Table 2 Studies involving autism and histamine
Year | Author | Number of patients | Number of controls | Main results |
|---|---|---|---|---|
1972 | Neville et al. | 7 | - | Elevated plasma histidine and low skin histidase levels [107]. |
1979 | Kotsopoulos and Kutty | 1 | - | Patient with autism presented histidine blood levels seven times higher than the upper normal values [108]. |
1988 | Launay et al. | 22 | 22 | Histamine levels in urine and whole blood or plasma of patients with autism did not differ from age- and sex-matched controls [109]. |
1999 | Rossi et al. | 25 | - | Niaprazine (H1R antagonist) showed a positive effect on hyperkinesias, unstable attention, resistance to change and frustration, mild anxiety signs, hetero-aggressiveness, and sleep disorders [110]. |
2001 | Linday et al. | 9 | - | Behavioral improvement in children treated with Famotidine (H2R antagonist) [57]. |
2010 | Rosales-Reynoso et al. | 10 | 10 | Downregulation of H3R in patients with Fragile X syndrome, subjects that usually meet diagnostic criteria for autism [111]. |
2012 | Ming et al. | 48 | 53 | Reduced urinary levels of histidine and other amino acids [112]. |
2013 | Naushad et al. | 138 | 138 | When compared to normal controls, autistic children showed elevated levels of histidine (58 +/– 15 vs. 45 +/– 21 micromol/L) [113]. |