Feasibility of Cell-Free DNA Collection and Clonal Immunoglobulin Sequencing in South African Patients With HIV-Associated Lymphoma.

PURPOSE: Diagnosis of AIDS lymphoma in low-resource settings, like South Africa, is often delayed, leaving patients with limited treatment options. In tuberculosis (TB) endemic regions, overlapping signs and symptoms often lead to diagnostic delays. Assessment of plasma cell-free DNA (cfDNA) by next-generation sequencing (NGS) may expedite the diagnosis of lymphoma but requires high-quality cfDNA. METHODS: People living with HIV with newly diagnosed aggressive B-cell lymphoma and those with newly diagnosed TB seeking care at Chris Hani Baragwanath Academic Hospital and its surrounding clinics, in Soweto, South Africa, were enrolled in this study. Each participant provided a whole blood specimen collected in cell-stabilizing tubes. Quantity and quality of plasma cfDNA were assessed. NGS of the immunoglobulin heavy chain was performed. RESULTS: Nine HIV+ patients with untreated lymphoma and eight HIV+ patients with TB, but without lymphoma, were enrolled. All cfDNA quantity and quality metrics were similar between the two groups, except that cfDNA accounted for a larger fraction of recovered plasma DNA in patients with lymphoma. The concentration of cfDNA in plasma also trended higher in patients with lymphoma. NGS of immunoglobulin heavy chain showed robust amplification of DNA, with large amplicons (> 250 bp) being more readily detected in patients with lymphoma. Clonal sequences were detected in five of nine patients with lymphoma, and none of the patients with TB. CONCLUSION: This proof-of-principle study demonstrates that whole blood collected for cfDNA in a low-resource setting is suitable for sophisticated sequencing analyses, including clonal immunoglobulin NGS. The detection of clonal sequences in more than half of patients with lymphoma shows promise as a diagnostic marker that may be explored in future studies.

Interstitial lung disease in South Africans with systemic sclerosis.

To investigate the frequency, severity and predictors of interstitial lung disease (ILD) in a cohort of South Africans with systemic sclerosis (SSc). Retrospective record review of SSc patients attending a tertiary Connective Tissue Diseases Clinic. Patients with ILD, defined by a combination of clinical findings, imaging, and lung function tests were compared to patients without ILD in terms of demographics, clinical features and autoantibodies. The majority (86.8%) of the 151 patients included were of Black ethnicity, 40% had ILD, of whom 39% had moderate-severe lung disease. Univariate predictors of ILD included: disease duration (OR 1.08, 95% CI 1.01-1.15); cough (OR 2.93, 95% CI 1.37-6.29); dyspnoea (OR 2.44, 95% CI 1.23-4.87); bibasal crackles (OR 7.58, 95% CI 3.31-17.37); diffuse cutaneous SSc (dcSSc) (OR 4.55, 95% CI 2.10-9.86) and a speckled anti-nuclear antibody (ANA) pattern (OR 2.47, 95% CI 1.25-4.90). Conversely, limited cutaneous disease (OR 0.22, 95% CI 0.09-0.50) and anti-centromere antibody (ACA) (OR 0.12, 95% CI 0.02-0.97) were protective. Independent predictors of ILD on multivariate analysis were bibasal crackles (OR 9.43, 95% CI 3.25-27.39), disease duration (OR 1.19, 95% CI 1.09-1.30) and speckled ANA (OR 2.95, 95% CI 1.22-7.15). Almost all (86.4%) patients received immunosuppressive treatment and the leading cause of death was related to ILD itself (44.4%). In this cohort of predominantly Black South Africans, SSc ILD was common and carried a poor prognosis. ILD occurred mainly, but not exclusively, in patients with dcSSc, especially those with a speckled ANA pattern. Conversely, the presence of ACA was protective against ILD.

Hepatosplenic T-cell lymphoma: A case series.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare type of Non-Hodgkin Lymphoma (NHL), grouped under the mature or peripheral T-cell lymphomas. It is characterised by extranodal infiltration and proliferation of malignant T-cells within the sinusoids of the liver, sinuses and red pulp of the spleen, and the bone marrow. The tumour cells express CD2 and CD3, but are CD4, CD5 and CD8 negative and express a clonally restricted gamma-delta (or less commonly alpha-beta) T-cell receptor. The disease has an aggressive clinical course associated with a poor prognosis. We highlight and report three patients from South Africa with HSTCL, all of whom had hepatosplenomegaly and cytopaenias, and despite being HIV seronegative and immunocompetent, had a poor outcome, with a mean survival of 7.5 months in the two evaluable patients. This rare entity has not previously been reported from South Africa and as yet needs to be adequately characterised in a population where lymphoma is the most common haematological malignancy in adults, and where approximately two thirds of the adult lymphoma population are HIV seropositive.