Haemophilia Rapid Card Test in Community Outreach Initiatives: Insights from a Single Centre in Kerala

Introduction:

India has a huge hemophilia burden with World Federation of Hemophilia 2022 survey estimating 25,715 persons with hemophlia with far more undiagnosed/ undocumented cases. There is currently inadequate data on prevalence of haemophilia in the country due to the high cost and lack of access to advanced coagulation laboratories in resource limited settings. This motivated us to use a first of its kind point of care testing (POCT) for hemophilia A developed by Indian Council of Medical research- National Institute of Immunohaematology (ICMR-NIIH), Mumbai for outreach programs in remote settings in Kerala, India.

Material and Methods :

Three hemophilia camps (54 individuals- 47Males; 7Females) were organised by multidisciplinary team of Amrita hemophilia treatment centre in remote and underserved areas of Kerala where nearest coagulation centre required extensive travel across challenging terrain. Detailed history was charted. After pedigree analysis, at- risk relatives were screened. Patients on regular prophylaxis, who received recent factor VIII (FVIII) infusion and had positive inhibitor screen were excluded. Venous blood was collected in citrated vacutainer (3.2% trisodium citrate, 0.109M, ratio 1:9), centrifuged at 4000 RPM-15 minutes to separate Platelet poor plasma (PPP). BhatBio-scan Hemophilia A rapid card was used for testing, which is a membrane based immunoassay designed for detection of FVIII antigen in human plasma. FVIII antibody is immobilised in test line region, after sample is added to specimen well, FVIII antigen in PPP reacts with FVIII antibody coated particles in conjugate pad. This mixture migrates chromatographically along length of test strip and interacts with immobilised FVIII antibody. Results are interpreted within 15 minutes, as negative (normal FVIII antigen test) if 2 intense bands present in both control and test line; whereas positive (deficiency of FVIII antigen) if faint or no band seen in test region along with band in control region. Ensuring proper cold chain, remainder Platelet Free Plasma was transported to our advanced coagulation laboratory for factor/inhibitor assay in fully automated analyser Compact Max2 (Diagnostica stago®). Differences in prevalence based on POCT and factor assay were assessed using Pearson’s chi-square test. Sensitivity/ specificity evaluated to assess true positive/true negative. All statistical analyses were performed in R version 4.3.0.

Results:

Over the three camps, we evaluated 54 individuals (patients and family members). Based on factor assay they were classified: 38 Hemophilia A (Mild-10; Moderate- 18; Severe- 10), 3 VWD, 4 Hemophilia B and 9 normal. On-site POCT detected low FVIII:- severe/moderate- 35; mild-7 and normal- 12. POCT could detect severe/moderate factor 8 deficiency with sensitivity- 87.5% and specificity- 97%. POCT could not detect Hemophilia B. One severe case was falsely negative; one normal case was falsely positive. Obligate carriers (three) showed normal FVIII / POCT. Three VWD (Type1) cases showed faint band. Notably, POCT aided in rapid diagnosis of a deprived child with significant bleeding and no prior diagnosis/ family history which enabled prompt factor replacement.

Conclusions:

The rapid card offers multiple benefits-

• - The flexibility for it to be performed anywhere e.g. primary health care, pre-hospital settings, rural hospitals alleviating need for travel to advanced set-up.
• - Remote areas typically need cost-effective/ efficient equipment to diagnose severe cases. POCT can serve as primary investigation for early management, followed by further investigations. The working cost of this test is only 350 INR (4.2USD) as opposed to 2000 INR (24USD) that one stage APTT based factor assay costs. No sophisticated equipment required.
• - Rapid turnaround time with the results obtained in under 25 min.
• - Help in surrogate detection of low factor 8 levels in VWD.

Overall, implementation of Hemophilia rapid card testing in camps has been a valuable strategy in expanding access to testing services, improving diagnosis rates, raising awareness about Hemophilia, enhancing overall care and support for individuals with Hemophilia.