# **Supplemental Online Content**

Boesjes CM, van der Gang LF, Bakker DS, et al. Dupilumab-associated lymphoid reactions in patients with atopic dermatitis: clinical and histopathologic characterization. *JAMA Dermatol*. Published online October 11, 2023. doi:10.1001/jamadermatol.2023.3849

**eTable 1.** Histopathologic findings of biopsies before dupilumab treatment **eTable 2.** Clinical features of patients with a lymphoid reaction or mycosis fungoides based on diagnostic criteria for MF

**eTable 3.** Histopathologic findings of the biopsies after dupilumab treatment **eTable 4.** Clinical follow-up of patients with lymphoid reactions up to 4 years after treatment discontinuation

This supplemental material has been provided by the authors to give readers additional information about their work.

| Patient | 1 | 2 | 3 | 5 | 6 | 8 | 12 | 13 | 14 |
|--------------------------|--------------|------------------|------------------|--------------|--------------|--------------|--------------|--------------|--------------|
| Diagnosis before | AD | AD | AD | AD | AD | AD | MF | MF | MF |
| dupilumab treatment | | | | | | | | | |
| Diagnosis during | LR | LR | LR | LR | LR | LR | MF | MF | MF |
| dupilumab treatment | | | | | | | | | |
| Start dupilumab | 09-2018 | 11-2018 | 10-2019 | 03-2021 | 08-2020 | 08-2020 | 09-2019 | 05-2020 | 10-2019 |
| treatment | | | | | | | | | |
| Available pre-biopsies | 1x (04-2017) | 3x (03-2008, 01- | 4x (07-2017, 09- | 1x (10-2020, | 1x (07-2018) | 3x (11-2013, | 2x (01-2018, | 1x (10-2019) | 1x (03-2007) |
| | | 2012, 02-2017) | 2018, 12-2018, | 01-2021) | | 03-2018, 08- | 08-2019) | | |
| | | | 01-2019) | | | 2018) | | | |
| Eczematous features | | | | | | | | | |
| - Acanthosis | +++ | + | ++ | ++ | +++ | ++ | + | ++ | + |
| - Spongiosis | ++ | +++ | +++ | ++ | ++ | ++ | + | + | + |
| - Parakeratosis | +++ | ++ | + | + | +++ | ++ | + | + | + |
| Presence of lymphoid | + | + | + | + | ++ | +++ | ++ | ++ | ++ |
| infiltrate | | | | | | | | | |
| Distribution lymphoid | | | | | | | | | |
| infiltrate stratum | | | | | | | | | |
| papillare | | | | | | | | | |
| - Perivascular | + | + | + | + | + | + | + | + | - |
| - Lichenoid | - | - | - | - | - | - | - | + | + |
| Intraepithelial T-cell | + | - | + | - | + | + | ++ | ++ | ++ |
| lymphocytes | | | | | | | | | |
| Lining of cells in basal | - | - | - | - | - | - | ++ | ++ | ++ |
| layer | | | | | | | | | |
| Sprinkled pattern in | - | - | - | - | - | + | - | + | - |
| epithelial layer | | | | | | | | | |
| IHC | | | | | | | | | |
| - CD2, CD3, CD5 | No loss | NA | No loss | No loss | No loss | No loss | No loss | No loss | No loss |

#### **eTable 1. Histopathological findings of biopsies before dupilumab treatment**

| - CD4/CD8 ratio | CD4:CD8 | NA | CD4 <cd8< th=""><th>CD4&gt;CD8</th><th>CD4:CD8</th><th>CD4<cd8< th=""><th>CD4&lt;<cd8< th=""><th>CD4<cd8< th=""><th>CD4&gt;&gt;CD8</th></cd8<></th></cd8<></th></cd8<></th></cd8<> | CD4>CD8 | CD4:CD8 | CD4 <cd8< th=""><th>CD4&lt;<cd8< th=""><th>CD4<cd8< th=""><th>CD4&gt;&gt;CD8</th></cd8<></th></cd8<></th></cd8<> | CD4< <cd8< th=""><th>CD4<cd8< th=""><th>CD4&gt;&gt;CD8</th></cd8<></th></cd8<> | CD4 <cd8< th=""><th>CD4&gt;&gt;CD8</th></cd8<> | CD4>>CD8 |
|----------------------|---------|----|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|---------|------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------|------------------------------------------------|----------|
| - CD30 expression | NA | NA | - | - | - | + | - | - | NA |

LR: Lymphoid reaction; MF: Mycosis fungoides; IHC: Immunohistochemical staining; NA: Not available. Presence of findings indicated with - (absence), + (mildly present), ++ (moderately present), +++ (severely present), ↓ (IHC decreased).

| Patient | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
|------------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|
| Diagnosis | LR | LR | LR | LR | LR | LR | LR | LR | LR | LR | LR | MF | MF/LR | MF |
| Clinical criteria | ++ | ++ | + | + | ++ | + | + | + | + | + | + | ++ | + | ++ |
| Histopathological | + | + | + | + | + | + | + | + | + | + | + | ++ | + | + |
| criteria | | | | | | | | | | | | | | |
| Molecular biological | NA | - | - | - | - | NA | NA | NA | NA | NA | NA | NA | + | - |
| criteria** | | | | | | | | | | | | | | |
| Immunopathologic | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | + | + | + |
| criteria | | | | | | | | | | | | | | |
| Total points¥ | 3 | 3 | 2 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 5 | 4 | 4 |
| Additional information | | | | | | | | | | | | | | |
| Type of lesions | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, | Patch, |
| | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque | Plaque |
| BSA in % | >80% | 70% | 20% | 75% | >80% | 15% | 40% | NA | 50% | 40% | 20% | 60% | NA | 75% |
| Adenopathy | NA | - | NA | - | NA | - | NA | NA | NA | NA | NA | - | NA | - |
| Lymphocytosis | - | - | - | - | - | - | - | - | - | + | - | - | NA | - |

### **eTable 2. Clinical features of patients with a lymphoid reaction or mycosis fungoides based on diagnostic criteria for MF\***

\*Diagnostic criteria for MF defined by International Society for Cutaneous Lymphoma.26 \*\*Indicates if clonal TCR gene rearrangement. ¥ If 4 or more points than a diagnosis of MF is determined. No presence (-) or presence (+ 1 point, ++ 2 points); MF: mycosis fungoides; LR: lymphoid reaction; BSA: body surface area; NA: not available.

| Patient | 1 | 2 | 3 | 5 | 8 | 9 | 12 |
|------------------------------------|-------------|--------------|-------------|-------------|-------------|------------|------------|
| Diagnosis | LR | LR | LR | LR | LR | LR | MF |
| Post-biopsies available | 1x (+7mths) | 1x (+11mths) | 1x (+4mths) | 1x (+3mths) | 1x (+6mths) | 1 (+9mths) | 2 (+8mths) |
| Eczematous features | | | | | | | |
| - Acanthosis | ++ | ++ | ++ | + | ++ | ++ | + |
| - Spongiosis | + | ++ | ++ | + | ++ | ++ | + |
| - Parakeratosis | + | + | + | + | ++ | + | + |
| Presence of lymphoid infiltrate | + | + | + | + | +++ | ++ | + |
| Distribution lymphoid infiltrate | | | | | | | |
| stratum papillare | | | | | | | |
| - Perivascular | + | + | + | + | + | + | + |
| - Lichenoid | - | - | - | - | - | - | - |
| Intraepithelial T-cell lymphocytes | + | - | - | - | - | + | ++ |
| Lining of cells in basal layer | - | - | - | - | - | - | ++ |
| Sprinkled pattern in epithelial | + | - | - | - | - | - | - |
| layer | | | | | | | |
| IHC | | | | | | | |
| - CD2, CD3, CD5 | No loss | NA | NA | No loss | No loss | NA | No loss |
| - CD4/CD8 ratio | CD4>CD8 | NA | NA | CD4>CD8 | CD4:CD8 | NA | CD4>CD8 |
| - CD30 expression | - | - | NA | - | +* | NA | NA |

## **eTable 3. Histopathologic findings of the biopsies after dupilumab treatment**

\*Patient 8 already had minor CD30 expression before dupilumab initiation (Table E1), the expression increased when developing a LR and decreased again (to only few cells expressing CD30) similar to the pre-biopsy (which is not uncommon as CD30 expression can be seen in a very active AD skin) LR: Lymphoid reaction; MF: Mycosis fungoides; IHC: Immunohistochemical staining; NA: not available. Presence of findings indicated with - (absence), + (mildly present), ++ (moderately present), +++ (severely present), ↓ (IHC decreased).

| Patient | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|-------------------|-------------|--------------|-------------|---------|-------------|--------------|--------------|--------------|-------------|------------|-------------|
| | | | | | | | | | | | |
| No. of follow-up | | | | | | | | | | | |
| months after | 23 | 35 | 29 | 56 | 25 | 14 | 20 | 23 | 23 | 9 | 14 |
| lymphoid reaction | | | | | | | | | | | |
| Current AD | Abrocitinib | Methotrexate | Baricitinib | Topical | Baricitinib | Upadacitinib | Upadacitinib | Methotrexate | Baricitinib | Prednisone | Abrocitinib |
| treatment | | | | therapy | | | | | | | |
| Current AD status | Mild | Mild | Clear | Mild | Clear | Mild | Mild | Mild | Severe | Mild | Mild |
| during follow-up* | | | | | | | | | | | |
| Post-biopsy | Yes | Yes | Yes | No | Yes | No | No | Yes | Yes | No | No |
| available | | | | | | | | | | | |
| Clearance of LR | Yes | Yes | Yes | NA | Yes | NA | NA | Yes | Yes | NA | NA |

### **eTable 4. Clinical follow-up of patients with lymphoid reactions up to 4 years after treatment discontinuation**

AD: atopic dermatitis; No: number; LR: lymphoid reaction; NA: not available. \*Median EASI score during follow-up, a score of 0 indicates clear or no eczema, 0.1 to 1.0 indicates almost clear, 1.1 to 7

indicates mild disease, 7.1 to 21 indicates moderate disease, 21.1 to 50 indicates severe disease, and greater than 51 indicates very severe disease. - (absence), + (mildly present),

JAMA Dermatology

<jats:sec id="ab-doi230050-4"><jats:title>Importance</jats:title><jats:p>Since the increased use of dupilumab for atopic dermatitis (AD) in daily practice, several cases have been reported on the development of cutaneous T-cell lymphomas (CTCL) and lymphoid infiltrates.</jats:p></jats:sec><jats:sec id="ab-doi230050-5"><jats:title>Objective</jats:title><jats:p>To provide insight in the clinical and histopathologic features of patients with AD clinically suspected for CTCL during dupilumab treatment.</jats:p></jats:sec><jats:sec id="ab-doi230050-6"><jats:title>Design, Setting, and Participants</jats:title><jats:p>This retrospective observational case series included adult (≥18 years) patients with AD treated with dupilumab between October 2017 and July 2022 at the University Medical Center Utrecht in the Netherlands.</jats:p></jats:sec><jats:sec id="ab-doi230050-7"><jats:title>Main outcomes and measures</jats:title><jats:p>Relevant patient, disease, and treatment characteristics were evaluated. Skin biopsies before, during, and after treatment were collected and reassessed.</jats:p></jats:sec><jats:sec id="ab-doi230050-8"><jats:title>Results</jats:title><jats:p>Fourteen patients (54.5% male) with a median (IQR) age of 56 (36-66) years suspected for CTCL with deterioration of symptoms during dupilumab treatment were included. Of 14 patients, 3 were retrospectively diagnosed with preexistent mycosis fungoides (MF). Eleven patients with AD were eventually diagnosed with a lymphoid reaction (LR). These patients showed MF-like symptoms; however, histopathologic findings were different, and included sprinkled distribution of small hyperchromatic lymphocytes in the upper epidermal section, a dysregulated CD4:CD8 ratio, and CD30 overexpression, without loss of CD2/CD3/CD5. The median time to clinical worsening was 4.0 months (IQR, 1.4-10.0). Posttreatment biopsies showed complete clearance of the LR in all patients.</jats:p></jats:sec><jats:sec id="ab-doi230050-9"><jats:title>Conclusions and relevance</jats:title><jats:p>This study found that dupilumab treatment can cause a reversible and benign LR, which mimics a CTCL, though has distinctive histopathologic features.</jats:p></jats:sec>

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Defining early mycosis fungoides.

Since the increased use of dupilumab for atopic dermatitis (AD) in daily practice, several cases have been reported on the development of cutaneous T-cell lymphomas (CTCL) and lymphoid infiltrates.
To provide insight in the clinical and histopathologic features of patients with AD clinically suspected for CTCL during dupilumab treatment.
This retrospective observational case series included adult (≥18 years) patients with AD treated with dupilumab between October 2017 and July 2022 at the University Medical Center Utrecht in the Netherlands.
Relevant patient, disease, and treatment characteristics were evaluated. Skin biopsies before, during, and after treatment were collected and reassessed.
Fourteen patients (54.5% male) with a median (IQR) age of 56 (36-66) years suspected for CTCL with deterioration of symptoms during dupilumab treatment were included. Of 14 patients, 3 were retrospectively diagnosed with preexistent mycosis fungoides (MF). Eleven patients with AD were eventually diagnosed with a lymphoid reaction (LR). These patients showed MF-like symptoms; however, histopathologic findings were different, and included sprinkled distribution of small hyperchromatic lymphocytes in the upper epidermal section, a dysregulated CD4:CD8 ratio, and CD30 overexpression, without loss of CD2/CD3/CD5. The median time to clinical worsening was 4.0 months (IQR, 1.4-10.0). Posttreatment biopsies showed complete clearance of the LR in all patients.
This study found that dupilumab treatment can cause a reversible and benign LR, which mimics a CTCL, though has distinctive histopathologic features.

Dupilumab-Associated Lymphoid Reactions in Patients With Atopic Dermatitis.

Dupilumab-Associated Lymphoid Reactions in Patients With Atopic Dermatitis

Dupilumab-Associated Lymphoid Reactions in Patients With Atopic Dermatitis

Clinical Summary

What was studied

Key findings

Study limitations

Clinical implications

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