencies (ESID) and Pan-American Group for Immunodeficiency (PAGID) criteria are the international diagnostic standard. CVID is clinically heterogeneous, with approximately 70% presenting with infections alone, and 30% manifesting immune dysregulation — including autoimmune cytopenias, granulomatous-lymphocytic interstitial lung disease (GLILD), enteropathy, and splenomegaly. Genetic mutations in TNFRSF13B (TACI), ICOS, BAFF-R, and LRBA are identified in approximately 10–20% of patients.

IgG Subclass Deficiency

IgG subclass deficiency refers to isolated reduction in one or more IgG subclasses (IgG1, IgG2, IgG3, or IgG4) with a normal total IgG level. IgG1 deficiency accounts for approximately 65% of IgG in serum; IgG2 deficiency is most commonly associated with impaired responses to polysaccharide antigens. Clinically significant IgG subclass deficiency should only be diagnosed in the presence of recurrent infections and impaired functional antibody responses — isolated subclass reductions without clinical correlation do not warrant immunoglobulin replacement therapy.

Selective IgM Deficiency

Selective IgM deficiency (SIgMD) is defined as an isolated reduction in serum IgM below the age-adjusted normal range with normal IgG and IgA levels. It is an underrecognised entity with an estimated prevalence of 0.03–1.7%. SIgMD is associated with recurrent sinopulmonary infections, severe allergic disease, and autoimmune disorders. Management is directed at infection prevention; immunoglobulin replacement is rarely indicated.

Type	Defining Feature	Prevalence	Infection Pattern
Selective IgA deficiency	IgA <0.07 g/L; normal IgG/IgM	1 in 300–700	Mucosal (respiratory, GI); most asymptomatic
CVID	↓IgG + ↓IgA and/or ↓IgM; impaired vaccine responses	1 in 25,000–50,000	Sinopulmonary; encapsulated organisms; opportunistic if CD4↓
IgG subclass deficiency	↓1–2 IgG subclasses; normal total IgG	Variable (1–10% of referrals)	Recurrent URTI, sinusitis, otitis; polysaccharide non-responders
Selective IgM deficiency	↓IgM; normal IgG/IgA	0.03–1.7%	Sinopulmonary; encapsulated organisms

Clinical Significance

The clinical significance of immunoglobulin deficiency varies substantially by type and severity. Key considerations include:

Infectious Complications

Patients with CVID and symptomatic IgG subclass deficiency suffer recurrent bacterial infections, most commonly involving the sinuses, middle ear, bronchi, and lungs. The predominant pathogens are encapsulated organisms — Streptococcus pneumoniae, Haemophilus influenzae (non-typeable), and Moraxella catarrhalis. Recurrent or severe infections lead to progressive bronchiectasis in up to 60% of CVID patients, which itself becomes a source of chronic infection with Pseudomonas aeruginosa and non-tuberculous mycobacteria. GI infections with Giardia lamblia, Campylobacter species, and norovirus are also overrepresented.

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Clinical red flag: Any adult presenting with ≥2 episodes of culture-confirmed bacterial pneumonia within 12 months, ≥4 episodes of otitis media or sinusitis per year, or new-onset bronchiectasis without an alternative explanation should have quantitative immunoglobulin levels measured as part of initial workup.

Autoimmune and Immune Dysregulation

Approximately 25–30% of CVID patients develop autoimmune complications, including autoimmune haemolytic anaemia (AIHA), immune thrombocytopenic purpura (ITP), autoimmune neutropenia, pernicious anaemia, and thyroiditis. Granulomatous-lymphocytic interstitial lung disease (GLILD) is a serious complication unique to CVID, presenting with diffuse pulmonary infiltrates and non-caseating granulomata, and is associated with significantly reduced survival.

Malignancy Risk

CVID carries a 1.8- to 4-fold increased risk of malignancy, predominantly non-Hodgkin lymphoma (particularly MALT lymphoma and diffuse large B-cell lymphoma) and gastric carcinoma. Regular surveillance — including age-appropriate cancer screening, gastroscopy for those with enteropathy, and low threshold for lymph node biopsy — is essential.

Quality of Life and Psychosocial Burden

Immunoglobulin deficiency significantly impairs quality of life. In a 2020 Australian patient survey, CVID patients reported a median of 14 days of illness per month, 3 hospitalisations in the preceding 12 months, and substantial impact on employment and social participation. The introduction of home-based SCIg therapy has demonstrated improvement in quality-of-life scores and reduced healthcare utilisation.

Diagnosis

The diagnostic approach to immunoglobulin deficiency requires a systematic evaluation combining quantitative immunoglobulin measurement, functional antibody assessment, exclusion of secondary causes, and — where indicated — advanced immunological testing. Diagnosis should be confirmed on at least two separate occasions at least 3 months apart.

Tier 1 — Initial Evaluation (Primary Care)

Essential

Quantitative serum immunoglobulins (IgG, IgA, IgM, IgE)

MBS Item 71112 — available through all Australian pathology services. Fasting not required. Age-adjusted reference ranges must be applied (paediatric ranges differ significantly).

Essential

Full blood examination (FBE) with differential

MBS Item 65070 — assess lymphocyte count, eosinophilia, cytopenias.

Essential

Serum protein electrophoresis (SPEP) + immunoglobulin quantitation

MBS Item 71112 — excludes paraproteinaemia, nephrotic syndrome, protein-losing enteropathy.

Available

Renal function, liver function, urinalysis (protein)

Exclude secondary causes — nephrotic syndrome, hepatic synthetic failure.

Available

Coeliac serology (anti-tTG IgA) + total IgA

Exclude IgA deficiency-related coeliac disease; note that anti-tTG IgA will be falsely negative in SIgAD — use deamidated gliadin peptide IgG antibodies (DGP-IgG) instead.

Tier 2 — Specialist Immunology Assessment

Specialist

Anti-pneumococcal serotype-specific IgG antibodies (pre- and post-vaccination)

Assesses functional antibody response to polysaccharide antigens; available through specialist immunology laboratories. Non-response defined as protective titres (≥1.3 mg/L or ≥1.0 µg/mL depending on assay) in <50% of serotypes tested (minimum 7 serotypes).

Specialist

Anti-tetanus toxoid IgG antibodies

Assesses protein antigen response; protective level ≥0.1 IU/mL.

Specialist

Lymphocyte subset analysis (CD3, CD4, CD8, CD19, CD56)

Distinguishes combined immunodeficiency phenotypes; B-cell enumeration (<1% CD19+ of lymphocytes defines "CVID-like" Euroclass Group Ba).

Specialist

IgG subclass panel (IgG1–IgG4)

Only indicated when total IgG is normal but clinical suspicion of immunodeficiency remains high with impaired vaccine responses.

Tier 3 — Advanced / Genetic Testing

Referral

Targeted gene panel or whole-exome sequencing (WES)

Indicated for early-onset CVID (<10 years), combined immunodeficiency phenotype, consanguinity, or family history of PID. TNFRSF13B (TACI), LRBA, CTLA4, PIK3CD gain-of-function panels available through specialised centres (e.g., Royal Children's Hospital Melbourne, Westmead Children's Hospital).

Referral

Anti-IgA antibody testing

Relevant in SIgAD patients prior to blood product administration; available at major hospital transfusion laboratories.

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Critical pitfall: Do not diagnose IgG subclass deficiency based on laboratory values alone. Many healthy individuals have low IgG3 or IgG4 levels without clinical significance. The diagnosis requires recurrent infections AND impaired functional antibody responses. Overdiagnosis leads to unnecessary immunoglobulin replacement therapy.

Management

Management of immunoglobulin deficiency encompasses immunoglobulin replacement therapy (when indicated), antimicrobial therapy for acute infections, vaccination optimisation, monitoring for complications, and patient education. The approach is tailored to the specific type and severity of deficiency.

Immunoglobulin Replacement Therapy

In Australia, access to government-funded immunoglobulin products is managed through the National Blood Authority (NBA) and State/Territory Blood Authorities. Indications for replacement are defined in the National Blood Authority Criteria for the Clinical Use of Immunoglobulin in Australia.

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Intravenous Immunoglobulin (IVIg)

Intragam P® · Privigen® · KIOVIG® · Immune globulin (human)

Adult dose 400–600 mg/kg IV every 3–4 weeks; target trough IgG >5–7 g/L (or >5 g/L above baseline)

Paediatric dose 400–600 mg/kg IV every 3–4 weeks; dose-adjusted to weight and trough levels

Route Intravenous infusion (hospital or home nursing)

Key adverse effects Headache, myalgia, rigors (infusion-related); aseptic meningitis; haemolysis (anti-A/anti-B); thromboembolic events (rare)

PBS status Authority Required — National Blood Authority

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Subcutaneous Immunoglobulin (SCIg)

Cuvitru® · Hizentra® · HyQvia® · Immune globulin (human) — subcutaneous

Adult dose 100–200 mg/kg/week (or equivalent 3–4 weekly cumulative dose); self-administered or administered by trained nurse

Paediatric dose 100–200 mg/kg/week; adapted for age and injection site tolerance

Route Subcutaneous infusion via programmable pump or rapid push; abdomen, thighs, upper arms

Advantages over IVIg Fewer systemic adverse effects; self-administration; reduced hospital attendance; stable serum IgG levels; preferred in rural/remote Australia

PBS status Authority Required — National Blood Authority

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Australian access pathway: All IVIg and SCIg use in Australia requires approval through the National Blood Authority (NBA) Patient Blood Management Information System (PBMIS). Applications are submitted by the treating immunologist and must document clinical indication, prior infection history, and baseline immunoglobulin levels. For rural and remote patients, SCIg home therapy programmes are strongly encouraged — training and supply logistics are coordinated through State/Territory Blood Authorities.

Antimicrobial Prophylaxis and Acute Therapy

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Amoxicillin–Clavulanate

Augmentin Duo Forte® · Amoxyclav®

Acute LRTI dose (adult) 875/125 mg PO BD for 7–14 days

Prophylaxis dose (adult) 500/125 mg PO daily or 875/125 mg PO BD 3 days/week

Paediatric dose 22.5 mg/kg (amoxicillin component) PO BD for 7–14 days (acute); 15 mg/kg PO daily (prophylaxis)

PBS status ✔ PBS General Benefit

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Roxithromycin

Rulide® · Biaxsig®

Adult dose 300 mg PO daily for 7–14 days (acute); 150 mg PO daily (prophylaxis)

Paediatric dose 2.5 mg/kg PO BD (max 150 mg/dose) for 7–14 days

PBS status ✔ PBS General Benefit

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Trimethoprim–Sulfamethoxazole

Bactrim DS® · Resprim®

Prophylaxis (adult) 160/800 mg PO daily or 3 times/week — indicated for Pneumocystis jirovecii prophylaxis when CD4+ count <200 cells/µL

Paediatric dose 5/25 mg/kg PO daily or 3 times/week

PBS status ✔ PBS General Benefit

Management by Immunoglobulin Type

Selective IgA Deficiency

Supportive + Infection Management

Immunoglobulin replacement generally NOT indicated. Manage with prompt antibiotics for infections, mucosal hygiene (saline nasal irrigation), vaccination optimisation, and monitoring for coeliac disease and autoimmune complications. Use IgA-depleted blood products in seropositive patients.

Setting: GP-led with immunology specialist referral for symptomatic patients

IgG Subclass Deficiency

Antibiotics ± Immunoglobulin

Immunoglobulin replacement only if recurrent infections AND impaired functional antibody responses. Otherwise manage with prophylactic antibiotics (e.g., roxithromycin 150 mg daily, or amoxicillin–clavulanate 500/125 mg daily). Annual reassessment with vaccine challenge.

Setting: Specialist immunology oversight for therapy decisions

CVID

Immunoglobulin Replacement + Surveillance

IVIg or SCIg replacement is standard of care. Trough IgG target >5–7 g/L. Annual review including spirometry, HRCT if bronchiectasis suspected, lymphocyte subsets, autoimmune screen, and age-appropriate cancer screening. Treat autoimmune complications with rituximab, corticosteroids, or mycophenolate as indicated.

Setting: Tertiary immunology centre with multidisciplinary team (respiratory, gastroenterology, haematology)

Vaccination Strategies

Vaccination is a critical component of immunoglobulin deficiency management. However, vaccine responses are often impaired, necessitating specific strategies.

Vaccine	Schedule	Notes
Pneumococcal conjugate (PCV13)	1 dose as priming immunisation	Followed by PPV23 booster at ≥8 weeks; assess response to serotypes
Pneumococcal polysaccharide (PPV23)	1 dose 8 weeks after PCV13; repeat every 5 years	Pre-vaccination serotype IgG drawn at time of vaccination; post-vaccination at 4–6 weeks
Influenza (inactivated)	Annual — high-dose or adjuvanted formulation preferred	Free under NIP for immunocompromised; live attenuated (FluMist®) contraindicated
COVID-19	Additional doses per ATAGI guidance for immunocompromised	mRNA vaccines preferred; booster doses recommended at 6-month intervals
Haemophilus influenzae type b (Hib)	2 primary doses + booster if not previously immunised or antibody-negative	Particularly important in CVID and IgG subclass deficiency

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Live vaccine contraindication: Live vaccines (MMR, varicella, yellow fever, oral polio, BCG, oral typhoid, live attenuated influenza) are CONTRAINDICATED in patients with CVID and combined immunodeficiency. In isolated SIgAD, MMR may be given with specialist guidance, as most SIgAD patients retain adequate T-cell immunity. Always seek specialist immunology advice before administering live vaccines.

Monitoring

Structured monitoring is essential to optimise immunoglobulin therapy, detect complications early, and improve long-term outcomes.

Every 3–6 months

Trough IgG level (measured immediately prior to next dose) — target >5–7 g/L. Dose adjustment based on infection frequency and trough levels. FBE, LFTs, CRP. Infection diary review.

Every 6–12 months

Annual comprehensive review: Spirometry (FEV₁, FVC, FEV₁/FVC). HRCT thorax if new or worsening respiratory symptoms. Autoimmune screen (FBE, direct antiglobulin test, thyroid function, ANA). Lymphocyte subsets if CVID. Liver function, renal function.

Every 2–3 years

Vaccine response reassessment — repeat pneumococcal serotype challenge (if >3 years since last IVIg dose). Sputum culture for mycobacteria if bronchiectasis. CT abdomen/pelvis if splenomegaly or lymphadenopathy.

Ongoing

Cancer surveillance: Age-appropriate screening (bowel, breast, cervical). Low threshold for gastroscopy in those with GI symptoms. Lymph node biopsy for persistent lymphadenopathy. Annual dermatological review.

Special Populations

🤰 Pregnancy

IVIg — Safe in pregnancy; continue replacement throughout gestation and postpartum. Dose adjustment may be required as pregnancy-associated plasma volume expansion dilutes IgG levels. IVIg does not cross the placenta as effectively as maternal IgG; neonatal IgG levels should be checked at birth.

SCIg — Safe and preferred for self-administering patients; no dose change required.

SIgAD mothers: neonates may develop transient IgA deficiency; use IgA-depleted products if neonatal transfusion required.

👶 Paediatrics

IgG and IgA levels are physiologically low in infants and do not reach adult ranges until age 10–12 years; age-adjusted reference ranges are mandatory for interpretation.

Transient hypogammaglobulinaemia of infancy (THI) is common and usually self-resolving by age 3–5 years; immunoglobulin replacement is generally not required unless severe recurrent infections persist.

SCIg is increasingly used in paediatric patients and is well tolerated with appropriate training and support.

👴 Elderly

Age-related immunosenescence causes a modest decline in IgG and IgA; secondary causes (myeloma, CLL, immunosuppressive medications) must be excluded.

IVIg infusion rate should be reduced due to increased risk of thromboembolic events, volume overload, and renal impairment in elderly patients.

🫘 Renal Impairment

Nephrotic syndrome is a common secondary cause of hypogammaglobulinaemia due to urinary IgG losses; immunoglobulin replacement may be indicated if recurrent infections are documented.

IVIg-associated acute kidney injury (AKI) is rare with modern sucrose-free products (Intragam P®, Privigen®); monitor renal function during infusion. Avoid IVIg products containing sucrose or high osmolality formulations in CKD stage 4–5.

🫁 Hepatic Impairment

Liver disease can cause hypogammaglobulinaemia through reduced synthetic function; consider hepatology referral to exclude autoimmune hepatitis or hepatic lymphoma.

No dose adjustment of IVIg/SCIg is required in hepatic impairment, but monitor for volume overload in cirrhosis with ascites.

🛡️ Immunocompromised

Iatrogenic hypogammaglobulinaemia following rituximab (anti-CD20) is increasingly common; IgG levels should be measured 6 months post-treatment and monitored every 3–6 months.

Post-haematopoietic stem cell transplant (HSCT) patients may develop prolonged hypogammaglobulinaemia requiring IVIg replacement until immune reconstitution (typically 6–12 months post-transplant).

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander peoples experience a disproportionate burden of respiratory infections, bronchiectasis, and chronic suppurative lung disease compared to non-Indigenous Australians. Immunoglobulin deficiency — particularly CVID and IgG subclass deficiency — may be an underrecognised contributing factor in patients with recurrent or severe sinopulmonary infections. Culturally safe, equitable access to immunology specialist assessment and immunoglobulin replacement therapy is essential.

Epidemiological context

Aboriginal and Torres Strait Islander children have 5–10 times higher rates of bronchiectasis than non-Indigenous children. Recurrent pneumonia, bronchiectasis, and suppurative lung disease are leading causes of morbidity. The prevalence of primary immunodeficiency in this population is poorly characterised, likely due to under-recognition and limited specialist access.

Diagnostic barriers

Access to specialist immunology services is limited in remote and very remote communities. The nearest immunology centre may be >1,000 km away. Quantitative immunoglobulin testing (MBS 71112) is available through regional pathology, but functional antibody testing and lymphocyte subsets require specialist laboratory referral. Telehealth (MBS items 91801–91805) can facilitate specialist consultation, but requires reliable internet connectivity.

Treatment access

SCIg home therapy programmes are particularly valuable for remote patients, eliminating the need for frequent hospital visits. Training programmes must be delivered in a culturally safe manner, incorporating Aboriginal Health Workers and community-based support. Cold chain management for SCIg storage in remote communities requires coordination with local health services.

Comorbidities

Higher background rates of chronic lung disease, rheumatic heart disease, diabetes, and renal impairment may complicate the clinical picture. Immunosuppressive medications (e.g., for rheumatic disease) can exacerbate underlying hypogammaglobulinaemia. A multidisciplinary approach involving Aboriginal Health Workers, community health services, and visiting specialists is recommended.

Vaccination

Aboriginal and Torres Strait Islander peoples are eligible for additional funded vaccines under the National Immunisation Program, including additional pneumococcal doses in childhood and additional influenza doses. Ensuring optimal vaccination status in patients with immunoglobulin deficiency is particularly important given the higher background infectious burden.

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Key actions for equitable care: (1) Consider immunoglobulin deficiency in any Aboriginal or Torres Strait Islander patient with recurrent sinopulmonary infections, bronchiectasis, or chronic suppurative lung disease. (2) Facilitate timely referral to immunology via telehealth. (3) Support SCIg home therapy programmes where feasible. (4) Collaborate with Aboriginal Health Workers and community health services to ensure culturally safe care. (5) Advocate for inclusion of Aboriginal and Torres Strait Islander populations in immunodeficiency epidemiological research.

📚 References

1. National Blood Authority. National Policy: Criteria for the Clinical Use of Immunoglobulin in Australia. Canberra: NBA; 2023.
2. Australasian Society of Clinical Immunology and Allergy (ASCIA). Primary Immunodeficiency Position Statement. Sydney: ASCIA; 2023. Available at: https://www.allergy.org.au
3. Seidel MG, Kindle G, Gathmann B, et al. The European Society for Immunodeficiencies (ESID) Registry working definitions for the clinical diagnosis of inborn errors of immunity. J Allergy Clin Immunol Pract. 2019;7(6):1763–1770.
4. Bogaert DJA, Dullaers M, Lambrecht BN, et al. Genes associated with common variable immunodeficiency: one diagnosis to rule them all? J Med Genet. 2016;53(9):575–590.
5. Cunningham-Rundles C. The many faces of common variable immunodeficiency. Hematology Am Soc Hematol Educ Program. 2012;2012:301–305.
6. >resnov T, Milota T, Litzman J, et al. Global prevalence of common variable immunodeficiency: a systematic review and meta-analysis. Front Immunol. 2023;14:1181585.
7. Abolhassani H, Aghamohammadi A, Imai K, et al. TNFRSF13B (TACI) mutations in patients with common variable immunodeficiency. J Allergy Clin Immunol. 2018;141(3):973–983.
8. AIHW (Australian Institute of Health and Welfare). Aboriginal and Torres Strait Islander Health Performance Framework 2020 Summary Report. Canberra: AIHW; 2020.
9. Chang AC, Gupte NL, Binks M, et al. Bronchiectasis in Indigenous children. Respirology. 2020;25(10):1044–1053.
10. Orange JS, Ballow M, Stiehm ER, et al. Use and interpretation of diagnostic vaccination in primary immunodeficiency: a working group report of the Basic and Clinical Immunology Interest Section of the American Academy of Allergy, Asthma & Immunology. J Allergy Clin Immunol. 2012;130(3 Suppl):S1–S24.
11. Bonilla FA, Barlan I, Chapel H, et al. International Consensus Document (ICON): common variable immunodeficiency disorders. J Allergy Clin Immunol Pract. 2016;4(1):38–59.
12. Queensland Health. Subcutaneous Immunoglobulin (SCIg) Home Therapy Programme — Clinical Guideline. Brisbane: Queensland Government; 2022.
13. American College of Rheumatology (ACR). 2022 Guideline for Vaccination in Patients with Rheumatic and Musculoskeletal Diseases. Arthritis Care Res. 2023;75(1):2–17.