Determinants of Keloid Recurrence in African Patients at Kenyatta National Hospital
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Date
2022Author
Nang'ole, Ferdinand, W
Type
ThesisLanguage
enMetadata
Show full item recordAbstract
Background: Keloids are fibro-proliferative disorders of the skin resulting in excessive tissue
overgrowth usually due to minor tissue injury. Keloids are attributed to abnormal wound healing
with an exaggerated inflammatory phase and a poorly controlled proliferative phase. Patients
with keloids have been shown to be heterogeneous in clinical, pathological and genetic make
ups. There are many modalities of treating keloids. However, all are associated with high
recurrence rates. Factors that influence keloid recurrence either locally or globally have not been
well demonstrated. This study therefore sought to determine factors that are associated with
keloid severity and recurrence among patient’s cohorts in KNH. A control of patients with no
keloids nor family history of keloids were also followed up in the study.
Rationale for the study: Keloid disease is a common medical condition. It results in both
psychological and physical stress to patients. The recurrence rates are high with studies quoting
recurrence of between 10 and 70%. To the best of my knowledge, no studies had been done to
determine factors that influence recurrence in our population. Understanding factors that
influence keloid recurrence would aid in keloid management by enabling patients to have an
informed mind on the chances of recurrence as well as allowing the physicians to start on second
line management early in cases where recurrences are likely to be high.
Objective: To determine the genetic, clinical, inflammatory and histo-pathological factors that
influence keloid recurrence.
Study Design: A Case control observational study of patients presenting with keloids at the
KNH.
Setting: Kenyatta National Hospital, Nairobi, Kenya.
Ethical considerations: This study was approved by the UON/KNH ethics and research
committee. Confidentiality ran supreme during the course of the study. Informed consent was
sought from all patients who participated in the study.
Methodology: Patients with keloids and a control with no keloids after consenting were
recruited for the study. Inclusion in the study was limited to patients whose keloids could be
excised and closed primarily. Excluded from the study were patients with extensive keloids that
could not be closed primarily after excision or those with chronic medical conditions. Targeted
history and physical examination on the causation of keloids and clinical presentation was taken.
Patients were managed by surgical excision followed by superficial radiotherapy. Specimens
from the excised keloids were analyzed for lymphocytes, macrophages, mast cells, fibroblasts as
well as extracellular matrix density. Immuno-histochemical studies were done on selected slides
to determine the presence of mast cells, fibroblasts and myofibroblasts. Mesenchymal stem cells
were assessed by flow cytometry studies. The extra-cellular matrix was analyzed for vascularity
and the collagen bundles densities. Blood samples were taken for blood groups, HLA sub-types
and inflammatory cytokines. Post-operatively, patients were followed up to a minimum of one
year and any keloid recurrences were noted.
Data and Statistical Analysis: All the information was collected in a pre-tested questionnaire. A
student T-test was used to compare means and a Chi-square was used to test variance from the
mean. Pearson’s correlation co-efficient (r) was used to measure the strength of the association
between the various variables and keloid recurrence. Analysis of variance (ANOVA) was done
to determine variance in the various groups. Bonferroni correction was done to determine the
significance of the statistical differences. Multiple regression analysis was done to determine the
strength of variables in keloid recurrence. Descriptive analysis, cross tabulation and comparison
of means were used in analysis. Odds ratios and mean difference were used to measure
association and 95% confidence intervals to measure significance. STATA/SE statistics/data
analysis version 10 software was used for analysis.
Results: A total of 90 patients and a control of 59 patients were recruited for the study. The
male to female ratio for the keloid and control patients was 1:2. The age ranges for the keloid
patients was 15 to 65 years with a mean age of 29.5 and a median age group of 20-25 years.
Familial keloids contributed to 53% of keloids with sporadic keloids at 47 %. Majority of the
keloids were due to trauma (63.5%). Ear keloids were the most common accounting for 43% of
the keloids. Male patients had a significantly higher recurrence rate of 31% compared to the
female patients at 12%. The recurrence rates were higher in the familial keloids at 26.9 %
compared to the sporadic keloids at 18.5%. There was no statistically significant difference in the
surface area of patients who had keloid recurrence and those with no recurrence. Keloid patients
with blood group A were more prone to recurrence compared to the other blood groups. Patients
with keloids had a significantly higher positive alleles of DQA*01, DQB1*05, DQB1*06 and
DRB1*15. Comparison between patients who had keloid recurrence and those who did not
revealed DQB1*06 to be significantly elevated in patients with keloids recurrence (p-value
<0.05). Keloid specimens had significantly higher MSC counts compared to the normal skin.
Further Keloid specimens had a higher ratio of MSC compared to the normal skin. Histological
parameters revealed that high macrophages, lymphocytes and fibroblast counts were
significantly associated with keloid recurrence.
Conclusion: This study demonstrates that keloid recurrence is influenced by many factors
including patients’ sex, history, clinical presentation, keloid histology and HLA subtypes. There
is need to identify these factors in patients that could influence keloid recurrence. Patients with
increased likelihood of keloid recurrence should be identified through proper history and
physical examination followed by relevant laboratory tests They should be managed by either
non - surgical methods or be given a higher dose of post excision superficial radiotherapy. They
could further be monitored closely so as to intervene as soon as any sign of recurrence occurs
Publisher
University of Nairobi
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Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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