Table 3B.

Summary of studies with no association

No	Author (Year)	Study design	Types of allergy	Purpose	Sample size and group comparison	Subjects’ characteristics	Association with ABO blood groups
1	Carpeggiani Country: Italy Year: 20113	Literature review	Allergic rhinitis	Not stated.	Not stated.	Not stated.	Association of blood group O with allergic rhinitis remains unknown due to limitations in some studies.
2	Dhiman et al Country: India Year: 199031	Case control	Asthma	To determine whether an association exists between ABO, Rh, and MN blood groups and asthma.	125 patients (70 males and 55 females) 6204 controls	Indoor and outdoor patients Age: 16–70 years	Non-significant differences between ABO phenotypes and asthma (0.7>p >0.5).
3	Bijanzadeh et al Country: India Year: 200932	Case control	Asthma	To evaluate the relationship between asthma and the ABO blood group in the population of Mysore, Karnataka State, South India.	200 (adults and children) 2000 controls	Asthmatic cases from university hospitals and allergy centre controls from blood donors at the hospital Age: Children: younger than 18 years Adults: older than 19 years	ABO blood group status has a non-significant association with asthma among the population of Mysore, Karnataka, South India. (p=0.931)

ENT, Ear, Nose and Throat; OPD, Outpatient Department.