Table 1.

Effect of heterophilic antibody blocking tubes (HBT) blocking on mast cell tryptase (MCT), rheumatoid factor (RF) and human anti-mouse antibodies (HAMA) in patients with raised RF and reduction of MCT >17%. Results in bold type highlight the specimens which became negative after HBT treatment and corresponding RF and HAMA levels.

	Pre-HBT tryptase µg/l	Post-HBT tryptase µg/l	Δ% tryptase	Pre-HBT RF IU/ml	Post-HBT RF IU/ml	Δ% RF	Pre-HBT HAMA OD (450)	Post-HBT HAMA OD (450)
1	9·1	7·5	18	321	140	56	0·064	0·058
2	7·07	5·56	21	316	109	66	0·104	0·074
3	12·5	7·9	37	393	124	68	0·095	0·08
4	13·9	7·3	47	2120	1510	29	0·067	0·065
5	6·22	2·76	56	525	347	34	0·086	0·09
6	10·6	4·6	57	350	219	37	Insufficient	Insufficient
7	14·8	8·4	43	341	94·2	72	0·107	0·056
8	25	12·9	48	364	104	71	0·127	0·08
9	29·3	13·9	53	374	112	70	0·105	0·072
10	18·9	8·9	53	1940	1570	19	0·108	0·091
11	31·9	6·7	79	260	63·8	75	0·107	Insufficient
12	41·8	2·6	94	3200	2670	17	0·104	0·088
13	160	5·2	97	550	338	39	0·132	0·077
14	200	4·1	98	4690	3730	20	0·197	0·057

OD: optical density.