Basic Characteristics with Descriptive Statistics
Graft-versus-host disease was confirmed by histopathology in 19 of the 20 allo-HSCT recipients. Four patients developed symptoms of AGvHD (2 patients with clinical overall grade I and skin score 1 and 2, respectively; 1 with grade II, skin score 3; and 1 with grade III, skin score 1 with gut score 2) without subsequently developing CGvHD; these patients were all evaluated as grade 2 on the modified Lerner’s scale. Five patients were previously diagnosed with AGvHD followed by CGvHD, and in ten patients cGvHD occurred without preceding AGvHD. All 15 cases of CGvHD were classified as “likely” in the histopathologic report [8]. The overall grading according to the NIH guidelines was as follows: mild cGvHD with skin score 1 (n = 7), moderate with skin score 2 (n = 5) and severe cGvHD with skin score 3 (n = 3). Time to onset of GvHD after the allo-HSCT procedure for all (n = 19) patients ranged from 22 to 1452 (median 259, interquartile range [IQR] 143.5–496.5) days. Median onset for CGvHD and AGvHD was 262 (IQR 173–573.5) and 22 (IQR 29.5–106.2) days, respectively.
Among all patients with both types of GvHD the most frequent clinical features were classic poikiloderma (n = 12; 63.2%) (Fig. 1a, d, g) and “other” features, including fine flakes scaling (n = 10; 52.6%) and perifollicular papules (n = 6; 31.6%). Maculopapular rash was present in all four cases of AGvHD and absent in all cases of CGvHD (p < 0.001). Classic poikiloderma and “other” features, including fine flakes scaling and perifollicular papules, were present in the majority of cGvHD cases (12 of 15, 80%; 10 of 15, 66.7%, 6 of 15, 40%, respectively), while absent in all AGvHD cases (p = 0.009; p = 0.03; p = 0.3, respectively). Statistically significant differences in occurrence of maculopapular rash and other fine flakes scaling were found to relate to grade of GvHD (p = 0.04). The complete set of data is shown in Table 2.
Table 2 Frequency of clinical, dermoscopic and histopathologic signs according to grade and type of graft-versus-host disease In our patient group, the most frequent dermoscopic signs, irrespective of the GvHD type (chronic vs. acute) and its grade, were type of vessels and scaling (each n = 14, 73.7%). Hyperpigmentation (Fig. 1b, e, h) and white patchy areas (Fig. 1b, e) were present in eight patients (42.1%). More detailed results are shown in Table 2. The most common histopathologic characteristics (regardless of the type of GvHD) were hyperkeratosis (17/19, 89.5%) and lymphocytic infiltration (15/19, 78.9%) (Fig. 1c, f, i). Our data have confirmed that collagen bundles (Fig. 1c) and melanophages (Fig. 1c, f, i) were significantly more frequently identified among patients with CGvHD (10/15; 66.7%, p = 0.03 and 11/15; 73.3%, p = 0.02, respectively), while presence of satellitosis may be one of the factors associated with grading of GvHD (p = 0.03). All results are shown in Table 2.
Concordance Between Different Methods
Concordance was assessed separately for all cases of AGvHD and CGvHD. To maintain the clarity and brevity of the results, we present only data for chronic cases.
Agreement Between Dermoscopy and Clinical Signs
Classic poikiloderma was associated positively with pigmentation (κ = 0.36; 95% CI 0.01–0.71) and possibly with granularity (κ = 0.29; 95% CI − 0.02 to 0.6). Classic sclerotic features were positively associated with white patchy areas and pigmentation (both κ = 0.44; 95% CI 0.06–0.83) (Fig. 2a–f). The presence of dermoscopic features within the skin lesions accompanied by classic lichen planus-like mucosa could be surrogate of pigmentation (κ = 0.44; 95% CI 0.06–0.83) and granularity (κ = 0.55; 95% CI 0.14–0.96). “Other” features, such as other perifollicular papule and fine flakes scaling, might be linked with the presence of scaling in dermoscopy (κ = − 0.43; 95% CI − 0.86 to 0, κ = 0.33; 95% CI − 0.17 to 0.83, respectively). The complete results for this analysis are presented in Table 3.
Table 3 Level of agreement between the presence of selected dermoscopic signs and clinical signs, pathologic signs and “other” dermoscopic signs as assessed with values of Cohen’s Kappa statistics and their 95% confidence intervals Agreement Between Dermoscopy and Histopathology
The histopathic examination found that lymphocytic infiltrations were less prevalent when dermoscopy revealed white patchy areas (κ = − 0.55; 95% CI − 0.96 to − 0.15). Agreement was fair between the occurrence of melanophages in the skin sample and dermoscopic granularity (κ = 0.39, 95% CI 0.04–0.74); in comparison, the histopathic findings of scaling and vessels were more scarce (κ = − 0.3, 95% CI − 0.52 to − 0.07; κ = − 0.42, 95% CI − 0.68 to − 0.16; respectively). The presence of vacuolar changes at the dermal–epidermal junction in the skin samples was inversely linked with scaling in the dermoscopic evaluation (κ = − 0.33; 95% CI − 0.6 to − 0.07). There was a trend for an association between the pathological sign of collagen bundles and dermoscopic findings of white patchy areas or scaling features (κ = 0.35, 95% CI − 0.08 to 0.78; κ = 0.33, 95% CI − 0.17 to 0.83; respectively). The complete results for this analysis are given in Table 3.
Agreement Between Dermoscopic Signs
We found an agreement between co-presence of pigmentation with: white patchy areas (κ = 0.73; 95% CI 0.39–1), granularity (κ = 0.59; 95% CI 0.19–1), while negative for vessels (κ = − 0.43; 95% CI − 0.87 to − 0.001). Presence of granularity feature was associated with absence of vessels (κ = − 0.75; 95% CI − 1 to − 0.3). The complete results from this analysis are given in Table 3.
Possible Determinants of Early or Late Onset of GvHD
The presence of a number of dermoscopic signs at the time of diagnosis may determine the onset of GvHD, but the results of our analysis (Mann–Whitney U test) were not statistically significant. For example, patients with presence of pigmentation may be more likely to have later onset of GvHD than those without (median time in days 351.0 [IQR 180.2–682.2] vs. 259.0 [IQR 119.0–299.5], respectively; p = 0.3); similarly with the occurrence of scaling (267.5 [IQR 196.8–603.2] vs. 157.0 [IQR 130.0–158.0]; p = 0.1) or granularity (370.5 [IQR 206.5–594.5] vs. 223.0 [IQR 108.0–326.0]; p = 0.3).
Earlier occurrence of GvHD was associated with the presence of vacuolar changes in the histopathologic examination (median time in days: 173.0 [IQR 113.5–270.2] vs. 514.0 [IQR 479.0–654.0]; p = 0.03), satellitosis (70.5 [IQR 32.8–120.2] vs. 273.0 [IQR 205.5–573.5]; p = 0.009) and (only a trend) apoptosis (33.0 [IQR 32.5–128.0] vs. 267.5 [IQR 157.8–543.8]; p = 0.08). Later occurrence of GvHD was associated with histopathologic signs of subepidermal homogenization (479.0 [IQR 259.0–654.0] vs. 143.5 [IQR 51.8–243.5]; p = 0.008), collagen bundles (496.5 [IQR 259.8–648.8] vs. 157.0 [IQR 33.0–223.0]; p = 0.006) and (statistically not significantly) with presence of macrophages with pigment (273.0 [IQR 173.0–573.5] vs. 165.5 [IQR 32.8–275.8]; p = 0.1).
Among the clinical signs, maculo-papular rash turned out to be typical for early GvHD (32.5 [IQR 29.5–106.2] vs. 262.0 [IQR 173.0–573.5]; p = 0.04), while for late GvHD it was classic sclerotic features sign (830.0 [IQR 731.5–1141.0] vs. 205.5 [IQR 124.5–286.2]; p = 0.004). The clinical cutaneous sign classic lichen planus-like was excluded from the analysis as it was absent in all cases.