Frequency of Antiphospholipid Antibodies
Twenty-one (9 male and 12 female) of 55 (38 percent) cases of sarcoidosis had aPL (IgG or IgM aPL or both). In contrast, only 5 (7 percent) of 70 cases in the control group were positive for aPL. The presence of aPL was significantly higher (p<0.01) in patients with sarcoidosis (Fig 1).
Regarding the classes of aPL, 10 cases (18 percent), 4 male and 6 female, had IgG aPL and 16 (29 percent), 7 male and 9 female, had IgM aPL. No significant difference was found between the frequency of IgG or IgM aPL in males (4 of 18 [32 percent] or 7 of 18 [39 percent], respectively) and that in females (6 of 37 [16 percent] or 9 of 37 [24 percent], respectively), as seen in Table 1. No particular antibody in either IgG or IgM was detected with significantly high incidence (Fig 1).
The age of the peak distribution in male subjects was in the 20s, while that in females was in the 50s to 60s other canadian family pharmacy. The average age of the aPL-positive group was 47.4 years old, which was not significantly different from that of the aPL-negative group (48.4 years old). Fifty percent of the male and 32 percent of the female subjects studied were found to have aPL. These percentages showed no significant difference (Fig 2).
Relationship Between Antiphospholipid Antibody Occurrence and Clinical Manifestation of Sarcoidosis
There was no significant correlation between the occurrence of aPL and serum levels of angiotensin-converting enzyme or lysozyme (data not shown). The aPL was found to be 25 percent (1 of 4 cases) in stage 0; 37 percent (13 of 35 cases) in stage I; 38 percent (5 of 13 cases) in stage II; and 67 percent (2 of 3 cases) in stage III. The aPL occurred at higher rates in patients at more advanced stages of the disease without any significant difference.
Twenty-nine percent of the cases (11 of 38) with less than one lesion in extrathoracic organs had aPL, as compared with 59 percent (10 of 17) of the cases having more than two lesions in extrathoracic organs. The frequency of aPL was significantly higher in the group with more than two lesions (p<0.05), as shown in Table 2. Seventeen of the 55 cases had skin lesions. Fifty-nine percent of them (10 of 17) had aPL, against 29 percent (11 of 38) with no skin lesions. The aPL frequency was significantly higher in the group with skin lesions (p<0.05). However, there was no significant difference in aPL frequency between patients with ocular or muscular lesions and those without such lesions. Furthermore, there was no significant difference between patients with and without cardiac lesions.
Figure 1. Anti-phospholipid antibodies in patients with sarcoidosis. The cutoff indices of patients with sarcoidosis and the normal upper limits for IgG and IgM antibodies against five types of phospholipids are shown. PS, phosphatidyl-serine; PI, phosphatidyl-inositol; PA, phosphatidic acid; PG, phosphatidyl-glycerol; CL, cardiolipin. The normal limits of each aPL are: IgG-PS=1.79, PI=2.25, PA=2.71, PG=2.70, CL=3.20; IgM-PS=1.44, PI=1.88, PA-1.81, PG=1.48, CL=2.01. The horizontal bar indicates the mean cutoff index of each aPL.
Figure 2. Age distribution of patients with sarcoidosis. The peak distribution of age in males was in the 20s, while that in females was in the 50s and 60s. The average age of the aPL-positive group was 47.4 years old, which was not significandy different from that (48.4 years old) of the aPL-negative group. Fifty percent of the male and 32 percent of the female subjects were found to have aPL. These percentages were not significantly different.
Table 1—IgG and IgM Antiphospholipid Antibodies in Patients With Sarcoidosis
|Class of aPL||Positive Case|
|IgG and IgM||2||3||5|
Table 2—Antiphospholipid Antibodies in Patients With Sarcoidosis
|TotalNo.||Positive for aPL||ProbabilityValue|
|Persistent abnormal chest x-ray film findings|