Comparison of Sarcoidosis Phenotypes Among Affected African-American Siblings: Research

Comparison of Sarcoidosis Phenotypes Among Affected African-American Siblings: ResearchTable 2 shows the sibling concordance by organ system. Overall к values were low, ranging from -0.04 to 0.18, demonstrating poor concordance for these phenotypes. There was significant but weak sibling concordance for ocular (к = 0.16; p < 0.05) and liver involvement (к = 0.16; p < 0.05). Concordance was also statistically significant, but weak, for ocular involvement when only full siblings were considered (к = 0.18; p < 0.05).
Table 3 shows the sibling concordance for other clinical outcomes of interest. For the full-sibling pairs and the full-sibling and half-sibling pairs, only receiving treatment showed a significant concordance between sibling pairs (p < 0.05), but the level of agreement was weak (к = 0.14 for full-sibling and half-sibling pairs, к = 0.15 for full-sibling pairs alone). Seventy-six percent of the sibling pairs were concordant with respect to ever being treated. whitening gel
Table 4 shows a logistic regression analysis of the likelihood that the second sibling with a diagnosis of sarcoidosis from a sarcoidosis sibling pair will have the same organ involved or clinical presentation as the first sibling. These models were adjusted for degree of relationship (full-sibling and half-sibling pairs). Only eye (OR, 3.02; 95% CI, 1.7 to 5.4) and liver (OR, 3.31; 95% CI, 1.5 to 7.4) involvement were found to be significantly more likely than expected in the second sibling if it is present in the first.
It has been well established that sarcoidosis is more severe in African-American compared to white populations. African Americans more frequently have symptomatic disease, require treatment, have extrathoracic disease, and have a worse prognosis than whites. However, no previous study has systematically examined if the phenotypic expression of sarcoidosis is more similar within families with multiple affected family members compared to unrelated cases. In this study of African-American sibling pairs affected with sarcoidosis, we identified only a few phenotypic similarities that were more common among the siblings, and the correlations were weak.

Table 2—Sibling Concordance of Organ Involvement in Affected Siblings With Sarcoidosis

Organ System Involved Prevalence,% Full-Sibling and Half-Sibling Pairs(n = 340) Full-Sibling Pairs Only(n = 254)
Observed (Expected) Concordant Pairs, No. Observed(Expected)

Discordant Pairs, No.

к Observed(Expected) Concordant Pairs, No. Observed(Expected)

Discordant Pairs, No.

к
Nonthoracic 75.7 166 (160.8) 111 (121.36) 0.08 126(121.92) 20 (15.9) 0.07
Ocular 26.8 30 (17.6) 83(107.8) 0.16 26(14.5) 59 (82.0) 0.18
Liver 16.4 11 (4.9) 55 (67.1) 0.16 7 (3.7) 43 (49.6) 0.13
Skin 41.7 39 (42.2) 144(137.6) – 0.04 32 (33.6) 106 (102.8) – 0.04
Lymph node 20.0 15 (10.3) 79 (88.4) 0.07 12 (7.6) 57 (65.7) 0.06
Upper respiratory tract 13.1 5 (5.0) 66 (66.0) – 0.01 3 (3.4) 48 (47.1) – 0.03
Bone and joint 11.8 4 (2.9) 52 (54.1) 0.02 4 (2.6) 40 (42.9) 0.05

Table 3—Sibling Concordance of Other Outcomes in Affected Siblings With Sarcoidosis

Other Outcomes Frequency,% Full-Sibling and Half-Sibling Pairs(n = 340) Full-Sibling Pairs Only(n = 254)
Observed(Expected)

Concordant Pairs, No

Observed (Expected) Discordant Pairs, No. к Observed(Expected)

Concordant Pairs, No.

Observed(Expected)

Discordant Pairs, No.

к
Scadding stage from chest radiograph closest to diagnosis (infiltrates vs no infiltrates) 67.6 125 (123.4) 111 (114.2) 0.04 93 (90.3) 78 (83.4) 0.03
Improved change in chest radiograph? (yes vs no) 70.3 127 (124.3) 103 (108.3) 0.10 98 (94.9) 72 (78.1) 0.12
Percentage change in FVC (> 10% vs < 10%) 50.6 24 (23.0) 47 (49.0) 0.01 18(15.3) 30 (35.4) 0.05
Percentage change in FEV1 (> 10% vs < 10%) 59.9 37 (36.4) 46 (46.7) 0.07 26 (25.5) 33 (34.0) 0.10
More than one organ involved (yes vs no) 71.3 164 (156.4) 124(139.1) 0.10 125 (119.4) 90(101.2) 0.08
At least one new organ involved (yes vs no) 63.9 129 (122.9) 143 (155.0) 0.07 99 (95.8) 107(113.4) 0.03
Patient ever been treated? (yes vs no) 86.1 247 (244.4) 70 (75.2) 0.14 181 (178.5) 53 (58.0) 0.15
Condition improved or remained stable? (yes vs no) 64.4 139 (135.2) 140 (147.6) 0.07 105 (102.8) 103 (107.4) 0.07

Table 4—Odds of Clinical Outcomes in a Second Sarcoidosis-Affected Sibling if Observed in the First Affected Sibling Based on General Estimating Equations Logistic Regression Modeling

Variables No. of Pairs OR 95% CI
Organ system involved
Nonthoracic 305 1.51 0.9-2.6
Ocular 288 3.02 1.7-5.4*
Liver 288 3.31 1.5-7.4*
Skin 292 0.82 0.5-1.3
Lymph node 288 1.89 0.9-3.8
Upper respiratory tract 286 1.01 0.4-2.8
Bone and joint 287 1.33 0.4-4.1
Other clinical outcomes
Scadding stage, infiltrates 264 1.21 0.7-2.1
Improved or stable change in 256 1.27 0.7-2.3
chest radiograph
Percentage change in FVC 98 0.72 0.3-1.7
Percentage change in FEV 98 0.92 0.4-2.1
More than one organ involved 326 0.62 0.4-1.0
At least one new organ involved 326 0.70 0.4-1.1
Patient ever been treated 325 1.91 0.8-4.6
Condition improved or remained stable 321 1.20 0.7-1.9
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