Immunodeficiency — Med2Date

📋 Key Information Summary

📋

Immunodeficiency is classified as primary (intrinsic immune defect, often genetic) or secondary (acquired due to disease, medication, or environmental factors).
Secondary immunodeficiency is far more common in Australian primary care; primary immunodeficiency (PID) affects an estimated 1 in 1,200–2,000 Australians, though many remain undiagnosed.
Suspect immunodeficiency when infections are unusually frequent, severe, atypical, or caused by opportunistic organisms.
Red-flag features include: ≥4 ear infections/year, ≥2 pneumonias/year, prolonged IV antibiotics required, failure to thrive, deep-organ abscesses, or family history of PID.
Initial investigations include FBC with differential, immunoglobulin levels (IgG, IgA, IgM, IgE), complement (CH50/C3/C4), lymphocyte subsets, and basic lymphocyte function (e.g., tetanus/diphtheria serology).
MBS items exist for immunoglobulin quantification (MBS item 65070) and lymphocyte subsets (MBS item 65073); genetic/genomic testing is increasingly accessible through specialised centres.
Management centres on infection prevention (vaccination, prophylactic antibiotics, immunoglobulin replacement), definitive therapy (haematopoietic stem-cell transplant, gene therapy for severe forms), and treatment of complications (autoimmunity, granulomas, lymphoma).
Immunoglobulin replacement (IVIG or SCIG) is the cornerstone therapy for antibody-deficient patients; PBS Authority Required for ≥2 indications.
Live vaccines (MMR, varicella, BCG, oral polio, yellow fever) are contraindicated in most PID; assess with an immunologist before live-vaccine administration in any suspected immunodeficiency.
Glucocorticoids ≥20 mg/day prednisolone for ≥14 days, anti-TNF agents, rituximab, and cytotoxic chemotherapy are the most common causes of secondary immunodeficiency in Australian practice.
Refer to a clinical immunologist/allergist for any patient with suspected PID; early referral improves outcomes and reduces organ damage.
Aboriginal and Torres Strait Islander peoples experience a disproportionate burden of secondary immunodeficiency related to chronic disease, rheumatic heart disease management, and remote access barriers to immunoglobulin supply.
Transition of care for adolescents with PID from paediatric to adult services should be actively managed using a structured transition plan.

Introduction & Australian Epidemiology

Immunodeficiency encompasses states in which the immune system's ability to fight infections and malignancies is compromised. The disorders are broadly classified as primary (intrinsic genetic or developmental defects of the immune system) or secondary (acquired through disease processes, medications, or environmental exposure). Immunodeficiency Australia-wide represents a significant and growing clinical burden, driven by an ageing population, expanding use of immunosuppressive biologics, and improved recognition of previously undiagnosed primary immunodeficiencies (PIDs).

Over 480 distinct primary immunodeficiency disorders are now catalogued by the International Union of Immunological Societies (IUIS), ranging from severe combined immunodeficiency (SCID) presenting in neonates to common variable immunodeficiency (CVID) diagnosed in adulthood. The Australian Immunodeficiency Registry and international prevalence data suggest approximately 1 in 1,200–2,000 Australians are affected by a PID, yet many individuals remain undiagnosed for years, accumulating preventable organ damage.

Secondary immunodeficiency is vastly more prevalent. Immunosuppressive therapy with glucocorticoids, calcineurin inhibitors, anti-TNF biologics, anti-CD20 agents (rituximab), and cytotoxic chemotherapy affects hundreds of thousands of Australians being treated for autoimmune disease, organ transplantation, and malignancy. The COVID-19 pandemic further highlighted the clinical significance of secondary immunodeficiency, with iatrogenic immunosuppression identified as a major risk factor for severe outcomes.

⚠️

Diagnostic delay is common. Median time to diagnosis for CVID is 5–7 years. Any patient presenting with recurrent, severe, or unusual infections should prompt consideration of immunodeficiency and early specialist referral.

This guideline provides an evidence-based framework for the recognition, investigation, and management of both primary and secondary immunodeficiency in the Australian healthcare context, including considerations for PBS-listed therapies, MBS investigations, vaccination strategies, and health equity for Aboriginal and Torres Strait Islander peoples.

Primary vs Secondary Immunodeficiency

Understanding the distinction between primary and secondary immunodeficiency is fundamental to appropriate investigation and management. While both share the endpoint of impaired host defence, they differ markedly in aetiology, population affected, diagnostic approach, and therapeutic strategy.

Feature	Primary Immunodeficiency (PID)	Secondary Immunodeficiency (SID)
Aetiology	Inborn genetic mutations affecting immune cell development, function, or regulation	Acquired: medications (glucocorticoids, biologics, cytotoxics), infection (HIV), malnutrition, malignancy, nephrotic syndrome, burns
Age of onset	Variable — severe forms (SCID) present in infancy; others (CVID, specific antibody deficiency) present in adolescence/adulthood	Any age; predominantly adults on immunosuppressive therapy
Prevalence	~1:1,200–2,000 (estimates; significant under-diagnosis)	Very common — hundreds of thousands of Australians affected
Family history	Often positive (autosomal recessive, X-linked, or autosomal dominant patterns)	Not typically relevant
Infection pattern	Often severe, recurrent, caused by opportunistic organisms; may involve atypical sites (liver abscess, brain abscess)	Proportionate to degree/type of immunosuppression; common pathogens predominate (e.g., encapsulated organisms in hypogammaglobulinaemia)
Genetic testing	Frequently diagnostic (next-generation sequencing panels, whole-exome/genome sequencing)	Not applicable
Definitive therapy	HSCT, gene therapy for severe forms; immunoglobulin replacement for antibody deficiencies	Identify and treat underlying cause; reduce/withdraw immunosuppression if safe; prophylactic antimicrobials
Reversibility	Generally permanent (except transient hypogammaglobulinaemia of infancy)	Often reversible if causative factor withdrawn

Primary Immunodeficiency — IUIS Classification (Simplified)

Category	Key Examples	Typical Defect
Combined immunodeficiencies	SCID, Omenn syndrome, ZAP-70 deficiency	T-cell ± B-cell development
Predominantly antibody deficiencies	CVID, XLA (Bruton's), specific antibody deficiency, transient hypogammaglobulinaemia of infancy	B-cell maturation, class-switch recombination
Combined immunodeficiencies with syndromic features	Wiskott–Aldrich syndrome, DiGeorge syndrome (22q11.2 deletion), Ataxia-telangiectasia	Multi-system (thymic, skeletal, neurological)
Phagocyte defects	Chronic granulomatous disease (CGD), severe congenital neutropenia, leukocyte adhesion deficiency	Oxidative burst, adhesion, chemotaxis
Complement deficiencies	C1q, C2, C3, C4, terminal pathway deficiencies	Classical, lectin, or terminal complement pathway
Immune dysregulation disorders	IPEX, APECED, CTLA-4 haploinsufficiency, LRBA deficiency	Regulatory T-cell function, immune tolerance
Inborn errors of immunity affecting intrinsic/innate immunity	TLR pathway defects, STAT1/STAT3 GOF/LOF	Pattern recognition, interferon signalling

Common Causes of Secondary Immunodeficiency in Australia

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Glucocorticoids

Prednisolone · Panafcortelone® · Broad immunosuppression

Risk threshold ≥20 mg/day prednisolone for ≥14 days significantly impairs cell-mediated immunity

Mechanism Lymphocyte apoptosis, impaired neutrophil migration, reduced cytokine production

PBS status ✔ PBS General Benefit

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Rituximab

MabThera® · Ruxience® · Anti-CD20 monoclonal antibody

Risk period Hypogammaglobulinaemia may persist 6–12 months post-last dose; cumulative risk with repeated cycles

Mechanism B-cell depletion, reduced antibody production

PBS status PBS Authority Required

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Anti-TNF agents

Adalimumab (Humira®) · Infliximab (Remicade®) · Etanercept (Enbrel®)

Key risk Increased susceptibility to intracellular pathogens: TB reactivation, non-tuberculous mycobacteria, listeria, histoplasmosis

Mandatory screening IGRA or tuberculin skin test + chest X-ray before commencing

PBS status PBS Authority Required

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HIV infection

CD4+ T-cell depletion

Key feature Progressive CD4+ T-cell decline; opportunistic infection risk proportional to nadir CD4 count

Management Antiretroviral therapy (ART) restores immune function; prophylaxis against PJP, Toxoplasma, MAC when CD4 <200/<50 cells/µL

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Anti-TNF therapy mandate: All patients must be screened for latent tuberculosis (IGRA or TST + CXR) before initiating anti-TNF agents. Failure to screen exposes patients to risk of disseminated TB — a notifiable condition in Australia.

Clinical Features

The clinical presentation of immunodeficiency is heterogeneous, ranging from neonatal emergencies (SCID) to insidious-onset recurrent infections in adults (CVID). A high index of suspicion is required, as the presenting features often mimic common infectious or inflammatory conditions.

Warning Signs — The Jeffrey Modell Foundation "10 Warning Signs"

≥4 new ear infections within 12 months
≥2 serious sinus infections within 12 months
≥2 months on antibiotics with little effect
≥2 pneumonias within 12 months
Failure to thrive or poor weight gain in infants
Recurrent deep skin or organ abscesses
Persistent oral thrush or cutaneous fungal infection beyond infancy
Need for IV antibiotics to clear infections
≥2 deep-seated infections (meningitis, osteomyelitis, septicaemia)
Family history of primary immunodeficiency

Clinical Features by Immunodeficiency Type

Antibody Deficiency

CVID / XLA / SAD

Recurrent sinopulmonary infections (S. pneumoniae, H. influenzae); bronchiectasis; chronic diarrhoea (Giardia); autoimmune cytopenias; granulomatous disease (GLILD in CVID); increased lymphoma risk.

Onset: childhood (XLA) or 2nd–4th decade (CVID)

Combined Deficiency

SCID / CID

Severe failure to thrive; opportunistic infections (PJP, CMV, candida); persistent diarrhoea; chronic candidiasis; absent lymphoid tissue; rash (Omenn syndrome). Fatal without treatment by age 1–2 years (SCID).

Onset: first 3–6 months of life — neonatal emergency

Phagocyte Defect

CGD / Neutropenia

Skin abscesses, lymphadenitis, hepatic/splenic abscesses; pneumonia (Aspergillus, S. aureus); poor wound healing; granuloma formation. In CGD, infections are catalase-positive organisms.

Onset: infancy to early childhood

Complement Deficiency

C1q–C4 deficiency

Recurrent Neisseria meningitidis; SLE-like illness; encapsulated organism infections (late components); hereditary angioedema (C1-INH).

Onset: variable; may present at any age

Immune Dysregulation

IPEX / APECED / CTLA-4

Early-onset autoimmune enteropathy, type 1 diabetes, eczema, cytopenias (IPEX); hypoparathyroidism, Addison's, mucocutaneous candidiasis (APECED); lymphoproliferation, autoimmunity, hypogammaglobulinaemia (CTLA-4).

Onset: neonatal (IPEX) to adult (CTLA-4)

Secondary (Iatrogenic)

Biologics / Steroids / Chemo

Respiratory infections (bacterial, fungal, viral); reactivation of latent TB, hepatitis B, VZV; opportunistic infections with prolonged immunosuppression; impaired vaccine responses.

Setting: any patient on immunosuppressive therapy

Infections Suggestive of Specific Immune Defects

Immune Component Affected	Typical Organisms / Infections	Examples
Antibody (B-cell / humoral)	Encapsulated bacteria (S. pneumoniae, H. influenzae), Giardia lamblia, enteroviruses	CVID, XLA, SAD
T-cell (cellular)	Viruses (CMV, EBV, VZV, adenovirus), fungi (Candida, PJP), intracellular bacteria (mycobacteria, Listeria)	SCID, DiGeorge, HIV
Phagocytes	Catalase-positive bacteria (S. aureus, Serratia, Burkholderia), Aspergillus, Nocardia	CGD, neutropenia
Complement (terminal)	Neisseria meningitidis, N. gonorrhoeae	C5–C9 deficiency
Complement (early/classical)	Encapsulated bacteria; immune-complex disease (SLE)	C1q, C2, C4 deficiency
Innate / interferon pathway	Mycobacteria (BCG disease), herpes viruses, intracellular bacteria	STAT1 GOF, IFN-γR deficiency

Investigations

Investigation of suspected immunodeficiency should follow a stepwise approach — from basic screening tests available in primary care through to advanced functional and genetic assays performed in specialist centres. The Australasian Society of Clinical Immunology and Allergy (ASCIA) provides an investigation algorithm endorsed for Australian practice.

Tier 1 — Primary Care Screening (Available via MBS)

Essential

FBC with differential and blood film

MBS Item 65070. Evaluate lymphocyte, neutrophil, eosinophil, and monocyte counts. Lymphopenia in infancy suggests SCID (<3,000 cells/µL at birth).

Essential

Quantitative immunoglobulins (IgG, IgA, IgM, IgE)

MBS Item 65070. Low IgG +/− low IgA/IgM in an adult with recurrent infections is highly suggestive of CVID. Age-matched paediatric reference ranges are essential.

Available

Renal function, liver function, urinalysis (proteinuria)

Nephrotic syndrome causes urinary IgG loss; liver disease impairs complement synthesis.

Available

HIV serology

Must be excluded in any patient with unexplained immunodeficiency. 4th-generation Ag/Ab assay (MBS Item 69485).

Available

Vaccine response (functional antibody)

Pre- and post-vaccination titres for tetanus and pneumococcal serotypes. Poor response despite adequate vaccination suggests specific antibody deficiency.

Tier 2 — Immunology Specialist Investigations

Specialist

Lymphocyte subsets (CD3, CD4, CD8, CD19, CD16/56)

MBS Item 65073. Evaluates T-cell, B-cell, and NK-cell compartments. Critical for SCID, HIV monitoring, and rituximab-associated immunodeficiency.

Specialist

Complement studies (CH50, AH50, C3, C4)

CH50 = classical pathway; AH50 = alternative pathway. Absent CH50 with normal C3/C4 suggests terminal complement deficiency (C5–C9).

Specialist

Neutrophil function (DHR flow cytometry or NBT test)

Diagnostic for CGD. DHR is the preferred modern assay — quantifies oxidative burst.

Specialist

Lymphocyte proliferation (mitogen/antigen stimulation)

Assesses T-cell function. Markedly reduced proliferation to PHA mitogen suggests severe T-cell defect.

Specialist

IGRA (QuantiFERON-TB Gold Plus) or TST

Mandatory screening before anti-TNF or other potent immunosuppressive therapy.

Specialist

Serum free light chains, protein electrophoresis

Exclude myeloma or lymphoproliferative disease as a cause of secondary hypogammaglobulinaemia.

Tier 3 — Advanced / Genetic Testing

Referral Required

Targeted gene sequencing / PID gene panel

Available through specialised genetics services (e.g., Victorian Clinical Genetics Services, SA Pathology). Covers >400 PID genes.

Referral Required

Whole-exome sequencing (WES) / whole-genome sequencing (WGS)

For undiagnosed cases after initial gene panel negative. Increasingly funded through research programmes and hospital genomics services.

Referral Required

TREC/KREC newborn screening

Detects SCID and some severe B-cell deficiencies. Not yet nationally implemented in Australia; pilot programmes active in some states.

⚠️

Do not delay investigation while awaiting specialist referral. FBC, immunoglobulins, and HIV serology can and should be performed in primary care if immunodeficiency is suspected. These results significantly accelerate the specialist diagnostic pathway.

Management

Management of immunodeficiency is guided by the underlying mechanism, severity, and reversibility. The core principles are: (1) prevent and treat infections, (2) replace deficient immune components, (3) correct the underlying defect where possible, and (4) manage complications.

Immunoglobulin Replacement Therapy

Immunoglobulin replacement is the cornerstone of treatment for patients with primary antibody deficiency and selected patients with secondary hypogammaglobulinaemia (e.g., post-rituximab, CLL, myeloma).

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IV Immunoglobulin (IVIG)

Intragam® P · Privigen® · Octagam®

Adult dose 400–600 mg/kg IV every 3–4 weeks; target trough IgG ≥7 g/L (higher for bronchiectasis)

Paediatric dose 400–600 mg/kg IV every 3–4 weeks; dose adjusted for growth and trough levels

Adverse effects Headache, myalgia, chills (rate-related); rarely anaphylaxis (IgA-deficient patients); thrombotic risk in elderly

PBS status PBS Authority Required

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SC Immunoglobulin (SCIG)

Hizentra® · HyQvia® · Subcuvia®

Adult dose 100–200 mg/kg SC weekly (or 200–400 mg/kg fortnightly); self-administered at home after training

Advantage Home-based therapy, reduced systemic adverse effects, stable serum IgG levels; preferred by many patients

PBS status PBS Authority Required

Prophylactic Antimicrobials

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Co-trimoxazole

Bactrim® · Resprim® · TMP-SMX

Indication PJP prophylaxis (CD4 <200, CGD); broad-spectrum prophylaxis in T-cell deficiency

Adult dose TMP 160 mg/SMX 800 mg PO daily or 3 times/week

PBS status ✔ PBS General Benefit

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Azithromycin

Zithromax®

Indication MAC prophylaxis (CD4 <50 in HIV); CGD prophylaxis (alternative); bronchiectasis maintenance

Adult dose 500 mg PO three times weekly or 250 mg PO daily

PBS status ✔ PBS General Benefit

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Itraconazole

Sporanox®

Indication Antifungal prophylaxis in CGD, post-HSCT, prolonged neutropenia

Adult dose 200 mg PO daily (capsule with food) or 2.5 mg/kg BD oral solution

PBS status ✔ PBS General Benefit

Definitive Therapies for Severe Primary Immunodeficiency

Therapy	Indication	Availability in Australia
Haematopoietic stem-cell transplant (HSCT)	SCID, CGD, Wiskott–Aldrich, HLH, severe CID — curative intent	Major paediatric transplant centres (RCH Melbourne, SCH Sydney, QCH Brisbane, PMH Perth). Matched sibling preferred; haploidentical increasingly available.
Gene therapy	ADA-SCID, X-linked SCID, WAS, CGD — emerging standard for selected PIDs	Clinical trials and compassionate access through specialised centres; not yet standard-of-care in Australia for most conditions.
Thymus transplantation	Complete DiGeorge syndrome (athymia)	Limited international centres; not currently performed in Australia — patients referred overseas.

Vaccination Considerations

🚨

Live vaccines are contraindicated in most primary immunodeficiencies and in patients on significant immunosuppressive therapy. This includes MMR, varicella, BCG, oral polio (Sabin), yellow fever, and rotavirus vaccines. Always consult a clinical immunologist before administering any live vaccine to a patient with known or suspected immunodeficiency.

Inactivated vaccines are generally safe and recommended, though efficacy may be reduced in immunodeficient patients.
Household contacts of PID patients should be fully vaccinated, including live vaccines (with the exception of oral polio, which should be avoided in contacts of SCID patients).
Influenza vaccine (inactivated) — recommended annually for all immunodeficient patients and their household contacts.
COVID-19 vaccination — mRNA and protein subunit vaccines are safe; additional booster doses are recommended per ATAGI guidance for immunocompromised individuals.
Pneumococcal vaccination — 23vPPV + PCV13 schedule recommended for antibody-deficient patients, though response may be suboptimal (document response).
Post-immunoglobulin: Live vaccines should be deferred ≥8 months after IVIG/SCIG due to passive antibody interference; inactivated vaccines can be given but response assessment may be confounded.

Management of Specific Complications

Complication	Association	Management
Bronchiectasis	CVID, XLA, other antibody deficiencies	Optimise immunoglobulin; chest physiotherapy; azithromycin maintenance; annual influenza + pneumococcal vaccination
Autoimmune cytopenias	CVID (30% of patients), ALPS	First-line: glucocorticoids; refractory: rituximab (with immunoglobulin monitoring), splenectomy (last resort)
GLILD (granulomatous-lymphocytic interstitial lung disease)	CVID	Azathioprine or mycophenolate +/− rituximab; multidisciplinary team management
Lymphoma	CVID, ALPS, Wiskott–Aldrich	Standard lymphoma protocols with immunology oversight; immunoglobulin replacement throughout treatment
Splenomegaly / granulomas	CVID, CGD	Avoid splenectomy if possible; immunomodulatory therapy for granulomas (steroids, TNF inhibitors with caution)

Special Populations

🤰 Pregnancy

IVIG

Safe in pregnancy — Category A equivalent. Continue replacement throughout pregnancy; dose may need adjustment as plasma volume increases.

Co-trimoxazole

Avoid in first trimester (folate antagonist risk); may use in second/third trimester if clearly indicated.

Live vaccines

Contraindicated in pregnancy regardless of immunodeficiency status.

Passive immunity

Infant receives transplacental IgG — may be low in mother with severe antibody deficiency. Monitor infant closely after birth.

👶 Paediatrics

SCID screen

Lymphopenia on FBC at birth (<3,000 lymphocytes/µL) is a red flag. TREC screening where available. If SCID suspected, protect from infections immediately — no live vaccines, breast milk OK, reverse isolation.

Transient hypogammaglobulinaemia of infancy (THI)

Most common cause of low IgG in infants <2 years. Usually self-resolving — monitor with serial immunoglobulins; do not commence IVIG unless clinically indicated.

Vaccination

Inactivated schedule is safe; document any adverse events. Refer to ASCIA/PICF guidelines for modified schedules in confirmed PID.

👴 Elderly

Immunosenescence

Age-related decline in adaptive immunity (reduced naive T-cells, impaired vaccine responses) predisposes to infections. Distinguish from pathological immunodeficiency.

IVIG thrombotic risk

Patients ≥65 years on IVIG have increased risk of venous thromboembolism and stroke. Use slower infusion rates, consider SCIG, and assess VTE risk.

🫘 Renal Impairment

Nephrotic syndrome

Urinary IgG loss causes secondary hypogammaglobulinaemia — treat underlying nephrotic syndrome; immunoglobulin replacement if recurrent infections despite treatment.

IVIG in CKD

Sucrose-containing IVIG preparations (e.g., Privigen®) preferred in renal impairment; avoid sucrose-free high-osmolality products. Monitor renal function during infusion.

🫁 Hepatic Disease

Complement deficiency

Liver cirrhosis reduces complement synthesis — may mimic primary complement deficiency. Assess with CH50 + C3/C4.

Hepatitis B reactivation

Screen HBsAg and anti-HBc before rituximab or other B-cell-depleting therapy. Antiviral prophylaxis (entecavir) required if HBsAg+.

🛡️ Immunocompromised (Secondary)

Pre-immunosuppression checklist

IGRA/TST, HBV/HCV serology, VZV IgG, HIV, baseline immunoglobulins, FBC. Vaccinate (inactivated) before commencing therapy.

Antimicrobial prophylaxis

Tailored to specific immunosuppressive agent and degree of immune suppression. Co-trimoxazole for PJP if prolonged steroids; aciclovir for VZV-seronegative on rituximab.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander peoples experience a disproportionate burden of infectious disease and secondary immunodeficiency-related complications. Structural inequities in healthcare access, higher prevalence of chronic conditions requiring immunosuppressive therapy, and the legacy of rheumatic heart disease (RHD) management all intersect with immunodeficiency care.

Rheumatic heart disease & immunosuppression

RHD disproportionately affects Aboriginal and Torres Strait Islander peoples, particularly in remote Northern Territory, Queensland, and Western Australian communities. Long-term secondary prophylaxis with benzathine penicillin G is standard; however, some patients with autoimmune complications of RHD may require immunosuppressive agents (e.g., corticosteroids, azathioprine) that compound infection risk.

Remote and very remote access

Clinical immunology specialists are concentrated in capital cities. Patients in remote NT, QLD, and WA communities face multi-thousand-kilometre travel for specialist review. Telehealth immunology consultations (MBS item 91822) are essential for ongoing management. Immunoglobulin supply to remote clinics requires cold-chain logistics coordination with the National Blood Authority.

Infectious disease burden

Higher rates of bronchiectasis, otitis media, skin infections (S. aureus, Group A Streptococcus), and rheumatic fever in Aboriginal and Torres Strait Islander communities. These infections may be the presenting feature of an underlying primary immunodeficiency or may be compounded by secondary immunosuppression.

BCG vaccination

BCG is recommended for Aboriginal and Torres Strait Islander neonates in high-TB-incidence areas. In regions with very low TB incidence, BCG may be deferred. BCG is a live vaccine — contraindicated in SCID and other severe T-cell deficiencies. Ensure immunodeficiency is excluded before BCG administration in any neonate with a family history of PID or concerning clinical features.

Cultural safety

Engage Aboriginal and Torres Strait Islander Health Workers and Liaison Officers in the care team. Use culturally appropriate communication strategies. Ensure patients and families understand the chronic nature of immunodeficiency and the importance of adherence to prophylactic therapy and follow-up.

Genetic testing considerations

Some PIDs have higher prevalence in specific populations due to founder effects. Genetic counselling should be culturally sensitive and involve family/kinship structures. Access to genetic testing may be limited by geography and cost; advocate for equitable access through genomics referral pathways.

📚 References

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2. Australasian Society of Clinical Immunology and Allergy (ASCIA). Primary Immunodeficiency (PID) Guide for Health Professionals. ASCIA; 2024. Available at: https://www.allergy.org.au.
3. Boyle JM, Buckley RH. Population prevalence of diagnosed primary immunodeficiency diseases in the United States. J Clin Immunol. 2007;27(5):497–502.
4. National Blood Authority Australia. Criteria for the Clinical Use of Intravenous Immunoglobulin in Australia. 3rd ed. NBA; 2012 (updated 2023).
5. Risma KA, Bhatt RR, Bhatt S, et al. COVID-19 outcomes in patients with primary immunodeficiency. J Allergy Clin Immunol Pract. 2022;10(3):762–771.
6. Patel SY, Carbone J, Jolles S. The expanding field of secondary antibody deficiency: causes, diagnosis, and management. Front Immunol. 2019;10:33.
7. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available at: https://immunisationhandbook.health.gov.au.
8. AIHW (Australian Institute of Health and Welfare). Aboriginal and Torres Strait Islander Health Performance Framework: Immunisation. AIHW; 2023.
9. RHDAustralia (Rheumatic Heart Disease Australia). The 2020 Australian Guideline for Prevention, Diagnosis and Management of Acute Rheumatic Fever and Rheumatic Heart Disease. 3rd ed. Menzies School of Health Research; 2020.
10. Bousfiha A, Moundir A, Tangye SG, et al. The 2022 Update of IUIS Phenotypical Classification for Human Inborn Errors of Immunity. J Clin Immunol. 2022;42(5):1008–1020.
11. Bonilla FA, Khan DA, Ballas ZK, et al. Practice parameter for the diagnosis and management of primary immunodeficiency. J Allergy Clin Immunol. 2015;136(5):1186–1205.
12. Phospholipidosis and related considerations. In: Australian Medicines Handbook (AMH). Adelaide: AMH Pty Ltd; 2024.